Quantum Theory and The Many Worlds Theory [Archive]

cacian

11-09-2012, 07:39 AM

I know I have to study this to get to the bottom of it.
I do not like theories only practices but one has to brave if one has to discover things. It is better then reading an epic poem that does not make sense.
The word quantum from quantity quantifying means a rough measurement number either in weight distance or heights.
Quantum is what establishes that something exists?
Without a quantity something is apparently not.
According to this I quote:

Niels Bohr proposed the Copenhagen interpretation of quantum theory, which asserts that a particle is whatever it is measured to be (for example, a wave or a particle), but that it cannot be assumed to have specific properties, or even to exist, until it is measured.
Bohr was saying that objective reality does not exist. This translates to a principle called superposition that claims that while we do not know what the state of any object is, it is actually in all possible states simultaneously, as long as we don't look to check.

After reading this I am at this point total at loss to what is actually going.
So if one is to understand an object ceases to be on the ground of lack of referral or reference units.
Presumable that includes a human a box fire or a word anything that is visual to the naked eye is an object/abject.

The worst is not over yet because the cat comes up, confusion all around, Cat or Schrodinger's Cat.
What is a cat doing in a box let alone a lead box? is my gut reaction ? then I read on:

First, we have a living cat and place it in a thick lead box. At this stage, there is no question that the cat is alive. We then throw in a vial of cyanide and seal the box. We do not know if the cat is alive or if it has broken the cyanide capsule and died. Since we do not know, the cat is both dead and alive, according to quantum law - in a superposition of states. It is only when we break open the box and see what condition the cat is that the superposition is lost, and the cat must be either alive or dead

Anyone care to add or maybe clarify how the cat and quantum are related?
I must add that I do like cats and quantum but I do not like physics if it helps at all haha.

Charles Darnay

11-09-2012, 11:16 AM

"Lasciate ogne speranza, voi ch'intrate"

hillwalker

11-09-2012, 11:22 AM

:confused:

Quantum theory as I understand it implies there are an infinite number of realities - and any one of those can co-exist until we interfere by actually 'looking' at one of those realities.
That act of looking and determining which reality is the one we can actually see is enough to make all the other possible realities redundant and to make the reality we do see the only true reality at that moment of looking.
With me so far?

So the act of opening the box makes only one reality possible - a reality in which the cat is either dead or alive. Before we interfered by opening the box the cat was both dead and alive because both realities were possible until proven otherwise.
See - it's simple.
I also used to hate Physics in school.

H

YesNo

11-09-2012, 11:44 AM

The worst is not over yet because the cat comes up, confusion all around, Cat or Schrodinger's Cat.
What is a cat doing in a box let alone a lead box? is my gut reaction ? then I read on:

First of all, I'm no expert on this and not a physicist. I would like to understand this better myself.

As I understand it at the moment, this use of a cat was a concept designed by Schrodinger to challenge or perhaps mock Bohr. He tried to imply that quantum theory was missing something in its probabilistic interpretation of reality. This would not happen to a real cat because it is too big, but it would happen to some quantum particle whose state was unknown until it was observed. The cat is an exaggeration.

cacian

11-09-2012, 11:53 AM

"Lasciate ogne speranza, voi ch'intrate"

LOL :lol:
''canto di mane el papa mandare alora por favora'' :idea:

First of all, I'm no expert on this and not a physicist. I would like to understand this better myself.

As I understand it at the moment, this use of a cat was a concept designed by Schrodinger to challenge or perhaps mock Bohr. He tried to imply that quantum theory was missing something in its probabilistic interpretation of reality. This would not happen to a real cat because it is too big, but it would happen to some quantum particle whose state was unknown until it was observed. The cat is an exaggeration.

Hi YesNo I think I am a bit lost like you haha. I find the Cat most confusing because the first bit here is this:

''we have a living cat and place it in a thick lead box. At this stage, there is no question that the cat is alive''

At this point I am thinking what? no air in the box for the poor cat can only mean death. Unless I am reading this wrong. It is a lead box which air tight. So the concept in itself is wrong and there would no needfor cynade to show the cat is dead. The lack of air would do it.

Anyway I was thinking along the lines of photographic memory.
Once the mind had it in place first that the cat when put was alive then that is the point.
What we do not know is what memory does not grasp it will remember hence confirm that the cat was alive when put in the box.
If one takes a camera and takes a picture of the cat being put in the box that is the only picture we have.
What we don't know we cannot take picture of.

[QUOTE=hillwalker;1183623]:confused:

Quantum theory as I understand it implies there are an infinite number of realities - and any one of those can co-exist until we interfere by actually 'looking' at one of those realities.
That act of looking and determining which reality is the one we can actually see is enough to make all the other possible realities redundant and to make the reality we do see the only true reality at that moment of looking.
With me so far?

Hummm let see yes maybe but what about naming things? If a name something then surely I have quantified it.
It is reactionary to name an object.

So the act of opening the box makes only one reality possible - a reality in which the cat is either dead or alive. Before we interfered by opening the box the cat was both dead and alive because both realities were possible until proven otherwise.
See - it's simple.
I also used to hate Physics in school.

H
I am not sure I agree because the only reality I am able to state is that there is a cat in the box because I put there.
Dead or alive is secondary and therefore unimportant.
Dead does not mean it does not exist. It just mean it's there but not alive. That is one reality that counts for something.
Well that is how I see it.

Here is a question about quantum.
How many temperature/s are they a day?

Lokasenna

11-09-2012, 12:49 PM

...

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...

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...you do know the cat is a metaphor, right?

cacian

11-09-2012, 12:57 PM

...

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...

...

...you do know the cat is a metaphor, right?
Yes and no I had my doubts when I came across it and started reading it.
I realise cruelty would not allow for it.
But it is a metaphor that is easily reality ie doable hence my overseeing being a metaphor for about a moment or two.
I guess my trust on people not to carry on the test using a cat I would not have excluded knowing their history of animal abuse.

TheFifthElement

11-09-2012, 02:14 PM

You should read How to Teach Quantum Physics to Your Dog by Chad Orzel. It's a good introduction to quantum theory for a lay person.

YesNo

11-09-2012, 08:13 PM

Hi YesNo I think I am a bit lost like you haha. I find the Cat most confusing because the first bit here is this:

''we have a living cat and place it in a thick lead box. At this stage, there is no question that the cat is alive''

At this point I am thinking what? no air in the box for the poor cat can only mean death. Unless I am reading this wrong. It is a lead box which air tight. So the concept in itself is wrong and there would no needfor cynade to show the cat is dead. The lack of air would do it.

Anyway I was thinking along the lines of photographic memory.
Once the mind had it in place first that the cat when put was alive then that is the point.
What we do not know is what memory does not grasp it will remember hence confirm that the cat was alive when put in the box.
If one takes a camera and takes a picture of the cat being put in the box that is the only picture we have.
What we don't know we cannot take picture of.

Being in a state where "alive" is superimposed on "dead" doesn't happen to cats. At no time is a cat both alive and dead. It is either alive or dead. You don't have to worry about someone trying this experiment on any real cat.

However, a quantum particle could be in an unknown state with regards to, say, "spin". For the particle, the spin could be either "up" or "down" which are contradictory states like being alive or dead. Until someone checks, there is just a probability for what the spin would turn out to be.

Einstein and Schrodinger had no problem with probability, but they figured the probability was caused by not having enough information. If they could get all the information contained in the "hidden variables", they would be able to say what the spin was of the particle before anyone checked. However, it turns out there is no other information. There are no hidden variables. So Bohr's side claimed the particle had both up and down spin until someone checked. That is like saying it was both alive and dead.

Schrodinger didn't like this and so he created the cat paradox. The paradox breaks down because he assumed that a cat has the same kind of reality as a quantum particle. He wanted to show that quantum theory did not make sense as Bohr was presenting it.

Suppose the hypothetical cat was in the box for 60 minutes and the cyanide was released 30 minutes after the cat was placed in the box. When did the cat actually die? Most people would agree with Einstein and Schrodinger (and likely also Bohr) and say that the cat died after being in the box 30 minutes, even though no one checked until 60 minutes later. Were the cat a quantum particle, quantum theory would say it "died" only after the box was opened 60 minutes later. Before that it was both alive and dead.

Neither Einstein nor Schrodinger liked that way of dealing with quantum particles, but that is the way these particles seem to behave.

Anyway, that's how I see this at the moment.

Mutatis-Mutandis

11-09-2012, 08:24 PM

Isn't there some physics/science forum you could find to ask questions such as these? You'd probably get better responses, and I'm sure another forum would appreciate you're conversation starters as much as we do.

YesNo

11-09-2012, 11:58 PM

I actually like cacian's conversation starters.

Mutatis-Mutandis

11-10-2012, 01:46 AM

Now, whatever gave you the idea that I don't?

cacian

11-10-2012, 04:27 AM

You should read How to Teach Quantum Physics to Your Dog by Chad Orzel. It's a good introduction to quantum theory for a lay person.

Thank TheFifthElement I shall have a read. I noticed you are reading too.
Any that stood out in your mind as you are. I just thought I will ask.
Thanks!

Delta40

11-10-2012, 04:39 AM

Now, whatever gave you the idea that I don't?

Errr the sly look in your eyes?

MorpheusSandman

11-10-2012, 07:39 AM

For those looking for a good intro to QP and MW, I recommend Yudkowsky's online sequence: http://lesswrong.com/lw/r5/the_quantum_physics_sequence/

cacian

11-10-2012, 09:52 AM

For those looking for a good intro to QP and MW, I recommend Yudkowsky's online sequence: http://lesswrong.com/lw/r5/the_quantum_physics_sequence/

Morpheus thanks for the link.
This caught my eye:
•Identity Isn't In Specific Atoms, Three Dialogues on Identity:
Given that there's no such thing as "the same atom", whether you are "the same person" from one time to another can't possibly depend on whether you're made out of the same atoms

Cioran

11-10-2012, 12:37 PM

As YesNo states, Schrodinger’s cat constituted a reductio ad absurdum to discredit quantum mechanics as a complete theory. Einstein agreed that this reductio succeeded, and insisted to his dying day that there were hidden variables in QM. Strictly, QM was false, he said, and he came up with a thought experiment intended to demonstrate this point, one that could not be carried out at the time, but was in fact carried out in the early 1980s. More about that in a bit.

Here is the problem. If we say that quantum particles have no properties prior to observation/measurement, then all of our cherished notions of reality are undermined. QM, in the Copenhagen Interpretation, undermines the following notions of reality:

Localism The idea that effects cannot propagate instantaneously across arbitrarily large distances. Einstein’s 1930s thought experiment showed this “spooky action at a distance” and he concluded this was absurd. It also seemed to conflict (though it actually does not) with the speed-of-light limitation on information transfer disclosed by his own relativity theory.

Realism The idea that there is a mind-independent reality. In Copenhagen QM, measuring quantum particles is precisely what gives them properties. Prior to measurement they are at best Aristotelian potentia endowed with potential to “be” something but are not actually anything. This prior measurement state is described mathematically by the wave function, in which the particles are “superposed” in every possible state, none of them actual until measurement. On the moment of measurement, the wave function is said to “collapse” and the particle takes on classical properties. So if Copenhagen QM is right, there is no mind-independent reality and a certain Berkeleyian ideality is introduced into the world.

Determinism QM is inherently indeterministic. One can calculate the probabilities of something happening when an observation is made, but the actual outcome is inherently random.

So if Copenhagen QM is right, the world is non-local, non-real and non-deterministic.

The problem is that we never encounter this in our ordinary every-day world, which seems to be local, real and deterministic. The cat thought experiment was a way to connect the microworld with the macroworld, and to demonstrate that if Copenhagen QM was correct, we can amplify the quantum state into the macrostate.

Skipping the details, the upshot is that if Copenhagen QM is right, we can amplify a state of indeterminate or superposed quantum particles up to a cat. Therefore the cat is in a state of superposition, neither alive nor dead, but a 50/50 probability of both until someone opens the box and looks. When someone opens the box, the cat’s wave function is randomly collapsed, in 50/50 probability, to either alive or dead. Both Schrodinger and Einstein thought this absurd and from this they concluded that QM is an incomplete theory and that there had to be hidden variables that guaranteed a mind-independent, deterministic and local reality.

Einstein’s thought experiment was finally put to actual test in the early 80s, armed with Bell’s Theorem, a mathematical tool developed after Einstein died. The experiment, and all experiments since, confirmed QM, ruled out hidden variables and refuted Einstein. An even stronger conclusion was drawn: even if Quantum Mechanics eventually turns out to be a false theory, no succeeding theory can restore localism and realism to the world. But this fact is contingent on a certain interpretation of QM – viz., Copenhagen.

Two years after Einstein died, Hugh Everett introduced the Many Worlds interpretation of QM. In so doing he completely restored localism, realism and determinism to physics, while keeping quantum mechanics a complete theory and without introducing hidden variables.

Simply put, the cat in the box is both alive and dead, in different versions of reality. When Sam opens the box, one version of Sam is entangled with a dead cat, and a different version of Sam is entangled with a live cat. So there are parallel universes.

Thus there is no wave-function collapse, no randomness, and no mind-dependent reality. Reality is every way that it can be, evolving deterministically according to the Schrodinger wave equation. There is also no spooky action at a distance under Many Worlds QM, because this phenomenon is introduced only by wave function collapse. There is no wave function collapse in MW, which is precisely why there are many worlds: All the potential worlds described by the wave function are real worlds, in their own quantum branch of reality.

YesNo

11-10-2012, 03:48 PM

Is there any way to decide which is correct, the Copenhagen QM or the Many Worlds QM? It seems that both lead to a description of reality that is hard to accept. Perhaps there is a third option.

MorpheusSandman

11-11-2012, 01:49 AM

Yeah, I'd be interested to hear more from you, cioran. What has been done in the last few decades to attempt to test the various QM theories/interpretations? From what little I've read, it seems that MW is the most favored today, but I also know there's a lot of disagreement. I'm curious, though, as to how it would be possible to test such interpretations... if there are "many worlds" out there, where/how does one find the evidence?

mal4mac

11-11-2012, 01:35 PM

Is there any way to decide which is correct, the Copenhagen QM or the Many Worlds QM? It seems that both lead to a description of reality that is hard to accept. Perhaps there is a third option.

There many other options! Try John Gribbin's "Q is for Quantum" for an encyclopaedic breakdown that isn't too painful to read. He's also someone who very much favours the "all these theories are just models" approach that you like YesNo. Gribbin argues that there is no way to decide which interpretation is correct, they all "work", but they are all "hard to accept", given a Newtonian mind set. They all explain all the experiments, and deciding between them awaits someone to come up with ideas for other experiments. It isn't like the GR situation, where all it took was someone to get in a ship to go and observe an eclipse. No one has any (good) idea on how we could begin to design an experiment that would reveal the best interpretation, and there certainly aren't any good theoretical arguments to make one an obvious winner.

YesNo

11-11-2012, 07:02 PM

Delta40

11-11-2012, 07:57 PM

I'm not educated enough to enter into the discussion but I must say it's been very interesting reading the posts and the relevant links. I doubt I would have ever touched the subject of QM and MW had it not been for this thread so I'm glad that it's here. The idea of parallel universes is so exciting - but of course I'm sure I have watched that played out in a Red Dwarf episode! Now don't anybody curl their lip in contempt at me....

russellb

11-11-2012, 10:51 PM

What about the observer of Schrodingers cat? Can he/she only exist (or not) when observed? Does this imply a so called 'infinite regress?'

YesNo

11-12-2012, 01:03 AM

I finished the Wikipedia article on Many Worlds.

So far, the Red Dwarf, that Delta40 suggested, or The Big Bang Theory look like the most appropriate universes for MW.

While following various links in the article I clicked onto "superdeterminism" where the experimenter is also completely determined through hidden variables and cannot even choose what questions to ask. I think this might have something to do with suggestions that russellb raised about the observer being part of the Schrodinger cat paradox, but it is getting late.

Cioran

11-12-2012, 03:26 AM

I'm trying to make sense out of these interpretations of QM. Here is the article I'm looking at now: http://en.wikipedia.org/wiki/Interpretations_of_quantum_mechanics

It seems that the Many Worlds interpretation is the nuttiest of all: http://en.wikipedia.org/wiki/Many-worlds_interpretation

The obvious objections to it, such as Occam's Razor, conservation of energy, non-local instantaneous copying of the universe every time a photon hits someone's eye, make me think this would better be described as the "mad scientist" interpretation of QM.

Not a single one of these objections has the slightest force against the Many Worlds interpretation, and indeed every one of them betrays a total misunderstanding of it. Many Worlds is fully local and deterministic (unlike Copenahagen), and does not contradict the conservation laws. Nor does it contradict Occam's Razor at all. Not that the razor is any kind of law or anything to be paid much attention to in the first place.

cacian

11-12-2012, 04:10 AM

What about the observer of Schrodingers cat? Can he/she only exist (or not) when observed? Does this imply a so called 'infinite regress?'

Photographic memory applies here.
Just because you put something away and you do not see it does not mean your memory has not stored it.
There is a French saying that goes
''Loin des yeux loin du coeur'' meaning ''away from sight away from heart'' and of course I do not believe that for a second I could not my memory won't let me.

mal4mac

11-12-2012, 06:54 AM

Not a single one of these objections has the slightest force against the Many Worlds interpretation, and indeed every one of them betrays a total misunderstanding of it. Many Worlds is fully local and deterministic (unlike Copenahagen), and does not contradict the conservation laws. Nor does it contradict Occam's Razor at all. Not that the razor is any kind of law or anything to be paid much attention to in the first place.

Al these interpretations (models) have their own supporters, not any of them are 'the truth', all of them 'work'. One model might be easier to use in one context, another in another, that's what working physicists do - use the model that works. They don't try and decide between them to see which is "best". Gribbin suggests the Copenhagen interpretation is not the right model to apply to the puzzle of Schrodinger's cat, but the many worlds interpretation works very well... So in trying to grasp the cat puzzle, I'd look at it through the lens of various interpretations and if one gets you to understanding it, then you can be happy! You then understand it! You don't have to understand it via all interpretations, because all interpretations work.

Many-worlds explains the cat so nicely, to a seven year old, that I recommend using that, and get over the "there's too many worlds!" complaint. I mean, there are too many galaxies, 100 billion when one seemed quite enough... so why not many worlds, why not multiverses... why not?

I know I have to study this [many Worlds] to get to the bottom of it.
I do not like theories only practices but one has to brave if one has to discover things. It is better then reading an epic poem that does not make sense...

Why do you have to study this? Why not not just stick to practices? Why not read a nice 19th century novel that does make sense?

For the seven year old, if he hears about that darn cat, and asks about, I'd suggest he look into that after doing GCSE physics and read him Treasure Island... I mean you don't wan to encourage him to be a phycicist do you? There aren't any jobs in physics, and they don't get the girls...

No one understands quantum theory, as Richard Feynman said. All you get are "mad scientist" theories, as YesNo said, that will make you mad if you try and understand them. Of course the equations in this un-understandable theory work, so if you are a physicist you should "shut up and calculate" and gingerly adopt whatever Alice in Wonderland interpretation works for your problem at hand.

cacian

11-12-2012, 07:53 AM

Why do you have to study this? Why not not just stick to practices? Why not read a nice 19th century novel that does make sense?
I have to study this because it is interesting and intricate at the same time. Reading a book does not generate as much excitement about the real world. Quantum does. It is about the environment the real world.

For the seven year old, if he hears about that darn cat, and asks about, I'd suggest he look into that after doing GCSE physics and read him Treasure Island... I mean you don't wan to encourage him to be a phycicist do you? There aren't any jobs in physics, and they don't get the girls...

Lol well actually I do not want the seven year old to hear about the cat. It would upset him to find out an adult thought something so cruel to do a cat as part of a concept experiment.
Although the idea of a physicist is very appealing think of all the theories one can create and can impress the girls with.

No one understands quantum theory, as Richard Feynman said. All you get are "mad scientist" theories, as YesNo said, that will make you mad if you try and understand them. Of course the equations in this un-understandable theory work, so if you are a physicist you should "shut up and calculate" and gingerly adopt whatever Alice in Wonderland interpretation works for your problem at hand.
I agree that no one understands it and that is the issue. Physics should be about understanding that something is exact.
I am one to believe there is an answer to everything.
I find for example that one can draw a a three sided linear triangle and yet when you build it you end up with something different.
The triangle one draws on a piece of paper is different from the triangle one builds because of 3d.
The same with a circle.
Again put a dot with a pencil on piece of paper and yet it is totally useless because a dot is irrelevant after that.
It would not be if it was not for the pencil.

mal4mac

11-12-2012, 11:06 AM

I have to study this because it is interesting and intricate at the same time. Reading a book does not generate as much excitement about the real world. Quantum does. It is about the environment the real world.

The Trainspotter's guide is about the real world. Is that exciting? Most popular quantum books are as tedious as the Trainspotter's guide, and as perplexing as Joyce. Give me Treasure island anyday, far more exciting... (and understandable...)

Lol well actually I do not want the seven year old to hear about the cat. It would upset him to find out an adult thought something so cruel to do a cat as part of a concept experiment.

Good point - and what about poor Wigner's friend?

I agree that no one understands it and that is the issue. Physics should be about understanding that something is exact.

But uncertainty is built into QM - you can't have exact - ask Mr Heisenberg.

The triangle one draws on a piece of paper is different from the triangle one builds because of 3d.

The triangle on paper is 3d, although the vertical dimension is very small. How can you draw a proper triangle on a piece of paper?

cacian

11-12-2012, 11:38 AM

The triangle on paper is 3d, although the vertical dimension is very small. How can you draw a proper triangle on a piece of paper?

Oh it is not about proper it is about the 'rough idea' like an architect or even a sketecher would do it on a piece paper.
It is just a rough representation of a triangle the way we were taught at school when we talked arithmetics and theorems.
And so it is just three sides to it with a ruler and so if we cut it then one can see it is never the same copy as the one build for truth.
This is the only inexactness or uncertainty I am able to talk about.
The rest universe and humans are to be exact or at least how I see it.
And there is always an and to the most intriguing of all and that is the dot I mentioned earlier. Now that is uncertainty at its best. I see it and now I don't. :biggrin5:

YesNo

11-12-2012, 11:43 AM

Cioran

11-12-2012, 01:45 PM

Al these interpretations (models) have their own supporters, not any of them are 'the truth', all of them 'work'. One model might be easier to use in one context, another in another, that's what working physicists do - use the model that works. They don't try and decide between them to see which is "best". Gribbin suggests the Copenhagen interpretation is not the right model to apply to the puzzle of Schrodinger's cat, but the many worlds interpretation works very well... So in trying to grasp the cat puzzle, I'd look at it through the lens of various interpretations and if one gets you to understanding it, then you can be happy! You then understand it! You don't have to understand it via all interpretations, because all interpretations work.

Many-worlds explains the cat so nicely, to a seven year old, that I recommend using that, and get over the "there's too many worlds!" complaint. I mean, there are too many galaxies, 100 billion when one seemed quite enough... so why not many worlds, why not multiverses... why not?

Scientists make models of reality that "work." If they don't work, the models are discarded.

QM works, that much is definite. Many scientists would dismiss the question of what it means -- what QM tells us about the ontology of the world, and of epistemology -- as unimportant. Others, principally philosophers, are not satisfied by this "shut up and calculate" approach. Indeed, Copenhagen is pre-eminently a "shut up and calculate" approach to QM

All the interpretations of QM are consistent with the observed facts. Therefore one is free to accept any interpretation, unless and until there can be empirical confirmation of one over the other. This might be possible, though currently it is not. MWI could be confirmed or ruled out by use of a special computer (not currently within our technology) and a certain type of experiment. There may be other ways to gather empirical evidence for one or another interpretation.

Just to clarify:

Conservation objection: MWI is NOT a theory of branching or splitting worlds, no matter how many times this description has been used in the literature, even by those who ought to know better. New worlds are not "created" and hence there is no violation of the conservation laws. The universe is an isolated system, and the wave function encodes/describes the totality of it -- which happens to contain many worlds. None of these worlds are "brought into existence" by splitting. They simply are.

Spooky action at a distance: There is no spooky action at a distance in MWI. MWI in fact solves the problem of spooky action at a distance, showing it to be illusory. Spooky action at a distance depends on wave function collapse. There is no wave function collapse in MWI. There is just the wave function, which is the totality of reality.

Occham's Razor: The razor counsels that we not multiple assumptions unnecessarily in trying to explain some fact of reality. MWI is victorious under Occham, because it simplifies quantum theory, removing assumptions like hidden variables (which have been experimentally ruled out anyway). That fact that MWI multiplies worlds is irrelevant. Worlds are not assumptions. MWI is the victor if we invoke the razor.

Technical discussion at the following link (depending on your computer/browser, you may have to scroll side to side as well as up and down to read the whole PDF).

Many Worlds or Many Words? (http://arxiv.org/pdf/quant-ph/9709032v1.pdf)

It's worth noting also that Copenhagen, in addition to destroying determinism, locality and mind-independent realism, destroys cause and effect. This is easily shown. Two quantum-entangled particles are spacelike separated. Mary observes the state of one particle. Magically -- without any explanation whatsoever! -- her very act of observing the particle collapses the wave function, instantanelously across the entire universe if the two quantum entangled particles are that far apart -- and causes the result of the second particle that Sam later records.

But wait! Since the particles are spacelike separated, relativity theory shows that there is no objective fact of the matter about whether Mary looks at her particle first, collapsing the wave function and causing Sam to get his result, or whether Sam looks first and collapses the wave function and causes Mary to get her result! Two observers in different relative notion will disagree on whether Mary looked first or Sam looked first. Thus QM in conjunction with SR renders cause and effect meaningless. :eek:

MWI clears up this problem quite nicely. There is a world in which Mary looked first, and a different world in which Sam looked first. And no wave function is collapsed anyway. There are just different "pairings" of the particle states that are possible according to the wave function. The act of looking by either Mary or Sam causes nothing, under MWI.

mal4mac

11-13-2012, 08:25 AM

I don't see the non-locality nor the indeterminate nature of the Copenhagen interpretation as problems. I do see the parallel universes however as problematic because I see no evidence for their existence except as a way to add determinism to QM.

I think it's all a matter of taste - you have a taste for Copenhagen, Cioran has a taste for MW. The fact is that both interpretations are correct! They are both models that work - one kid might prefer the lego robot, the other the meccano robot, but both work, even if one says "I can't stand bricks" and the other says "I can't be doing with screws."... but they both are good little robots...

cacian

11-13-2012, 10:06 AM

This thread actually made me think of metaphysics.
the word "metaphysics" goes back to Aristotelean philosophy, Aristotle himself credited earlier philosophers with dealing with metaphysical questions. The first known philosopher, according to Aristotle, is Thales of Miletus, who taught that all things derive from a single first cause or Arche.
The science behinds it is to try and determine what is there and what it is like.

Arche meaning:

.Arche (ἀρχή) is a Greek word with primary senses 'beginning', 'origin' or 'first cause' and 'power', 'sovereignty', 'domination' as extended meanings.[1] This list is extended to 'ultimate underlying substance' and 'ultimate undemonstrable principle'.[2] In the language of the archaic period (8th-6th century BC) arche (or archai) designates the source, origin or root of things that exist. If a thing is to be well established or founded, its arche or starting point must be secure, and the most secure foundations are those provided by the gods-the indestructible, immutable and eternal ordering of things. In ancient Greek Philosophy, Aristotle foregrounded the meaning of arche as the element or principle of a thing, which although undemonstrable and intangible in itself, provides the conditions of the possibility of that thing.

YesNo

11-13-2012, 11:13 AM

I think it's all a matter of taste - you have a taste for Copenhagen, Cioran has a taste for MW. The fact is that both interpretations are correct! They are both models that work - one kid might prefer the lego robot, the other the meccano robot, but both work, even if one says "I can't stand bricks" and the other says "I can't be doing with screws."... but they both are good little robots...

I think it might be possible to say that Heisenberg's matrix model and Schrodinger's wave model are equivalent and so it is a matter of convenience which one a physicist uses. I actually don't know if that is the case, but if they are equivalent the physicist would get the same results in all cases no matter which model they used.

However, these interpretations are different from a mathematical model and they conflict with each other. The Many Worlds and Copenhagen interpretations don't give the same results. One says there are many worlds. The other says there is only one. Since they are contradictory, they can't both be right.

I have just started reading cioran's reference to Max Tegmark's 1997 paper. Cioran brings up an interesting issue of cause and effect associated with non-local behavior that I hadn't thought about. Actually, this is the first time I've thought much about any of these issues.

It's worth noting also that Copenhagen, in addition to destroying determinism, locality and mind-independent realism, destroys cause and effect. This is easily shown. Two quantum-entangled particles are spacelike separated. Mary observes the state of one particle. Magically -- without any explanation whatsoever! -- her very act of observing the particle collapses the wave function, instantanelously across the entire universe if the two quantum entangled particles are that far apart -- and causes the result of the second particle that Sam later records.

But wait! Since the particles are spacelike separated, relativity theory shows that there is no objective fact of the matter about whether Mary looks at her particle first, collapsing the wave function and causing Sam to get his result, or whether Sam looks first and collapses the wave function and causes Mary to get her result! Two observers in different relative notion will disagree on whether Mary looked first or Sam looked first. Thus QM in conjunction with SR renders cause and effect meaningless. :eek:

MWI clears up this problem quite nicely. There is a world in which Mary looked first, and a different world in which Sam looked first. And no wave function is collapsed anyway. There are just different "pairings" of the particle states that are possible according to the wave function. The act of looking by either Mary or Sam causes nothing, under MWI.

Are there worlds in MWI where the assumptions of non-locality are false?

I could see this happening, for example, if Mary's entangled particle no longer has a pair in her world. Sam and his observation would be in some other world. Or it could occur if Mary looks first, gets a result, but Sam gets a result that is not consistent with non-locality. The reason I think this should be possible is because of the cause and effect criticism you made. It also appears the MWI does not support non-locality except as an illusion. I would expect in some world the illusion would not exist.

I found Max Tegmark's article interesting, but it mainly helped reinforce the vocabulary. I find it difficult to trust the article since Tegmark quoted a poll at the beginning of the paper that he admitted was unscientific and then used it as if it provided evidence of something.

mal4mac

11-14-2012, 08:17 AM

However, these interpretations are different from a mathematical model and they conflict with each other. The Many Worlds and Copenhagen interpretations don't give the same results. One says there are many worlds. The other says there is only one. Since they are contradictory, they can't both be right.

They do give the same, right, results, otherwise the one that didn't would be rejected out of hand. Wave collapse or MW can't be detected experimentally, so about such things it's better to be silent, or just treat them as mental props that help you (perhaps) get (some) understanding of what is going on (though probably don't help much...)

Personally, I think a "no interpretation" approach might be most useful, and honest, for laymen, especially seven year olds. Just say what the actual experimental results are... in actual experiments like "double slit" and "Aspect". (Ignore that non-experiment with Schrodingers darn cat!) Then when particles go through the double slit one by one and give a wave pattern just fess up and say, "As Feynman says, even we physicists don't understand, can't even comprehend, why this happens, it goes against all our everyday understanding, and can never be comprehended like we can comprehend Newton's laws in a simple 3D force/reaction model, or any other model graspable by the human mind. But it happens, and our equations predict the results, and you can calculate them yourself if you study theoretical physics night and day from O level to MSc level..."

If you tell the seven year old "there is wave collapse" or "there are many worlds", this is lying. We don't know what happens!

Cioran

11-14-2012, 11:39 AM

I find it difficult to trust the article since Tegmark quoted a poll at the beginning of the paper that he admitted was unscientific and then used it as if it provided evidence of something.

He did nothing of the kind. I've no idea where you got that idea.

YesNo

11-14-2012, 12:57 PM

He did nothing of the kind. I've no idea where you got that idea.

This is what I'm referring to (http://arxiv.org/pdf/quant-ph/9709032v1.pdf)

At the quantum mechanics workshop to which these
proceedings are dedicated, held in August 1997 at
UMBC, the participants were polled as to their preferred
interpretation of quantum mechanics. The results are
shown in Table 1.
Interpretation Votes
Copenhagen 13
Many Worlds 8
Bohm 4
Consistent Histories 4
Modified dynamics (GRW/DRM) 1
None of the above/undecided 18
Although the poll was highly informal and unscientific
(several people voted more than once, many abstained,
etc), it nonetheless indicated a rather striking shift in
opinion compared to the old days when the Copenhagen
interpretation reigned supreme.

The part in bold is where Tegmark draws a conclusion from a poll that is unscientific. The part in red is what I find most troubling about this poll.

Later under the "III. C." section he writes:

One reason why experimentalists are becoming increasingly
positive to the MWI

On what basis, besides the unscientific poll he cites at the beginning of the paper, does he have to make this claim about experimentalists?

Is there any other article that you might recommend? I would like to know more about what this split actually is and how it relates to non-local entangled events. The statement Tegmark makes about what Everett did not claim is interesting:

At certain magic instances, the the world undergoes
some sort of metaphysical “split” into two branches
that subsequently never interact.

However, it is too vague to be useful.

Cioran

11-14-2012, 02:47 PM

He did not tout the poll as providing evidence of MWI, merely to note that it was becoming a more mainstream idea among those who study the matter. That was 1997, and I expect it's even more mainstream now.

He's very clear in the paper: while (currently) there is no empirical way to distinguish between MWI and Copenhagen, or other various interpretations, which version you find more plausible might depend on whether you take a natural language or a mathematical view of reality. The mathematical view of reality favors MWI -- not to mention that Copenhagen is replete with unexplained magic, like consciousness magically without any observable mechanism collapsing the wave function instantaneously across the whole universe.

mal4mac

11-14-2012, 03:18 PM

Cioran

11-14-2012, 07:03 PM

MWI is replete with unexplained magic, like universes magically splitting without any observable mechanism, and we can't even see these other universes.

Big Endian - Little Endian....

As explained by Tegmark, the universes do not split. The wave function is the totality of reality, and it contains many diffrerent versions of the world.

