Theory of Relativity

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Originally Posted by Mutatis-Mutandis

Of course I can. Who better to blame, really? Darwin made it quite clear for millions of people. If one person doesn't understand it, the fault is with that one person more than it is with Darwin.



I felt it relevant to remind people what kind of reactions they'd get if they actually decided to take the time to truly explain the theory of relativity to cacian.

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I somehow differ on the view that Darwin has clearly demonstrated his thoughts on this subject.
It is down to the master to lead by examples and demonstrates capabilities to those who wish to learn.
Unfortunately in this particular example the knowledgable master has failed the tasks to issue a clear pervoyance upon my will to understand and therefore the failures is with him and him alone for not having achieved knowledge to base.
A child learns from adult. I take it that would the same similaritie between a Darwin and a mere person.

Back to the topic:
How old is the child? How brilliant is the child? Are we talking about the special theory or the general? Does the child know basic Newtonian mechanics? If not, why bother with relativity just yet?

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Originally Posted by Summer M

Back to the topic:
How old is the child? How brilliant is the child? Are we talking about the special theory or the general? Does the child know basic Newtonian mechanics? If not, why bother with relativity just yet?

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Hi Summer back to topic indeed.
The child between seven and eight.
I am talking any theory general or specific.
I am looking for an ouversture a simplified one to give a basic generals about this theory sets out be.
For example something like this

I will explain to a child that I want to reach number 8 using numerals and so will ask what mathematicals rethorics is one to use to reach that number.
The child should conclude that one needs to use 'adding' to do so.
I will leave the multiply and division for later on.

So I am after logical steps to give the child an image like the number 8 is an image.

Are you home schooling your child?

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Originally Posted by Scheherazade

Are you home schooling your child?

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No this came up in a conversation with some children and so I could not explain it because I do not understand myself.

Forget about the general theory, as it is way too difficult. I'd say forget about the special, too, but if you insist, I'd say look at Brian Greene's The Elegant Universe, which explains the rudiments quite well. But really, at eight years old there is plenty to learn before relativity.

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Originally Posted by cacian

How do I explain this theory to a child without getting myslef too hyped up about it?

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I sometimes wonder how to explain it to myself, but here is something to go on and what I would use as a reference:

http://en.wikipedia.org/wiki/Theory_of_relativity

It might be an interesting challenge to see how one would actually say this to a child.

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Originally Posted by YesNo

I sometimes wonder how to explain it to myself, but here is something to go on and what I would use as a reference:

http://en.wikipedia.org/wiki/Theory_of_relativity

It might be an interesting challenge to see how one would actually say this to a child.

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Einstein didn't win the Nobel for the theory of relativity. And when it came to that, there was very little that was his in that stuff.
For the rest, he was as retarded as his professors said he was. For the special as well as the general.

Explain to him the general outline of the thought process that Einstein had.


Start talking about light. Ask him if he ever wondered if when he switched on the lights, the light was inmediatly in all the room or it traveled too fast to tell. If he never thought of that explain him that light actually travels (you figure it out how, remember the example of the sun, etc). Highlight the point that - therefore- it has a certain speed.
Now, long time ago people aknowledged this, and for many centuries scientist have been trying it to calculate or messure the speed somehow. Astronomers came up with a way to messure it with some aproximation.

Now explain to him a little bit what happens with velocities. It's intuitive actually: Imagine that you get in a train. Now you start running in the hallway in the same direction than the train does. You run at 10km/h. The train moves at 20km/h. Then you are moving 30km/h respect to the ground. Conclusion:Velocities add up.

Now what is to expect is that in the same situation, but standing still in the hallway, if you switch on a flashlight pointing again at the same direction than the train, the beam of light will move at c (c= the speed of light) PLUS 20km/h respect to the ground.

In 1887 an experiment took place in the USA. It involves light and its speed. The results of the experiment contradicted the principle of addition of velocities, because they meassured the same speed of light respect to the ground for a beam that came from a source standing still and from a beam that came from a source in motion. (This is a lie, it's all simplified and adapted).

So at first scientist thought the experiment was a failure. But Einstein asked himself: What if the experiment was correct? What would it mean? Why didn't the speed of light added up with the speed of it's source?
"Mmmhh my best guess -he said to himself- is that, maybe, there is a universal limit to how fast something can travel, like a speed limit, and it happens to be the speed of light, and that explains why the velocities didn't add up in the experiment"

Now, why would there be a universal speed limit?: "I don't know! For some obscure underlying reason. But lets suspend this questioning, because I can't keep too many lines of thought at the same time. Let's pretend my guess is right and figure out what consecuenses it would have. Maybe I can deal with that later"


(To be continued...)

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Originally Posted by Anymodal

Explain to him the general outline of the thought process that Einstein had.


Start talking about light. Ask him if he ever wondered if when he switched on the lights, the light was inmediatly in all the room or it traveled too fast to tell. If he never thought of that explain him that light actually travels (you figure it out how, remember the example of the sun, etc). Highlight the point that - therefore- it has a certain speed.
Now, long time ago people aknowledged this, and for many centuries scientist have been trying it to calculate or messure the speed somehow. Astronomers came up with a way to messure it with some aproximation.