YesNo

11-15-2012, 12:10 AM

YesNo, why are you so troubled that some people are happy with many interpretations? It's well known in physics circles that people use whatever interpretation works best for the job at hand. Working physicists use MW today, Copenhagen tomorrow, whatever next week. I thought you were a fan of the 'model view of reality'? if so, what's wrong with people using different models - Lego today, Airfix tomorrow...

Everything in this area is vague, Tegmark is a really bright chap and usually the clearest on these matters... so if I were you I'd give up, you aren't going to find anyone to clear this mess up... I recommend reading Swift, Gulliver's travels, this is really Big Endian territory...

I'm just trying to understand. I don't really know what it means to be a fan of the model view of reality. Perhaps I was trying on an idea in the past. MWI still sounds too much like science fiction to me, but this is a literature forum.

He's very clear in the paper: while (currently) there is no empirical way to distinguish between MWI and Copenhagen, or other various interpretations, which version you find more plausible might depend on whether you take a natural language or a mathematical view of reality. The mathematical view of reality favors MWI -- not to mention that Copenhagen is replete with unexplained magic, like consciousness magically without any observable mechanism collapsing the wave function instantaneously across the whole universe.

Well, the Copenhagen interpretation is also a mathematical view of reality. The main difference between it and MWI is that MWI keeps all the outcomes, even those that don't happen, while CI just hangs onto what actually happens in the real world. Regardless of the existence of multiple worlds in which we supposedly exist, there is only one world that need concern us.

I think the MWI approach is interesting because it forces people to define their positions better. There is nothing like contention to clarify issues. And who knows? It may be right, but I have no intention of being the cat in a quantum suicide experiment.

Cioran

11-15-2012, 01:32 AM

mal4mac

11-15-2012, 08:23 AM

I'm just trying to understand. I don't really know what it means to be a fan of the model view of reality. Perhaps I was trying on an idea in the past. MWI still sounds too much like science fiction to me, but this is a literature forum.

I had the impression you believe there is no reality, there are only models. So neither Copenhagen or MW interpretation reflects reality, they are just models.

Quantum mechanics consists primarily of mathematical equations describing the world of the very small. This is something that it does very well, with only one problem; these equations defy common sense. Hence the scramble to provide interpretations like "many worlds" theory or the Copenhagen Interpretation. From the point of view of instrumentalism such interpretations are unnecessary as all quantum theory needs to do is predict the behaviour of atoms and molecules.

So you can give an account of the results of the double slit experiment, and you can provide the equations that predict the results. But you can't provide an explanation that appeals to common sense. You say "I'm just trying to understand", but you never will, because nobody understands it, and you aren't the one person in seven billion who will make the conceptual leap to understanding (are you?)

"I think I can safely say that nobody understands quantum mechanics.", Richard Feynman, in The Character of Physical Law (1965) [... an exceptional book, by the way]

This is probably the most repeated quote in modern physics, often quoted wryly by aged physics professors to their over-avid students, followed by the second favourite quote "Shut up and calculate" - down to David Mermin.

So the main thing you need to understand, I suggest, if you and your seven year old are wanting to avoid being totally lost in frustrating perplexity, is that *you cannot understand it*. If he says "you mean *you* don't understand it dad," you can produce the key quote from the greatest physicist since Einstein...

P.S. If you tell your seven year old this, when he's a teenager, trying his hardest to prove dad & everyone wrong, he just might be that one in seven billion :)

Einstein, though, because he was a classical natural philosopher and not just a "shut up and calculate" modern scientist, wanted to find out how the world really was.

The Quixotic nature of that particular quest was revealed by Kant in his first critique. If you want something racier & more modern than that I recommend taking a crack at "Integral Spirituality" by Ken Wilbur. This also has its Quixotic aspects, but it takes Kant & post-modernism seriously.

YesNo

11-15-2012, 11:05 AM

Here (http://www.pbs.org/wgbh/nova/physics/many-worlds-theory-today.html) is a PBS interview from a few years ago about the Many Worlds that is very accessible to the lay reader (the Tegmark paper, not so much). It also talks about the shameful way Hugh Everett, who first mooted Many Worlds, was treated by some of the founders of original Copenhagen QM and their acolytes -- Einstein not among them, because he, alas, had died two years before Everett unveiled his theory which restored everything to 'QM that Einstein protested was lacking in it: determinism, realism, localism and no spooky action at a distance. Einstein opposed Copenhagen because, of course, Copenhagen is ridiculous. It's worse than magic or saying "God did it."' It is true that Copenhagen successfully "models" the world, in such a way that useful predictions can be made and we can build televisions (which depend on QM to work. So does your computer) This only goes to show that science is not (necessarily) about finding out the truth of the world, but only in making sucessful predictions that are instrumentally useful. Einstein, though, because he was a classical natural philosopher and not just a "shut up and calculate" modern scientist, wanted to find out how the world really was. He died two years before he would have gotten his answer from Everett.

ETA: of course, that is only in this branch he died before Everett unveiled MW. In others he lived and remarked upon it. But then again, Mitt Romney was elected last week somewhere on the wave function, and somewhere else Hitler won the war.

When I encounter science fiction containing ideas of parallel universes, I previously thought this was some nonsense these authors came up with. I didn't realize anyone actually believed other worlds were true. Also, when I heard the Schrodinger's Cat paradox, I didn't think that anyone believed this actually happens to a real cat. Apparently, the MWI supporters believe that a real cat in the experiment actually is still alive in some other world.

As far as "spooky" stuff goes, what MWI does is replace spooky action at a distance with spooky other worlds, which is actually spookier in my opinion.

mal4mac suggests I might be an "instrumentalist" which is what I suspect I am. Since all of these interpretations work, it is more like a religious choice which interpretation one prefers. Hmmm, Krishna or Jesus?

-------

Just thought of something! Perhaps Occam's Razor should be modified or why not create a new razor, call it the YesNo Razor :), that says the theory with the least spooky stuff is better all other things being equal.

cacian

11-15-2012, 12:13 PM

The Quixotic nature of that particular quest was revealed by Kant in his first critique. If you want something racier & more modern than that I recommend taking a crack at "Integral Spirituality" by Ken Wilbur. This also has its Quixotic aspects, but it takes Kant & post-modernism seriously.

Quixotic? and what a word? At first I thought the word exotic was there but then it said something different.
How does one over idealise without going religious?

Cioran

11-15-2012, 12:49 PM

"I think I can safely say that nobody understands quantum mechanics.", Richard Feynman, in The Character of Physical Law (1965) [... an exceptional book, by the way)

Invalid appeal to authority and also argumentum ad hominem, in fact. (Feynman is really smart, so it must be that no one can understand QM because this smart guy says so. This shows that not all ad hominem forms of argument rely on discrediting the speaker; some rely on praising him.)

But, of course, we can understand QM -- and many other things besides! We are a very clever species.

The people who invented/discovered QM were shocked by it, because none of it made sense. It was inconsistent with classical reality -- our everyday world where things and people are only one way at a time, and behave in a common-sense fashion. After all, we never observe superpositions in real life -- but they exist at the microlevel. Ergo, something must make these superpositions "go away" at the macro level.

That "something" was put in by hand by the founders of QM -- they called it "wave function collapse." When a measurement of the micro world is made, the wave function is magically collapsed to instantiate a single version of reality, the reality that we all see. No explanation is offered of wave function collapse, no mechanism, no idea is mooted of how the wave function collapses instantaneously across the entire universe, and so on. It is all magic! This is as unscientific as one can be. This is why we get monstrosities like "shut up and calculate" from many modern scientists -- a notion anathema to the greats like Einstein, Newton, Galileo, and others. When it comes to finding out how the world really is, as opposed to mere models of it, modern scientists of the Copenhagen school punt. In fact they forbid you to talk about it -- like priests in a church forbidding you to question sacred Scripture.

Hugh Everett's key insight was to notice that there is no such thing as classical reality, and hence there is no wave function collapse. Reality is entirely quantum mechanical, from top to bottom. In effect, what the pioneers of QM were doing was splitting reality into two domains: the classical and quantum. Then, in setups like the two-slit experiment, they were treating the electrons going through the slits as a quantum world, which then interacted with the classical world of the observers.

Everett says no, everything is quantum, including the observers conducting the two-slit experiment. And of course this must be the case. We are made up entirely of quantum particles!

Everett is saying that when we do a quantum experiment, we are inside the quantum system, not outside it. There is no classical world.

This is why Schrodinger's attempted reductio of QM as a complete theory misfires. In his thought experiment, he was showing a way to "amplify" quantum mechanical effects at the micro-level all the way up to the "classical" level of a cat. And when you do that, (he says) you get a cat that is both alive and dead! This is ridiculous (he thought) and of course we never observe "classical" superpositions and so QM must be an incomplete theory. There must, Einstein insisted, be hidden variables to explain away the mystery of QM.

But there are no hidden variables. This was demonstrated experimentally beginning in the early 1980s. Contra Einstein, QM is a complete theory. Where he and the others went wrong, and where Everett corrected their error, was their assumption that the world is divided into classical and quantum domains. They had the right theory but the wrong interpretation of it.

In the case of the cat, there is no "amplification" of the quantum mechanical state to the classical state, because there is no classical state. The cat was, is, and always will be, in superposition. But now suppose Fred is conducting the cat experiment. What Fred has not taken note of (because he is indoctrinated with Copenhagen) is that he, Fred, is also in superposition; always has been, and always will be. Like the cat, Fred lives in many worlds.

Why, then, when Fred opens the box, does he see only a live cat or a dead cat but never both? But he does! Fred sees a live cat, and his superposed doppelgänger on the wave function sees a dead cat. It's true that neither Fred nor his doppelgänger see a live/dead cat at the same time, but that's because there are two Freds as well as two cats, and each reports a different outcome. What we call the classical world is a perspectival limitation, in which we take a small cross section of all of reality and assume this little slice is all that there is. Exactly the same thing happens, by the way, with relativity theory. Relativity theory shows that the past, present and future all exist. There is no such thing as "passing time," and no single "Now." What we call the "now" is a little cross section of a much larger existent reality in which the people of the past and the people of the future exist just as do you and I.

cacian

11-15-2012, 01:34 PM

Well let put this idea to the test.

If one asks the time the probable answer is something like ''an hour and O'clock'' ie
Three O'clock
or
Ten O'clock.
These are precise answers that indicates that someone is talking time.

If then someone asks how long does it take and the answer is 45 minutes/3hours/2minutes. That becomes a number which could be quantified as quantum physic notions because take the 45 minutes/3hours/2minutes out of context and it is not specific to time or O'clock and could mean all sorts of meanings.
These answers although clock related they are not telling the time.

YesNo

11-15-2012, 07:23 PM

The people who invented/discovered QM were shocked by it, because none of it made sense. It was inconsistent with classical reality -- our everyday world where things and people are only one way at a time, and behave in a common-sense fashion. After all, we never observe superpositions in real life -- but they exist at the microlevel. Ergo, something must make these superpositions "go away" at the macro level.

There are many superpositions in real life. You can find them every time you are presented with a choice. Prior to making the choice, whether a candidate on a ballot or when to step in a particular line at a store or whether to buy this brand or that brand, you are in a superposition of possible outcomes. You choose one of them. The others you do not choose. It happens all the time. There is nothing unusual about it.

That "something" was put in by hand by the founders of QM -- they called it "wave function collapse." When a measurement of the micro world is made, the wave function is magically collapsed to instantiate a single version of reality, the reality that we all see. No explanation is offered of wave function collapse, no mechanism, no idea is mooted of how the wave function collapses instantaneously across the entire universe, and so on. It is all magic! This is as unscientific as one can be. This is why we get monstrosities like "shut up and calculate" from many modern scientists -- a notion anathema to the greats like Einstein, Newton, Galileo, and others. When it comes to finding out how the world really is, as opposed to mere models of it, modern scientists of the Copenhagen school punt. In fact they forbid you to talk about it -- like priests in a church forbidding you to question sacred Scripture.

It is easy to rewrite this from the perspective of someone who might support the Copenhagen interpretation as follows:

That "something" was put in by hand by the founders of QM -- they called it "world split." When a measurement of the micro world is made, the wave function is magically split to instantiate a new version of reality, the reality that we can't see. No explanation is offered of world splitting, no mechanism, no idea is mooted of how the world splits instantaneously across the entire universe, and so on. It is all magic! This is as unscientific as one can be. This is why we get monstrosities like "shut up and calculate" from many modern scientists -- a notion anathema to the greats like Einstein, Newton, Galileo, and others. When it comes to finding out how the world really is, as opposed to mere models of it, modern scientists of the Many Worlds school punt. In fact they forbid you to talk about it -- like priests in a church forbidding you to question sacred Scripture.

Everett says no, everything is quantum, including the observers conducting the two-slit experiment. And of course this must be the case. We are made up entirely of quantum particles!

This is true, but the objects that make up each of us become something more than the sum of their parts. These combinations get names, like YesNo, Cioran, cacian or mal4mac, and can act and make free choices.

I'm mentioning "free choice" here to try to see whether you think we have any free choice or not. Because MWI is deterministic and carries the wave function into classical reality, I wonder if there is any freedom for the experimenter under MWI. I think I heard that MWI might be implying something called "superdeterminism".

Cioran

11-15-2012, 10:22 PM

There are many superpositions in real life. You can find them every time you are presented with a choice. Prior to making the choice, whether a candidate on a ballot or when to step in a particular line at a store or whether to buy this brand or that brand, you are in a superposition of possible outcomes. You choose one of them. The others you do not choose. It happens all the time. There is nothing unusual about it.

These are not quantum superpositions. To experience a quantum superposition, you would have to vote both for and against a candidate at the same time, or buy and not buy a brand at the same time -- you would, in short, have to violate Aristotle's Non-Contradiction.

It is easy to rewrite this from the perspective of someone who might support the Copenhagen interpretation as follows:

That "something" was put in by hand by the founders of QM -- they called it "world split." When a measurement of the micro world is made, the wave function is magically split to instantiate a new version of reality, the reality that we can't see. No explanation is offered of world splitting, no mechanism, no idea is mooted of how the world splits instantaneously across the entire universe, and so on. It is all magic! This is as unscientific as one can be. This is why we get monstrosities like "shut up and calculate" from many modern scientists -- a notion anathema to the greats like Einstein, Newton, Galileo, and others. When it comes to finding out how the world really is, as opposed to mere models of it, modern scientists of the Many Worlds school punt. In fact they forbid you to talk about it -- like priests in a church forbidding you to question sacred Scripture.

Easy to do, hard to be accurate. The above is a strawman caricature of what the Many Worlds says. Notwithstanding the fact that even Everett talked in a loose manner of "splitting" universes, nothing splits, as Tegmark explains in the paper that I linked. So your above re-write is simply a false description of what Many Worlds says. You might also read the layman-geared interview that I linked last night.

YesNo

11-16-2012, 12:00 AM

These are not quantum superpositions. To experience a quantum superposition, you would have to vote both for and against a candidate at the same time, or buy and not buy a brand at the same time -- you would, in short, have to violate Aristotle's Non-Contradiction.

Well, I agree that you can't vote both for and against a candidate in the real world, but I thought Many Worlds would have solved that problem. In one world I would vote for Candidate X. In the other I would vote for Candidate Y. At the point where I press the complete ballot button on the screen, there is no turning back. My one reality in the real world voted for Candidate X. My other reality in the cloned world voted for Candidate Y.

If that doesn't work as a quantum superposition according to MWI, then I'm confused. How does Schrodinger's cat pull that off? In one world the cat is alive. In the other world the cat is dead.

Cioran

11-16-2012, 12:10 AM

Well, I agree that you can't vote both for and against a candidate in the real world, but I thought Many Worlds would have solved that problem. In one world I would vote for Candidate X. In the other I would vote for Candidate Y. At the point where I press the complete ballot button on the screen, there is no turning back. My one reality in the real world voted for Candidate X. My other reality in the cloned world voted for Candidate Y.

If that doesn't work as a quantum superposition according to MWI, then I'm confused. How does Schrodinger's cat pull that off? In one world the cat is alive. In the other world the cat is dead.

I am talking about experiencing a quantum superposition, which is what I thought you were talking about. We clearly don't experience them. But, yes, in one world you vote for x and in the other for y. You don't just don't experience voting for x and y at the same time.

cacian

11-16-2012, 06:50 AM

mal4mac

11-16-2012, 09:22 AM

Invalid appeal to authority and also argumentum ad hominem, in fact. (Feynman is really smart, so it must be that no one can understand QM ...)

Of course smart guys can be wrong, but in this case Feynman is right.

But, of course, we can understand QM -- and many other things besides! We are a very clever species.

We can't understand it in terms of common sense, if you want to equate "having an equation" and "experimental results" to "understanding" then fair enough...

When it comes to finding out how the world really is, as opposed to mere models of it, modern scientists of the Copenhagen school punt. In fact they forbid you to talk about it -- like priests in a church forbidding you to question sacred Scripture.

How on Earth can they forbid you talk about it?! Why would they? There is no Copenhagen Inquisition marching round the countryside looking to burn Many Worlders... it's just that Many Worlders are not convincing... Galileo proved the moon wasn't an ideal object by producing a telescope, where is the MW telescope?

Hugh Everett's theories have no general acceptance. In any case, this sort of arcane discussion should surely take place on physics forums, if anywhere, not here. It's bad enough having to suffer Big Endian discussion in ones own discipline without having one in someone else's discipline. Lay people should be protected from these kind of discussions...

For those wanting to dip their toe in "the other culture", a bare instrumentalist account is all that is needed, and the literate layman can happily avoid the "interpretation wars" that happen on the fringes of physics - most sensible physicists do, so they certainly should!

YesNo

11-16-2012, 10:02 AM

Another question about quantum is this:

whilst we are able to determine our weight at a static phase, what is the actual weight for a non static object say thrown in the air?
Whilst the object is moving it has a determined weight are we able to tell it?
Quantum physic or meta-physics or quantum in the move?

If we are in free fall we wouldn't have any weight. We wouldn't think we are moving either. Supposedly the laws of physics should be the same in these frame of references, but I wonder whether that is true for quantum physics laws.

Cioran

11-16-2012, 01:36 PM

Of course smart guys can be wrong, but in this case Feynman is right.

*Shrug* So you say. By the way, Feynman's elaboration of QM is essentially the Many Worlds.

We can't understand it in terms of common sense, if you want to equate "having an equation" and "experimental results" to "understanding" then fair enough...

There are tons of things we can't understand in terms of common sense. The universe can, however, be described mathematically, and understood to a good degree in that way.

How on Earth can they forbid you talk about it?! Why would they? There is no Copenhagen Inquisition marching round the countryside looking to burn Many Worlders...

Did you read the essay I linked on Hugh Everett? Nobody said there was an inquisition marching around to burn Many Worlders; this is a silly strawman of what I said. But, yes, you're not supposed to talk about what this means; just crunch the numbers was a big thing in QM for a long time. Read about how Everett was treated after he unveiled MW. He was essentially driven out of doing physics! Which shows that scientists can be petty, defend their domains with sometimes religious fervor, and in general behave like anyone else; i.e., badly.

it's just that Many Worlders are not convincing...

Not convincing to whom? MW is mainstream now, even boring. That's because Copenhagen with its magical wavefunction collapse is entirely unconvincing. Of course it's probably true that most scientists "shut up and calculate" and ignore what QM means. This puts them outside of the great tradition of the natural philosophers, like Galileo, Einstein and Newton, who wanted to understand how the world really was, and not just crunch numbers like mindless caclulators.

Galileo proved the moon wasn't an ideal object by producing a telescope, where is the MW telescope?

Where is the Copenhagen telescope? But, since you ask, here are the Many Worlds telescopes: Quantum computation, in its infancy but working and Buckyballs observed to be in superposition. Both demonstrate the Many Worlds. David Deutsch, in his book the Fabric of Reality from some fourteen years ago, makes a convincing case that quantum computation proves the existence of the many worlds, at least as far as anything can said to be "proved" in science.

Hugh Everett's theories have no general acceptance.

Sure, they do. Did you read the two papers that I linked? In his most recent book, Stephen Hawking talks not only about the Many Worlds, but about how in one of them the moon is made of Roquefort cheese! Literally! In any event, truth is not a matter of popular opinion, so the acceptance or non-aceeptance of a theory is irrelevant. Newton's theories were accepted for hundreds of years and are still taught in school, because they're useful. They're also wrong.

In any case, this sort of arcane discussion should surely take place on physics forums, if anywhere, not here. It's bad enough having to suffer Big Endian discussion in ones own discipline without having one in someone else's discipline. Lay people should be protected from these kind of discussions...

Laugh out loud, protected? If you want to be "protected" from some of the most interesting philosophy and science that you will ever encounter, don't read this thread! But don't presume to tell others what they can read or talk about. This particular forum is about philosophical literature. Thus thus this topic is perfectly appropriate, indeed one might say paradigmatically appropriate, for this particular forum.

For those wanting to dip their toe in "the other culture", a bare instrumentalist account is all that is needed, and the literate layman can happily avoid the "interpretation wars" that happen on the fringes of physics - most sensible physicists do, so they certainly should!

Right, exactly my point earlier, that the Copenhagen school of instrumentalism actually seeks to forbid these sorts of discussions -- which you yourself evidently are trying to do! Thanks for demonstrating my point.

mal4mac

11-16-2012, 03:15 PM

By the way, Feynman's elaboration of QM is essentially the Many Worlds.

Yes - Sum over Histories, another insult to common sense. No wonder he said you can't [really] understand it!

Read about how Everett was treated after he unveiled MW. He was essentially driven out of doing physics! Which shows that scientists can be petty, defend their domains with sometimes religious fervor, and in general behave like anyone else; i.e., badly.

Einstein was also "driven out" of physics, into the patent office, but it didn't stop him doing physics that was quickly *accepted by all physicists*.

This puts them outside of the great tradition of the natural philosophers, like Galileo, Einstein and Newton, who wanted to understand how the world really was, and not just crunch numbers like mindless caclulators.

"World really was"?! I can here Kant and the Buddha laughing in heaven at that one... Galileo, Einstein and Newton just gave us models, QT is a mathematical model.

Right, exactly my point earlier, that the Copenhagen school of instrumentalism actually seeks to forbid these sorts of discussions -- which you yourself evidently are trying to do! Thanks for demonstrating my point.

They don't forbid these discussions, how could they? They just try to discourage them, in the way that rational philosophers tried to discourage discussion of how many angels can dance on the head of a pin - there are better things to discuss.

YesNo

11-16-2012, 03:27 PM

I am talking about experiencing a quantum superposition, which is what I thought you were talking about. We clearly don't experience them. But, yes, in one world you vote for x and in the other for y. You don't just don't experience voting for x and y at the same time.

I don't know what you mean by experiencing a quantum superposition. I understand that MWI wants to extend the quantum wave to classical reality. I understand that MWI believes that Schrodinger's cat is alive in one world and dead in another. Perhaps I am wrong with those assumptions.

If I am not mistaken, I maintain that prior to voting the voter is in a superposition of (a) vote for X and (b) vote for Y. The voter has not yet chosen which it will be. In a similar way the photon is in a superposition prior to being measured of (a) spin up and (b) spin down. The photon has not yet chosen which it will be. When the voter makes a choice in voting, the machine registers that choice and a measurement is recorded. The voter should be in two different worlds now based on MWI. When the photon is measured, it also makes a choice between up and down and a measurement is recorded. The photon should be in two different worlds now based on MWI.

Perhaps MWI is false and there is only one world and looking at indeterminacy at the classical level rather than the quantum level is a way to expose the problems with MWI.

I have also been putting this in terms of "making a choice" and earlier with "free will". At the moment I am looking at Conway and Kochen's The Strong Free Will Theorem hoping to clarify some of the issues that MWI bring up for me: http://www.ams.org/notices/200902/rtx090200226p.pdf

Cioran

11-16-2012, 06:06 PM

I don't know what you mean by experiencing a quantum superposition. I understand that MWI wants to extend the quantum wave to classical reality. I understand that MWI believes that Schrodinger's cat is alive in one world and dead in another. Perhaps I am wrong with those assumptions.

If I am not mistaken, I maintain that prior to voting the voter is in a superposition of (a) vote for X and (b) vote for Y. The voter has not yet chosen which it will be. In a similar way the photon is in a superposition prior to being measured of (a) spin up and (b) spin down. The photon has not yet chosen which it will be. When the voter makes a choice in voting, the machine registers that choice and a measurement is recorded. The voter should be in two different worlds now based on MWI. When the photon is measured, it also makes a choice between up and down and a measurement is recorded. The photon should be in two different worlds now based on MWI.

I'm pointing out that some people felt (and many still feel) that there is a classical world in distinction to the quantum world because we never notice superpositions in ordinary life. They seemed to feel that unless the superposition of the quantum world "gave way" to what we called the classical world at some point, then we ought to experience superpositions in ordinary life -- actually experience being in many different states. But the MWI answer to this is simply that each of our "versions" experiences only one particular branch. In the case of the voter, the voter is always in superposition -- before, during, and after the vote. This is why, technically, there is no "splitting" -- everything is already "split" to begin with. But our minds are "split" among the different branches as well, so each mind experiences only a single branch and thinks (wrongly, under MWI) that that particular branch is the totality of reality.

Yes - Sum over Histories, another insult to common sense. No wonder he said you can't [really] understand it!

What is this with your devotion to common sense? Does common sense tell you that the world is quantum or relativstic (it's both)? Did common sense tell everyone that the reason that the apple falls to the ground is the same reason that the moon circles the earth, or did it take civilization 5,000 some years until someone came around and figured that out? Common sense is a notoriously poor guide to the world. Do you recall what Einstein said about common sense?

Einstein was also "driven out" of physics, into the patent office, but it didn't stop him doing physics that was quickly *accepted by all physicists*.

Excuse me? Einstein was "driven out of physics" into the patent office? Maybe you should check your history. As to being "accepted by all physicists," acceptance has nothing to do with whether something is true or not. Copernicanism was certainly not accepted for a long time, and Galileo's attempt to teach it as "true" as opposed merely to a model that gave identical predictions with Ptolemy gave him a fair spot of trouble with the Church, as I recall.

"World really was"?! I can here Kant and the Buddha laughing in heaven at that one... Galileo, Einstein and Newton just gave us models, QT is a mathematical model.

Of course it's a mathematical model. Are you saying that there can only be models, and the world has no actual true nature? If the world has no actual true nature, is it all in the mind, or a matter of opinion? Are you advocating philosophical idealism? Also, see above, on the debate of Ptolemy vs. Copernicus. Both provided models of the solar system. Both models made identical predictions. The Church told Galielo that it was fine to teach Copernicanism as a model to make predictions, but that it was not fine to teach it as showing how the solar system really is. And yet, it turned out that solar system really is heliocentric, and so Potelmy's model, while useful, was wrong. Here is a clear example of what you seem to be denying can happen: an example of a model not just being useful, but actually true. Would you deny that heliocentrism is actually true?

They don't forbid these discussions, how could they?

Read the piece on Everett.

They just try to discourage them, in the way that rational philosophers tried to discourage discussion of how many angels can dance on the head of a pin - there are better things to discuss.

This comparison is invalid. QM is a fact; angels are a fiction. When we discuss interpretations of QM, we are discussing a factual reality that, if it were not a fact, would instantly render your TV and your computer useless, among many other devices. So disucssing interpretations of a factual state of affairs has nothing in common with angels dancing on pins.

Again, if you don't approve of the discussion, feel free to recuse yourself from it.

YesNo

11-16-2012, 09:03 PM

I was reading Max Born's 1954 Nobel Prize address, "The statistical interpretation of quantum mechanics": http://www.nobelprize.org/nobel_prizes/physics/laureates/1954/born-lecture.pdf

In this address he wrote something about determinism that I think resolves the issue against the MWI. He describes how determinism started and remained as a belief that the laws of mechanics can accept an initial state from which all other states are derived.

Newtonian mechanics is deterministic in the following sense:

If the initial state (positions and velocities of all particles) of a system is accurately given, then the state at any other time (earlier or later) can be calculated from the laws of mechanics. All the other branches of classical physics have been built up according to this model. Mechanical determinism gradually became a kind of article of faith: the world as a machine, an automaton. As far as I can see, this idea has no forerunners in ancient and medieval philosophy. The idea is a product of the immense success of Newtonian mechanics, particularly in astronomy. In the 19th century it became a basic philosophical principle for the whole of exact science.

He then argues that one cannot get precise enough initial states to make predictions that remain accurate over time. His conclusion is the following:

I should like only to say this: the determinism of classical physics turns out to be an illusion, created by overrating mathematico-logical concepts. It is an idol, not an ideal in scientific research and cannot, therefore, be used as an objection to the essentially indeterministic statistical interpretation of quantum mechanics.

Born removes determinism from both classical and quantum physics. An initial state cannot be obtained that would allow any law to derive with adequate accuracy any future state after a certain point of time.

The MWI attempts to restore determinacy to physics by using a separate world for each branch in an indeterminate situation. This creates separate worlds in which QM should be true or MWI is not an interpretation for QM. However, if such an initial state and wave function existed for any particular world in the universe, that would contradict the indeterminacy of QM. Therefore, no initial state and wave function exists that will deterministically predict events for any particular world in the universe. Should such an initial state and wave function exist for the entire universe then in particular it would be a deterministic solution for some particular world and again QM would be contradicted. Therefore, no initial state and wave function exists that will predict all events for the entire universe.

And now for the conclusion:

Since MWI requires an initial state and wave function to exist for a deterministic physics either in each particular world or the universe as a whole, MWI is not a valid interpretation of QM.

Cioran

11-16-2012, 11:54 PM

Well, in honesty, I don't really follow your argument, YesNo. I'm not sure what the conclusion is supposed to mean, or how it derives from the premises. I don't really even understand the premises you are arguing.

I'd have to read Born's address, but I suspect what he is getting at is that determinism in a classical universe, even if true, is useful only in idealized states (as in the lab) because in tracing antecedent conditions, things get so complicated so fast that we can't trace the determinism.

This is true for all law-like statements about nature. We had to go to the moon and drop two objects of different size to determine them hitting the ground at the same time, because we needed a frictionless environment (no atmosphere, idealized) to show empirically that this is how nature behaves.

Many Worlds removes statistical indeterminacy from QM because the indeterminacy is a function of supposing there is wave function collapse. Without wave function collapse, a statement like, "there is a seventy percent chance that x will be found located at y, and a thirty percent chance that it will be found at z" resolves to seventy worlds with x at y and thirty worlds with x at z.

The goal of MW was not to restore determinism to physics. Rather, that was a consequence of the interpretation. The goal was to treat the whole universe as a quantum mechanical system, rather than arbitrarily split between a quantum world and a classical world; to show that this could be described mathematically (it can) and then to work out the ontological consequences.

MorpheusSandman

11-17-2012, 12:08 AM

While I'm far too ignorant about QM to discuss this on the level Cioran is, one piece of "common sense" philosophy I might introduce that could aid in his points is this: Consider that we evolved to be able to cope with and interpret reality in a manner that aided our survival. Most of our instincts and "common sense" comes from having to survive and reproduce, with surviving involving things like escaping from predators and being able to hunt and eat prey. This level of reality appears so differently to what happens on a quantum level that we have difficult grasping it. This is a limitation of our perspective, specifically, of how evolution has programmed us to think with regards to survival and reproduction. As I've said before, crocodiles don't need to understand QM in order to be able to eat and reproduce. It's entirely possible that reality is completely and utterly different to how we are programmed to experience, and, in fact, the history of scientific endeavor is an tome-like account of our common sense perceptions being subverted upon learning how things ACTUALLY work. Trying to understand MW on the level of our common sense, everyday experience would be like expecting a frilled shark to understand that the sun revolves around the earth. It's simply not a part of how they experience reality. The point of this is that what is true about the universe may very well never make sense to us on an intuitive, common-sense, instinctual level, for no other reason than that our evolution was not concerned with dealing with how reality actually works to begin with. We have to realize that our limitations of perspective may be the greatest thing preventing us from understanding how reality works.

Delta40

11-17-2012, 05:52 AM

That's a spectacular point MS.

mal4mac

11-17-2012, 08:13 AM

What is this with your devotion to common sense? Does common sense tell you that the world is quantum or relativstic (it's both)?

It's neither.

You can't say what the world *is*. Even within the confines of physics, you can only produce models that predict things in different domains. For instance GR only works in the large, QM in the small. At the Big Bang we have both situations, and our little physics models break down. The human being evolved from slime into being a clever, if barely sane, ape. How can we expect such a being to understand "the world"?

I prefer to accept my limits as an ape and play in the sandbox of common sense. If you like to play with wacky MW models then fine, each to his own. But you shouldn't mislead people into thinking that MW is the answer to life, the universe and everything.

Did common sense tell everyone that the reason that the apple falls to the ground is the same reason that the moon circles the earth...

Common sense evolves, the Newtonian model that fits nicely into our limited ape mind, and so common sense adapts to take it in very happily. But the Quantum Interpretations do not, they make no appeal to common sense, that's why there are so many of them and why physicists who Quixotically refuse to "shut up and calculate" can't agree on a good interpretation.

Excuse me? Einstein was "driven out of physics" into the patent office? Maybe you should check your history.

By "driven out" of physics I was assuming you meant "was forced to take a paid job outside physics". But really "driven out" can only be used in an ironic fashion here, Everett wasn't, really, in any sense "driven out". Theoretical physics is something you can do anywhere, so how can you be driven out of it?

As to being "accepted by all physicists," acceptance has nothing to do with whether something is true or not. Copernicanism was certainly not accepted for a long time, and Galileo's attempt to teach it as "true" as opposed merely to a model that gave identical predictions with Ptolemy gave him a fair spot of trouble with the Church, as I recall.

I agree, but it doesn't follow that any wacky interpretation is true. And discussing the wacky interpretations of Quantum Mechanics are not something that should be part of anyones general culture - it's a Big Endian activity

Of course it's a mathematical model. Are you saying that there can only be models, and the world has no actual true nature? If the world has no actual true nature, is it all in the mind, or a matter of opinion? Are you advocating philosophical idealism?
Of course there can only be models. What do you mean by "true nature"? How can we know such a thing. We are only apes limited by our little ape brains. I'm advocating Kant's transcendental idealism, which aknowledges the limitations of our little ape brain. Read his first critique to "get" this...

Also, see above, on the debate of Ptolemy vs. Copernicus. Both provided models of the solar system. Both models made identical predictions. The Church told Galielo that it was fine to teach Copernicanism as a model to make predictions, but that it was not fine to teach it as showing how the solar system really is. And yet, it turned out that solar system really is heliocentric, and so Potelmy's model, while useful, was wrong. Here is a clear example of what you seem to be denying can happen: an example of a model not just being useful, but actually true. Would you deny that heliocentrism is actually true?

Yes, it's just a better model.

Actually Copernicus' model wasn't as good Kepler's, which showed that the Sun isn't actually at the center of the solar system, it's at the focus of an ellipse.

There is no way you can get to "actually true".

Read the piece on Everett.

Nah. I've read too many pieces on Everett... I'm off to play internet chess...

...QM is a fact; angels are a fiction.

The results of QM experiments are facts, MW is a fiction. Actually people see angels in altered states of consciousness so they are less fictional than MW (or have you seen Universes splitting in your dreams...)

Again, if you don't approve of the discussion, feel free to recuse yourself from it.
You complained about people driving Everett out of physics, and now you're trying to drive me out of the thread!

Since MWI requires an initial state and wave function to exist for a deterministic physics either in each particular world or the universe as a whole, MWI is not a valid interpretation of QM.

I'm sorry YesNo, I have to agree with Cioran here. I'm not sure what your conclusion is supposed to mean, or how it derives from the premises. I don't really even understand the premises you are arguing.

MW, Copenhagen, Transactional... are all valid interpetations, all valid models. Just like Copernicus and Ptolemy (with) Epicycles are valid models... Tycho Brahe had another intruiging model... an interesting "sun and earth centred model".

Maybe the main problem with quantum interpretations is that, speaking metaphorically, THEY ALL HAVE EPICYCLES. And who can be bothered with epicycles... far too messy... hence the nicety of instrumental approach... you don't have to think about epicycles, just apply the equations and look at the planets in the sky, and ignore the daft arguments between Brahe, Copernicus, Ptolemy, et. al....

By the way, Kepler was also wrong of course, the planets don't move in smooth ellipses, there is, for instance, a precession in the perihelion of mercury. This is predicted by Newtonian theory... but even that model is wrong! The precession of the perihelion of mercury is predicted accurately only by GR. And GR, as Quantum cosmologists point out, is a limited theory. So we don't have any grasp on the reality of the solar system, just a cascade of models that get more accurate, but become increasingly difficult to play with.

Consider that we evolved to be able to cope with and interpret reality in a manner that aided our survival. Most of our instincts and "common sense" comes from having to survive and reproduce, with surviving involving things like escaping from predators and being able to hunt and eat prey. This level of reality appears so differently to what happens on a quantum level that we have difficult grasping it. This is a limitation of our perspective, specifically, of how evolution has programmed us to think with regards to survival and reproduction. As I've said before, crocodiles don't need to understand QM in order to be able to eat and reproduce. It's entirely possible that reality is completely and utterly different to how we are programmed to experience, and, in fact, the history of scientific endeavour is a tome-like account of our common sense perceptions being subverted upon learning how things ACTUALLY work. Trying to understand MW on the level of our common sense, everyday experience would be like expecting a frilled shark to understand that the sun revolves around the earth. It's simply not a part of how they experience reality. The point of this is that what is true about the universe may very well never make sense to us on an intuitive, common-sense, instinctual level, for no other reason than that our evolution was not concerned with dealing with how reality actually works to begin with. We have to realize that our limitations of perspective may be the greatest thing preventing us from understanding how reality works.

Great point MS! A point I made in my last post before reading yours... but you put it far better...

Cioran seems to think he is getting a grasp on reality through studying MW, but MS is far more compelling in his reasons why this is probably a futile endeavour. If, like me, you agree with MS, then why should anyone read Everett? I have read some Everett and it's not much fun; far better to read Dickens, or if you must explore "the big questions", a proper philosopher like Plato or Kant. Why get lost in backwaters like Everett?

Cioran

11-17-2012, 02:09 PM

It's neither.

You can't say what the world *is*. Even within the confines of physics, you can only produce models that predict things in different domains. For instance GR only works in the large, QM in the small. At the Big Bang we have both situations, and our little physics models break down. The human being evolved from slime into being a clever, if barely sane, ape. How can we expect such a being to understand "the world"?

And yet these same apes came up with GR and QM in the first place -- totally outside common sense, yet both work and are true.

I prefer to accept my limits as an ape and play in the sandbox of common sense.

Each to his own.

If you like to play with wacky MW models then fine, each to his own. But you shouldn't mislead people into thinking that MW is the answer to life, the universe and everything.

I've never said any such thing. You should stop misleading others that others are misleading them.

Common sense evolves, the Newtonian model that fits nicely into our limited ape mind, and so common sense adapts to take it in very happily. But the Quantum Interpretations do not, they make no appeal to common sense, that's why there are so many of them and why physicists who Quixotically refuse to "shut up and calculate" can't agree on a good interpretation.

You do know that Newtonian mechanics is false, right?

By "driven out" of physics I was assuming you meant "was forced to take a paid job outside physics". But really "driven out" can only be used in an ironic fashion here, Everett wasn't, really, in any sense "driven out". Theoretical physics is something you can do anywhere, so how can you be driven out of it?

He was driven out by negative ad homimen attacks that soured him on academia in general.

I agree, but it doesn't follow that any wacky interpretation is true. And discussing the wacky interpretations of Quantum Mechanics are not something that should be part of anyones general culture - it's a Big Endian activity

So something that has captivated the greatest minds in science for a century is not something that should be part of anyone's general culture? I suggest you speak for yourself.

Of course there can only be models. What do you mean by "true nature"? How can we know such a thing. We are only apes limited by our little ape brains. I'm advocating Kant's transcendental idealism, which aknowledges the limitations of our little ape brain. Read his first critique to "get" this...

Thanks, I've read Kant.

Yes, it's just a better model.

Actually Copernicus' model wasn't as good Kepler's, which showed that the Sun isn't actually at the center of the solar system, it's at the focus of an ellipse.

There is no way you can get to "actually true".

Is true that the sun goes around the earth, or is it false? Once you admit it is false, then your whole argument that all we can have are models, and that there is no "true way" the world "is," fall to pieces, doesn't it?

Nah. I've read too many pieces on Everett... I'm off to play internet chess...

The results of QM experiments are facts, MW is a fiction. Actually people see angels in altered states of consciousness so they are less fictional than MW (or have you seen Universes splitting in your dreams...)

This objection is remarkably vacuous. It's like someone in Galileo's time saying, "We don't feel the earth moving, or have you felt it move in your dreams?"

You complained about people driving Everett out of physics, and now you're trying to drive me out of the thread!

Not at all. You keep complaining that people should not be talking about this stuff. So why are you still talking about it?

Great point MS! A point I made in my last post before reading yours... but you put it far better...

Cioran seems to think he is getting a grasp on reality through studying MW, but MS is far more compelling in his reasons why this is probably a futile endeavour. If, like me, you agree with MS, then why should anyone read Everett? I have read some Everett and it's not much fun; far better to read Dickens, or if you must explore "the big questions", a proper philosopher like Plato or Kant. Why get lost in backwaters like Everett?

Ironically enough, I think you completly missed the point of MS's post. He's saying that we should not expect the world to conform to our common sense. I think that is correct, and it supports my interpretive arguments and goes against your own.

I might point out that the theoretical physicist David Deutsch thinks we already have the empirical demonstration of the truth of the Many Worlds, and he wrote about this as far back as 1998 in his book The Fabric of Reality. The proof is quantum computers, which already exist in a rudimentary form.

Here in an interview with Deuttsch. (http://www.wired.com/science/discoveries/news/2007/02/72734?currentPage=all) A nicely relevant quote is produced below. (mal4mac, you may skip all this for Internet chess, of course!)

WN: How do you think using quantum computers will change how people think about computing, and consequently the universe and nature?

Deutsch: "How they will think about it" is the relevant phrase here. This is a philosophical and psychological question you're asking. You're not asking a question about the physics or the logic of the situation.

I think that when universal quantum computers are finally achieved technologically, and when they are routinely performing computations where there is simply more going on there than a classical computer or even the whole universe acting as a computer could possibly achieve, then people will get very impatient and bored, I think, with attempts to say that those computations don't really happen, and that the equations of quantum mechanics are merely ways of expressing what the answer would be but not how it was obtained.

The programmers will know perfectly well how it was obtained, and they will have programmed the steps that will have obtained it. The fact that answers are obtained from a quantum computer that couldn't be obtained any other way will make people take seriously that the process that obtained them was objectively real.

Nothing more than that is needed to lead to the conclusion that there are parallel universes, because that is specifically how quantum computers work.

Quantum computers work by computing in superposition. That means real resources are really used; it’s real matter and energy. That means the other computers in the other words are real. That’s Deutsch’s position. It’s a pretty compelling point.

YesNo

11-17-2012, 02:51 PM

Well, in honesty, I don't really follow your argument, YesNo. I'm not sure what the conclusion is supposed to mean, or how it derives from the premises. I don't really even understand the premises you are arguing.

I'm just beginning to understand this. I see that both you and mal4mac found it confusing, so maybe rephrasing it like this is better:

No deterministic theory or interpretation can adequately describe QM which is non-deterministic.

There are at least two places where non-determinism enters QM:

1) One source of non-determinism comes from Heisenberg's uncertainty principle where some paired measurements, such as position and momentum, cannot be determined because the order of measuring them does not commute. As I see it this is what MWI attempts to address in QM by replacing the wave function collapse with many worlds.

2) The restriction of matter to quanta rather than allowing it to get arbitrarily small is another source of non-determinism. This is what Born is saying implies that even classical physics is non-deterministic. Eventually the imprecision in the initial state leads to a drift. That is, there is no initial state that works indefinitely. That initial state must always be refreshed and is therefore not deterministic.

It is only an illusion of classical physics that it ever was deterministic.

I'd have to read Born's address, but I suspect what he is getting at is that determinism in a classical universe, even if true, is useful only in idealized states (as in the lab) because in tracing antecedent conditions, things get so complicated so fast that we can't trace the determinism.

This is true for all law-like statements about nature. We had to go to the moon and drop two objects of different size to determine them hitting the ground at the same time, because we needed a frictionless environment (no atmosphere, idealized) to show empirically that this is how nature behaves.

It is not just the complicated nature of the results. Because of quantum theory, there is ultimately no way to get adequate precision to construct a deterministic theory of reality.

Any attempt to create a classical Newtonian deterministic explanation is forced to accept imprecision at the quantum level in measuring an initial state. What I learned from Born is that a deterministic solution requires that a single initial state be used to predict the entire future. If such an initial state can be constructed then quantum theory is false.

All physics is non-deterministic, both classical and quantum, because of quantum theory.

Many Worlds removes statistical indeterminacy from QM because the indeterminacy is a function of supposing there is wave function collapse. Without wave function collapse, a statement like, "there is a seventy percent chance that x will be found located at y, and a thirty percent chance that it will be found at z" resolves to seventy worlds with x at y and thirty worlds with x at z.

The goal of MW was not to restore determinism to physics. Rather, that was a consequence of the interpretation. The goal was to treat the whole universe as a quantum mechanical system, rather than arbitrarily split between a quantum world and a classical world; to show that this could be described mathematically (it can) and then to work out the ontological consequences.

As I understand Born, the initial state problem is not contained in the wave function collapsing or not. He is mainly addressing classical physics. It has to do with the imprecision of the measurements of the system. For determinism to work, the initial state cannot change. It cannot be refreshed and because of the imprecision required by quantum mechanics, future results will drift. Eventually, what originally came out as a "seventy percent chance that x will be found located at y" will be calculated as a sixty-nine percent chance that x will be found located at y". Soon the drift from reality will become an issue for technology and then MWI will be rejected.

The ontological consequence is that the stuff of reality is inherently non-deterministic. Because MWI is deterministic, it does not describe reality. Therefore, the MWI has no basis in reality on which to make an ontological claim that many worlds exist.

Cioran

11-17-2012, 03:04 PM

Btw, mal4mac, since you are interested in Internet chess, you might be interested in David Deutsch’s multiverse chess. From the article:

Thus a single quantum processor, with the same clock rate as one of Deep Blue’s processors, could examine a trillion chess positions in one second — and in two seconds it could examine four trillion, in three seconds nine trillion, and so on [see corrections below – DD].

Then follow the correction and the correction to the correction.

And this (bold face mine; it was italicized by Deutsch for emphasis in the article but since all pulled quotes here are italic, I bolded it instead):

To predict that future quantum computers, made to a given specification, will work in the ways I have described, one need only solve a few uncontroversial equations. But to explain exactly how they will work, some form of multiple-universe language is unavoidable. Thus quantum computers provide irresistible evidence that the multiverse is real. One especially convincing argument is provided by quantum algorithms — even more powerful than Grover’s — which calculate more intermediate results in the course of a single computation than there are atoms in the visible universe. When a quantum computer delivers the output of such a computation, we shall know that those intermediate results must have been computed somewhere, because they were needed to produce the right answer. So I issue this challenge to those who still cling to a single-universe world view: if the universe we see around us is all there is, where are quantum computations performed? I have yet to receive a plausible reply.

MorpheusSandman

11-18-2012, 02:34 AM

He's saying that we should not expect the world to conform to our common sense. That's what I was saying in a nutshell. Invoking common sense after a century of scientists dealing with QM seems a bit pointless...

I have read some Everett and it's not much fun; far better to read Dickens, or if you must explore "the big questions", a proper philosopher like Plato or Kant. Why get lost in backwaters like Everett?Not that I object to reading Dickens or Plato or Kant, but it seems like you're making this more a matter of personal aesthetic preference than about a desire to understand how reality works. Yes, all we have are predictive models, but that's all we've ever really had to begin with. Our entire brain can only be a map, but never the territory it's representing; in that sense, even our senses don't directly connect us to reality. However, when we're able to use models to predict outcomes, to predict sense experience, it does start to appear as if those models are an accurate representation of something external to our subjective biases, that the map reflects the territory.

mal4mac

11-18-2012, 09:07 AM

... it seems like you're making this more a matter of personal aesthetic preference than about a desire to understand how reality works.

Yes, I prefer things that give delight to mechanical understanding. If you get most delight in playing with quantum stuff, then fine. I did that for too long perhaps, these days I prefer Sherlock Holmes or whatever classic novel I might be reading at the moment. Novels give me more delight.

I wouldn't actually recommend reading Kant, his writing style is not delightful. But I think you are really wrong in thinking you are "understanding reality" in imbibing these models - try reading through the philsophy section of the library, and popular works that take Kant seriously (e.g., anthing by Bryan Magee.) That was probably the main thing that got me off this "reality quest" an dthe much more fun "delight quest".

The map being close to reality stuff is nonsense - try going for a nice country walk on map of the Cotswolds!

Yes, all we have are predictive models, but that's all we've ever really had to begin with....

So are sunsets or Picasso's paintings predictive models?

And yet these same apes came up with GR and QM in the first place -- totally outside common sense, yet both work and are true.

They work in a limited context, but like Socrates said, "we know nothing", translated: "we can't know the truth". And that's because as MS pointed out, we are apes, not Gods.

He was driven out by negative ad homimen attacks that soured him on academia in general.

Poor baby. The way his supporters complain you'd think he'd joined Bruno on the Inquisitions' stake.

So something that has captivated the greatest minds in science for a century is not something that should be part of anyone's general culture? I suggest you speak for yourself.

The basic ideas of the truly great minds, Einstein, Feynman and Bohr, say, should be. The rest, why bother... At school, and even University, only the truly greats *were* mentioned! No mention of Everett, or the other wacky interpretations. So the school system, backed by the mass of academia, agrees with me...

Is true that the sun goes around the earth, or is it false? Once you admit it is false, then your whole argument that all we can have are models, and that there is no "true way" the world "is," fall to pieces, doesn't it?
In the Biblical model, and everyday experience model, the Sun does go round the Earth. The Newtonian model works better for sending things to the moon, and the like.

Not at all. You keep complaining that people should not be talking about this stuff. So why are you still talking about it?
I think people should be talking about what stuff should be talked about.

YesNo

11-18-2012, 10:09 AM

Besides the Copenhagen and Many Worlds Interpretations, there is also the Penrose Interpretation which may offer a way for gravity to get involved with QM: http://en.wikipedia.org/wiki/Penrose_interpretation

This is an "objective collapse theory". It still has indeterminism. Penrose claims that particles can be in more than one place at a time yet lose that ability as the gravitational stress goes beyond one "graviton". He also describes an experiment to test his theory.

What I find interesting about this is the inclusion of general relativity in QM. It also makes some sense out of the superposition of a particle in more than one location. And he outlines an experiment to test the theory. To my knowledge the experiment has not been run.

This would be an alternative to MWI that would explain the superpositions prior to wave function collapse avoiding the need even at that stage to conjecture the existence of other worlds. A particle being at more than one location would be explained by gravity rather than the existence of other worlds in which it exists simultaneously.

Cioran

11-18-2012, 02:20 PM

They work in a limited context, but like Socrates said, "we know nothing", translated: "we can't know the truth". And that's because as MS pointed out, we are apes, not Gods.

The ancient Greeks were sharp cookies. Unfortunately most of their best guesses were wrong. We've moved on since Socrates. Also, you seem to have missed the post where MS was confirming that his point supported my argument, not yours.

Poor baby. The way his supporters complain you'd think he'd joined Bruno on the Inquisitions' stake.

The basic ideas of the truly great minds, Einstein, Feynman and Bohr, say, should be. The rest, why bother... At school, and even University, only the truly greats *were* mentioned! No mention of Everett, or the other wacky interpretations. So the school system, backed by the mass of academia, agrees with me...

That's not true. Everett and his work is in the forefront today. Stephen Hawking is a Many Worldist, for example. So is David Deutsch, the theoretical physicist and founder of quantum computing. Deutsch is still waiting for you (or someone) to answer a simple question: If superposition calculations are taking place that produce a result -- calculations being a physical enterprise involving matter and energy -- then where are they taking place? If they are not taking place in parallel worlds, then they are simply magic! Like saying God did it!

In the Biblical model, and everyday experience model, the Sun does go round the Earth. The Newtonian model works better for sending things to the moon, and the like.

Does the sun orbit the earth, or not? Are you seriously trying to suggest that you don't know the answer to the question? Because once you answer it, of course, your suggestion that all we have are models, and as apes we are foreclosed to knowing reality, is kaput.

I think people should be talking about what stuff should be talked about.

Who appointed you the arbiter of what people should and should not talk about? The conceit of this pretension is breathtaking. Again, if you find this topic uninteresting or futile, then absent yourself from the discussion. To try to dictate to others what they should and should not talk about is rather repellant, IMO.

YesNo

11-18-2012, 02:57 PM

Deutsch is still waiting for you (or someone) to answer a simple question: If superposition calculations are taking place that produce a result -- calculations being a physical enterprise involving matter and energy -- then where are they taking place? If they are not taking place in parallel worlds, then they are simply magic! Like saying God did it!

I think interpretations such as the one Penrose presented would explain where quantum superpositions occur: They occur in the real world. There is no need for other parallel worlds.

Cioran

11-18-2012, 03:00 PM

I think interpretations such as the one Penrose presented would explain where quantum superpositions occur: They occur in the real world. There is no need for other parallel worlds.

E-mail Deutsch and see what he says. Maybe he'll even joint this discussion if we're lucky.

Yes, I prefer things that give delight to mechanical understanding.

Newtonian mechanics is a false theory.

mal4mac

11-18-2012, 03:13 PM

Does the sun orbit the earth, or not? Are you seriously trying to suggest that you don't know the answer to the question? Because once you answer it, of course, your suggestion that all we have are models, and as apes we are foreclosed to knowing reality, is kaput.

I did! In the "everyday" model the sun orbits the Earth and the Earth stands still and the Earth is flat.

In the Copernican, Kepler, and Newtonian models the Earth orbits the sun.

Who appointed you the arbiter of what people should and should not talk about? The conceit of this pretension is breathtaking. Again, if you find this topic uninteresting or futile, then absent yourself from the discussion. To try to dictate to others what they should and should not talk about is rather repellant, IMO.

I'm not trying to force anyone, and how can I dictate anything? I can't get my Inquisition torture equipment down the internet superhighway. Why can't one question how interesting a topic is? Anyway, you're the one keeping the conversation going, if you find it repellent then stop conversing!

YesNo

11-18-2012, 05:17 PM

E-mail Deutsch and see what he says. Maybe he'll even joint this discussion if we're lucky.

I'm reading his The Fabric of Reality hoping to find out more precisely what WMI is attempting to say. Chapters 2, 9, 11, 12, 13, and 14 are supposed to be related to QM. So far from chapter 2, I understand that interference patterns are supposed to be the evidence for parallel worlds visible within each of the worlds. Penrose has a more interesting explanation for this paradoxical behavior of quantum particles based on gravity. That may not be verified, but I think something along the lines Penrose is considering will be found and verified. The parallel worlds idea appears too arbitrary a solution for me. I might as well say fairies do it.

Cioran

11-18-2012, 05:30 PM

I did! In the "everyday" model the sun orbits the Earth and the Earth stands still and the Earth is flat.

In the Copernican, Kepler, and Newtonian models the Earth orbits the sun.

Does the sun actually orbit the earth, or not? You really don't know the answer to the question? I suggest you are being evasive because answering correctly "no, the sun does not orbit the earth" undermines your argument that all we have are models. Do you seriously expect us to believe that you think the question of whether the sun orbits the earth is undecided or undecidable, because in some models it does and in others it doesn't? If that really is your answer, it's the exact same answer the Church gave some 400 years ago and which brought Galileo before the Inquisition.

I'm not trying to force anyone, and how can I dictate anything? I can't get my Inquisition torture equipment down the internet superhighway. Why can't one question how interesting a topic is? Anyway, you're the one keeping the conversation going, if you find it repellent then stop conversing!

You're confused again. It's you who finds the conversatin repellant, yet for some reason you keep conversing. I said that what I found repellant is how you set yourself up as arbiter of the things that should and should not be discussed.

YesNo

11-18-2012, 07:05 PM

I finished chapter 2 of Deutsch's The Fabric of Reality and I think I can describe an experiment that could be constructed to test whether there are parallel worlds or not.

According to Deutsch, when photons interfere in the double slit experiment there are tangible photons and shadow photons involved. The tangible photons are the ones that the experimenter sees and the shadow photons are in the parallel worlds. They only interact to make the interference phenomenon work. Otherwise, they cannot be detected.

What that means is that these worlds must be synced together so that the interference can occur or not occur depending on whether the experimenter opens both slits or covers one of them up. Deutsch claims this about parallel universes (page 51):

It is the explanation--the only one that is tenable--of a remarkable and counter-intuitive reality.

I think Penrose has a way to consider photons being in two places at once without requiring parallel universes, so this is not the only tenable explanation regardless of Deutsch's claim. If Penrose is right, his approach would also lead to a deeper understanding of the universe and not just compound the counter-intuitiveness of reality.

But in any case the many worlder's need an experiment to prove that these other universes exist. I think the following would work.

Shine a single photon through a double slit until it reaches a photomultiplier that will signal a computer to generate a random number. This random number will be the seed to a series of random numbers that will either cover the second slit or open it depending on whether the random number is even or odd. If the slit is covered there should be no interference. If the second slit is open, interference should be detectable. Set up a mechanism to automatically register whether the interference pattern occurred when it was expected to occur or not and look for a situation when the interference pattern was missed. Automate the test so it can be repeated as rapidly as possible to generate many tests results.

If there really are other universes the interference pattern should be missed every now and then. That would be the proof that the many worlds exist although it would contradict the double slit experiment's expected results.

If the interference pattern is never missed the many worlders then need to explain how this counter-intuitive synching process occurs. That would not prove they are wrong, but it would make one wonder what difference it makes to compound a simple counter-intuitive observation with an explanation that is way more counter-intuitive and which cannot be detected by experiment.

Cioran

11-18-2012, 09:16 PM

If there really are other universes the interference pattern should be missed every now and then.

Why? I don't follow your logic here.

Regardless of which interpretation of QM is correct, if any, the wave interference pattern always appears when the experimental setup is right. That's part and parcel of the theory, and if the wave interference pattern failed to appear, QM would be a false theory.

YesNo

11-18-2012, 10:17 PM

Why? I don't follow your logic here.

Regardless of which interpretation of QM is correct, if any, the wave interference pattern always appears when the experimental setup is right. That's part and parcel of the theory, and if the wave interference pattern failed to appear, QM would be a false theory.

I agree with that. If this test actually showed a miss on the interference pattern it would show that QM is false and WMI is correct for some other theory, not QM. The interference pattern should always work correctly if QM is correct.

But if it works correctly, and it involves a syncing with parallel universes, how does this syncing occur? Deutsch doesn't provide any information on that at least so far. What the experiment is trying to show is the existence of these other universes by seeing if the syncing fails occasionally. I'm looking for a validation that these other worlds actually exist that is stronger than Deutsch just insisting it is true.

What evidence is there that these other worlds exist? The interference patterns are not in themselves evidence. They are what one is trying to explain.

------ added

There would also be a concern if the syncing process occurred faster than the speed of light or if these other universes occupied the same space-time location.

If these universes were in the same space-time location so that there is no distance between them, that seems to be as counter-intuitive as claiming a photon can be at two different space-time locations at one time.

If they were at different space-time locations is the information that allows them to sync traveling between the different universes going faster or slower than the speed of light?

Cioran

11-18-2012, 10:49 PM

I'm not sure what you mean by synching, but just briefly (no time for larger points now), Deutch's evidence is not that he simply "insists that it is true." His evidence is the fact that quantum computation is a physical process that can employ resources many times greater than available to our visible universe. They are real, physical processes involving mass and energy. Where is this stuff coming from, if not from the many worlds? That is his question.

MorpheusSandman

11-19-2012, 12:26 AM

Yes, I prefer things that give delight to mechanical understanding.Again, I have no problem with that; I'm more of an aesthete than a scientist/logician myself, but I don't confuse my aesthetic preference for the most effective methods of understanding how reality actually functions.

The map being close to reality stuff is nonsenseWhy so? It's probably the best metaphor available for describing the relationship between reality and how we understand it: http://wiki.lesswrong.com/wiki/The_map_is_not_the_territory Your recent posts about the different "models" of how the sun/earth revolves around each other is dangerously reminiscent of this: http://lesswrong.com/lw/om/qualitatively_confused/

So are sunsets or Picasso's paintings predictive models?Neither helps us understand how reality works. They may help us appreciate it, they may help us to see it, feel it, and think about it in different ways, but no experience of natural phenomena or mimetic representation of phenomena is going to aid in answering the questions of how these things work, or why we experience them as we do.

Cioran

11-19-2012, 12:56 AM

Wikipedia is often justly criticized, but its essay on Many Worlds, which I had never read before tonight, is superb. It is here. (http://en.wikipedia.org/wiki/Many-worlds_interpretation)

It basically answers all the objections to Many Worlds and emphasizes the point that impresses me: Many Worlds, in actuality, is far less weird than all other QM interpretations; in fact it restores the world to common sense, rather then dethrone it from common sense as QM in its original iterations did.

The article is geared toward intermediate understanding. One must have some understanding of QM and related science issues, but if one does it is non-technical enough to be very understandable.

I also learned some amazing things I did not know. Hugh Everett, way ahead of his time, evidently believed in quantum immortality (don't ask. If you must ask, Google "quantum immortality" and "quantum suicide.")

The most surprising thing is that empirical tests for MWI have actually been proposed, and the idea that there is no relation or communication possible between the parallel worlds is debunked. Indeed, it turns out that if the parallel worlds exist, it may even be possible to send television images between them. :eek:

cacian

11-19-2012, 05:27 AM

YesNo I am trying to understand what you have posted.
There is a lot of information there indeed. You are very well read.
If I may take bits and pieces in my own way to make some sense in my head.

I finished chapter 2 of Deutsch's The Fabric of Reality and I think I can describe an experiment that could be constructed to test whether there are parallel worlds or not.

About parallel universe this make think this:
If there was a parallel world why are we not able to see it?
We see all the rest of the planets such as the sun the moon and so. If there is such a thing then juxtapositions should be able to reflect the parallelism for us to see.
As far as light is concerned there has to be a reflection. Everything including us have a reflection.

According to Deutsch, when photons interfere in the double slit experiment there are tangible photons and shadow photons involved. The tangible photons are the ones that the experimenter sees and the shadow photons are in the parallel worlds. They only interact to make the interference phenomenon work. Otherwise, they cannot be detected.

Why a photon?
How about vibrations. If one is to vibrate an object then there is a movement that we see. That is a parallelogy to a photon silt.
The movement is seen on the computer say whilst the object vibrate. The traces it leads to are the only parallelism there is.
The same with heart beat. A computer picks a graph that is the only parallelism that exist between a phenomena and that is trough movement. Movement creates a visible parallel.
Again the same with music. Hit a note and gives you sound. Read the notes and then make music. A note is a shape. That is again a parallelism.
If you observe sunlight peeking through a window one can see a ray of dusts held again say a screen. That ray of dust particles is the only parallel there is to light.
Light embodies shapes.

YesNo

11-19-2012, 01:16 PM

About parallel universe this make think this:
If there was a parallel world why are we not able to see it?
We see all the rest of the planets such as the sun the moon and so. If there is such a thing then juxtapositions should be able to reflect the parallelism for us to see.
As far as light is concerned there has to be a reflection. Everything including us have a reflection.

According to those supporting Many Worlds the after effects of these parallel universes are seen when quantum particles make an interference pattern.

There are two basic ways to explain this interference pattern: (1) a single particle in a single world can be in more than one superposition state at a time, or (2) more than one particle is involved, the one we see and the other "shadow" particles each from a different parallel universe with no superposition for any individual particle.

So, the evidence for the parallel universes is the existence of interference patterns for quantum particles sent through a double slit experiment one particle at a time. The MWI expects an interference pattern to imply that more than one particle was causing the interference on the other which leads to a deterministic explanation. However, the interference patterns are also evidence that quantum particles have superposition states which leads to a non-deterministic explanation.

Why a photon?
How about vibrations. If one is to vibrate an object then there is a movement that we see. That is a parallelogy to a photon silt.
The movement is seen on the computer say whilst the object vibrate. The traces it leads to are the only parallelism there is.
The same with heart beat. A computer picks a graph that is the only parallelism that exist between a phenomena and that is trough movement. Movement creates a visible parallel.
Again the same with music. Hit a note and gives you sound. Read the notes and then make music. A note is a shape. That is again a parallelism.
If you observe sunlight peeking through a window one can see a ray of dusts held again say a screen. That ray of dust particles is the only parallel there is to light.
Light embodies shapes.

The interference pattern is not restricted to a photon. An electron would work as well as some larger objects, so I've heard.

Cioran

11-19-2012, 03:37 PM

mal4mac

11-19-2012, 03:39 PM

Does the sun actually orbit the earth, or not? You really don't know the answer to the question? I suggest you are being evasive ...

I don't think I am, you just don't get my "everything is a model" argument. In a plastic model of the solar system does the earth go round the sun. No the little plastic ball goes round the other little plastic ball!

Do you seriously expect us to believe that you think the question of whether the sun orbits the earth is undecided or undecidable, because in some models it does and in others it doesn't? If that really is your answer, it's the exact same answer the Church gave some 400 years ago and which brought Galileo before the Inquisition.

The church can have their model if the want, it might not be so usable for sending out moon shots as NASAs, though. The inquisition were a nasty bunch, but some nice people have been attached to an Earth centred model. Are you really trying to argue that because the SI were nasty their model isn't allowed?

YesNo

11-19-2012, 05:18 PM

An isolated system is in superposition.

The universe is an isolated system (there is nothing outside it)

Therefore, the universe is in superposition and evolves deterministically according to the Schrodinger wave equation. Therefore, we get many worlds. In getting the many worlds, we get rid of all the weirdness of quantum mechanics: indeterminism, spooky action at a distance and the inexplicable wave function collapse.

Experimentally, objects as large as Buckyballs and molecules with as many as 240 atoms, according to my latest knowledge, have been placed in superposition in the two-slit experiment. Everything is in superposition all the time, if MW is true, so in theory we could send a superposed person through the two slits, but in practice this could not be done.

One of the things I am having trouble with is the way MWI treats the word "superposition". Deutsch seemed to clarify this for me with the following from chapter 2 of The Fabric of Reality, pages 44-45:

I shall now start calling the interfering entities 'photons'. That is what they are, though for the moment it does appear that photons come in two sorts, which I shall temporarily call "tangible" photons and "shadow" photons. Tangible photons are the ones we can see, or detect with instruments, whereas the shadow photons are intangible (invisible) -- detectable only indirectly through their interference effects on the tangible photons. (Later, we shall see that there is no intrinsic difference between tangible and shadow photons: each photon is tangible in one universe and intangible in all the other parallel universes -- but I anticipate.)

What this means to me is that superposition is not at the level of the states that a single particle could have, but is a way to represent the superposition of worlds. In the MWI view each particle can be in only one state.

There is a problem with associating a probability with each particle's state. I think you attempted to resolve that by increasing the number of worlds so there are 30 worlds to represent 30%. That seems very arbitrary. The probability value could have an arbitrarily large number of decimal points. So you would need infinitely many worlds just to represent that number accurately--for each item you measured!

Without accuracy the determinism falls apart. Of course, in practice, we can use approximations, but MWI is claiming that reality is deterministic, so those infinitely many worlds for each measurement would have to exist for their position to be correct.

I am amazed to what extent people will go to keep determinism. It isn't worth keeping.

Cioran

11-19-2012, 08:50 PM

I don't think I am, you just don't get my "everything is a model" argument. In a plastic model of the solar system does the earth go round the sun. No the little plastic ball goes round the other little plastic ball!

The church can have their model if the want, it might not be so usable for sending out moon shots as NASAs, though. The inquisition were a nasty bunch, but some nice people have been attached to an Earth centred model. Are you really trying to argue that because the SI were nasty their model isn't allowed?

Laugh out loud.

You just really can't stand to admit that you are wrong, can you?

Does the sun orbit the earth, or not?

As to "SI." I don't know what you mean by that. Whatever "SI" is, to argue that because "SI" (whatever that is) is nasty, SI's model "isnt allowed," is to commit the logical fallacy of ad hominen. Nothing that I would do, but that is something surely that you might do.

Does the sun orbit the earth? Are you able to answer the question?

Cioran

11-19-2012, 09:06 PM

I am amazed to what extent people will go to keep determinism. It isn't worth keeping.

Yet again, determinism is not a precondition of the Many Worlds interpretation. It is a consequence of it. If it so happens that determinism is rendered false in any interpretation of reality, then this fact (if it is a fact) does not impeach the Many Worlds interpretation. It just means that whether MWI is true or not true, determinism is false. What MWI does is restore classical determinism. If it so happens that classical determinism turns out to be false, then it is false regardless of whether MWI is true, and so has no bearing on the truth or falsity of MWI.

Cioran

11-19-2012, 09:14 PM

Are you really trying to argue that because the SI were nasty their model isn't allowed?

I wanted to return to this again, to stress the point:

Please point out where I have committed a classic ad hom argument, as charged above. If you can't point out where I have done so, please retract the charge and apologize for making it.

Spoiler alert: I've made no ad hom argument, and you won't retract your charge that I did, nor will you apologize for your false charge.

Now, I'd like you to answer the following question:

Does the sun revolve around the earth?

Sorry, I had to make it big and bold, to counter your weaselly evasiveness.

Cioran

11-19-2012, 09:28 PM

Albert Einstein: "The Old One does not play dice."

Many Worlds: "You're right again, Einstein!"

YesNo

11-20-2012, 12:51 AM

Yet again, determinism is not a precondition of the Many Worlds interpretation. It is a consequence of it. If it so happens that determinism is rendered false in any interpretation of reality, then this fact (if it is a fact) does not impeach the Many Worlds interpretation. It just means that whether MWI is true or not true, determinism is false. What MWI does is restore classical determinism. If it so happens that classical determinism turns out to be false, then it is false regardless of whether MWI is true, and so has no bearing on the truth or falsity of MWI.

I have learned a lot about this topic because of your participation, Cioran. Thanks! I don't understand all the implications of the determinism issue, nor much about QM, but if one hears the ideas used they start making sense.

There is the topic of "copying" that is now on my mind. Deutsch used the idea in The Fabric of Reality, page 307. Here's just some sentences using the word related to "time travel":

It is not meaningful to ask "which" copy of me would have which experience: so long as we are identical, there is no such thing as 'which' of us. Parallel universes do not have hidden serial numbers: they are distinguished only by what happens in them. Therefore in rendering all this for the benefit of one copy of me, the virtual-reality generator must recreate for me the effect of existing as two identical copies who then become different and have different experiences.

I was also looking at the "no-cloning theorem" of QM: http://en.wikipedia.org/wiki/No-cloning_theorem

There are a bunch of these "no-go" theorems, but it seems that QM prohibits copies, or clones, being made of a universe even on a small scale. The question that is in my mind at the moment is whether the MWI is in conflict with QM because of all the copies that it needs. Now I don't understand the proof of this theorem. I wish I did, but I think it means that QM does not allow copies of the world to be created.

If that is true, that would mean that the multiverse has only one universe in it--or QM is false.

cacian

11-20-2012, 05:48 AM

Laugh out loud.

You just really can't stand to admit that you are wrong, can you?

Does the sun orbit the earth, or not?

As to "SI." I don't know what you mean by that. Whatever "SI" is, to argue that because "SI" (whatever that is) is nasty, SI's model "isnt allowed," is to commit the logical fallacy of ad hominen. Nothing that I would do, but that is something surely that you might do.

Does the sun orbit the earth? Are you able to answer the question?

Ad Hominen argument. First time I have heard of it thanks for bringing it up.
''Nothing that I would do but that is something surely that you might do'' is this what it means?
Sorry I just want to confirm.
I was reading about 'ad hom' this and found this:

Inductive fallacies are not formal in this sense. Their merit is judged in terms of rational persuasiveness, inductive strength or methodology (for example, statistical inference). For instance, the fallacy of hasty generalization, can be roughly stated as an invalid syllogism:

1.A is an X
2.A is also a Y
3.Therefore, all Xs are also Ys

The answer surely is
therefore X and Y are As.
because it should be
a=x
a=y
then
a=y=x
That is the answer A=X=Y. The only answer.

Is this the same as saying two rights do not make it wrong? or two wrongs don't make it right?

mal4mac

11-20-2012, 08:43 AM

Laugh out loud.

You just really can't stand to admit that you are wrong, can you?

I can stand to admit when I'm wrong. But on this topic, I'm not wrong.

P.S. Sorry about the SI abbreviation - I was too lazy to spell out Spanish Inquisition thinking it was obvious from context, and I was wrong about that...

Scheherazade

11-20-2012, 08:54 AM

~

R e m i n d e r

Please do not personalise your arguments.

Off-topic and/or inflammatory posts will be removed without further notice.

~

cacian

11-20-2012, 09:42 AM

I can stand to admit when I'm wrong. But on this topic, I'm not wrong.

P.S. Sorry about the SI abbreviation - I was too lazy to spell out Spanish Inquisition thinking it was obvious from context, and I was wrong about that...

Spanish Inquisition? that sounds like a good topic to tackle haha. SI is Spanish for YES so you are not too far out.
It is nice to see the Spanish Inquisition in QP. A bit of spice does not hurt.

Cioran

11-20-2012, 06:00 PM

I can stand to admit when I'm wrong. But on this topic, I'm not wrong.

Not wrong about what? Are you saying that you are right that we cannot know whether sun the sun orbits the earth?

Does the sun orbit the earth, or not?

P.S. Sorry about the SI abbreviation - I was too lazy to spell out Spanish Inquisition thinking it was obvious from context, and I was wrong about that...

Why would Galileo have been hauled before the Spanish Inquisition? He was not a subject of the kingdom of Spain. He was summoned before the Roman Inquisition.

Where did I make an argument that because the inquisition was a bad thing, then its arguments about the geocentrism v. heliocentrism debate were wrong? Clearly I made no such ad hominem attack, so why did you suggest that I did?

Cioran

11-20-2012, 06:10 PM

YesNo

11-20-2012, 07:39 PM

If the sun, along with the other stars, revolved around the earth, that would contradict special relativity which says that matter does not go faster than the speed of light. There are stars that are more than one light-day from earth. If they were moving in a circle around the earth, they would travel more than 2*pi*1 light-days in one day's time which means they would go faster than light.

One would have to choose between that model and special relativity. There may be other objections to the sun going around the earth that I can't think of at the moment.

cacian

11-21-2012, 03:03 AM

ad homimem:

a claims x

a has some personal characteristic of the nature y.

Therefore, because a has characteristic y, his claim of x is false.

In fact, x is true or false regardless of whether a has characteristic y or not. So ad hominem is fallacious argumentation.

Example:

Hitler said vegetarianism is good.

Hilter was an evil man who killed millions.

Therefore, vegetarianism is bad
This intricate so what you are suggesting is that the conclusive sentence can be both.
This does not make sense because
While
a says something
and
a is something else

There is a link missing between the first and the second. How does one go from x to y?
Unless there is a link then there is no third consequential correct or fallacious.

The only time one this work is this
a=x
a-y
then a=y=x. That is the only preposition and it is exact.

mal4mac

11-21-2012, 05:22 AM

If the sun, along with the other stars, revolved around the earth, that would contradict special relativity which says that matter does not go faster than the speed of light.

The equations do tend to simplify when you think of the sun as being in the center of our system, but that doesn't make it true.

If someone was motivated enough they would be able to patch together a "still Earth" model that gets around your objection. Just search the web, you'll find many doing this :)

http://primecrackpot.blogspot.co.uk/2012/03/demise-of-earth-centered-universe.html

Maybe the speed of light is infinite until it gets close to Earth?

As the Earth is "the special thing at the centre" you can validly concoct any model to get around any objection. The Roma Catholic church did this for a long time, and only stopped when the power base moved to the military-industrial-science complex. And the RC church have always been much more inclined to cosy up to power than to stick to their original metaphysics.

The Michelson-Morley experiment showed that light was going the same speed in the direction of motion of the Earth, and at right angles to it. Relativity was needed to explain that observation. But in a model where the Earth doesn't move the explanation of Michelson-Morley is extremely simple, it does away with the need for special relativity.

I was going to try out the "bat signal argument" to defeat you, but I couldn't make it work "in reverse" :( It's interesting in showing how to get speeds of 2pi light years/ per second, though, and I did work hard(ish) on it, so here it is:

Paste black paper shaped like a bat onto a spotlight; the signal used to summon Batman. Broadcast the Bat-call to the cosmos. Rotate the spotlight. As the light turns, the bat shadow sweeps across the sky. Just as the rim of a bicycle wheel moves faster than its hub, so too, our bat shadow will fly faster and faster. If the spotlight takes a second to rotate, at one light year out the bat shadow will have to travel at 2pi light years per second. In the "usual" model, this does not violate relativity because a shadow carries no energy. But what about the circle of light "setting off" the bat shadow, you may ask? Isn't the light itself traveling far faster than the speed of light, through rotating in space? No! The bulbs that produce the light are spinning, but the light particles leave the source at 186,000 miles a second. Once emitted, the photons continue to travel at this speed directly away from the source.

Science has nothing to do with "truth"; its intent is actually to develop a set of codes that allow us to make accurate predictions about observations. Regardless of any external, objective truth.

ad homimem:

a claims x

a has some personal characteristic of the nature y.

Therefore, because a has characteristic y, his claim of x is false.

In fact, x is true or false regardless of whether a has characteristic y or not. So ad hominem is fallacious argumentation.

Example:

Hitler said vegetarianism is good.

Hilter was an evil man who killed millions.

Therefore, vegetarianism is bad

Not correct - this is just an illogical argument.

An ad hominem argument "appeals to feelings not reason". An example: "Everett was badly treated by his colleagues which makes me feel bad, so Everett's theory is correct." Or, "I've spent my whole life studying physics and would feel totally downhearted if it was all "just models" rather than Reality, so Everett must have discovered Reality."

MorpheusSandman

11-21-2012, 05:52 AM

Not correct - this is just an illogical argument.Logical fallacies like ad hominems are synonymous with "illogical arguments" because that's literally what they are; the explanation Cioran gave of an ad hominem was just fine. The fallacy you gave an example of (regarding Everett being badly treated) is actually a different fallacy known as "Appeal to pity." All of them are sub-fallacies of the more general "Appeal to emotion" category of fallacy.

cacian

11-21-2012, 06:37 AM

Logical fallacies like ad hominems are synonymous with "illogical arguments" because that's literally what they are; the explanation Cioran gave of an ad hominem was just fine. The fallacy you gave an example of (regarding Everett being badly treated) is actually a different fallacy known as "Appeal to pity." All of them are sub-fallacies of the more general "Appeal to emotion" category of fallacy.

If it is fallacy which obviously derives from the word FALSE why is LOGIC word there?

cacian

11-21-2012, 06:42 AM

An ad hominem argument "appeals to feelings not reason". An example: "Everett was badly treated by his colleagues which makes me feel bad, so Everett's theory is correct.

Which theory?

" Or, "I've spent my whole life studying physics and would feel totally downhearted if it was all "just models" rather than Reality, so Everett must have discovered Reality."

Everett involved here when you are talking using I? I do not get this.

MorpheusSandman

11-21-2012, 06:48 AM

If it is fallacy which obviously derives from the word FALSE why is LOGIC word there?I'm not sure what you're asking... logical fallacies are incorrect methods of reasoning. The word "fallacy" may share a root with "false," but logic doesn't deal with whether or not propositions are true or false, it only deals with whether or not the methods used to reach conclusions from multiple propositions are correct or fallacious.

cacian

11-21-2012, 09:00 AM

I'm not sure what you're asking... logical fallacies are incorrect methods of reasoning. The word "fallacy" may share a root with "false," but logic doesn't deal with whether or not propositions are true or false, it only deals with whether or not the methods used to reach conclusions from multiple propositions are correct or fallacious.

Ah I understand now.
That is why I was completely at loss with the word logic.
I see logic differently.
The logic I know is the one that starts from correct and leads to correct. Therefore logic is correct or exact at any given time all the time.
By definition logic is what determines the methods to reach an exact conclusion in other words logic consequential and therefore there is no incorrect or fallacious prepositions. It is exact with is no room for mistakes when logic is concerned.

YesNo

11-21-2012, 12:54 PM

The equations do tend to simplify when you think of the sun as being in the center of our system, but that doesn't make it true.

If someone was motivated enough they would be able to patch together a "still Earth" model that gets around your objection. Just search the web, you'll find many doing this :)

http://primecrackpot.blogspot.co.uk/2012/03/demise-of-earth-centered-universe.html

Maybe the speed of light is infinite until it gets close to Earth?

As the Earth is "the special thing at the centre" you can validly concoct any model to get around any objection. The Roma Catholic church did this for a long time, and only stopped when the power base moved to the military-industrial-science complex. And the RC church have always been much more inclined to cosy up to power than to stick to their original metaphysics.

The Michelson-Morley experiment showed that light was going the same speed in the direction of motion of the Earth, and at right angles to it. Relativity was needed to explain that observation. But in a model where the Earth doesn't move the explanation of Michelson-Morley is extremely simple, it does away with the need for special relativity.

I agree. If one has to explain something one wants to believe in, whether it is geocentrism, determinism, or Santa coming down the chimney, one can always find a way to do it. It may not always convince someone else.

I'm pleased to see that even the Prime Crackpot site considers geocentrism and relativity contradictory.

Theories should be able to predict something interesting. I don't know what MWI has actually predicted. I don't even think it makes a good retrodiction of QM and classical physics. Can you imagine someone telling Newton that he needs a multiverse for physics to be viable? I wonder what Einstein would have thought about that.

I was going to try out the "bat signal argument" to defeat you, but I couldn't make it work "in reverse" :( It's interesting in showing how to get speeds of 2pi light years/ per second, though, and I did work hard(ish) on it, so here it is:

Paste black paper shaped like a bat onto a spotlight; the signal used to summon Batman. Broadcast the Bat-call to the cosmos. Rotate the spotlight. As the light turns, the bat shadow sweeps across the sky. Just as the rim of a bicycle wheel moves faster than its hub, so too, our bat shadow will fly faster and faster. If the spotlight takes a second to rotate, at one light year out the bat shadow will have to travel at 2pi light years per second. In the "usual" model, this does not violate relativity because a shadow carries no energy. But what about the circle of light "setting off" the bat shadow, you may ask? Isn't the light itself traveling far faster than the speed of light, through rotating in space? No! The bulbs that produce the light are spinning, but the light particles leave the source at 186,000 miles a second. Once emitted, the photons continue to travel at this speed directly away from the source.

I'm glad you explained why it doesn't contradict relativity. :)

Science has nothing to do with "truth"; its intent is actually to develop a set of codes that allow us to make accurate predictions about observations. Regardless of any external, objective truth.

Does that make you an instrumentalist as well? That seems like the main use for science and its limitation. Philosophy and religion can debate the truth of it all.

Cioran

11-21-2012, 03:42 PM

The Michelson-Morley experiment showed that light was going the same speed in the direction of motion of the Earth, and at right angles to it. Relativity was needed to explain that observation. But in a model where the Earth doesn't move the explanation of Michelson-Morley is extremely simple, it does away with the need for special relativity.

Of course it doesn't. Even if the sun revolved around the earth, special relativity can be shown to be true regardless in hundreds of different ways. Of course, SR cannot be wholly correct, since it is subsumed by general relativity, and there still needs to be a way to reconcile GR with QM.

Does the earth revolve around the sun, or does the sun revolve around the earth? Can you answer the question?

Notice also that even if the earth were at the center of the solar system, the does not mean that it is stationary. As a matter of fact the earth (like everything else) has dozens of different motions, and NOTHING in the universe is ABSOLUTELY at rest; and this lack of an absolute-at-rest reference frame is what dismantles Newtonian physics and motivates relativity theory.

Not correct - this is just an illogical argument.

No, it is correct.

An ad hominem argument "appeals to feelings not reason". An example: "Everett was badly treated by his colleagues which makes me feel bad, so Everett's theory is correct." Or, "I've spent my whole life studying physics and would feel totally downhearted if it was all "just models" rather than Reality, so Everett must have discovered Reality."

How thoroughly ridiculous this is.

Yes, the above is ad hom. But so is what I quoted. If you had bothered to check, you would see that both these invalid arguments, though they share different content, have the same invalid logical form.

Now, as to the substance of your example, you are implying that these are my arguments for Everettian Many Worlds, i.e., invalid ad hom formulations. This is pure BS, of course. I have explained repeatedly why there are good grounds to accept Everett (as many and perhaps most physicists now do), and none of them have anything whatever to do with the strawman caricature you just invented above.

They have to do with facts like:

1. Wave function collapse is completely unexplained in Copenhagen and other collapse interpretations, making it unscientific and akin to magic. MW does away with wave function collapse, solving this problem.

2. In addition to wave function collapse, other unexplained (and probably unexplainable) properties of Copenhagen and other non-MWI interpretations include spooky action at a distance and indeterminacy. Spooky action at a distance and indeterminacy vanish under MWI,

3. The universe is an isolated system. Isolated systems are in superposition. Therefore, the universe is in superposition. Therefore, the parsimonious assumption is that MWI reflects how the world is.

In sum, please stop mischaracterizing my posts.

Oh, and by the way: does the sun orbit the earth, or not?

ETA: I mentioned in passing that Everett had been badly treated (at first) by the physics community, though his reputation is now fully rehabilitated. I never said, nor did I imply, nor in any way suggest, the utterly ridiculous argument that Many Worlds must be right because Everett was badly treated. Moreover, you know that I never did that, yet you allege that did so anyway, contrary to the facts.

Why?

YesNo

11-21-2012, 04:50 PM

Of course it doesn't. Even if the sun revolved around the earth, special relativity can be shown to be true regardless in hundreds of different ways. Of course, SR cannot be wholly correct, since it is subsumed by general relativity, and there still needs to be a way to reconcile GR with QM.

Does the earth revolve around the sun, or does the sun revolve around the earth? Can you answer the question?

I know you are addressing, mal4mac, but I just want to say that he does make a point.

The results of the Michelson-Morley experiment suggest either that the earth is the center of the universe or there must be some other explanation. Since scientists would not accept that the earth is the center of the universe, Einstein went for a different explanation. That explanation led to predictions that worked.

Now, as to the substance of your example, you are implying that these are my arguments for Everettian Many Worlds, i.e., invalid ad hom formulations. This is pure BS, of course. I have explained repeatedly why there are good grounds to accept Everett (as many and perhaps most physicists now do), and none of them have anything whatever to do with the strawman caricature you just invented above.

I don't see any good grounds to accept Everett's many worlds theory. I don't think most physicists do either, but I don't know. They may use various sums of histories as techniques to make calculations, but that doesn't mean they accept the reality of many worlds. Even if they did, this is not a popularity contest.

Here is a comment by R. F. Streater in "Lost causes in theoretical physics" that seems to represent well my own view of the subject: http://www.mth.kcl.ac.uk/~streater/lostcauses.html#XII

There is nothing to the many-worlds theory. There are no theorems, conjectures, experimental predictions or results of any sort, other than those of Hilbert space. It is not a cogent idea.

I don't know who Streater is, but what he says makes sense and there is at least one person out there who is not on the MWI bandwagon.

1. Wave function collapse is completely unexplained in Copenhagen and other collapse interpretations, making it unscientific and akin to magic. MW does away with wave function collapse, solving this problem.

I think MWI violates the conservation of mass-energy of classical physics as well as the conservation of quantum information. I don't accept some other world where Santa can shrink enough to get down the chimney as a way out of needing to meet these conservation laws across the entire multiverse whether that contains one or many universes.

2. In addition to wave function collapse, other unexplained (and probably unexplainable) properties of Copenhagen and other non-MWI interpretations include spooky action at a distance and indeterminacy. Spooky action at a distance and indeterminacy vanish under MWI,

The other worlds are even spookier and offer nothing except a way to take a reactionary position in an effort to maintain an outdated determinacy in the face of evidence against it. The fact that indeterminacy vanishes in MWI is evidence that MWI is not a model for QM.

I noticed in Deutsch's The Fabric of Reality, chapter 13, that he was complaining that physicists do not accept the MWI. He was positioning himself as some sort of scientific revolutionary, when all he looked like to me was an old-school physicist refusing to get out of the way.

3. The universe is an isolated system. Isolated systems are in superposition. Therefore, the universe is in superposition. Therefore, the parsimonious assumption is that MWI reflects how the world is.

I don't see any other worlds. The wave behavior of particles can be modeled using standard QM without resorting to other worlds. One day, we may understand more about the superposition of particle states, so there is no need to jump to a superposition of worlds to resolve anything especially since making that leap of faith gives us nothing in return.

Cioran

11-21-2012, 05:40 PM

I know you are addressing, mal4mac, but I just want to say that he does make a point.

The results of the Michelson-Morley experiment suggest either that the earth is the center of the universe or there must be some other explanation. Since scientists would not accept that the earth is the center of the universe, Einstein went for a different explanation. That explanation led to predictions that worked.

Actually, his point is off tangent to what I am asking. I am asking whether he thinks the sun revolves around the earth. I am NOT asking whether he further thinks that the earth is absolutely at rest at the center of the universe.

Because, of course, we know that there is no absolute rest reference frame, and that the universe has no center! For the Michelson Morley experiment to be explained other than relativistically, it would not be enough for the sun to be orbiting the earth. In that case, the earth STILL would have multiple motions: The orbit of the solar system itself around the center of the galaxy, the movement of the galaxy as a whole, the precession motion, and so on. I dare say NO model can be constructed in which the universe has a center, and the earth is motionless in the center of it, which is also consistent with empirical facts. Therefore this undermines his claim that all we have are models. We also have reality. His argument is like saying all we have our maps. Well, yes, we have maps, but we also have territory. One shouldn't confuse the two, but it's silly to suggest that only maps exist and no territory.

I don't see any good grounds to accept Everett's many worlds theory. I don't think most physicists do either, but I don't know.

Yes, and I linked Tegmark on the wide acceptance of MW.

They may use various sums of histories as techniques to make calculations, but that doesn't mean they accept the reality of many worlds. Even if they did, this is not a popularity contest.

Right, it's not! Who said it was? I only mentioned the acceptance of MW in the physics community to rebut mal4mac's claim that no one pays attention to Everett in the physics community. Clearly, they do. Of course, even if they didn't, it wouldn't make MW wrong, anymore than the fact that most DO pay attention to it makes it right.

I'll address the rest of your points later.

I think MWI violates the conservation of mass-energy of classical physics as well as the conservation of quantum information.

No it does not. The links provided already explain this.

The other worlds are even spookier and offer nothing except a way to take a reactionary position in an effort to maintain an outdated determinacy in the face of evidence against it. The fact that indeterminacy vanishes in MWI is evidence that MWI is not a model for QM.

With all respect, this is a total muddle. As I've already explained at least twice, determinacy in MW is a consequence of the interpretation and not either a cause of justification of it. The last sentence from the quote above is flatly wrong. QM is only indeterministic if there is wave function collapse! Which in Copenhagen and other interpretations is put in by hand without any explanation whatever of how it is supposed to work. The Schrodinger wave equation itself is fully determistic.

I noticed in Deutsch's The Fabric of Reality, chapter 13, that he was complaining that physicists do not accept the MWI. He was positioning himself as some sort of scientific revolutionary, when all he looked like to me was an old-school physicist refusing to get out of the way.

So where is your answer to Deutsch's quantum computation question?

The question turns on the ontology of these particles. If they are not real but just some kind of spooky "potential" or "probability," then they don't have mass and energy. But they do, because they are computational resources in quantum computing. Since they DO have mass and energy, they exist; if the wave function collapses them out of existence then it is Copenhagen that violates conservation because in that case matter and energy is being destroyed and not merely transformed!

I don't see any other worlds.

Right. And MWI explains why you don't see them! However, if you read the Wiki link I gave, you would have encountered a proposed experiment in which it may be possible to exchange signals between these worlds, if they exist.

The wave behavior of particles can be modeled using standard QM without resorting to other worlds.

Er, yes, it can, but that is the gist of the whole discussion: whether instrumentalism is good enough. "Shut up and calculate" may be a good predictive tool, but many, like Einstein, want to find out about the ontology of the world, if possible.

One day, we may understand more about the superposition of particle states, so there is no need to jump to a superposition of worlds to resolve anything especially since making that leap of faith gives us nothing in return.

There is no leap of faith at all, merely an interpretation that removes all the unexplained quantum weirdness.

YesNo

11-21-2012, 07:18 PM

MorpheusSandman

11-22-2012, 12:55 AM

I see logic differently. The logic I know is the one that starts from correct and leads to correct. There is a nuanced--some would argue pedantic--distinction to be made: All logic utilizes initial propositions that are assumed true but are not proved by the argument. Logic states that if these propositions are true, and if the argument form is valid, then the conclusion will be correct (assuming it's a deductive argument). The only way to use logic to prove the initial propositions would be to make them the conclusions of another logical argument, but then that argument will equally rest on other assumed propositions, and so on ad infinitum. The question of what propositions we should assume true is really the property of epistemology, ie, the philosophical study of knowledge. Logic is strictly just about the "rules" that govern correct reasoning in which we use assumed propositions in combination to produce new conclusive propositions.

Cioran

11-22-2012, 01:31 AM

I probably can't follow what you and mal4mac are arguing about, so I won't comment further on what may or may not be the center of the universe. I've read that the universe doesn't have a center, so I'll go with that until I hear some compelling evidence against it.

I have looked at all the links you referenced, Cioran, as well as some of the items they linked to. They have not convinced me that MWI is correct, however, I have learned a lot about the details of MWI and QM in the process that I didn't realize before.

At the moment, I prefer the "shut up and calculate" instrumentalist approach when it comes to quantum superposition unless the explanation offers something that has predictive power. The quantum computation that Deutsch is researching has to do with particle superposition which occurs in the real world. That is my answer to Deutsch which I have already given: what he is studying is the particle in a superposition state in the real world. The problem is Deutsch doesn't believe that a particle can be in a superposition state. That is why he needs many worlds. My problem is that I don't believe that a many worlds superposition exists at all. I see no evidence for it at that level--nor any need for it.

1. Theories have predictive powers, which QM does par excellence. Many Worlds, Copenhagen and the others are not theories, they are interpretations of a theory -- or, as Everett had it, a metatheory. So a charge that MW doesn't make "predictions" like a theory is irrelevant, because the same goes for all the other interpretations.

2. Non wave-function collapse interpretations do NOT state that the superpositions "exist" in the real world; they state that the superpositions are probability waves that have no properties until measured. Stuff with no properties can't be used to do number crunching. But, they can.

If you say the superposed particles DO exist in the world, then you support the multiverse! it's just that the multiverse is the whole world, whereas any particular branch of it is a small cross-section of the whole.

YesNo

11-22-2012, 10:28 AM

1. Theories have predictive powers, which QM does par excellence. Many Worlds, Copenhagen and the others are not theories, they are interpretations of a theory -- or, as Everett had it, a metatheory. So a charge that MW doesn't make "predictions" like a theory is irrelevant, because the same goes for all the other interpretations.

I have no problem viewing Many Worlds as a religion. It has come up with the idea of "quantum immortality" so maybe it is not all that far from a religion. The Copenhagen interpretation appears more open to experimentation. It does not jump to conclusions about reality beyond what the evidence provides.

2. Non wave-function collapse interpretations do NOT state that the superpositions "exist" in the real world; they state that the superpositions are probability waves that have no properties until measured. Stuff with no properties can't be used to do number crunching. But, they can.

As I understand it, a single photon or electron prior to being measured is viewed as a probability wave for convenience sake, because that is all one knows about it. It is real, but the properties are not known until measured. My problem is with the statement: "Stuff with no properties can't be used to do number crunching." If quantum computing is getting results, why not? We are looking at matter-energy at a level where it does not behave in a billiard ball fashion. That is all.

If you say the superposed particles DO exist in the world, then you support the multiverse! it's just that the multiverse is the whole world, whereas any particular branch of it is a small cross-section of the whole.

The multiverse I would support has only one universe, or world, in it. It is also non-deterministic which ultimately allows the researcher enough freedom to choose an experiment.

The difference I see between the Copenhagen and Many Worlds interpretations is that CI acknowledges quantum superposition of particle states while MWI refuses to accept that. Instead, MWI prefers a billiard ball model of quantum particles. That is an old view of such particles and it is why I view MWI as essentially reactionary. To get that billiard ball model to work, they need other shadow billiard balls to create an interference wave. This requires a theoretical superposition of worlds when all one needs, indeed all the evidence requires, is a superposition of particle states.

Cioran

11-22-2012, 01:05 PM

I have no problem viewing Many Worlds as a religion.

*sigh*

A metatheory is NOT a religion. it is a theory about a theory. ALL the theories about the theory of QM are metatheories. Hence, if MW is a religion, then by logical extension so are Copenhagen et all.

It has come up with the idea of "quantum immortality" so maybe it is not all that far from a religion.

Quantum immortality is an inference from the model. Max Tegmark has a different inference and so rejects Quantum Immortality, but he embraces MW.

The Copenhagen interpretation appears more open to experimentation. It does not jump to conclusions about reality beyond what the evidence provides.

Of course, this is wrong. It does make a conclusion about reality. And, as already noted, metathories are not open to experimentation, at least not until one can devise an experiment that can distinguish one metatheory from another empirically. That said, David Deutsch maintains that quantum computation empirically confirms the metatheory of MW, such that, if quantum computing failed to work, MW would be falsified as a metatheory.

As I understand it, a single photon or electron prior to being measured is viewed as a probability wave for convenience sake, because that is all one knows about it. It is real, but the properties are not known until measured.

No, this is fully incorrect. In fact, this is a restatement of Einstein's hidden variables, which have been experimentally ruled out. The metatheory of wavefunction collapse states that these particles have no properties prior to a measurement. This is why Einstein rejected it. Copenhagen is anti-realist (it says there is no mind-independent reality) and also anti-local (it claims that effects can propagate instantaneously across the entire universe via magical wave function collapse.) MW, by contrast, restores both realism and localism to physics.

My problem is with the statement: "Stuff with no properties can't be used to do number crunching."

That would be magic, for entities without properties to do number crunching. Ergo, they have properties, which is denied by Copenhagen.

The multiverse I would support has only one universe, or world, in it. It is also non-deterministic which ultimately allows the researcher enough freedom to choose an experiment.

Yes, as I have explained, however, this on the assumption of wave function collapse. MW is a no-collapse interpretation.

The difference I see between the Copenhagen and Many Worlds interpretations is that CI acknowledges quantum superposition of particle states while MWI refuses to accept that.

It's exactly the opposite. Many Worlds acknowledges that the superpositions are real. Copenhagen treats them as abstract mathematical entities that are used only to make calculations, period

Instead, MWI prefers a billiard ball model of quantum particles. That is an old view of such particles and it is why I view MWI as essentially reactionary. To get that billiard ball model to work, they need other shadow billiard balls to create an interference wave. This requires a theoretical superposition of worlds when all one needs, indeed all the evidence requires, is a superposition of particle states.

The "billiard ball model" is ruled out under the assumption of wave function collapse. Since MWI is a no-collapse metatheory, this argument against it is wholly irrelevant.

To emphasize: not only does Many Worlds accept superposition, contrary to YesNo's characterization, it says that these superpositions never go away. Indeed, that is the whole point of the interpretation!

YesNo

11-22-2012, 02:02 PM

Quantum immortality is an inference from the model. Max Tegmark has a different inference and so rejects Quantum Immortality, but he embraces MW.

Do you have a source where Tegmark's explains his view? It sounds interesting. I don't really understand quantum immortality. It seems that ultimately all of the copies of each of us will die.

Of course, this is wrong. It does make a conclusion about reality. And, as already noted, metathories are not open to experimentation, at least not until one can devise an experiment that can distinguish one metatheory from another empirically. That said, David Deutsch maintains that quantum computation empirically confirms the metatheory of MW, such that, if quantum computing failed to work, MW would be falsified as a metatheory.

It appears that a quantum computer is able to factor 21 into 3*7, so I assume it works: http://www.nature.com/nphoton/journal/v6/n11/full/nphoton.2012.259.html

No, this is fully incorrect. In fact, this is a restatement of Einstein's hidden variables, which have been experimentally ruled out. The metatheory of wavefunction collapse states that these particles have no properties prior to a measurement. This is why Einstein rejected it. Copenhagen is anti-realist (it says there is no mind-independent reality) and also anti-local (it claims that effects can propagate instantaneously across the entire universe via magical wave function collapse.) MW, by contrast, restores both realism and localism to physics.

I have heard that some CI proponents involve a consciousness collapsing the wave function. I don't think that is a necessary feature of CI which I suspect at heart is a "shut up and calculate" approach. This is different than taking an anti-realist position. So, I would say the choice is not between an anti-realist version of CI and the unrealistic version that MWI presents. I would suggest that proponents of many worlds hold back on committing to a perspective until there is experimental evidence for a separate world.

As far as nonlocalism goes, this has been experimentally verified in the 1980's and it continues to be tested. A local QM metatheory could be viewed as having been falsified by these experiments.

Yes, as I have explained, however, this on the assumption of wave function collapse. MW is a no-collapse interpretation.

It's exactly the opposite. Many Worlds acknowledges that the superpositions are real. Copenhagen treats them as abstract mathematical entities that are used only to make calculations, period

As I see it, MWI does not even believe in a wave function except as a calculation convenience. All MWI has are particles from many worlds interacting to give the illusion of interference patterns when a single photon goes through a double slit experiment. A superposition is a wave function that describes a particle by combining many different wave equations that are superimposed upon each other. The square of the amplitudes of the waves give the probability that that particle will take a specific value when measured. Each MWI particle should not need a wave function to describe its properties.

Again, the reality argument against CI is not strong. They are just not making any commitments. The wave function or the Heisenberg matrix or the sum of histories is just a convenience to get a useful result. It is not that there is no reality behind the math, it is that one doesn't know much more about that reality except as it behaves.

The "billiard ball model" is ruled out under the assumption of wave function collapse. Since MWI is a no-collapse metatheory, this argument against it is wholly irrelevant.

I don't understand. I am claiming that MWI is a billiard ball model because the particles all have definite properties. I thought that is what you were claiming. This is how the determinism is achieved. The many worlds are needed to explain the illusion of indeterminacy for MWI. The wave function is a measure of the indeterminacy in any particular world, but the particles in that world should be deterministic billiard balls. If that is not what MWI is saying, perhaps we should get some quotes to work from.

Cioran

11-22-2012, 02:25 PM

For now, just this.

As far as nonlocalism goes, this has been experimentally verified in the 1980's and it continues to be tested. A local QM metatheory could be viewed as having been falsified by these experiments.

No. I think I've already mentioned this.

The experiments you allude to rule out a combination of realism and localism, though one or the other could still be true (though both may be false.) In fact, the experiments do more than that; they rule out realism and localism together, even if QM turns out to be a false theory.

There is, however, a huge caveat. These experiments rule out realism and localism together only on the assumption of wave-function collapse. Discarding wave function collapse, the results of these experiments, on the MW model, are fully explained in terms of both realism and localism. There are papers on this subject on the Web, some highly technical. There is also a book called Schrodingers's Kittens that addresses this.

YesNo

11-22-2012, 02:36 PM

Which paper on the web are you referring to?

Cioran

11-22-2012, 02:49 PM

Which paper on the web are you referring to?

Here, as one example. (http://quantum3000.narod.ru/papers/advanced/nonloc6.pdf)

Here, as one example. (http://quantum3000.narod.ru/papers/advanced/nonloc6.pdf)

Er, on a different computer than the one I originally used to post, this links goes to a Cyrillic language page first, which contains a link to the paper. Let's try again and see if it's a direct link (it went directly there on the laptop from which I originally posted).

http://quantum3000.narod.ru/papers/advanced/nonloc6.pdf

Same problem! Weird. Well, if you click on the link and get the page on cyrillic, just click on the link at the top of the page, which is the exact same link given above, then you will get the page. No idea why it is redirecting to this cyrillic stuff.

Quoted from the linked paper by Frank Tipler (which is exactly what I've been arguing since the beginning of this thread!). Since the quote function here renders quotes in italics, I've reproduced Tipler's own italics, done for emphasis, in bold instead.

Nonlocality arises if and only if we assume that the measurement of the spin of a particle "collapses the
wave function" from the linear superposition to either j ">1 j #>2 or j #>1 j ">2 in (1). If such a collapse
occurs, then measuring the spin of particle one would fix the spin of particle two. The spin of particle two
would be fixed instantaneously, even if the particles had been allowed to separate to large distances. If at the
location of particle one, we make a last minute decision to measure the spin of particle one in the left-right
direction rather than the up-down direction, then instantaneously the spin of particle two would be fixed in
the opposite direction as particle one -- if we assume that (2) collapses at the instant we measure the spin
of particle one. The mystery of quantum nonlocality lies in trying to understand how particle two changes
-- instantaneously-- in response to what has happened in the location of particle one.

There is no mystery. There is no quantum nonlocality. Particle two doesn't know what has happened
to particle one when its spin is measured. State transitions are nice and local in quantum mechanics.
These statements are true because quantum mechanics tells us that the wave function does not collapse
when the state of a system is measured. In particular, nonlocality disappears when the Many-Worlds
Interpretation (MWI) [6,7,8,16] is adopted. The MWI dispels the mysteries of quantum mechanics.

YesNo

11-22-2012, 05:22 PM

I was able to get the English version.

Cioran

11-22-2012, 05:46 PM

More from Frank Tipler: Many Worlds is not only EASILY TESTABLE, it is an essential idea for many areas of biology, physics and engineering. (http://arxiv.org/pdf/0809.4422v1.pdf)

Tipler on the Many Worlds, fwiw:

I definitely accept the MWI. The MWI is not an option, but as I show in my book, a necessary mathematical consequence of quantum mechanics applying at all levels: not just atoms, but also humans are quantum mechanical objects. So if the MWI is actually false, then quantum mechanics must also be false at some level of complexity. All competent mathematical physicists know this perfectly well.

YesNo

11-23-2012, 03:01 AM

Cioran

11-23-2012, 03:22 AM

I'm still reading Tipler's article, but your comment that Many Worlds being "easily testable" makes me wonder how such a test would be done.

I don't trust Tipler's statement that you quote: "All competent mathematical physicists know this perfectly well." Nor the idea that MWI is "not an option". Here is the Wikipedia article on Tipler: http://en.wikipedia.org/wiki/Frank_J._Tipler

Classic ad hominen attack.

YesNo, honestly, you don't understand these ideas. You've got everything mixed up, as you've demonstrated over and over again. And I have pointed out your confusion over and over, and you have not met these points. I suggest you educate yourself more fully on these ideas and then comment on them. There is a huge literature on the Many Worlds in the academic/scientific/mathematical community, by people other than Tipler who have less controversial ideas on other matters. You can find deep technical papers, and papers more geared toward laymen, all over the Internet. That you would Google Tipler and try to find something personally to discredit him is not just classic ad hom, but demonstrates to me that you have no interest in actually learning about this subject and, like so many Internet interlocutors, you are primarily interested in defending a view you hold because you want to doggedly stick to what you believe whether there are good grounds for your beliefs or not. This is not a discussion. It's a game of one-upmanship.

Tipler's ideas on the Omega Point are of course wholly irrelevant to the validity of Many Worlds. This is a useless discussion. A typically retarded Internet discussion

ETA: Just to be specific, let's identify your implied ad hom. It is, after all, clearly why you made the Wiki link. It is this:

Frank Jennings Tipler (born February 1, 1947) is a mathematical physicist and cosmologist, holding a joint appointment in the Departments of Mathematics and Physics at Tulane University.[2] Tipler has authored books and papers on the Omega Point, which he claims is a mechanism for the resurrection of the dead. Some have argued that it is pseudoscience.

So obviously this "resurrection of the dead" bit and "pseudoscience" bit got you all hot and bothered. Yet what about the fact that Tipler is a mathematical physicist and cosmologist, who also holds a joint appointment in the Department of Mathematics and Physics at Tulane? Are his professional credentials irrelevant? Of course, his professional credentials don't make his ideas right, any more than his more irreverant ideas make him wrong. All of this is classic ad hom.

Can you address the substance of his discussion on how Many Worlds solves the problem of quantum non-locality and indeterminism, or not? I expect not. I also expect you never read his book on the Omega Point, and indeed never even heard of Tipler, until you Googled him. So you also have no idea on whether his ideas on the Omega Point have any validity or not, obviously! But all it takes is a quick link cherry-picked up from Google to try to discredit someone in order to support ideas you have no grasp of anyway.

Disgusting.

mal4mac

11-23-2012, 05:57 AM

YesNo, honestly, you don't understand these ideas. You've got everything mixed up, as you've demonstrated over and over again.

I think you're doing very well in digging into this material YesNo - especially that article about which interpretation physicists believe, and showed the wide variety of views held, some even changing their views. Copenhagen on Monday, MWI on Tuesday,...

Tipler is another fringe figure, like Everett, as comments by serious physicists make plain: "George Ellis, writing in the journal Nature, described Tipler's book on the Omega Point as "a masterpiece of pseudoscience ... the product of a fertile and creative imagination unhampered by the normal constraints of scientific and philosophical discipline"... Physicist Sean M. Carroll thought Tipler's early work was constructive but that now he has become a "crackpot".

So when Tiper says, "I definitely accept the MWI. The MWI is not an option, but as I show in my book, a necessary mathematical consequence of quantum mechanics applying at all levels.", how can you trust him? You can spend many years studying Theoretical physics to MSc level to check out his views, or you can look at what mainstream physicists say, and it certainly isn't that MWI is the only necessary theory and not an option! Some of the physics he did, as Sean M. Carroll points out, was constructive, but how can a lay person sort out the constructive from the crackpot?

P.S. Sean M. Carroll and George Ellis really are world-class figures, well worth exploring them on Wikipedia... Carroll has written the most recent MSc level textbook on GR to gain general applause. YesNo, you can get a free online version if you want a challenge...its gentler and clearer than most other texts at that level... Ellis co-authored the classic monograph the Large Scale Structure of Space and Time with Hawking (but that book is *really* tough... if you finish Caroll maybe try it...)

Logical fallacies like ad hominems are synonymous with "illogical arguments" because that's literally what they are

There are multiple definition of this term. I quoted one from the Concise OED, but I think I like the other better, it's just "personal". So an "ad hominem attack" is simply "a personal attack".

cacian

11-23-2012, 09:24 AM

There are multiple definition of this term. I quoted one from the Concise OED, but I think I like the other better, it's just "personal". So an "ad hominem attack" is simply "a personal attack".

I thought a fallacy is a false statement and an argument is when two views collide.
They collide because there is no understanding between the interlocutors themselves and not what is actually being said or discussed.
When there is a failure to connect between two standing people there is no understanding from either part and therefore the blame is past on to the argument rather then the argumentees themselves. This is how I see it.
And so there is no fallacy of an argument as such but only misunderstanding of two minds not being able to connect. Failure to connect is what I call it.

MorpheusSandman

11-23-2012, 09:37 AM

There are multiple definition of this term. I quoted one from the Concise OEDIt's a term from logic, so you really need to quote a dictionary of logic that has categories and sub-categories of fallacies listed. Here's one I found online. (http://www.ozarkia.net/bill/anarchism/Fallacies.html#Hominem%20Abusive)

YesNo

11-23-2012, 10:48 AM

YesNo, honestly, you don't understand these ideas. You've got everything mixed up, as you've demonstrated over and over again. And I have pointed out your confusion over and over, and you have not met these points. I suggest you educate yourself more fully on these ideas and then comment on them.

I admit that I don't understand these ideas and that's why I find the thread interesting. I'm trying to un-mix things in my mind.

The only reason I mentioned the Wikipedia article is that I thought you were quoting him as an authority. He's doesn't have much authority, but I don't actually care. Regardless of who he is, I'm still trying to make sense out of the ideas in the article he posted. I don't consider the Wikipedia article evidence that he is wrong in the particular article you cited.

Essentially the article says, if you accept MWI, the EPR paradox loses its non-locality and anti-realist features. That's not a surprise claim for an MWI proponent to make. I'm still confused by the argument since it seems to involve the confirmation step as well to make this work. In other words, and I might have this wrong, MWI would always lead one to think that one got the nonlocal answer, even if one didn't, after the experiment was confirmed, but it is only the local answer in the appropriate world. That part I'm still puzzled by because I don't think the confirmation should matter. Of course, I might be completely misunderstanding it.

One thing I've learned from the article is that I didn't understand what the term "realism" meant before. Here's what I think it means based on http://en.wikipedia.org/wiki/Principle_of_locality:

Local realism is the combination of the principle of locality with the "realistic" assumption that all objects must objectively have a pre-existing value for any possible measurement before the measurement is made. And so be time independent.

I started searching the Stanford Encyclopedia of Philosophy rather than Wikipedia for information. Here's an initial link: http://plato.stanford.edu/entries/qm-bohm/

Regarding the Tipler article, I've run into two problems:

ONE

With entangled particles separated by great distances where spin up or down is being measured, I realize that there are two outcomes predicted by EPR but there are four worlds involved. We get the following four outcomes:

(up)(up) + (up)(down) + (down)(up) + (down)(down)

Only the ones in red are permitted by QM for the entangled particles since their outcomes are initially entangled to give opposite results. My problem is I don't see what happens to the other two worlds in the final result. How are they eliminated so that MWI agrees with QM results?

TWO

It appears having probabilities that cannot be represented as rational numbers is a problem for MWI based on this comment from Tipler:

Applying the Principle of Indifference to this new set of coefficients yields the BI for the coefficients in the original basis. Continuity in the Hilbert space of wave functions yields the BI for irrational coefficients (although it is a presupposition of the MWI that only coefficients with rational squares are allowed since irrational squares would imply an irrational number of worlds). In particular, the percentage of worlds with the value of a given basis vector is given by the square of the coefficient.

The WMI technique of simulating probabilities in the universe is to assume that the probabilities are represented as rational numbers. They use the Principle of Indifference and take the least common multiple of the denominators of the probabilities and construct the appropriate number of worlds for each outcome. If the probabilities can only be represented as irrational numbers then there is no least common multiple of the denominators since the probabilities cannot be represented in that manner. This is the problem emphasized in bold above.

There are two concerns with this MWI view of probability:

1) Why can't probabilities be represented as irrational numbers in a universe where realism is supposed to be true? Even a 50-50 chance may only be an approximation. One cannot assume for any coin in one's pocket that it has not been irregularly worn enough that the real probability is not something like 50.000000001-49.999999999 or something requiring even infinitely many decimals to correctly represent it. It seems that WMI requires reality to come in rational numbers.

2) Why does MWI think it can get out of problems such as probability, non-locality, or realism by just creating additional worlds whenever it feels like?

Calidore

11-23-2012, 05:29 PM

[...]that article about which interpretation physicists believe, and showed the wide variety of views held, some even changing their views. Copenhagen on Monday, MWI on Tuesday,...

Tipler is another fringe figure, like Everett, as comments by serious physicists make plain: "George Ellis, writing in the journal Nature, described Tipler's book on the Omega Point as "a masterpiece of pseudoscience ... the product of a fertile and creative imagination unhampered by the normal constraints of scientific and philosophical discipline"...

So when Tiper says, "I definitely accept the MWI. The MWI is not an option, but as I show in my book, a necessary mathematical consequence of quantum mechanics applying at all levels.", how can you trust him? You can spend many years studying Theoretical physics to MSc level to check out his views, or you can look at what mainstream physicists say, and it certainly isn't that MWI is the only necessary theory and not an option! Some of the physics he did, as Sean M. Carroll points out, was constructive, but how can a lay person sort out the constructive from the crackpot?

The above lines I snipped highlight the reason why I don't even try reading this stuff, even though I would in theory find it interesting. It seems this field is almost entirely made up of people who spend their time writing and trying to sell books that point out why everyone else's theory is wrong and mine works, all about things that nobody knows for certain. It seems to be all about being as convincing as possible and recruiting as many believers/followers as possible, and claiming right that way. That's religion, not science.

Can anyone here summarize what's actually known, through verifiable and repeatable experimentation, what we have good reason to believe is true though we haven't quite nailed it down yet, and what's simply speculation that sounded good to someone?

YesNo

11-24-2012, 01:23 PM

Can anyone here summarize what's actually known, through verifiable and repeatable experimentation, what we have good reason to believe is true though we haven't quite nailed it down yet, and what's simply speculation that sounded good to someone?

I was hoping someone would have answered this since I'd like to know as well. I look at all of these threads as exercises in expository prose so I'll try to answer the question as an exercise.

There are at least two related puzzles of quantum mechanics that lead to these disagreements and stimulate further research.

First, quantum particles make wavelike interference patterns on a detector even if one sends a single particle through a barrier with two slits in it. Does that mean that a single particle interfered with itself by going through both slits? If one closes one of the slits, the wavelike pattern disappears. If one measures the particle before it hits the detector to see which slit it went through, the wavelike pattern also disappears.

That is the problem of "realism". Realism expects that whatever measurement one gets says something about the particle-wave prior to the measurement. But these experiments make it look as if the particle-wave is either making a choice right when the measurement occurred or the measurement itself forced a state on the particle-wave that it didn't previously have. The evidence shows that scientific realism does not seem to work for quantum-sized particles.

How does one make sense out of that?

On one extreme, the end of realism is just accepted. That is the "anti-realistic" position. On the other extreme, there are some who claim that there are many particles in many worlds, one in the real world and the others in shadow worlds each having a distinct possible value. This claims to restore realism, because each particle would have its value prior to measurement, but it does this in an "unrealistic" way. In the middle are the people who use quantum mechanics for practical purposes only and don't care about the philosophy. They might be called the indifferent, uncommitted, "non-realistic", or "shut up and calculate" engineers.

The second problem carries this measurement issue to two particles that have been "entangled" so that if one particle is ultimately measured to have spin up the other is forced to have spin down. These two particles have been correlated. Now separate the particles across some distance and check to see what their spins are. The experiments show that their spins are still correlated even if they have been separated so far apart that any communication between them to synchronize the results would have to go faster than light. The experiments also show that there are no hidden variables that are shared between these particles to help them determine what the spin of the other particle would be before the measurement occurred.

That is the problem of "localism". Localism expects causality to flow slower than the speed of light, but these entangled particles are determining each others' measurements across distances implying causality to have seemingly instantaneous effects.

So how does that happen?

On one extreme, nonlocalism is just accepted. That's the way things are. On the other, many worlds are set up to avoid this issue in some way that I don't understand. In the middle are the engineers who use quantum mechanics and don't worry about it. They leave it for the theoretical physicists, philosophers or people on forums such as this to sort out.

mal4mac

11-24-2012, 04:23 PM

The above lines I snipped highlight the reason why I don't even try reading this stuff, even though I would in theory find it interesting. It seems this field is almost entirely made up of people who spend their time writing and trying to sell books that point out why everyone else's theory is wrong and mine works, all about things that nobody knows for certain. It seems to be all about being as convincing as possible and recruiting as many believers/followers as possible, and claiming right that way. That's religion, not science.

I think it's more about selling books, since Hawking publishers have realised they can get best sellers in this area. To get an easy sell they push interpretations like Many Worlds and Omega Point that are zany and instantly appealing. They are like fairground callers: "Come and see the many universes!", "Live forever!". "Come and see the dead radioactive cat!" For non-scientists the briefest, to the point book, I've seen is:

The Magic of Reality by Richard Dawkins

It's a bit light, and ironic, about "the particle zoo" and "time beginning with the Big Bang", but that's probably a good thing :)

First, quantum particles make wavelike interference patterns on a detector even if one sends a single particle through a barrier with two slits in it. Does that mean that a single particle interfered with itself by going through both slits? If one closes one of the slits, the wavelike pattern disappears. If one measures the particle before it hits the detector to see which slit it went through, the wavelike pattern also disappears.

That is the problem of "realism". Realism expects that whatever measurement one gets says something about the particle-wave prior to the measurement. But these experiments make it look as if the particle-wave is either making a choice right when the measurement occurred or the measurement itself forced a state on the particle-wave that it didn't previously have. The evidence shows that scientific realism does not seem to work for quantum-sized particles.

How does one make sense out of that?

On one extreme, the end of realism is just accepted. That is the "anti-realistic" position. On the other extreme, there are some who claim that there are many particles in many worlds, one in the real world and the others in shadow worlds each having a distinct possible value. This claims to restore realism, because each particle would have its value prior to measurement, but it does this in an "unrealistic" way. In the middle are the people who use quantum mechanics for practical purposes only and don't care about the philosophy. They might be called the indifferent, uncommitted, "non-realistic", or "shut up and calculate" engineers.

What's the difference between "anti-realistic" and "non-realistic/shut-up and calculate"?

On one extreme, nonlocalism is just accepted. That's the way things are. On the other, many worlds are set up to avoid this issue in some way that I don't understand. In the middle are the engineers who use quantum mechanics and don't worry about it. They leave it for the theoretical physicists, philosophers or people on forums such as this to sort out.

Again, what's the difference between the "acceptor of the mystery" and the "pragmatic engineer"? The theoretical physicists, philosophers, and paperback writers, are nowhere near to sorting out these mysteries... they make lots of money by befuddling us all though...

If you want to go deeper than Dawkins, on quantum in particular, then try Feynman's "The Character of Physical Law":

http://www.youtube.com/watch?v=aAgcqgDc-YM

The most famous quote in modern physics is at 8:05...

YesNo

11-25-2012, 12:57 AM

What's the difference between "anti-realistic" and "non-realistic/shut-up and calculate"?

Again, what's the difference between the "acceptor of the mystery" and the "pragmatic engineer"? The theoretical physicists, philosophers, and paperback writers, are nowhere near to sorting out these mysteries... they make lots of money by befuddling us all though...

If you want to go deeper than Dawkins, on quantum in particular, then try Feynman's "The Character of Physical Law":

http://www.youtube.com/watch?v=aAgcqgDc-YM

The most famous quote in modern physics is at 8:05...

Most definitely I want to go deeper than Dawkins.

That Feynman lecture was great. He was actually using real chalk and blackboards. His accent and humor were perfect. The mathematical description of interference as the overall intensity not being equal to the sum of the intensities that would occur through each individual hole is something I didn't realize. "Nobody understands quantum mechanics."

After thinking about it, I realize there isn't much difference between the "acceptor of the mystery" and a "pragmatic engineer" except the pragmatic engineer tries to pretend that there might be some middle ground on which to avoid the controversy. There probably isn't any.

MorpheusSandman

11-25-2012, 01:24 AM

I don't know why we're mentioning Dawkins (evolutionary biologist) in a discussion of theoretical quantum physics (he's already admitted his limited knowledge in the field).

mal4mac

11-25-2012, 06:38 AM

That Feynman lecture was great...

Yeah. Probably the best way, and certainly the most fun way, to go deeper is "more Feynman". Though, as he says in the lecture, you can't go deeper, only broader. Start with the book of those lectures "The Character of Physical Law", follow it up with his wonderfully light autobiographies, and the popular out-takes from his famous "lectures on physics". Also check out the other lectures on utube - the Horizon interviews are other BBC classics. His full set of "lectures" is quite heavy, it was aimed at top Caltech physics undergraduates and went over their heads several times, but it's worth dipping into. When doing my physics degree we were recommended other textbooks, and to dip into Feynman to *really* understand certain difficult concepts, but not to worry if he lost us now and again - this was good advice. I've browsed a few university physics websites recently and many (of the best), I see, still make that recommendation. After reading all his popular stuff you might want to dive into the third volume of the lectures, which is all on quantum physics. To get into his own seminal work on QED you might attempt his semi-popular book of that name, and then (if you are really keen) his PhD level text book, Quantum Mechanics and Path Integrals, recently republished in Dover. The following site is also interesting, it stresses the use being made of Feynman's approach to QM by one of the most admired educators in the physics community:

http://www.eftaylor.com/quantum.html

Note that, although Feynman didn't mention it in his lectures, he did invent a very popular interpretation of his own:

http://www.quora.com/What-is-Richard-Feynmans-sum-over-paths-approach-to-quantum-mechanics

But he's great enough not to feel the need to mention this, it would just confuse the main message: "no one understands..."

cacian

11-25-2012, 09:23 AM

YesNo about the center of the universe not in existence it just occurred to me how does one explain the moon phenomena?
In the sense that it increases and decreases.

YesNo

11-25-2012, 12:10 PM

I didn't realize Feynman was so accessible, mal4mac. I'll have to read and watch more of this. The Edwin Taylor site looks like it can keep me busy for a while as well.

Regarding Dawkins, MorpheusSandman, I agree he has little to do with this thread. I assume he was introduced because his style seems quite different from Feynman's. From my limited experience with Dawkins, he seems ready to pontificate about stuff he knows little about while Feynman humorously will say things like "We call it a probability amplitude because we don't know what it means."

I don't think a specific center of the universe should exist based on relativity, cacian, but perhaps each inertial frame of reference could be considered a center of the universe at least for the purposes of aligning a coordinate system with that frame of reference.

Here are some links I've found on related subjects in this thread:

1) The Stanford Enyclopedia of Philosophy has an interesting article on Everett: http://plato.stanford.edu/entries/qm-everett/

This provides some history and mentions five modifications to Everett's relative state interpretation of QM that have tried to overcome problems with the original theory. We have only discussed the "many world" modification, but there are also the "Bare Theory", "Many Minds", "Many Histories" and "Relative Facts" modifications. The article makes me wonder if any of these modified theories actually model QM adequately. I previously assumed that Many Worlds did so.

2) Deutsch challenged people to explain where the quantum computer's calculations occurred. Deutsche seemed to think one would have to say they occurred in many worlds. A. M. Steane has a different answer in "A quantum computer only needs one universe": http://xxx.lanl.gov/pdf/quant-ph/0003084v3.pdf The title says it all, but the body gives the explanation.

MorpheusSandman

11-26-2012, 03:42 AM

From my limited experience with Dawkins, he seems ready to pontificate about stuff he knows little aboutI haven't noticed that myself. What he writes most about is how morality is linked with genetics as opposed to something supernatural/divine. He's never spoken at length on theoretical physics AFAIK.

YesNo

11-26-2012, 06:43 AM

I haven't noticed that myself. What he writes most about is how morality is linked with genetics as opposed to something supernatural/divine. He's never spoken at length on theoretical physics AFAIK.

I don't know. I just prefer Feynman to Dawkins.

If I haven't misunderstood, I think you are in favor of the Many Worlds position. I wonder how someone comes to accept such a position. One of the things I've learned from this thread is that there are people who do take it seriously and that's good because it gives everyone a chance to clarify what they are talking about.

mal4mac

11-26-2012, 06:54 AM

Regarding Dawkins, MorpheusSandman, I agree he has little to do with this thread. I assume he was introduced because his style seems quite different from Feynman's. From my limited experience with Dawkins, he seems ready to pontificate about stuff he knows little about...

Dawkins is worth listening to on science in general, including quantum mechanics. Someone was complaining about having all these different interpretations imposed on them, so I thought I'd mention a book that doesn't bother with them much, but stresses other (more interesting) areas of science - "The Magic of Reality". And he's good on Quantum; he's at least read Feynman's popular stuff, and puts things so well:

http://www.youtube.com/watch?v=R9Wr-nmXIFk

Cioran

11-26-2012, 08:50 PM

I think you're doing very well in digging into this material YesNo - especially that article about which interpretation physicists believe, and showed the wide variety of views held, some even changing their views. Copenhagen on Monday, MWI on Tuesday,...

Tipler is another fringe figure, like Everett, as comments by serious physicists make plain:

This is just more ad hom, but also false. Tipler and Everett are not fringe figures. There is a huge literature devoted to Everettian MWI that you can find in science and philosophy journals online. Have you checked any of it out? I know the answer. It is "no."

"George Ellis, writing in the journal Nature, described Tipler's book on the Omega Point as "a masterpiece of pseudoscience ... the product of a fertile and creative imagination unhampered by the normal constraints of scientific and philosophical discipline"... Physicist Sean M. Carroll thought Tipler's early work was constructive but that now he has become a "crackpot".

So when Tiper says, "I definitely accept the MWI. The MWI is not an option, but as I show in my book, a necessary mathematical consequence of quantum mechanics applying at all levels.", how can you trust him?

Shall I introduce you to hundreds of other articles supporting MWI NOT written by Tipler?

I admit that I don't understand these ideas and that's why I find the thread interesting. I'm trying to un-mix things in my mind.

The only reason I mentioned the Wikipedia article is that I thought you were quoting him as an authority.

Laugh Out Loud.

There are multiple definition of this term. I quoted one from the Concise OED, but I think I like the other better, it's just "personal". So an "ad hominem attack" is simply "a personal attack".

I'm sorry, but you are wrong again.

Ad ad hominem attack is not a personal attack. In fact, ad hom can even be praise.

As stated before: ad hom is the logical fallacy of supposing that an argument is false because of some personal characteristic of the person making the argument.

Here are two ad hom arguments:

First:

1. Hitler praised eating vegetables.

2. Hitler was an evil man.

3. Therefore, eating vegetables is bad.

Second:

1. Cassandra advocates voting for Republicans.

2. Cassandra is much too intelligent to really believe in such advocacy.

3. Therefore, one should not vote for Republicans.

Are you able to process ad hom now? Are you able to understand it's just not an "insult"?

I'd guess not.

I think it's more about selling books, since Hawking publishers have realised they can get best sellers in this area. To get an easy sell they push interpretations like Many Worlds and Omega Point that are zany and instantly appealing.

To conflate MWI with Tipler's Omega Point speculation is just breathtakingly dishonest, isn't it? One has nothing to do with the other. But I guess you don't care about honesty.

Mal4Mac, does the sun revolve around the earth, or not?

YesNo

11-26-2012, 10:23 PM

Laugh Out Loud.

I'm glad you're back! I don't understand how Many Worlds proponents handle the entanglement of particles, but I've run into a new problem with it.

After mal4mac's introduction to Feynman, I started reading Six Easy Pieces. On page 34, Feynman asks, "Why are atoms so big?" Then he gave an answer that surprised me:

What keeps the electrons from simply falling in? This principle: If they were in the nucleus, we would know their position precisely, and the uncertainty principle would then require that they have a very 'large' (but uncertain) momentum, i.e., a very large 'kinetic energy'. With this energy they would break away from the nucleus. They make a compromise: they leave themselves a little room for this uncertainty and then jiggle with a certain amount of minimum motion in accordance with this rule.

What that means is the uncertainty principle is what makes atoms so large. Now Many Worlds does away with the uncertainty principle. The probabilities are illusions that we calculate. That must mean that for any particular world, there is no uncertainty and so there is no need for the electrons to jiggle around.

So, here is the next question I've got: How does Many Worlds account for the fact that atoms are so big? How do these worlds jiggle in superposition to generate the illusion of the atom's size?

MorpheusSandman

11-27-2012, 12:48 AM

I think you are in favor of the Many Worlds position. I wonder how someone comes to accept such a position. To put it simply, the physicists I trust most seem to support that interpretation. I'm certainly willing to change my position if any of the other interpretations begin coming out clearly ahead, but right now I'd echo Yudkowsky's arguments: http://lesswrong.com/lw/q8/many_worlds_one_best_guess/

cacian

11-27-2012, 05:25 AM

[QUOTE=Cioran;1188195]I'm sorry, but you are wrong again.

Ad ad hominem attack is not a personal attack. In fact, ad hom can even be praise.

As stated before: ad hom is the logical fallacy of supposing that an argument is false because of some personal characteristic of the person making the argument.

Hi Cioran what I am not getting how does a personal enters into an argument?
How does it make a jump? In any argument no one cares about who you are or what you did.
It is about what you say there and there that counts.

Here are two ad hom arguments:

First:

1. Hitler praised eating vegetables.

2. Hitler was an evil man.

3. Therefore, eating vegetables is bad.

This does not look like an argument. It looks like a set of facts being listed as some kind of a CV to jusfiy a third unrealate subject/conets whatever you call it.

How does one move from to 1 to 2? Where is the link?

For example:
1. I speak Spanish
2. I speak French
3. I don't speak Japanese or I speak Chinese.

You can see that 1 and 2 and 3 eventually are all related because they make sense.
So because 1 and 2 are it must mean 3 is in either I do not speak Japanese or I speak Chinese.
so in sequencial logic:
1=2=3 is perfect because they all link.
And since we know that the answer in mathematical is this
a=x
a=y
then a=x=y is the ONLY correct answer and all argument must adhere to this.

So your argument is incorrect because they do not fit with the sequence of a=x=y

Second:

1. Cassandra advocates voting for Republicans.

2. Cassandra is much too intelligent to really believe in such advocacy.

3. Therefore, one should not vote for Republicans.

Are you able to process ad hom now? Are you able to understand it's just not an "insult"?

I'd guess not.
Again this is not correct because it does not fit with the sequence of a=x=y.

YesNo just to point about parallel worlds existing or not there is in fact NO SYMMETRY in reverse and therefore there are no parallel universe.
In other words a shape in reverse is dissimilar to its original shape.
Parallelism is also dissimilar when put in reverse.

YesNo

11-27-2012, 12:21 PM

To put it simply, the physicists I trust most seem to support that interpretation. I'm certainly willing to change my position if any of the other interpretations begin coming out clearly ahead, but right now I'd echo Yudkowsky's arguments: http://lesswrong.com/lw/q8/many_worlds_one_best_guess/

Thanks for the link to Yudkowsky's blog. In anything I might say that would disagree with Yudkowsky, my intention is not to try to convince you to change your mind. I'm just trying to clarify what is at stake by making it conscious.

Yudkowsky doesn't present arguments as much as make claims that MW is true. It is more rhetoric than science. Here is an example:

Could there be some as-yet-unknown fundamental law, that gives the universe a privileged center, which happens to coincide with Earth—thus proving that Copernicus was wrong all along, and the Bible right?

In this the "privileged center" is the one world that he opposes. He is associating the acceptance of one world as claiming that we accept the existence of a privileged center and that we want to prove Copernicus wrong and that we support the Bible. I don't see why anyone should bring the Bible into this discussion. Is he trying to portray the Copenhagan Interpretation as being Christian and perhaps reactionary? This is rhetoric, not science.

Here is another example of rhetoric rather than science:

So too with asking whether there might be only one world. It betrays a sentimental attachment to human intuitions already proven wrong. The wheel of science turns, but it doesn't turn backward.

Notice how he portrays people supporting the Copenhagen Interpretation as being "sentimental" and "backward"? That sounds like an ad hominem argument to me, but then he is just being rhetorical.

This type of paragraph is as close as he gets to giving some information:

There is no experimental evidence that the macroscopic world is single (we already know the microscopic world is superposed). And the prospect necessarily either violates Special Relativity, or takes an even more miraculous-seeming leap and violates seemingly impeccable logic. The latter, of course, being much more plausible in practice. But it isn't really that plausible in an absolute sense. Without experimental evidence, it is generally a bad sign to have to postulate arbitrary logical miracles.

The claim that there "is no experimental evidence" is pure pseudo-science. It makes a scientific sounding claim to rhetorically convince someone without providing evidence to accept one position over the other. The "we already know", the "necessarily" and the "miraculous-seeming" are more of the same.

The information he does provide relates to special relativity supposedly being violated with the EPR experiments although I think there are various "no-go" theorems that make the CI consistent. They also provide a challenge for the MWI since one of the no-go theorems is a no cloning theorem. That would violate the possibility of making copies of us and put in doubt the existence of many worlds.

If anything, the MWI appears to me reactionary and backward. The reason I say that is because it is trying to maintain the deterministic physics of the 17th century in the 21st century in spite of the evidence from quantum mechanics to the contrary.

In a recent post, I mentioned Feynman's claim that the size of the atom seems dependent upon the uncertainty principle. I suspect the size of the atom allows chemistry to work the way it does. MW does not have the uncertainty principle. It needs to explain how an atom can be as big as it is without the uncertainty principle that is part of the Copenhagen Interpretation.

YesNo just to point about parallel words existing or not there is in fact NO SYMETRY in reverse and therefore there are no parallel universe.

The idea of no symmetry is interesting, but I don't understand. It does seem that a deterministic universe should have laws that would not only predict any future state, but also describe any past state. I don't know if that would work in a MWI multiverse or not.

Cioran

11-27-2012, 01:13 PM

In order to properly understand what is being discussed here, one must first have a basic grasp of what quantum mechanics is, and why it was developed in the first place.

Fortunately, the Web is a wonderful place to employ Google for reasons other than digging up invalid ad hominen attacks on one's intellectual betters. It's also a place to learn. There is a wonderful article that first appeared in 2004 in Scientific American which takes the layman, in easy-to-understand way, through the history of QM from its inception. Here it is: 100 Years of the Quantum (http://arxiv.org/pdf/quant-ph/0101077v1.pdf)

The article explores all of the interpretations of QM, including Copenhagen and Many Worlds. It was written by Max Tax Tegmark and John Archibald Wheeler, the former whose work I linked earlier in this thread, and the latter one of the most prominent physicists in history. Tegmark is a Many Worldist; Wheeler is not. Because Wheeler accepts the reality of wave-function collapse, which Tegmark and other Many Worldists deny, Wheeler concludes that human beings bring the universe into existence, including its distant past, by acts of observation made in the present. And Many Worlds is strange? How strange are Wheeler's beliefs?

However, the strangeness of a belief has no bearing on its merits. Also, to link to a work by an authority on a subject is NOT to commit (as was laughably charged earlier) the fallacy of appeal to authority. Like ad homimen, the fallacy of appeal to authority is an informal (inductive) logical fallacy that comes in two forms. In the first form, y is presented as an expert, and it is noted that y claims x. The fallacy arises when x is now claimed to be correct just because y says so; after all, y is an expert.

Of course, no matter how great an authority y is, x cannot be correct solely on y's say-so. The second appeal to authority fallacy lies in justifying some claim in one field by appealing to an expert in another: We should believe some claim in biology, for instance, because a physicist supports it.

Other than those two fallacies, it is perfectly legitimate to invoke the writing of an expert on a subject, to explain the subject. That is what I did in linking to Tipler. That is NOT a fallacious appeal to authority. And, of course, as already noted, that Tipler may have a controversial theory on some other topic besides QM has no bearing whatsoever on his QM arguments. Just as his QM arguments are not correct just because he is an authority on QM (fallacy of appeal to authority), so too his arguments are not WRONG because he has controversial beliefs on another subject (fallacy of ad hominem).

Those who read the "100 Years of the Quantum" article that I linked will discover that the central mystery of QM lies in wave function collapse. In addition to wave function collapse being totally unexplained in its own right, the other mysteries fall out directly from it: quantum indeterminism (God "playing dice" that Einstein abhorred); non-locality ("spooky action at a distance," as Einstein scoffed) and non-realism: "Do you really mean to say," as Einstein asked a colleague, "that the moon doesn't exist if no one is looking at it?"

The paper by Tipler (and there are many others on the same topic) shows why all these mysteries go away under the Many Worlds Interpretation: He shows, in his paper, mathematically, why there is no spooky action at a distance, no non-locality and no anti-realism. All the QM mysteries go away under MW, simply be dispensing with the so-called wave function collapse. if one clings to wave function collapse, one is left in the position, like Wheeler, of suggesting that the human mind is somehow central to reality, and that the past did not actually exist until our measurements conjured it up out of nothing!

Basically, all collapse-postulate metatheories of QM treat the classical world and the quantum worlds as distinct; that there is a "cut" between the two realms, called the Heisenberg Cut. However, no one knows where this cut is, and in fact it doesn't exist. We have now put objects as big as Buckyballs and molecules with 240 atoms into superposition. Since the entire world is quantum and not classical, Many Worlds falls out of this. We get Many Worlds because there is no wave-function collapse which means that everything is always in superposition. When John sees result x, his doppelgänger, John', sees y because two different versions of John are quantum entangled with two different results.

Contrary to what has been claimed here, Many Worlds is very mainstream now, especially in conjunction with a phenomenon known as decoherence. Lest there by any doubt about this, I invite those who are interested to visit the Stanford Encyclopedia of Philosophy, and read the following article: Many-Worlds Interpretation of Quantum Mechanics. (http://plato.stanford.edu/entries/qm-manyworlds/) Notice that at the end of the article, there are supplementary links, including to preprint archives at arVix.org and the archives of the Philosophy of Science at the University of Pittsburgh. These archives give a wealth of additional information on MW, and show just how deeply imbedded it is in modern physics and philosophy.

With that I absent myself from further discussion on this topic; the level of discourse in this thread is far too primitive and ill-informed for me to waste any more time on. Also, blatantly dishonest claims have been made, such that my linking to Tipler's article constituted an "appeal to authority" and also the extraordinarily risible (and outrageously false) contention that I said Hugh Everett was right because he was treated badly! In a properly moderated forum, these falsities would not be allowed to stand. I do hope, though, that those who are interested in this topic will explore the fruitful links I have given. From this thread alone you will learn nothing, except from me, but I won't participating any longer.

MorpheusSandman

11-27-2012, 11:26 PM

Yudkowsky doesn't present arguments as much as make claims that MW is true. It is more rhetoric than science.I was linking to his summary. If you want to read his entire QM science and the reasons why he's come to believe MW is the winner, start here: http://lesswrong.com/lw/r5/the_quantum_physics_sequence/ Of course his summary is more rhetorical than scientific because he assumes his reader has already made it through the posts on the actual science. He also links to some preliminary articles that are necessary to understand where he's coming from. I still think this is essentially the strongest argument to be made for MW:
When we turn our attention to macroscopic phenomena, our sight is obscured. We cannot experiment on the wavefunction of a human in the way that we can experiment on the wavefunction of a hydrogen atom. In no case can you actually read off the wavefunction with a little quantum scanner. But in the case of, say, a human, the size of the entire organism defeats our ability to perform precise calculations or precise experiments—we cannot confirm that the quantum equations are being obeyed in precise detail.

We know that phenomena commonly thought of as "quantum" do not just disappear when many microscopic objects are aggregated. Lasers put out a flood of coherent photons, rather than, say, doing something completely different. Atoms have the chemical characteristics that quantum theory says they should, enabling them to aggregate into the stable molecules making up a human.

So in one sense, we have a great deal of evidence that quantum laws are aggregating to the macroscopic level without too much difference. Bulk chemistry still works.

But we cannot directly verify that the particles making up a human, have an aggregate wavefunction that behaves exactly the way the simplest quantum laws say. Oh, we know that molecules and atoms don't disintegrate, we know that macroscopic mirrors still reflect from the middle. We can get many high-level predictions from the assumption that the microscopic and the macroscopic are governed by the same laws, and every prediction tested has come true.

But if someone were to claim that the macroscopic quantum picture, differs from the microscopic one, in some as-yet-untestable detail—something that only shows up at the unmeasurable 20th decimal place of microscopic interactions, but aggregates into something bigger for macroscopic interactions—well, we can't prove they're wrong. It is Occam's Razor that says, "There are zillions of new fundamental laws you could postulate in the 20th decimal place; why are you even thinking about this one?"

...

The existence of other versions of ourselves, and indeed other Earths, is not supposed additionally. We are simply supposing that the same laws govern at all levels, having no reason to suppose differently, and all experimental tests having succeeded so far. The existence of other decoherent Earths is a logical consequence of the simplest generalization that fits all known facts. If you think that Occam's Razor says that the other worlds are "unnecessary entities" being multiplied, then you should check the probability-theoretic math; that is just not how Occam's Razor works.

YesNo

11-28-2012, 01:32 AM

I find it hard to follow Yudkowsky, MorpheusSandman, but I do find him interesting. I did read some of his other posts that you linked to earlier in this thread.

In Six Easy Pieces, page 135, Feynman tried to show that there is no way around the wave phenomenon in the double slit experiment. He wrote:

Suppose we were to assume that inside the electron there is some kind of machinery that determines where it is going to end up. That machine must 'also' determine which hole it is going to go through on its way. But we must not forget that what is inside the electron should not be dependent on what 'we' do, and in particular upon whether we open or close one of the holes. So if an electron, before it starts, has already made up its mind (a) which hole it is going to use and (b) where it is going to land, we should find P1 for those electrons that have chosen hole 1, P2 for those that have chosen hole 2, 'and necessarily' the sum P1 + P2 for those that arrive through the two holes. There seems to be no way around this. But we have verified experimentally that that is not the case.

I see MWI as a claim that there actually is some way around the wave phenomenon, some kind of machinery within the electron based on many worlds, each deterministically knowing which hole the electron in that world will go through and where it will end up. That means that there would be no interference pattern, no wave pattern, when we are not looking at the electrons. But there is a wave interference pattern. MWI contradicts QM rather than interprets it.

And so I conclude, since QM has been experimentally verified, that the MWI is false.

MorpheusSandman

11-28-2012, 02:04 AM

I find it hard to follow Yudkowsky, MorpheusSandman, but I do find him interesting.If you read him from the very beginning, including those essential preliminary posts, then he's much easier to follow. Yudkowsky is a Bayesian, first and foremost, and I'd recommend getting a firm understanding of how Bayes' Theorem works and how it can be used in assessing evidence, especially in cases like QM where we still don't have a decidedly definitive interpretation. One of great difficulties in understanding QM to begin with is understanding how our mind intuitively interprets reality, and how this interferes with our understanding of how reality actually functions. Yudkowsky is actually an AI Researcher, so his posts on cognition and rationality are very helpful in overcoming many of the various biases that we are hard-wired with that prevent us from accurately understanding reality. I had trouble at some points of his QM sequence, but he's probably the best combination I've found online of thorough yet laymen friendly, so I'd recommend really trying to work your way through him, perhaps with the assistance of someone who is actually studying QM that can address your questions/points as they come up.

And so I conclude, since QM has been experimentally verified, that the MWI is false.No. At its basic level, MW is saying that what is observed happening on a quantum level is happening at all levels, that the macro level is nothing but an aggregate of QM. It's the classic one-world view that states that there is some break between the quantum level and the macro level, the level we observe, despite the fact we have no reason to think this besides our already-proven wrong intuitions. It's the classic interpretation that is proposing some hidden mechanisms that are determining why the wave collapses as it does. MW is not getting around the wave phenomenon, it's just stating that there's no collapse, and what we observe is nothing but one particular world that the electron is ending up in (if Cioran's still reading this, he can correct me if necessary; it's been a while since I was reading about this).

YesNo

11-29-2012, 12:57 AM

No. At its basic level, MW is saying that what is observed happening on a quantum level is happening at all levels, that the macro level is nothing but an aggregate of QM. It's the classic one-world view that states that there is some break between the quantum level and the macro level, the level we observe, despite the fact we have no reason to think this besides our already-proven wrong intuitions.

At the macro level, trying to convince someone that there are many worlds would be like trying to convince an atheist that there is a God. It would require a lot of evidence and then once it is assembled the atheist would dismiss the evidence without considering it anyway. It is rather futile.

If one looks at many worlds and the uncertainty principle as opposites, individual "free will" might be at stake. Again, those who believe we have free will are not likely to accept a many worlds argument so there is no point in bringing it up. Besides, if the many world proponents are right and we have no free will, they won't be able to change anyone's mind anyway since no one's mind is free to change. So why bother?

However, the arguments against many worlds that I'm interested in are not at the macro level but at the micro level.

It's the classic interpretation that is proposing some hidden mechanisms that are determining why the wave collapses as it does. MW is not getting around the wave phenomenon, it's just stating that there's no collapse, and what we observe is nothing but one particular world that the electron is ending up in.

The "wave collapse" simply means that the electron or other particle-wave object no longer acts as a wave but only as a particle. That occurs when it rams into the detector wall at the end of a double slit experiment and a click is detected or when light is shone on the electron as it passes through one or the other slits and flashes. After that flash occurs a particle pattern appears on the detector wall rather than an wave interference pattern.

The collapse of the wave function is a pretty natural way to describe what actually happens to the particle.

But my arguments against many worlds come before the wave function collapses.

If many worlds and Heisenberg's uncertainty principle are at odds, then many worlds needs to explain some things about the behavior of these particles while they still act as waves, that is, while they are functioning as parts of atoms and while they are heading unobserved toward the detector wall in a double slit experiment. There are two places where Feynman in Six Easy Pieces makes me think that many worlds will have problems:

1) Feynman claims the uncertainty principle is responsible for why atoms are as big as they are. How would a many world proponent explain that without the uncertainty principle? See page 34.

2) Feynman claims if there were a deterministic mechanism, such as many worlds, manipulating the behavior of the electron then there wouldn't be a wave interference pattern in the double slit experiment when no one was looking, but there is one. How does a proponent of many worlds explain that? See page 135.

This is from the last paragraph, page 138:

The uncertainty principle "protects" quantum mechanics. Heisenberg recognized that if it were possible to measure the momentum and the position simultaneously with a greater accuracy, then quantum mechanics would collapse. So he proposed that it must be impossible.

If many worlds wants to replace the uncertainty principle with a deterministic solution, it must first get rid of quantum mechanics. Since QM has been experimentally verified, that is not likely to happen.

MorpheusSandman

11-29-2012, 03:33 AM

YesNo

11-29-2012, 10:04 AM

The fact that you're bringing up both theology (convincing people of MW is like convincing atheists of God? Huh?) and philosophy (MW threatens "free will?" Huh?) into this discussion suggests to me you have ulterior motives behind your "research" to begin with. As for this question: "if the many world proponents are right and we have no free will, they won't be able to change anyone's mind anyway since no one's mind is free to change. So why bother?" This conflates a lack of free will with the obtaining of omniscience. If we found out for 100% sure tomorrow that we had no free-will, this wouldn't change our ignorance of what world we will find ourselves in.

Of course there are ulterior motivations. We wouldn't be discussing this issue on a literature forum if there weren't.

What I am trying to emphasize is something obvious. To try to convince people that parallel universes exist in which there are copies of them running around that they conveniently cannot see and verify is like trying to convince them to believe in a God they do not want to believe in. That is all.

Regarding free will, it if does not exist, how can people obtain omniscience or even know they have obtained it? They have to move from a state of ignorance to a state of omniscience, but they have no free will to move from one state to the other.

As for the others, I don't see how 1) is a problem for MW since it's not even addressing that, and, as for 2), the interference can be explained by the interactions of the many worlds. MW doesn't need to "get rid of" QM, and that's a rather absurd thing to state. MW is just interpreting one aspect of observed QM (the wave function "collapse") and that's it. I can see why Cioran decided to exit this conversation.

How is the interference explained by the interactions of the many worlds? That is the heart of the matter. The reason why this is unlikely is that the many worlds interpretation is deterministic, but QM is not. All I am asking for is an explanation how this deterministic theory simulates the non-deterministic theory at the micro level.

In some ways, I think MWI piggy-backs on the Copenhagen Interpretation. It doesn't offer anything of its own except to claim that the CI non-determinism is an illusion of some sort that it doesn't know how to adequately explain.

I hope you don't leave the discussion. We should not hope to convince each other, because we probably won't. All we can do is clarify our individual positions.

Cioran

11-29-2012, 01:15 PM

The fact that you're bringing up both theology (convincing people of MW is like convincing atheists of God? Huh?) and philosophy (MW threatens "free will?" Huh?) into this discussion suggests to me you have ulterior motives behind your "research" to begin with. As for this question: "if the many world proponents are right and we have no free will, they won't be able to change anyone's mind anyway since no one's mind is free to change. So why bother?" This conflates a lack of free will with the obtaining of omniscience. If we found out for 100% sure tomorrow that we had no free-will, this wouldn't change our ignorance of what world we will find ourselves in.

As for the others, I don't see how 1) is a problem for MW since it's not even addressing that, and, as for 2), the interference can be explained by the interactions of the many worlds. MW doesn't need to "get rid of" QM, and that's a rather absurd thing to state. MW is just interpreting one aspect of observed QM (the wave function "collapse") and that's it. I can see why Cioran decided to exit this conversation.

Right, this is why I've dropped out of the conversation. It's the usual message board malady. A profoundly interesting topic is raised and right away the usual suspects move in to muck it up either with willful misunderstanding or some ulterior motive. Thanks for helping me to try to clear up these issues, but I judge the endeavor futile.

It's not that anyone must accept MWI. It's that, if someone wants to discuss it, then one must make at least a minimal effort to comprehend the material in question and not make blatantly asinine assertions, such as, for example: "And so I conclude, since QM has been experimentally verified, that the MWI is false." Uh, no. I explained this many times. MWI is an interpretation, a meta-theory, of QM. Everything about QM is perfectly consistent with MWI, and vice versa. If this were not so, why would MWI be so deeply woven into current academic discussions of QM?

For the last time, MWI is an interpretation of quantum mechanics that resolves all of the mysteries originally raised by QM. For instance, indeterminism in QM exists only if one accepts wave function collapse. The same is true of nonlocality and anti-realism. If one removes the wave function collapse postulate then all these mysteries go away. Unless one can understand this simple point, conversation is futile. And it's such a simple point to understand, backed up by me with so much linked reference material, then I conclude that the failure to grasp the point is deliberate and bespeaks ulterior motives.

Your explanation, btw, in your previous post of what MWI entails is absolute correct. But don't bang your head against a wall. All you'll get is a headache in addition to the same stupid comments over and over from your interlocutors.

mal4mac

11-29-2012, 03:11 PM

The "wave collapse" simply means that the electron or other particle-wave object no longer acts as a wave but only as a particle.

How do you know there is a wave to collapse?

The collapse of the wave function is a pretty natural way to describe what actually happens to the particle.

In what way is this pretty natural? Waves and particles are natural terms that everybody uses, but a wave function? I think this is the big problem in explaining this stuff to the layman; watch Feynman again and see how he is, rightly, laughing at tech. speak like 'wave function'. He talks about bullets and water, so even escapes the abstraction of particles and waves

By talking about a wave function collapsing you get oneself in a tiswas trying to visualise a wavey thingy folding up into a ball like thingy - but there is no wavey thingy! There is only the "particle of light' that you actually see, many of these particles of light build up into a dark light pattern in some situations, a "pile of particles" pattern in others. Why bother with interpretations at all, they only confuse, as is shown by there being so many, just describe what happens in experiments.

MorpheusSandman

11-29-2012, 11:04 PM

Of course there are ulterior motivations. We wouldn't be discussing this issue on a literature forum if there weren't.What does discussing this on a literary forum have to do with ulterior motives? When it comes to science, I'm interested in learning the truth; I have no ulterior motives, I want to align my beliefs with reality. Attempts to make reality align with one's prior beliefs is where reality-distortion biases come from. Again, read Yudkowsky who writes primarily about these reality-distorting biases that are hard-wired in our brains.

To try to convince people that parallel universes exist in which there are copies of them running around that they conveniently cannot see and verify is like trying to convince them to believe in a God they do not want to believe in.I don't know why it would be any harder to convince them of that then that there are mechanisms they cannot see and verify making particle waves collapse in a certain way that is indeterministic. Either way, we're dealing with aspects of reality that seem very strange to our natural intuitions.

Regarding free will, it if does not exist, how can people obtain omniscience or even know they have obtained it? I think you misunderstood me. People often bring up the argument that "if we have no free-will, then what we do does not matter." Well, that assumes several things: one being a single world, two being a predestined outcome in that world, three being that any actions lead to that predestined end, and finally it implies an omniscience in the person that realizes they have no free-will. All of these things are relevant to the argument that "it doesn't matter what one does because they have no free-will," and none of them may be relevant to the world we actually live in. Our belief or disbelief in free-will and what it means for our actions and, further, what it means regarding the world we end up in is probably more important than whether we ACTUALLY have "free-will" or not. Again, see Yudkowsky: http://lesswrong.com/lw/of/dissolving_the_question/ Let's assume for a moment that MW is correct and all you know is that you don't know which world you will find yourself in but you can envision what world you WANT to find yourself in. Well, there are well established means for choosing the path that is mostly likely to lead to the world you want to live in. I utilize this philosophy in the real world in my profession of poker. I never know the result of any hand going into it, but I know the odds of each outcome, and I choose the odds that are most likely to end in the outcome, the world, I want it to. The same is true for our actions influencing others. We have an established pattern of what actions are most likely to get others to believe something, so it's only a matter of taking those actions and having the best chance at ending up in the world we want to be in.

How is the interference explained by the interactions of the many worlds? Again, Cioran can correct me if I'm wrong, but I think it's David Deutsch that has written about this. He could probably give you links, but you seemed to have ignored many he's given you.

The reason why this is unlikely is that the many worlds interpretation is deterministic, but QM is not.QM is only indeterministic if the wave-function is actually collapsing into a single world.

Cioran

11-30-2012, 01:51 AM

QM is only indeterministic if the wave-function is actually collapsing into a single world.

Exactly! How many times does this elementary point need to be explained? Has YesNo read the links I have provided? Has he read some of them? Even ONE of them?

The answer is NO, isn't it, YesNo? So you can remove the first part of your user name and just call yourself No!

But keep on blathering without understanding!

mal4mac

11-30-2012, 07:41 AM

... I think it's David Deutsch that has written about this. He could probably give you links, but you seemed to have ignored many he's given you.

He may have better things to do than chase incomprehensible links all day. Why not just answer his question?

MorpheusSandman

11-30-2012, 07:57 AM

Why not just answer his question?Because I really don't feel knowledgeable enough to try and paraphrase the people that have devoted their lives to studying and explicating this subject. YesNo asked why I favored the MWI and I stated it as simply as possible. I'm sorry that you and he find many of these physicists "incomprehensible," but I'm not sure what else you want from Cioran, much less myself who is much less knowledgeable. Probably the only way to understand how the many worlds could interact would be to dig into the mathematical arguments.

YesNo

11-30-2012, 11:07 AM

Exactly! How many times does this elementary point need to be explained? Has YesNo read the links I have provided? Has he read some of them? Even ONE of them?

The answer is NO, isn't it, YesNo? So you can remove the first part of your user name and just call yourself No!

But keep on blathering without understanding!

I'm glad you're back, Cioran!

I have read every link you posted, some more than once.

I look at this as a jigsaw puzzle with over a thousand pieces in it. Sometimes you have to look at the piece more than once to understand it.

How do you know there is a wave to collapse?

I suspect there isn't a wave out there. That is just the equation used to describe the particle's probabilistic behavior.

In what way is this pretty natural? Waves and particles are natural terms that everybody uses, but a wave function? I think this is the big problem in explaining this stuff to the layman; watch Feynman again and see how he is, rightly, laughing at tech. speak like 'wave function'. He talks about bullets and water, so even escapes the abstraction of particles and waves

By talking about a wave function collapsing you get oneself in a tiswas trying to visualise a wavey thingy folding up into a ball like thingy - but there is no wavey thingy! There is only the "particle of light' that you actually see, many of these particles of light build up into a dark light pattern in some situations, a "pile of particles" pattern in others. Why bother with interpretations at all, they only confuse, as is shown by there being so many, just describe what happens in experiments.

I guess the wave portion only comes from the Schrodinger equation. I am reading more of Feynman. Thanks for the references to him. They have helped clarify this issue for me.

The reason I mentioned that the wave function collapse seemed natural was because after the light saw which slit the electron went through something changed about it. The probability seemed to go away and it behaved as a particle would. So the wave function that generated probabilities collapsed into a deterministic situation. That seemed like a reasonable way to describe that actually happened.

I don't think there is a universal world wave equation for the universe as a whole. These wave equations only work for specific quantum objects. What do you think?

mal4mac

11-30-2012, 12:26 PM

The reason I mentioned that the wave function collapse seemed natural was because after the light saw which slit the electron went through something changed about it. The probability seemed to go away and it behaved as a particle would. So the wave function that generated probabilities collapsed into a deterministic situation. That seemed like a reasonable way to describe that actually happened.

How can an equation collapse into a thing? I thought only things collapsed into things. Would you say the VAT equation collapsed into a pile of five pound notes? It just seems a strange way to describe things. It can only be metaphor, and a bad one at that.

Also, how can light see anything?

YesNo

11-30-2012, 01:34 PM

What does discussing this on a literary forum have to do with ulterior motives? When it comes to science, I'm interested in learning the truth; I have no ulterior motives, I want to align my beliefs with reality. Attempts to make reality align with one's prior beliefs is where reality-distortion biases come from. Again, read Yudkowsky who writes primarily about these reality-distorting biases that are hard-wired in our brains.

I have at least two ulterior motives that stimulate my participation in these threads. They could be seen as jigsaw puzzles that I am working on.

The first puzzle could be generically called "consciousness", or in this particular thread, it might be aliased as "free will". I think we actually have it, MWI would claim that we don't. The second puzzle could be called "authority vs evidence". I am interested in how authority uses literary devices to convince others even if the evidence does not support what the authority has to say.

I don't know why it would be any harder to convince them of that then that there are mechanisms they cannot see and verify making particle waves collapse in a certain way that is indeterministic. Either way, we're dealing with aspects of reality that seem very strange to our natural intuitions.

It would be easier to convince people that Gods, or superhuman intentional agents, exist than it would be to convince them that parallel universes exist. Essentially, developmental psychologists have found that children prior to being taught seem to believe in these agents. Since the MWI would reject free will or intentionality, it would go against this aspect of our nature.

I think you misunderstood me. People often bring up the argument that "if we have no free-will, then what we do does not matter." Well, that assumes several things: one being a single world, two being a predestined outcome in that world, three being that any actions lead to that predestined end, and finally it implies an omniscience in the person that realizes they have no free-will. All of these things are relevant to the argument that "it doesn't matter what one does because they have no free-will," and none of them may be relevant to the world we actually live in. Our belief or disbelief in free-will and what it means for our actions and, further, what it means regarding the world we end up in is probably more important than whether we ACTUALLY have "free-will" or not. Again, see Yudkowsky: http://lesswrong.com/lw/of/dissolving_the_question/

We have a lot of constraints on our behavior and free will is not absolute. I've noticed that Yudkowsky does not believe in the reality of free will, but he does believe in the reality of many worlds. Consider actually doing the assignment he makes:

Your homework assignment is to write a stack trace of the internal algorithms of the human mind as they produce the intuitions that power the whole damn philosophical argument.

But instead of the "damn philosophical argument" being whether we have free will or not, let it be whether many worlds exist or not.

Let's assume for a moment that MW is correct and all you know is that you don't know which world you will find yourself in but you can envision what world you WANT to find yourself in. Well, there are well established means for choosing the path that is mostly likely to lead to the world you want to live in. I utilize this philosophy in the real world in my profession of poker. I never know the result of any hand going into it, but I know the odds of each outcome, and I choose the odds that are most likely to end in the outcome, the world, I want it to. The same is true for our actions influencing others. We have an established pattern of what actions are most likely to get others to believe something, so it's only a matter of taking those actions and having the best chance at ending up in the world we want to be in.

In the case of playing poker, when do the worlds split? In one world you win the game in the other you don't.

Also if Yudkowsky is right, you don't "want" anything. That's an illusion. That's a feeling. That is just a program running in your mind in this particular world giving you a deterministic outcome based on input values making you feel that you made some sort of choice. In some other world, you will have different input values or maybe even a different program running in superposition of some sort with this world which will make you do something else.

Don't forget, you have no free will in the MWI world. Most everything you experience to the contrary of that belief is by definition an illusion and should have some sort of "stack trace" to explain it.

Again, Cioran can correct me if I'm wrong, but I think it's David Deutsch that has written about this. He could probably give you links, but you seemed to have ignored many he's given you.

QM is only indeterministic if the wave-function is actually collapsing into a single world.

The indeterminism occurs prior to the wave function collapse. It is only after the collapse that one has a deterministic system. That is one of the things I learned from Feynman.

This indeterminism, Heisenberg's uncertainty principle in action, is what makes the atom as large as it is according to Feynman. That's why I wanted to know how many worlds handles that without the uncertainty principle. The atom is in a state prior to any collapse of a wave function. Also, if there was some deterministic mechanism that could tell that this electron will go through hole 1 and line up in position P and another electron will go through hole 2 and line up also in position P, then the number of electrons that one will find in position P is P12 = P1+P2 which means there was no interference pattern. That contradictions QM. If we have not collapsed the wave function with an experiment, we should see an interference pattern. That means P12 <> P1+P2.

YesNo

11-30-2012, 01:37 PM

How can an equation collapse into a thing? I thought only things collapsed into things. Would you say the VAT equation collapsed into a pile of five pound notes? It just seems a strange way to describe things. It can only be metaphor, and a bad one at that.

Also, how can light see anything?

Light seeing something is a bad metaphor. Sorry.

How would you describe what happens to the electron after a measurement has been made?

KillCarneyKlans

11-30-2012, 04:12 PM

Contrary to to popular belief parallel universes do exist

http://www.unexplained-mysteries.com/forum/index.php?showtopic=196092&st=255
http://www.christianityboard.com/topic/12966-more-astonishing-bible-proof-warning-athiests-this-is-adult-sensitive-material/
http://www.historum.com/blogs/killcarneyklansman/569-hebrew-gematria-dna-big-bang.html

http://www.fixedearth.com/HB%20179%20PART%20II%20ATT.EVIDENCE.htm
Attachment of Evidence for HB or SB # Sections 2, 3, & 4 “Evidence Confirming ‘Establishment Clause’ Rulings Against ‘Creation Science’ In County And State Courts And The Supreme Court Of The United States”

“According to kabbalistic wisdom, there are two parallel universes; one highly ordered; the other; random and chaotic ....Author Ziman tells us that Kabbalah and physics “…work together to draw a picture of the mysteries of such phenomena as the big bang, parallel universes, relativity theory, and the superstring theory.” All of evolution’s essential concepts (15 billion years, relativity, heliocentricity, big bang, expanding universe)--which are now textbook “science”--are the same concepts that were formulated by Kabbalist(s) ... as far back at least as the 1st century A.D and expanded in the 12th, 13th, 16th and 20th centuries.

http://www.historum.com/blogs/killcarneyklansman/578-helping-darwinists-understand-origins.html
http://www.unexplained-mysteries.com/viewnews.php?id=196746
http://www.dailymail.co.uk/sciencetech/article-1338818/First-evidence-universes-exist-alongside-discovered.html
http://www.online-literature.com/forums/showthread.php?68852-William-Lane-Craig-and-the-Kalam-Cosmological-Argument/page3

Scientists say that they have found evidence that our universe was 'jostled' by other parallel universes in the distant past. The incredible claim emerged after they studied patterns in the cosmic microwave background radiation (CMB) – the after-effects of the Big Bang. They say they may have found evidence that four circular patterns found in the CMB are 'cosmic bruises' where our universe has crashed into other universes at least four times. The findings, by Stephen Feeney from the Department of Physics and Astronomy at University College London, are likely to be controversial.

The paper, published online yesterday, comes just a month after a similar study of the background radiation claimed to have discovered evidence that the universe existed before the Big Bang. They say they have discovered 12 examples of concentric circles, some of which have five rings, meaning the same object has had five massive events in its history. [This can also be linked to Geometric forms and Gematria, within the Genesis Narrative] The rings appear around galaxy clusters in which the variation in the background radiation appears to be strangely low. The research appears to cast aside the widely-held 'inflationary' theory of the origins of the universe, that it began with the Big Bang, and will continue to expand until a point in the future, when it will end. They believe the circles are imprints of extremely violent gravitational radiation waves generated by supermassive black hole collisions in a previous aeon before the last big bang.

http://newswatch.nationalgeographic.com/2012/11/30/is-this-the-biggest-black-hole-ever/
http://news.discovery.com/space/massive-black-hole-small-galaxy-121128.html
Astronomers have found a super-super-massive black hole comprising a whopping and unprecedented 59 percent of the mass of stars in the central bulge of its host galaxy

They just found a Galaxy smaller than the Milky Way that is an ancient black hole ... mostly black hole ... which leads me to my next point

http://www.huffingtonpost.com/2012/11/28/black-hole-quasar-eruption_n_2203663.html
The sheer size of this ejection demonstrates a way for young galaxies to off-load mass: The energy in a quasar we usually see as radiation can be turned into kinetic energy, or energy of motion. This eruption is throwing up some 400 times the mass of the sun every year, and such events last for anywhere from 10 million to 100 million years. That, Arav said, could be the key to why galaxies are generally less massive than they should be, and why the black holes at their centers are the sizes that they are. "It gives the theorists something to work with," he said.

http://en.wikipedia.org/wiki/Supermassive_black_hole
Supermassive black holes have properties which distinguish them from lower-mass classifications. First, the average density of a supermassive black hole (defined as the mass of the black hole divided by the volume within its Schwarzschild radius) can be less than the density of water in the case of some supermassive black holes. This is because the Schwarzschild radius is directly proportional to mass, while density is inversely proportional to the volume.

If Einstein coulda of discovered [not that it is possible to test] a (GUT) Grand Unified Theory ... the break down of physical matter constrained subtlety by the last elemental ... gravity ... everyone would understand it in a physical sense

Quatum Theory micromanages the physical ... still time is a constant ... past, present & future ... only string theory could raise a model, reality based on a higher order ... though all 3 maybe necessary constituents

YesNo

12-01-2012, 02:58 AM

MWI is an interpretation, a meta-theory, of QM. Everything about QM is perfectly consistent with MWI, and vice versa.

I know that is what MWI wants to believe, but I don't know that this consistency is true. I don't think a deterministic interpretation can consistently interpret a non-deterministic theory. That is the heart of my objection.

If this were not so, why would MWI be so deeply woven into current academic discussions of QM?

I find that suspicious also, but I don't think it is so deeply woven as you hope.

For the last time, MWI is an interpretation of quantum mechanics that resolves all of the mysteries originally raised by QM. For instance, indeterminism in QM exists only if one accepts wave function collapse. The same is true of nonlocality and anti-realism. If one removes the wave function collapse postulate then all these mysteries go away.

Again, I don't think MWI resolves many of the mysteries. It certainly adds the mystery of many worlds.

The indeterminism in QM exists before anyone makes a measurement and collapses the wave function or decoheres the world into many worlds if one wants to view it that way. It is prior to the collapse or decoherence that I have a problem with MWI. There are two places where that problem has manifested itself.

1) Feynman asks in Six Easy Pieces, page 34, "Why are atoms so big?" He justified the size of atoms by referring to the uncertainty principle:

What keeps the electrons from simply falling in? This principle: If they were in the nucleus, we would know their position precisely, and the uncertainty principle would then require that they have a very 'large' (but uncertain) momentum, i.e., a very large 'kinetic energy'. With this energy they would break away from the nucleus. They make a compromise: they leave themselves a little room for this uncertainty and then jiggle with a certain amount of minimum motion in accordance with this rule.

The wave functions for the components of atoms have not been collapsed or decohered. These are still atoms with all their components' superpositions of states and they are bigger than they should be based on a deterministic interpretation. So if MWI really does interpret QM, and MWI is deterministic, why are atoms so big?

2) Feynman also mentions in Six Easy Pieces, page 135, something interesting about the standard double slit experiment and any deterministic mechanism at work in the electron. I don't see why that would not include a many worlds deterministic superposition:

Suppose we were to assume that inside the electron there is some kind of machinery that determines where it is going to end up. That machine must 'also' determine which hole it is going to go through on its way. But we must not forget that what is inside the electron should not be dependent on what 'we' do, and in particular upon whether we open or close one of the holes. So if an electron, before it starts, has already made up its mind (a) which hole it is going to use and (b) where it is going to land, we should find P1 for those electrons that have chosen hole 1, P2 for those that have chosen hole 2, 'and necessarily' the sum P1 + P2 for those that arrive through the two holes. There seems to be no way around this. But we have verified experimentally that that is not the case.

If the electron's behavior were deterministic prior to any collapse of its wave function or prior to decohering, then it would not generate the results that are observed in the double slit experiment. There would be no wave interference pattern when there actually is one.

So how does MWI, a deterministic interpretation actually interpret QM without contradicting QM itself?

“According to kabbalistic wisdom, there are two parallel universes; one highly ordered; the other; random and chaotic ....Author Ziman tells us that Kabbalah and physics “…work together to draw a picture of the mysteries of such phenomena as the big bang, parallel universes, relativity theory, and the superstring theory.” All of evolution’s essential concepts (15 billion years, relativity, heliocentricity, big bang, expanding universe)--which are now textbook “science”--are the same concepts that were formulated by Kabbalist(s) ... as far back at least as the 1st century A.D and expanded in the 12th, 13th, 16th and 20th centuries.

I was reading a thread on Hinduism that also wanted to use the MWI interpretation to justify its religious perspectives. I think science offers many justifications for religious belief of various sorts, but the many worlds or parallel universe interpretation is an attempt to justify determinism. Unless the religion in question is promoting determinism, I doubt MWI would be on its side.

MorpheusSandman

12-01-2012, 04:58 AM

I have at least two ulterior motives that stimulate my participation in these threads. You should seriously consider how your ulterior motives are impacting your ability to neutrally and objectively weigh the evidence on either side. You believe in free will, you want to believe in free will, you don't like MWI because you feel it threatens both; your dislike of having this belief challenged is very likely negatively impacting your ability to understand MWI and assess the evidence for it fairly. FWIW, I've had an issue with the concept of "free-will" going back to when I was a child. I remember wondering about exactly what allowed me to make choices even then, and I never could get past the idea that I (and I've come to change that "I" to "we") simply don't have an adequate understanding of the cognitive process that would make any argument from either side meaningful. Arguing about things we don't understand is fruitless from the get-go. Like Yudkowsky, I've come to think that the belief in or lack of belief in free-will is more important than whether there actually is such a thing or not. For me, the latter question is as useful as asking if there are bloberblicks.

As for authorities using "literary devices to convince others," what you're talking about is rhetoric, which has been a subject for study from the Ancient Greeks to modern times. As far as that goes, IA Richards and Wayne C. Booth have excellent books on the subject (The Philosophy of Rhetoric from the former, The Rhetoric of Rhetoric from the latter). The thing to understand about rhetoric is that it's equally effective for both true and false statements, that makes it as dangerous as it is useful. That said, I don't think most scientists tend to be skilled rhetoricians because they're usually more concerned about discovering the truth as opposed to figuring out how to convince others they've found it. Rhetoric is probably more typically and powerfully practiced by people that already have their minds made up, have no desire to learn anything new, and are setting out to convince others. I think part of the lack of acceptance of science amongst the general public is partly due to the level of rhetoric for them as compared to their detractors.

Since the MWI would reject free will or intentionality, it would go against this aspect of our nature.QM runs contrary to our intuitive nature to begin with, and none of the interpretations adequately reconcile the two. Basically, 20th century science, in general, should've put the death-knell in the coffin of how much we humans value our intuitions when it comes to understanding reality. But, as Yudkowsky said, people cling to their intuitions even in the face of devastating contradictory evidence, and are then capable of doing some remarkable cognitive gymnastics to get out of it.

I've noticed that Yudkowsky does not believe in the reality of free will, but he does believe in the reality of many worlds.Yudkowsky believes that the current evidence favors Many Worlds, and he presented his lengthy sequence to argue why; have you read it all yet? As for the his opinion on free-will, I think he made it very clear that the argument is flawed from the get-go. There's no hope of fruitfully discussing free-will until we have a good grip on human cognition.

But instead of the "damn philosophical argument" being whether we have free will or not, let it be whether many worlds exist or not. You mean we should map the cognitive algorithms that lead to a belief in MW? It's not exactly an intuitive belief/concept, you know...

In the case of playing poker, when do the worlds split? In one world you win the game in the other you don't.The worlds are splitting all the time, because everything is always in superposition. So if the odds for me winning a hand are 70/30, there are 70 worlds in which I win and 30 worlds in which I lose (or the equivalent ratio).

Also if Yudkowsky is right, you don't "want" anything. That's an illusion. That's a feeling. That is just a program running in your mind in this particular world giving you a deterministic outcome based on input values making you feel that you made some sort of choice. In some other world, you will have different input values or maybe even a different program running in superposition of some sort with this world which will make you do something else. Everything after your third statement is correct, but the first three statements are non-sequitors. There’s nothing about my cognition being an input/output program that makes feelings or desire an illusion. Why would feelings be illusive in a deterministic universe? Further, are you really objecting to the notion that we come pre-wired with impulsive desires and our choices are always concerned with how to achieve those desire impulses? Seriously, name me a single choice you’ve ever made that did not have its root in an impulsive desire that you did not will to be there.

The indeterminism occurs prior to the wave function collapse. It is only after the collapse that one has a deterministic system. The indeterminism prior to the collapse is reflective of our lack of knowledge of what world it’s going to end up in. As Yudkowsky is fond of saying, mystery is a part of the map/mind, not the territory/reality.

This indeterminism, Heisenberg's uncertainty principle in action, is what makes the atom as large as it is according to Feynman. That's why I wanted to know how many worlds handles that without the uncertainty principle. As for that, I’d have to yield to Cioran.

the many worlds or parallel universe interpretation is an attempt to justify determinism. No, it's an attempt to solve all of the mysteries of QM (indeterminism, non-locality, non-realism) by doing away with the WF collapse. Why do you have no trouble accepting these mysteries under the classical interpretations? To believe them you have to believe that there is some split between the quantum level and macro level, even though none have been found; you have to believe that reality is inherently random at that quantum level (does that make the macro level the same or different?); you have to believe that the human mind is central to reality and that the past didn't even exist until our measurements conjured it up (as Cioran stated). I don't understand why all of these seem more innately believable than accepting that the wave is not collapsing and that we're merely observing one of the worlds it ends up in.

You bring up religion, but scholars have debated for centuries just how free-will can be reconciled with God's omniscience, since omniscience itself entails a deterministic universe. It's such an old debate that Chaucer even addressed it in Troilus and Criseyde. Whether the universe is deterministic or indeterministic there are going to be mysteries, unlikable and counter-intuitive concepts either way. For some reason, you feel more comfortable with the mysteries and consequences of indeterminism, but you should really meditate on whether your preference is blinding you to the truth. I honestly don't feel I have a dog in this fight; it doesn't really matter to me what the truth is, I just want to know what it is, and, again, the thinkers/scientists I respect most are coming on strongest for MWI. I also find it strange you keep quoting Feynman to support the classic interps. despite the fact that Feynman himself came to believe in MW...

mal4mac

12-01-2012, 07:05 AM

How would you describe what happens to the electron after a measurement has been made?

I have no idea what happens to the electron after the measurement, because I am no longer looking at it.

YesNo

12-01-2012, 03:56 PM

I have no idea what happens to the electron after the measurement, because I am no longer looking at it.

I wonder if anyone has checked where the electron was after the first measurement to see which hole it went through and before the final landing at the detector screen. I assumed it would be deterministic after this, but perhaps it isn't. Also, not using the Schrodinger wave equation might get one away from the metaphor of a wave. I understand the Heisenberg matrix approach generates the same probabilities.

More pieces to the puzzle.

You should seriously consider how your ulterior motives are impacting your ability to neutrally and objectively weigh the evidence on either side. You believe in free will, you want to believe in free will, you don't like MWI because you feel it threatens both; your dislike of having this belief challenged is very likely negatively impacting your ability to understand MWI and assess the evidence for it fairly. FWIW, I've had an issue with the concept of "free-will" going back to when I was a child. I remember wondering about exactly what allowed me to make choices even then, and I never could get past the idea that I (and I've come to change that "I" to "we") simply don't have an adequate understanding of the cognitive process that would make any argument from either side meaningful. Arguing about things we don't understand is fruitless from the get-go. Like Yudkowsky, I've come to think that the belief in or lack of belief in free-will is more important than whether there actually is such a thing or not. For me, the latter question is as useful as asking if there are bloberblicks.

The belief in something certainly influences how one will act, but ultimately we make a choice. I choose to believe that. Notice the choice involved.

As for authorities using "literary devices to convince others," what you're talking about is rhetoric, which has been a subject for study from the Ancient Greeks to modern times. As far as that goes, IA Richards and Wayne C. Booth have excellent books on the subject (The Philosophy of Rhetoric from the former, The Rhetoric of Rhetoric from the latter). The thing to understand about rhetoric is that it's equally effective for both true and false statements, that makes it as dangerous as it is useful. That said, I don't think most scientists tend to be skilled rhetoricians because they're usually more concerned about discovering the truth as opposed to figuring out how to convince others they've found it. Rhetoric is probably more typically and powerfully practiced by people that already have their minds made up, have no desire to learn anything new, and are setting out to convince others. I think part of the lack of acceptance of science amongst the general public is partly due to the level of rhetoric for them as compared to their detractors.

I find Yudkowsky interesting mainly for the issue of authority vs evidence. I need to see more evidence for MWI and less rhetorical arguments in favor of it by Yudkowsky, Deutsch, or Tegmark. It is a lot like a jigsaw puzzle. I look at the pieces that seem to offer the most promise at any one time.

QM runs contrary to our intuitive nature to begin with, and none of the interpretations adequately reconcile the two. Basically, 20th century science, in general, should've put the death-knell in the coffin of how much we humans value our intuitions when it comes to understanding reality. But, as Yudkowsky said, people cling to their intuitions even in the face of devastating contradictory evidence, and are then capable of doing some remarkable cognitive gymnastics to get out of it.

I think 20th century science put an end to materialistic determinism. I sort of agree with Yudkowsky. The devastating contradictory evidence is that QM is non-deterministic. In order to bring back his deterministic intuitions, he has to support something as unintuitive as many worlds. If that does not constitute "remarkable cognitive gymnastics" I don't know what does.

Yudkowsky believes that the current evidence favors Many Worlds, and he presented his lengthy sequence to argue why; have you read it all yet? As for the his opinion on free-will, I think he made it very clear that the argument is flawed from the get-go. There's no hope of fruitfully discussing free-will until we have a good grip on human cognition.

I have read about 10 pages of his blog. I plan to read more, but only as I find it might help understand what MWI is all about. At the moment I see him more as a fundamentalist preacher who can't see outside his own box. Now there is nothing wrong with listening to these kind of people, but I am currently looking for harder evidence.

You mean we should map the cognitive algorithms that lead to a belief in MW? It's not exactly an intuitive belief/concept, you know...

What I am saying is that Yudkowsky's arguments against free will could be turned on many worlds. I consider many worlds a belief system. So how does it happen that one actually acquires such a belief system? That might be worth a cognitive study in itself.

The worlds are splitting all the time, because everything is always in superposition. So if the odds for me winning a hand are 70/30, there are 70 worlds in which I win and 30 worlds in which I lose (or the equivalent ratio).

The idea of worlds splitting needs to become more precise.

Everything after your third statement is correct, but the first three statements are non-sequitors. There’s nothing about my cognition being an input/output program that makes feelings or desire an illusion. Why would feelings be illusive in a deterministic universe? Further, are you really objecting to the notion that we come pre-wired with impulsive desires and our choices are always concerned with how to achieve those desire impulses? Seriously, name me a single choice you’ve ever made that did not have its root in an impulsive desire that you did not will to be there.

When I press the "Submit Reply" button to any post, I've made a choice. There is a lot influencing that choice, but the choice is mine and I must assume responsibility for it. If I have no free will, then I have no responsibility. Admittedly, we have a lot of constraints on our actions, but we are not totally constrained.

The indeterminism prior to the collapse is reflective of our lack of knowledge of what world it’s going to end up in. As Yudkowsky is fond of saying, mystery is a part of the map/mind, not the territory/reality.

The "lack of knowledge" idea is interesting. There are two different ways of viewing it. On one hand one could say that we don't know what happens prior to the measurement, but there is nonetheless something there to know. On the other hand, there might be nothing to know. Perhaps even the electron doesn't know which hole it went through until it was questioned and then made a choice. Perhaps it was lying. Some say it went through both holes. Maybe it went through neither.

No, it's an attempt to solve all of the mysteries of QM (indeterminism, non-locality, non-realism) by doing away with the WF collapse. Why do you have no trouble accepting these mysteries under the classical interpretations?

For why I have no trouble believing these mysteries, it seems that we are responsible for our actions and so there is some indeterminism and free will. I linked to a paper by Conway earlier that associated our free will with the uncertainty of these particles. As far as non-locality goes, I have heard of people who had out-of-body experiences also having non-local experiences. They were seemingly instantaneously in a separate location. Now, I realize you don't believe that these things happen, but the non-locality at the particle level may offer some insight into those accounts. The non-reality I am still puzzling over. I understand it to mean that what we learn about the electron was not necessarily the state of the electron prior to that time, but only the state of the electron at the moment of the experiment. That makes more sense than there being many worlds.

To believe them you have to believe that there is some split between the quantum level and macro level, even though none have been found; you have to believe that reality is inherently random at that quantum level (does that make the macro level the same or different?);

I don't know how random it is. There are constraints at the quantum level, but there is uncertainty. The split between the quantum and the macro level could be explained as a point where our greater mass dominates in some way. Again, which is harder to believe: that we are likely to behave differently than a quantum particle or that there are many worlds with copies of us running around in them?

you have to believe that the human mind is central to reality and that the past didn't even exist until our measurements conjured it up (as Cioran stated). I don't understand why all of these seem more innately believable than accepting that the wave is not collapsing and that we're merely observing one of the worlds it ends up in.

I don't think our consciousness is the only thing that makes a wave function collapse.

You bring up religion, but scholars have debated for centuries just how free-will can be reconciled with God's omniscience, since omniscience itself entails a deterministic universe. It's such an old debate that Chaucer even addressed it in Troilus and Criseyde. Whether the universe is deterministic or indeterministic there are going to be mysteries, unlikable and counter-intuitive concepts either way. For some reason, you feel more comfortable with the mysteries and consequences of indeterminism, but you should really meditate on whether your preference is blinding you to the truth. I honestly don't feel I have a dog in this fight; it doesn't really matter to me what the truth is, I just want to know what it is, and, again, the thinkers/scientists I respect most are coming on strongest for MWI. I also find it strange you keep quoting Feynman to support the classic interps. despite the fact that Feynman himself came to believe in MW...

I don't have any specific religion to offer. The only reason I'm reading Feynman is because mal4mac recommended him. The reason I quote Feynmen is because I think what he says about the size of the atom and the inconsistency of assuming that there are deterministic mechanisms in the electron that we are unaware of make sense to me.

mal4mac

12-01-2012, 07:33 PM

The belief in something certainly influences how one will act, but ultimately we make a choice. I choose to believe that. Notice the choice involved.

How can you believe in something for which there is no good argument? There is no good argument for, or against, free will, so why not just suspend belief on this issue? You may have a choice, but that choice may be determined.

When I press the "Submit Reply" button to any post, I've made a choice. There is a lot influencing that choice, but the choice is mine and I must assume responsibility for it. If I have no free will, then I have no responsibility. Admittedly, we have a lot of constraints on our actions, but we are not totally constrained.

How do you know that you are not totally constrained? Why can't you be held responsible even though totally constrained? If you kill someone I don't see why you shouldn't go to prison, even if totally constrained by genetics and environment. Sending you there is likely to act as deterrent to others, and at least keeps you away from harming other people.

Cioran

12-01-2012, 09:11 PM

You should seriously consider how your ulterior motives are impacting your ability to neutrally and objectively weigh the evidence on either side. .

YesNo has said, in another thread, that he is a theist. I don't know if he has said that in this thread, because I have stopped reading his posts here.

I imagine he thinks that MWI is incompatible with theism for two reasons: it seems to negate free will (this is actually debatable) and because, of course, every version of him is real. YesNo is good in one branch of the multiverse and bad in another. He, like all of us, is saint and sinner, benefactor and malefactor, helper and hit man.

So his is a fallacious argument to adverse consequences. He doesn't like what MWI implies, so it's false. That is what this is all about. LOL.

Once again, we see the fundamentally destructive and intellectually dishonest nature of vile theism on full display.

YesNo

12-01-2012, 09:54 PM

How can you believe in something for which there is no good argument? There is no good argument for, or against, free will, so why not just suspend belief on this issue? You may have a choice, but that choice may be determined.

I think a good argument for free will is that we make choices.

How do you know that you are not totally constrained? Why can't you be held responsible even though totally constrained? If you kill someone I don't see why you shouldn't go to prison, even if totally constrained by genetics and environment. Sending you there is likely to act as deterrent to others, and at least keeps you away from harming other people.

I don't know that I am not totally constrained. If I were totally constrained then my experience of making a choice would have to be an illusion. It seems like I have a choice to make. Do I have some free will or don't I? I choose, and note that I am exercising my free will at the moment, to assume that I do.

YesNo

12-01-2012, 10:10 PM

YesNo has said, in another thread, that he is a theist. I don't know if he has said that in this thread, because I have stopped reading his posts here.

I'm a generic panentheist: http://en.wikipedia.org/wiki/Panentheism

However, I don't have any specific religion to offer. I like a few of them, some more than others.

I imagine he thinks that MWI is incompatible with theism for two reasons: it seems to negate free will (this is actually debatable) and because, of course, every version of him is real. YesNo is good in one branch of the multiverse and bad in another. He, like all of us, is saint and sinner, benefactor and malefactor, helper and hit man.

There is only one world in our multiverse.

So his is a fallacious argument to adverse consequences. He doesn't like what MWI implies, so it's false. That is what this is all about. LOL.

What is fallacious about my arguments? Shall I summarize them again?

1) I don't see how an indeterministic theory such as QM can be modeled by a deterministic theory such as MWI.

2) Why is the atom so large without resorting to the Heisenberg uncertainty principle?

3) Why is there a wave-like interference pattern when electrons strike a detection barrier if there is a deterministic explanation for the electron's behavior in this world or others?

4) How does MWI get around the no-cloning theorem of QM when the worlds split?

Once again, we see the fundamentally destructive and intellectually dishonest nature of vile theism on full display.

:) As I mentioned, I am also interested in the issues of authority vs evidence.

MorpheusSandman

12-01-2012, 11:54 PM

The belief in something certainly influences how one will act, but ultimately we make a choice. I choose to believe that. Notice the choice involved.I remember us discussing various things in a thread I started on the Kalam Cosmological Argument, and one point I kept trying to stress when replying to you was that you were trying to understand early cosmology through the constraints of spacetime when, back then, no spacetime existed. There are certain intuitions we have about the way things are that are near impossible to shed when trying to think about how reality functions. That we feel like we make choices is a fact, but how does this play out in our cognition? How and why are choices actually made? You can’t keep repeating “I chose” the same way you can’t keep repeating “before spacetime,” because the issue is how/why these things came to be, how they function (“before” itself implies spacetime, “I chose” doesn’t answer the question of how/why this happens).

I find Yudkowsky interesting mainly for the issue of authority vs evidence. I need to see more evidence for MWI and less rhetorical arguments in favor of it by Yudkowsky, Deutsch, or Tegmark.If you want to look beyond the rhetoric then you probably have to dig into the math, because this is simply how most physics works. Sans that, you have to accept that your understanding will be, at the very best, incomplete, and you’ll be relying on the authority of experts. However, I think it’s rather foolish to think that these experts have missed something so trivial that would easily falsify MWI that you, in your relative ignorance of the subject, happened to discover. Which do you think is more likely: these experts have very good reasons for supporting MWI that you don’t understand, or that you understand something they don’t that falsifies MWI?

If that does not constitute "remarkable cognitive gymnastics" I don't know what does.An interpretation that solves all the mysteries of indeterministic QMI is not “remarkable cognitive gymnastics,” no more so than saying that the Earth revolves around the sun and the appearance of the reverse is merely the product of our biased perspective.

At the moment I see him more as a fundamentalist preacher who can't see outside his own box. :rolleyes:

What I am saying is that Yudkowsky's arguments against free will could be turned on many worlds. I consider many worlds a belief system. So how does it happen that one actually acquires such a belief system?He pretty much details his belief system from a cognitive perspective in the whole “The Map and the Territory” Sequence.

The idea of worlds splitting needs to become more precise. But you’re fine with the lack of precision in the classical interps? How could you determine the precision without understanding the math to begin with?

When I press the "Submit Reply" button to any post, I've made a choice. There is a lot influencing that choice, but the choice is mine and I must assume responsibility for it. If I have no free will, then I have no responsibility. Admittedly, we have a lot of constraints on our actions, but we are not totally constrained.You didn’t answer any of my questions. The whole “no free-will, no responsibility” is a dead-end argument. Don’t pursue it. It only justifies itself by circular reasoning, in a similar way that QM is only indeterministic if you take for granted the WF collapse.

The "lack of knowledge" idea is interesting.Indeed.

For why I have no trouble believing these mysteries, it seems that we are responsible for our actions and so there is some indeterminism and free will.This is a fallacy known as wishful thinking. You can accept mysteries as long as they support your preferred version of reality.

As far as non-locality goes, I have heard of people who had out-of-body experiences also having non-local experiences. No. I remember linking you in another thread to a very detailed paper that dealt with these claims and definitively debunked them.

The split between the quantum and the macro level could be explained as a point where our greater mass dominates in some way.Except there’s no evidence for it. Increasingly larger masses are being put into quantum superposition and they all hold. As Yudkowsky says, we know that a laser aggregates as it should instead of doing something completely different. There’s no reason whatsoever to think that there’s some split besides our distorted perspective, the same distorted perspective that lead us to think that the sun revolves around the Earth and that empty space is actually empty.

Again, which is harder to believe: that we are likely to behave differently than a quantum particle or that there are many worlds with copies of us running around in them?Fallacy of incredulity. Plus, explain any interp of QM to someone in the 19th century and see if they have a hard time believing it. Our incredulity is not an accurate gage for determining truth.

I don't think our consciousness is the only thing that makes a wave function collapse.Then what does?

The reason I quote Feynmen is because I think what he says about the size of the atom and the inconsistency of assuming that there are deterministic mechanisms in the electron that we are unaware of make sense to me.Well, you’re going to have to explain why Feynman is contradicting a view that he believed in his own book! Again, is it more likely that Feynman is contradicting his position or that you simply don’t understand?

MorpheusSandman

12-02-2012, 12:07 AM

1) I don't see how an indeterministic theory such as QM can be modeled by a deterministic theory such as MWI.

2) Why is the atom so large without resorting to the Heisenberg uncertainty principle?

3) Why is there a wave-like interference pattern when electrons strike a detection barrier if there is a deterministic explanation for the electron's behavior in this world or others?

4) How does MWI get around the no-cloning theorem of QM when the worlds split?.1. QM is only indeterministic IF YOU ACCEPT/TAKE FOR GRANTED THE WF COLLAPSE!

2. As far as I can remember, the size of atoms are only estimable, and I don't know what you think this has to do with MW since MW is only addressing what happens after the WF collapse. As for the size of particles, have you heard of the Higgs field?

3. Interraction of the many worlds.

4. I don't see that there's anything to get around...

Calidore

12-02-2012, 12:47 AM

If you want to look beyond the rhetoric then you probably have to dig into the math, because this is simply how most physics works. Sans that, you have to accept that your understanding will be, at the very best, incomplete, and you’ll be relying on the authority of experts.

So what to do when the experts disagree? There are experts who know more than I ever will who support MW, and there are experts who know more than I ever will who don't. So who to believe, and why do we need to believe anyone? Faith, factions, stronger personalities shouldn't be the guiding forces in science.

What I'd like to know is, at what point do the beliefs start branching off from knowledge? What is known to be true, and where does the debating start?

MorpheusSandman

12-02-2012, 01:07 AM

What you're asking is more about epistemology (philosophical study of knowledge) than anything. Again, I'm more or less in agreement with Yudkowsky's views on this subject, Bayes' Theory applied on a more intuitive level. When you're relying on experts, one can put one's level of confidence in any proposition in alignment with the ratio of opinions on the matter. Eg, if 60% of experts believe in MWI, then put your confidence level at 60% that MWI is true. One doesn't have to split all beliefs into binary/boolean true/false, 0/1. Bayes itself says that there can be levels, and it's more about being "less wrong" than guessing the right answer. If I want to be less wrong then I'm going to favor what the leading experts tend to favor. Of course it can't guarantee truth, but the need for such certainty is in itself a cognitive trap. However, I do find what YesNo's doing, essentially "investigating" QM and trying to make it fit his preconceived beliefs, very counter-productive, if not dishonest. I myself have admitted I don't know enough to confidently answer many of his questions, so I've simply tried to point him (like Cioran) to those that do (or seem to).

As far as belief branching off from knowledge, this happens most strongly when beliefs stop being thought of as maps and start being confused for the territory itself. If one thinks of beliefs as a map then, like with any map, there is a way to compare it with reality. If I believe there's a mountain in Colorado, I should be able to go to Colorado and see a mountain, so my belief, my map, is confirmed by seeing the mountain. People's beliefs tend to get out of whack with reality when they stop making this map/territory connection, when beliefs become disconnected from verifiable, predictable sense experience. A lot has been said against positivism and verificationism in 20th century philosophy, and Popper's notion of falsifiability could be said to be an even better way to think of it than either, but I tend to find that when you get away from either then that's where quackery and pseudo-science flourishes.

YesNo

12-02-2012, 01:35 AM

1. QM is only indeterministic IF YOU ACCEPT/TAKE FOR GRANTED THE WF COLLAPSE!

The problem is with Heisenberg's uncertainty principle. That makes QM indeterministic prior to any wave function collapse. You need to show that the indeterminism even without a wave function collapse is still present as at least an illusion. What happens after the wave function collapses is irrelevant. At that point I assume the particle behaves deterministically.

Admittedly I don't believe the world splits and so I am pretty sure these parallel universes don't exist, but the problem that I have with MWI is prior to any splitting into parallel universes. MWI does not interpret an indeterministic theory at that point.

2. As far as I can remember, the size of atoms are only estimable, and I don't know what you think this has to do with MW since MW is only addressing what happens after the WF collapse. As for the size of particles, have you heard of the Higgs field?

You should be able to find Feynman's Six Easy Pieces in a library near you. Let's examine the text itself. Feynman is saying that without the uncertainty principle, the electron would fall into the center and stay with the proton. It would be tiny. Why is it so large? He claims it is because of the uncertainty principle--or in other words indeterminism.

I think you are mistaken about the MWI. It does not just interpret QM after the wave function collapses. It must be an interpretation of QM even before the collapse occurs or before the worlds split. Perhaps that is where the difficulty lies. If MWI cannot do that then in doesn't adequately interpret QM.

3. Interraction of the many worlds.

Reading Deutsch he would have particles in various worlds somehow being present in each world prior to a wave function collapse. That is the idea I am using. These individual worlds would be in superposition but each of them would be deterministic. Because they are deterministic there should be no wave interference pattern displayed in the double slit experiment, but there is.

4. I don't see that there's anything to get around...

The point is that you cannot create a copy of a quantum object, so the worlds cannot split. That means there are no copies of us or anything else in the "multiverse".

YesNo

12-02-2012, 01:54 AM

But you’re fine with the lack of precision in the classical interps? How could you determine the precision without understanding the math to begin with?

I have no problem with Heisenberg's uncertainty principle. The lack of precision doesn't bother me and from a practical perspective it doesn't stop QM from being technically useful.

No. I remember linking you in another thread to a very detailed paper that dealt with these claims and definitively debunked them.

Apparently that did not convince me.

Well, you’re going to have to explain why Feynman is contradicting a view that he believed in his own book! Again, is it more likely that Feynman is contradicting his position or that you simply don’t understand?

I have only started reading Feynman. What book are you referring to?

MorpheusSandman

12-02-2012, 02:24 AM

Apparently that did not convince me.Same could be said for any expert that disagrees with your prior beliefs. I'm seriously tiring of this game.

I have only started reading Feynman. What book are you referring to?It's not a book, he was asked in a poll amongst leading QPs (done the year he died, IIRC) what they thought of MW, and he was in the "yes, I believe in it" camp.

billl

12-02-2012, 03:56 AM

It's been a long time since I read/studied any of this, but I think it might clear things up to remember that MWI is (I think) generally considered to be a deterministic theory. That is, all of this wondering about how the wave function collapses, or how the superposition needs to be resolved and so on are, in the MWI, side-effects of being in just one of the worlds. The MWI isn't going to help you pinpoint which of the worlds you are in--from our perspective, the fate of the wave-form is as much of a mystery as ever, because we only inhabit one of the worlds. It's ridiculous to find the MWI to be disproven by our limited perspective, as far as that goes. It'd be like a person who received a certain sum of money from a deceased parent's estate concluding that there couldn't have been a will written up before the death, since they only knew the outcome afterwards. Of course, in that example the will exists in the world with us--but the basic idea is there in the analogy, I think. The mystery/uncertainty/seeming-indeterminism would result from the lack of access to existing information (although the existence of the info would be elsewhere in space-time).

I'm all for skepticism about MW, but my occasional looks at this thread haven't encountered any reasonable objections to it. I think that it might be interesting to carefully consider what "cause and effect" might mean in a deterministic framework, first of all. Does it make sense to get up in arms about measurements "causing" new worlds to suddenly become manifest? It seems strange, yes, but I think Everett and others who support the idea have probably always thought it was counter-intuitive--or would at least understand why many people would be taken aback at the idea. And I don't know if they would go along with the word "cause" being used there.

I think it's an interesting idea, but not something that gets me excited anymore. It's easier to develop enthusiasm for non-deterministic models--at least for me it is, when I'm inclined to get worked up about the subject at all. But I still have a fondness for Everett and his idea. I like what Morph said, something about not needing to commit oneself completely for or against these interpretations.

YesNo

12-02-2012, 11:33 AM

The mystery/uncertainty/seeming-indeterminism would result from the lack of access to existing information (although the existence of the info would be elsewhere in space-time).

That sounds like a hidden variables theory that I think has been ruled out by the experiments verifying Bell's inequalities in testing the EPR paradox. I have heard that Bohm might have a way around that, but I don't know how that works yet or why it would be different from a hidden variables theory. The MWI does look like a hidden variables theory to me.

billl

12-02-2012, 01:05 PM

No, it's not about hidden variables. The information (and it's strange for me to even call it that) would be the determined history in all the existing worlds. If I'm holding a coin and it is face up, the other side is not a "hidden variable". Similarly, if I'm in a world where the collapse went one way, the world in which it went the other way would not be a hidden variable.

YesNo

12-02-2012, 04:36 PM

OK. That makes sense, billb, and is probably why MWI is not considered a hidden variables theory.

I've wondered about each of those worlds in superposition, one with the coin up and one with the coin down. As I understand it, prior to the collapse, the MWI assumption is that there are two worlds with the coins in superposition where the outcomes of the coins are definitely either up or down otherwise there is no determinism and we are back to Heisenberg's uncertainty principle.

Suppose we extend that to electrons, some in our world and some in other worlds in superposition with the ones in our world, going through a double slit experiment. Some electrons head through hole 1 toward a definite target position because of determinism. Other electrons head through hole 2 toward a definite target position because of determinism. We only see detections of the electrons from our world.

Assume both holes are open and we do not measure which hole the electrons went through in our world, what pattern should we expect to see on the detector screen in our world?

billl

12-02-2012, 05:15 PM

I'm not sure how to word this (I've already been sloppy by using the word "collapse" while describing MWI) but, to begin with, I'm pretty sure you already know the pattern we are expected to see. MWI explains the interference pattern in the double-slit experiment as a result of interference between "versions" of the particle(s) in different worlds. At least that's my shorthand way of thinking of it, I wouldn't be surprised if I'm somehow getting it wrong or being simple-minded about it, missing nuances, etc. Anyhow, by all accounts the MWI explains the results of the double-slit experiment, it is not undone by the results of the experiment.

I'm not sure if it can be fairly said that this would suggest the existence of a sort of interface between the worlds or not, perhaps there's some interesting stuff going on with the existence-as-a-wave portion of the model beyond just what we see in the experiment. There's a certain sense of arbitrariness about MWI, I think, yet it handles the situation very well, mathematically--and the arbitrariness of course is just coming from my everyday perspective, not the perspective of someone actually trained and capable to really try and understand advanced physics. Anyhow, in the end, I'm not sure the MWI is too much stranger than other respected interpretations.

YesNo

12-02-2012, 08:01 PM

The question was somewhat rhetorical to focus on the problem.

With the double slit experiment, without measurements being performed, and with both holes open, one would see a wave interference-like pattern signalling a non-deterministic pattern and not a particle pattern signalling determinism. If one of the holes were closed one would get a particle pattern with all the electrons coming from the open hole in a deterministic manner.

A deterministic result would be a sum of the patterns with first one hole closed and then the other. Given a position P on the detector screen and P12 being the electrons coming from both holes 1 and 2 going to that position, the number of electrons one would expect to arrive at P would be P12 = P1 + P2. But that is not the wave interference pattern that is actually seen. The wave pattern would get results suggesting that P12 <> P1 + P2.

I think there are two alternatives:

1) Either MWI does not actually interpret QM since each world contributing to the superposition is assumed to be deterministic and should generate a particle pattern even though a wave pattern actually appears,

2) or, MWI is not deterministic, but uses enough of the Schrodinger wave function to get Heisenberg's uncertain principle in play prior to collapse or decoherence, to generate the wave interference pattern.

In the second case, MWI doesn't resolve any mystery of QM since the indeterminism is still present, but it does add the mystery of many worlds to the problem after the collapse or decoherence. In the first case, MWI is a false interpretation of QM since it would not account for actual experimental results.

billl

12-02-2012, 08:49 PM

MorpheusSandman

12-03-2012, 12:29 AM

I'm not sure you're attacking what the MWI actually is.He's not. I, like you, don't remember enough about my research/reading to correct him in detail with a high confidence level, but I'm pretty sure Cioran knows more than both of us combined and even he had no luck; so there you go.

Cioran

12-03-2012, 03:01 AM

1. QM is only indeterministic IF YOU ACCEPT/TAKE FOR GRANTED THE WF COLLAPSE!

Laugh. Out. Loud. And there YesNo goes again. I mean, seriously? Has he read any of the material I linked? How stupid is this?

Hey, YesNo: QM IS ONLY INDETERMINISTIC ON THE ASSUMPTION OF WAVE FUNCTION COLLAPSE! Capice?

Jesus. Crackers.

MorpheusSandman

12-03-2012, 03:14 AM

I'll take some Jesus crackers... so long as they're not the ones YesNo's been eating... and I can put some cheese whiz on them.

Cioran

12-03-2012, 03:23 AM

Same could be said for any expert that disagrees with your prior beliefs. I'm seriously tiring of this game.

Yup, And that's all it is with him, a game. He has no interest in an honest and unbiased exploration of this issue. He has an agenda, which is that x cannot be right because he doesn't like x. Really, it's sickening.

Cioran

12-03-2012, 03:25 AM

You can certainly put some Cheese Whiz on Jesus Crackers if you like, though it might piss Him off, since after all, it's His body. The Bible doesn't say whether Jesus approved of cheese or not (I don't think), so those of us who eat it do so at our own risk!

YesNo

12-03-2012, 11:23 AM

Well, I can just recommend that you maybe look over MWI a bit more, because your number 1) doesn't seem to be taking into account what MWI suggests (which I tried to point out in the previous post). I don't think we need to consider the second part of the either/or, I really can't see how it could apply to the MWI.

Again, I am all for skepticism in regards to MWI, but I'm not sure you're attacking what the MWI actually is.

I'm aware that MWI claims that multiple versions of the world account for the indeterminacy, but I don't see how that is done. Any way one tries to put on the electron some deterministic way to tell which hole it will go through and where it will land on the detector will destroy the wave interference pattern.

However, something occurred to me yesterday. Rather than the two alternatives between MWI either being (1) incorrect, or (2) non-deterministic itself, I think it is actually both.

I assume that MWI still uses the Schrodinger wave function. If that is the case, then Heisenberg's uncertainty principle is a mathematical derivation from the wave function itself. The proof was first given by Earle Hesse Kennard and is displayed in the Wikipedia article on the Uncertainty Principle: http://en.wikipedia.org/wiki/Uncertainty_principle

As far as the mathematics goes, unless MWI uses something different than the wave function, MWI has not resolved Heisenberg's uncertainty principle. Non-determinism will remain there as long as MWI continues to use a wave function. That is why I think MWI is still non-deterministic even though it claims that it is not. This is also why it can say that everything that the QM experimentally observes it agrees with. They both use the same wave function. They are both non-deterministic.

I am aware that MWI tries to get around the non-determinism in the wave function itself by claiming that an electron can be split into various versions, superpositions or worlds, or whatever, each of which is deterministic. But if that were the case, then each of these individual versions would know which hole its component went through and where it landed in a deterministic manner. If there were a way for that to occur, according to Feynman that I quoted earlier, the wave interference pattern would not occur. That would make MWI not only non-deterministic, but also incorrrect.

I am aware that Cioran has claimed things like "QM IS ONLY INDETERMINISTIC ON THE ASSUMPTION OF WAVE FUNCTION COLLAPSE!", but that is not the case. As long as you have a wave function, you have indeterminism. The only time you get determinism is if the wave function collapses.

Consider it in this manner. Prior to the collapse, the wave function might say the electron has a 40% chance of going through hole 1 and a 60% chance of going through hole 2. Suppose you measured which hole the election went through and found it was hole 1. At that point the probability distribution of the wave function collapses to a deterministic situation and you have the chance of going through hole 1 as 100% and the chance of going through hole 2 as 0%. The indeterminism leaves only with a wave function collapse.

Calidore

12-03-2012, 03:41 PM

billl

12-03-2012, 04:51 PM

For the record, it's been years since I even looked over a popularization-type paperback on these subjects, and I don't want to sound like I think I'm an authority or anything. I've clicked here and there over the past two days, and I'm sure I will fail here to completely accurately get across what I've been reviewing. But I'll try.

Like a few posts ago, the key thing to keep in mind here is the difference between "subjective determinism" and "objective determinism", I think. In the MWI, things seem indeterminate because we are taking the measurements in one particular world. We can't inhabit/experience all of the worlds, only one. Since the worlds are different, we subjectively experience "random"/indeterminate measurements over time, our world is unique in comparison to the others, and the particulars are revealed to us as we check on them. From the perspective of the theory, though, all of the branches occur and represent a deterministic unfolding of events. It is all there, from the perspective of the MWI--however the particular world in which this particular version of you and I occur is just one out of many, and for us, with our limited perspective, events are subjectively indeterminate.

For a different, but I think analogous, example: Imagine we had an enormous mansion with thousands of rooms. In each room we have a table and an unstarted game of checkers set-up on a table, as well as an (undoubtedly patient) observer in each room. I think there are six possible moves for the first player to make, and so we could go to each room, performing one of the six different moves in each room after the other--moves 1 to 6 each in the appropriately numbered rooms 1 to 6--and then repeated them for the next six rooms and so on for some time. Then we could try out the next possible move on the board, and distribute the possibilities across the games just underway in the succeeding rooms. For us, it would be a systematic way to play-out the early moves of each possible checkers game (each room being a slight variation from some other room), but for the observers the game taking place before them in their particular room would appear random. In that enormous Checkers Mansion, we have arranged things so that the games are objectively deterministic, but subjectively indeterministic to observers in particular rooms.

Regarding the double-slit experiment:

1) the strange behavior of particles being sent individually at the double-slit, yet ultimately forming the interference pattern is explained in the MWI by saying that different versions of the particle interfered with itself. Perhaps important to remember is that the arrival of the particle against the plotting surface indicates its existence in "our" world, and the "other" particle would be somewhere else on such a plotting surface in "another" world. Prior to that, the two worlds were the same, in complete overlap, with the wave function equation providing explanation of the interference (I think this is close enough of an explanation). The measurement itself (the arrival of the photon on the plotting surface) means a separate and distinct world. Rather than a "collapse" we have a "split". So ends my rudimentary effort at explaining "decoherence"--perhaps other sources can help patch up my failures to explain sufficiently.

Before moving on, I want to mention that my understanding of when the splitting occurs is not firm, but I think the basic idea is that the measurement marks a difference in the two worlds, "causing" the split (I need quotes around "causing" though...). Of course this is strange, but the flavor of it might come out a bit more if we take into account the theoretical (though not yet tested, I don't think?) notion of worlds returning to the exact same state. In theory, erasing all trace and memory of a measurement might allow two recently separated worlds to recohere or become "one" again (or something like that), but this is just a very specific and theoretical consideration. It isn't something that's normally going to happen, it's hard to imagine how we could measure such an event, and it is generally completely out of the question. (And I've probably "explained" this theoretical side-note inaccurately, while attempting to get the jist.)

2) The strange behavior of individual particles getting measured at one of two slits is also explained by this decoherence idea in the MWI. The measurement is performed (and we learn which world we are in--left-slit-world, or right-slit-world, which is a a subjectively indeterminate result...) and as the particle proceeds to the plotting surface, the "split" has occurred (the measurement makes "this" world distinct), and the particle is no longer interfered with by the other particle (which provided a different measurement result in a separate world).

Again, I'm not so sure how this is any less or more arbitrary than other interpretations. My suspicion is that a more thorough understanding of decoherence might help in envisioning the MWI, but it looks to me like some people find it satisfying, and others don't.

MorpheusSandman

12-04-2012, 03:43 AM

I'm afraid I'm not sure how we got from science to philosophy, unless there's so little basis for these various quantum-related theories that that's the only option. Perhaps I misunderstood, but your questions seemed more philosophical in nature than purely scientific. At least, the whole question of "who do we believe/how do we choose is more likely right" is a philosophical issue that transcends science itself. The distinction to made is that MW and Copenhagen are "interpretations" of QP and not "theories." They're all looking at the same experimental data and offering explanations that are consistent, but, AFAIK, there are still no valid testing methods to choose between them. There was even a joke about this on The Big Bang Theory:

Penny: So, what's new in the world of physics?
Leonard: Nothing.
Penny: Really, nothing?
Leonard: Well, with the exception of string theory, not much has happened since the 1930s and you can't prove string theory. At best you can, "Hey, look, my idea has an internal logical consistency."
Penny: Well, I'm sure things will pick up.

Now, I do know of the idea of quantum computing, which may be able to eventually provide a basis for testing MW. However, I think the reason that MW is becoming favored is because, at the core, it's a far simpler theory that removes a lot of mysteries by simply not taking the WF collapse for granted. Merely assuming that the WF is real, is an object itself, rather than something that's indeterminate until we measure it (making our mere observation the force behind every quantum event observed; which is horribly anthropomorphic thinking), makes all of the other aspects of MW a consequence. People don't like/don't get the consequences, so that's why I think there's so much enmity towards it. Plus, most of the classical theories were quite well entrenched before MW came along, and science is like any other discipline in that it can be slow to shift its paradigms even when clearly better answers are first presented--but that's especially true with something like MW and QP where we don't yet have adequate testing means.

YesNo

12-04-2012, 11:44 AM

Like a few posts ago, the key thing to keep in mind here is the difference between "subjective determinism" and "objective determinism", I think. In the MWI, things seem indeterminate because we are taking the measurements in one particular world. We can't inhabit/experience all of the worlds, only one. Since the worlds are different, we subjectively experience "random"/indeterminate measurements over time, our world is unique in comparison to the others, and the particulars are revealed to us as we check on them. From the perspective of the theory, though, all of the branches occur and represent a deterministic unfolding of events. It is all there, from the perspective of the MWI--however the particular world in which this particular version of you and I occur is just one out of many, and for us, with our limited perspective, events are subjectively indeterminate.

The "subjective" adjective makes me think of something that is not-real or that is an illusion. I do think that is what MWI is trying to say: The indeterminacy evidence in the double slit experiment is an illusion; if we could only see the real, objective reality, we would see it as determinate.

However, the use of the wave function makes me think this is misguided, at least the way MWI is approaching it. The Heisenberg uncertainty principle is mathematically derived from the Schrodinger wave function. So, if anyone, including MWI, uses a wave function to mathematically describe reality, the reality that they describe is indeterminate. It cannot be determinate. It is part of the mathematics of the formalism. For MWI to be correct there must be some non-wave mathematical formalism that simulates the illusion of the mathematical wave formalism. I don't think such a formalism is possible. If it were, we would have it by now.

Now I don't see MWI providing an alternate mathematical formulation. They even claim there is a universal wave function or that the wave function splits because of its linear nature, but in either case they still have a wave function either at the universal level or at the split component level.

They have not formulated their interpretation to avoid indeterminacy. They only claim they have.

For a different, but I think analogous, example: Imagine we had an enormous mansion with thousands of rooms. In each room we have a table and an unstarted game of checkers set-up on a table, as well as an (undoubtedly patient) observer in each room. I think there are six possible moves for the first player to make, and so we could go to each room, performing one of the six different moves in each room after the other--moves 1 to 6 each in the appropriately numbered rooms 1 to 6--and then repeated them for the next six rooms and so on for some time. Then we could try out the next possible move on the board, and distribute the possibilities across the games just underway in the succeeding rooms. For us, it would be a systematic way to play-out the early moves of each possible checkers game (each room being a slight variation from some other room), but for the observers the game taking place before them in their particular room would appear random. In that enormous Checkers Mansion, we have arranged things so that the games are objectively deterministic, but subjectively indeterministic to observers in particular rooms.

This is a good example of the problem that I have with MWI. Consider all these checker games. They represent discrete outcomes and behave much as particles do. I agree that they can be represented in a deterministic way.

Now ask yourself, how would these checker games interfere with each other? In the case of the checker games, they really don't interfere at all. But if they were particles, such as bullets going through a double hole experiment, one could see them interfering with each other as particles would. That is, they would bounce off each other and in general create a scattered pattern on the detector wall. As particles they would not create a wave pattern which is more orderly than the scattered pattern of particles bouncing off each other.

In order to get the subjective indeterministic wave pattern it takes more than many particles interacting deterministically. That is why MWI is an incorrect interpretation of QM and to the extent that it continues to use wave functions is not even deterministic.

mal4mac

12-04-2012, 01:52 PM

However, the use of the wave function makes me think this is misguided, at least the way MWI is approaching it. The Heisenberg uncertainty principle is mathematically derived from the Schrodinger wave function. So, if anyone, including MWI, uses a wave function to mathematically describe reality, the reality that they describe is indeterminate. It cannot be determinate. It is part of the mathematics of the formalism. For MWI to be correct there must be some non-wave mathematical formalism that simulates the illusion of the mathematical wave formalism. I don't think such a formalism is possible. If it were, we would have it by now.

Now I don't see MWI providing an alternate mathematical formulation. They even claim there is a universal wave function or that the wave function splits because of its linear nature, but in either case they still have a wave function either at the universal level or at the split component level.

Have a glance at a few MWI papers. Of course there is mathematical formalism! If there isn't it's just not physics...

Actually, can't you just use the wave equation? In one universe its indeterministic, but if there are many universes then *all* solutions are instantiated, i.e. determined.

billl

12-04-2012, 07:54 PM

YesNo

12-05-2012, 01:15 AM

Have a glance at a few MWI papers. Of course there is mathematical formalism! If there isn't it's just not physics...

Actually, can't you just use the wave equation? In one universe its indeterministic, but if there are many universes then *all* solutions are instantiated, i.e. determined.

What MWI paper do you recommend?

No one can use the wave equation if they want a deterministic solution. They need some sort of particle equation, but that no one has been able to provide so far. Here's the Wikipedia article on the uncertainty principle to prove this: http://en.wikipedia.org/wiki/Uncertainty_principle Look at the "Proof of the Kennard inequality using wave mechanics". The uncertainty principle is derived from wave mechanics. It is part of wave mechanics. If you use wave mechanics, you use the uncertainty principle. I think this is why Schrodinger and Einstein were hoping there was something else, some hidden variables. Bell's inequality and the tests that confirmed it showed that was not possible.

If you do come up with a particle equation, you would then have determinism, but would it simulate the results of the wave pattern observed in QM? I don't think it can, no matter how many worlds you employ. Actually, the more worlds the more unlikely one can simulate a wave pattern. What you would get would look like a random scattering of particles, a uniform distribution on the detector screen, not the oddly ordered wave pattern that is actually observed.

Look at the wave pattern in the talk Feynman described that you referred me to earlier: http://www.youtube.com/watch?v=aAgcqgDc-YM The wave pattern is not random. It is not deterministic either. How can particles coming from a single or many worlds simulate that?

YesNo

12-05-2012, 01:27 AM

Anyhow, Yes/No, I tried. I don't think I can do much better. It should be obvious that Everett was never at all sheepish about involving the wave function in the MWI--it is an absolutely essential and core part of MWI and part and parcel of his inspiration in formulating it. The interference between versions of a particle might be strange/mysterious (it obviously is), and you might not see reason to consider it as a reasonable interpretation, but for many people it is preferable to other strange/mysterious interpretations. If you believe that the MWI is not determinate, I don't know what more to do to help get you past that, but it is obviously an indication that you're still struggling with this.

The reason Everett liked the wave function was that it was linear. He could keep all the results that didn't happen as summands, much like a pack rat. Then he assumed that by discretizing any potential result set of the wave equation and putting the results that we don't see magically in other worlds, he solved the problem of uncertainty. But the problem of uncertainty is contained within the wave equation itself. If the wave equation never collapses, there is always uncertainty. That means one never gets a deterministic result.

I see MWI as influential in some philosophy, some new age religions and science fiction. I don't see it useful for science itself.

MorpheusSandman

12-05-2012, 01:39 AM

I see MWI as influential in some philosophy, some new age religions and science fiction. I don't see it useful for science itself.You're wrong, and your combination of prior beliefs and ignorance is blinding you as to why. Every objection you raise implicitly assumes this is the only world and that the wave function is collapsing into this single world indeterministically. You've yet to to present one thing that is relevant to the alternative that MWI proposes, and are instead using the single-world/indeterminate assumptions to disprove the interp that questions/challenges both. This wouldn't be so bad if you weren't combining it with the implied arrogance that the majority of QPs are not only wrong, but that you, someone who is admittedly rather ignorant on this subject, knows something they don't that falsifies their interpretation. I'm begging you, YesNo, would you please just admit that the fault more likely lies with your misunderstanding than with the various MW advocates whom you haven't read in full?

FWIW, I seemed to have bookmarked this FAQ (http://www.hedweb.com/manworld.htm) back when I was reading up on this. I remember thinking that it seemed to do a good job of explaining what MWI exactly is and why it fares better with the data than the others. You might want to give it a thorough read-through.

KillCarneyKlans

12-05-2012, 02:20 AM

Sorry, for the late response, I haven't much time lately ...

MS: I was reading a thread on Hinduism that also wanted to use the MWI interpretation to justify its religious perspectives. I think science offers many justifications for religious belief of various sorts, but the many worlds or parallel universe interpretation is an attempt to justify determinism. Unless the religion in question is promoting determinism, I doubt MWI would be on its side.

As far as Hinduism or Far East Religions which sprung from the Axial Age ... in terms of multple worlds, environs, places or even multi-dimensional entities which may exist in a time, place or event ... be a good place to start ... but determinism states a philosophical doctrine holding that every event, mental as well as physical, has a cause, and that, the cause being given, the event follows invariably. This theory denies the element of chance or contingency.

Cause, casuality, retro-causuality, the cause maybe a time, place or thing, the cause may serve some other purpose ... pre-emergence and entanglement are to such examples of questions which change the focus considerably ... Its still the best of all possible worlds ... everything has a beginning and an end ... If in the beginning God brought order to chaos and it was complete and then re-creation began [and for how long] ... everything has a beginning, everything has an end, everything that seeks life seeks greater conciousness, all that live die ... in eastern terms they wish to escape the wheel or cycle of materialism ... I can guarantee you as far as sentinence goes all understand life and death, pain and love

http://philosophynow.org/issues/89/The_Multiverse_Conundrum
In his 1895 essay Is Life Worth Living? the American philosopher William James wrote, “Truly, all we know of good and duty proceeds from nature… [which] is all plasticity and indifference – a moral multiverse, as one might call it” and a new word was born. A century later, and James’s neologism has been commandeered by physicists and pressed into service in a somewhat different context ... [Leibniz was a] polymath of such remarkable achievements that Gottlob Frege described him as being “virtually in a class of his own.” To Leibniz’s way of thinking there were infinitely many possible worlds, each with different physics, subject to the overarching principle that all the laws of nature should together not imply a contradiction.

Most physicists agree: the harmonious results of the universe’s precise physical constants seems a bit too convenient to be overlooked as sheer accident, but what are we to make of the apparent coincidences? One possibility is that cosmic fine-tuning is the result of actual design ... When Albert Einstein asked, “Did God have any choice when he created the universe?” he was wondering whether physical constants such as the mass of the proton are not mere coincidences, but arise naturally from some as-yet-undiscovered physical laws which cover most possible worlds. If we could uncover such laws, we might even find that a universe like this one was almost inevitable.

A better argument for the multiverse is that the idea of it arises naturally from many of the mathematical models currently being deployed in theoretical physics. Eternal inflation, string theory and even Hugh Everett III’s ‘many worlds’ interpretation of good old-fashioned quantum mechanics, all suggest a vast number of universes, and conditions have to be bolted onto each of the theories to get the number of universes down to one. Without conditions the theories are much neater, but this theoretical simplicity comes at the cost of multiple universes. The various theories also suggest that the multiverse could come in different forms: the extra universes might be separated by tremendous distances, be embedded in different spatial dimensions, or might be separated only by time.

Andrei Linde argues that inflation could spawn new, disconnected regions of space, each with different properties, and that over time this process could give rise to all the different universes predicted by string theory. Researchers have recently noticed that the cosmic microwave background radiation – the echo left over from the Big Bang – contains traces of what might be ‘bruises’ caused by collisions between Linde’s other universes and our own.

© 1993-2003 ENCARTA Microsoft Corporation. All rights reserved.
Superstring theories are one of the leading candidates in the quest to unify gravitation with the other forces. The mathematics of superstring theories incorporates gravity into particle physics easily.

http://philosophynow.org/issues/89/The_Multiverse_Conundrum
An infinite multiverse also completely does away with the fine-tuning problem. Any sentient being thinking about the problem could only be doing so from the comfort of one of the inhabitable universes, and that is all there is to be said on the matter ... As Tegmark points out though, the almost spooky power of mathematics to describe the world would hardly be a surprise if there was a direct correspondence between mathematical structures and actually existing universes.

http://www.philosophyetc.net/2008/11/morality-in-multiverse-revisited.html
"The particular multiverse hypothesis I have in mind is the claim that every possible cosmos is realized exactly once. It's not a matter of "causation", exactly, but if it's necessarily the case that exactly one Richard-counterpart will kick a puppy, then note the following two implications:"

This, I think, can be examined without the multiverse. With 5+ billion souls on earth someone, somewhere is going to kick a puppy. Given that a puppy is going to get kicked, should you kick one too? It would seem the answer is still no as you have the ability to control only your behavior, not everyone else's whether they exist in this universe or others.

If all possiblities exist then this is really an argument against free will. Every possible you exists ranging from perfect you to perfectly evil you and trillions of in between yous. If you kick the puppy you are simply demonstrating that we are in one of the middle universes with an imperfect [MS]. If you refrain we may hope we are in the universe with the better [MS].

YesNo

12-05-2012, 12:21 PM

http://philosophynow.org/issues/89/The_Multiverse_Conundrum
An infinite multiverse also completely does away with the fine-tuning problem. Any sentient being thinking about the problem could only be doing so from the comfort of one of the inhabitable universes, and that is all there is to be said on the matter ... As Tegmark points out though, the almost spooky power of mathematics to describe the world would hardly be a surprise if there was a direct correspondence between mathematical structures and actually existing universes.

If there were these multiverses, it would do away with the issue of fine-tuning. That is one of the purposes of presenting them.

I don't see any reason to accept a multiverse since the fine-tuning doesn't bother me.

MorpheusSandman

12-05-2012, 11:31 PM

That is one of the purposes of presenting them. No, that's just one of the consequences of it. Scientists don't bother with such trivial silliness.

KillCarneyKlans

12-06-2012, 02:19 AM

Fine-tuning is one minor at best component but it can be complicated a bit by the fact that the bio-info [which is 6x the normal rate of correlation] in the cosmological constant ... had to be there before the process of evolution could occur ... so we can assume that worlds like ours would be similar with slightly different physics [communication still possible]. Also to note, if this was a one time event as they assume here

http://www.philosophyetc.net/2008/11/morality-in-multiverse-revisited.html

We would have to assume a "template" for they bio-info from which all other could be drawn from and the problem of overcoming the condition of some form of intelligent design would get much trickier, Anyways

http://www.historum.com/blogs/killcarneyklansman/722-causation-effectation-intelligence.html
http://www.historum.com/blogs/killcarneyklansman/578-helping-darwinists-understand-origins.html
http://www.online-literature.com/forums/showthread.php?t=68852&page=5

http://www.historum.com/blogs/killcarneyklansman/570-perfect-number-496-prime-number-37.html
Strings unlike the chaotic Quatum World or the rather? .. the mundane physical world, dimensions itself in a torus or torodial plane, a donut shape ... Which leads me back to 496 and transcendental dimensionless numbers and 37 and prime numbers, computer encryption, the [Bible] text, and last but not least, apparent Data in life forms that began as a pre-cursor to evolution ... They refute traditional ideas about the stochastic origin of the genetic code. A new order in the genetic code hardly ever went through chemical evolution and, seemingly, originally appeared as pure information like arithmetic itself."

YesNo

12-06-2012, 11:26 AM

YesNo

12-06-2012, 11:44 AM

No, that's just one of the consequences of it. Scientists don't bother with such trivial silliness.

I don't want to change your mind on this topic. It is good to discuss issues with people who have different viewpoints.

My viewpoint is that many worlds was created to put determinism back into QM. I don't think Everett succeeded since he used the wave equation from which uncertainty can be derived. The fine-tuning issue probably was not on Everett's mind, but the many worlds provides a solution for that as well and would be a reason today for people to accept it who are becoming more aware of that issue.

I think the need for many worlds or multiverses in general corresponds to a need to bring back an out-of-date materialistic determinism. It looks like desperation to me. The way it gets presented, especially by people like Yudkowsky, sounds more like proselytizing than scientific argument.

MorpheusSandman

12-07-2012, 12:12 AM

My viewpoint is that many worlds was created to put determinism back into QM. There's not a single shred of evidence for this and your viewpoint is blinded by a bias to confirm your prior beliefs. . MWI interpretation is a direct consequence of taking the wavefunction as a real, objective entity. All of your objections come from assuming the very things that MWI are questioning.

The way it gets presented, especially by people like Yudkowsky, sounds more like proselytizing than scientific argument.You haven't read all of Yudkowsky, so, fail. Yudkowsky is trying to present it to laymen, which you are. You object to his rhetoric but you can't follow the technical science from people like Tegemark and Deutsch. You've clearly fortified yourself against believing it regardless. That you've had at least three different people in this thread trying to show you why you're wrong, that you've been given countless links to people that explain it, but continue to not address their relevant claims, is a clear-as-day indication of this.

YesNo

12-07-2012, 12:44 AM

There's not a single shred of evidence for this and your viewpoint is blinded by a bias to confirm your prior beliefs. . MWI interpretation is a direct consequence of taking the wavefunction as a real, objective entity. All of your objections come from assuming the very things that MWI are questioning.

I've provided the evidence for my viewpoint. I haven't heard anyone adequately address it.

What does it mean to take "the wavefunction as a real, objective entity"? The wave function is supposedly equivalent to Heisenberg's matrix formulation. So instead of saying the wave function is a real, objective entity, you could say the matrix formulation is a real, objective entity. In either case, what does that mean?

As a result of this thread, I have read enough of the MWI to be convinced that it has "not a single shred of evidence" for its position. It is all spooky magic and weird fantasy. You might as well believe that Santa comes down the chimney. The Copenhagen interpretation makes more sense.

You haven't read all of Yudkowsky, so, fail. Yudkowsky is trying to present it to laymen, which you are. You object to his rhetoric but you can't follow the technical science from people like Tegemark and Deutsch. You've clearly fortified yourself against believing it regardless. That you've had at least three different people in this thread trying to show you why you're wrong, that you've been given countless links to people that explain it, but continue to not address their relevant claims, is a clear-as-day indication of this.

I'll probably read more of Yudkowsky, but at the moment I'm reading Barry Parker's Quantum Legacy. Refreshingly, I haven't seen any reference to many worlds in it. I also was not impressed by either Max Tegmark or David Deutsch. I don't see why Tegmark has to bring up unscientific polls. I find that very suspicious. Deutsch just rambled. I felt he was wasting my time. Of course, that's my opinion, but I stand by it.

The "countless" links you refer to were actually countable and I did check out each one. That I haven't been convinced is not evidence that there is something wrong with me. It just means that I haven't been convinced.

MorpheusSandman

12-07-2012, 02:08 AM

I've provided the evidence for my viewpoint.Your evidence would get you laughed out of any university by any student of QP.

What does it mean to take "the wavefunction as a real, objective entity"? http://www.physics.wustl.edu/~alford/many_worlds_FAQ.html#faqThe bolded part is what I was referring to:
Many-worlds comprises of two assumptions and some consequences. The assumptions are quite modest:
1) The metaphysical assumption: That the wavefunction does not merely encode the all the information about an object, but has an observer-independent objective existence and actually is the object. For a non-relativistic N-particle system the wavefunction is a complex-valued field in a 3-N dimensional space.

2) The physical assumption: The wavefunction obeys the empirically derived standard linear deterministic wave equations at all times. The observer plays no special role in the theory and, consequently, there is no collapse of the wavefunction. For non-relativistic systems the Schrodinger wave equation is a good approximation to reality. (See "Is many-worlds a relativistic theory?" for how the more general case is handled with quantum field theory or third quantisation.)

The rest of the theory is just working out consequences of the above assumptions. Measurements and observations by a subject on an object are modelled by applying the wave equation to the joint subject-object system. Some consequences are:
1) That each measurement causes a decomposition or decoherence of the universal wavefunction into non-interacting and mostly non- interfering branches, histories or worlds. (See "What is decoherence?") The histories form a branching tree which encompasses all the possible outcomes of each interaction. (See "Why do worlds split?" and "When do worlds split?") Every historical what-if compatible with the initial conditions and physical law is realised.

2) That the conventional statistical Born interpretation of the amplitudes in quantum theory is derived from within the theory rather than having to be assumed as an additional axiom. (See "How do probabilities emerge within many-worlds?")

Many-worlds is a re-formulation of quantum theory [1], published in 1957 by Dr Hugh Everett III [2], which treats the process of observation or measurement entirely within the wave-mechanics of quantum theory, rather than an input as additional assumption, as in the Copenhagen interpretation. Everett considered the wavefunction a real object. Many-worlds is a return to the classical, pre-quantum view of the universe in which all the mathematical entities of a physical theory are real. For example the electromagnetic fields of James Clark Maxwell or the atoms of Dalton were considered as real objects in classical physics. Everett treats the wavefunction in a similar fashion. Everett also assumed that the wavefunction obeyed the same wave equation during observation or measurement as at all other times. This is the central assumption of many-worlds: that the wave equation is obeyed universally and at all times.

Everett discovered that the new, simpler theory - which he named the "relative state" formulation - predicts that interactions between two (or more) macrosystems typically split the joint system into a superposition of products of relative states. The states of the macrosystems are, after the subsystems have jointly interacted, henceforth correlated with, or dependent upon, each other. Each element of the superposition - each a product of subsystem states - evolves independently of the other elements in the superposition. The states of the macrosystems are, by becoming correlated or entangled with each other, impossible to understand in isolation from each other and must be viewed as one composite system. It is no longer possible to speak the state of one (sub)system in isolation from the other (sub)systems. Instead we are forced to deal with the states of subsystems relative to each other. Specifying the state of one subsystem leads to a unique specification of the state (the "relative state") of the other subsystems. (See "What is a relative state?")

If one of the systems is an observer and the interaction an observation then the effect of the observation is to split the observer into a number of copies, each copy observing just one of the possible results of a measurement and unaware of the other results and all its observer- copies. Interactions between systems and their environments, including communication between different observers in the same world, transmits the correlations that induce local splitting or decoherence into non- interfering branches of the universal wavefunction. Thus the entire world is split, quite rapidly, into a host of mutually unobservable but equally real worlds.

According to many-worlds all the possible outcomes of a quantum interaction are realised. The wavefunction, instead of collapsing at the moment of observation, carries on evolving in a deterministic fashion, embracing all possibilities embedded within it. All outcomes exist simultaneously but do not interfere further with each other, each single prior world having split into mutually unobservable but equally real worlds.

I have read enough of the MWI to be convinced that it has "not a single shred of evidence" for its position.Sure you have. I'm sure you'll be explaining why quantum computing is bunk now.

Refreshingly, I haven't seen any reference to many worlds in it. I also was not impressed by either Max Tegmark or David Deutsch. I don't see why Tegmark has to bring up unscientific polls. I find that very suspicious. Deutsch just rambled. I felt he was wasting my time. Of course, that's my opinion, but I stand by it. :rolleyes:

That I haven't been convinced is not evidence that there is something wrong with me.It's not about you not being convinced, it's about you clearly not understanding and continually misrepresenting the theory every time you present "evidence" against it, despite three different posters trying to correct you, and despite the majority of physicists being against you, including the one you were reading and "citing" as evidence against MW. Your bias is as clear as the nose on your face. That you continually refuse to recognize it IS evidence that there's something wrong with you.