Now explain to him a little bit what happens with velocities. It's intuitive actually: Imagine that you get in a train. Now you start running in the hallway in the same direction than the train does. You run at 10km/h. The train moves at 20km/h. Then you are moving 30km/h respect to the ground. Conclusion:Velocities add up.

Now what is to expect is that in the same situation, but standing still in the hallway, if you switch on a flashlight pointing again at the same direction than the train, the beam of light will move at c (c= the speed of light) PLUS 20km/h respect to the ground.

In 1887 an experiment took place in the USA. It involves light and its speed. The results of the experiment contradicted the principle of addition of velocities, because they meassured the same speed of light respect to the ground for a beam that came from a source standing still and from a beam that came from a source in motion. (This is a lie, it's all simplified and adapted).

So at first scientist thought the experiment was a failure. But Einstein asked himself: What if the experiment was correct? What would it mean? Why didn't the speed of light added up with the speed of it's source?
"Mmmhh my best guess -he said to himself- is that, maybe, there is a universal limit to how fast something can travel, like a speed limit, and it happens to be the speed of light, and that explains why the velocities didn't add up in the experiment"

Now, why would there be a universal speed limit?: "I don't know! For some obscure underlying reason. But lets suspend this questioning, because I can't keep too many lines of thought at the same time. Let's pretend my guess is right and figure out what consecuenses it would have. Maybe I can deal with that later"


(To be continued...)

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At this point in my life, the subject of Einstein bores me to dead. There were days in my youth when I got entangled with it and I figure him out one by one. Have fun.

I don't think I will ever get bored of relativity. And I already understand it quite well by the way :yesnod:. I stoped the explanation because I just got lazy of thinking how to explain it to an 8 year old.. but then I'll continue :D

Well, if you were going to explain it to someone, whether 7 or 70, you would probably have to start out by explaining that physical laws are supposedly independent of the velocity of any particular frame of reference, otherwise they wouldn't be physical laws. That goes back to Galileo.

Then you would have to say that a physical law related to the velocity of light was discovered, namely, that nothing can go faster than it. That goes back to the Michelson-Morley experiment that failed to find the speed of the ether.

Since the speed of light as a maximum speed is a physical law, it must be independent of the velocity of any particular frame of reference. So every frame of reference, no matter whether it is rushing toward the light source or rushing away from the light source, will have to come up with the same measure for the velocity of the light source.

Check out "Mr Tompkins in Paperback" by George Gamow. I read it when I was about 10 and found it very inspirational.

Simon Singh's "Big Bang" has some very good explanations and diagrams - it's really aimed at adults, but might inspire you to some good explanations.

I second Brian Greene's The Elegant Universe.

Careful of Wikipedia - it gets hard very quickly! Encyclopedia Britannica is more straightforward.

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Originally Posted by YesNo

I sometimes wonder how to explain it to myself, but here is something to go on and what I would use as a reference:

http://en.wikipedia.org/wiki/Theory_of_relativity

It might be an interesting challenge to see how one would actually say this to a child.

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Indeed. Thnak you YesNo it is all an adult world out there.

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Originally Posted by cafolini

Einstein didn't win the Nobel for the theory of relativity. And when it came to that, there was very little that was his in that stuff.
For the rest, he was as retarded as his professors said he was. For the special as well as the general.

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Einstein retarded? Now that is a first for me.
Since when?:p

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Originally Posted by Anymodal

I don't think I will ever get bored of relativity. And I already understand it quite well by the way :yesnod:. I stoped the explanation because I just got lazy of thinking how to explain it to an 8 year old.. but then I'll continue :D

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Please do. I have to admit I kept up reading up to a point and I felt a headache coming on.
I wondered about someone running on a train that is already running.
Is that a possibility to run that fast on a train that is already very fast?

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Originally Posted by YesNo

Well, if you were going to explain it to someone, whether 7 or 70, you would probably have to start out by explaining that physical laws are supposedly independent of the velocity of any particular frame of reference, otherwise they wouldn't be physical laws. That goes back to Galileo.

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One could use speed rather then velocity because velo-city is composed of two words velo=bike and city= city. It can be misleading for a French speaker like me. I can't help but stop the velo in there.
It is almost half french and english this word.
The other thing what about buyancy interms of speed? Is there anything in there about in relativity?

Then you would have to say that a physical law related to the velocity of

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light was discovered, namely, that nothing can go faster than it. That goes back to the Michelson-Morley experiment that failed to find the speed of the ether.

Since the speed of light as a maximum speed is a physical law, it must be independent of the velocity of any particular frame of reference. So every frame of reference, no matter whether it is rushing toward the light source or rushing away from the light source, will have to come up with the same measure for the velocity of the light source.

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Ouch that is too much information for me haha. :p
How about a simple drawing just to settle a picture in one's mind haha.

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Originally Posted by cacian

One could use speed rather then velocity because velo-city is composed of two words velo=bike and city= city. It can be misleading for a French speaker like me. I can't help but stop the velo in there.
It is almost half french and english this word.
The other thing what about buyancy interms of speed? Is there anything in there about in relativity?

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In English, I've learned that "velocity" means speed with a direction. The main reason I use it is to make me look as if I know what I'm talking about. If I wrote, "speed", some reader would think, "Oh, the dummy doesn't know the correct term is 'velocity'". For the purposes of this thread, however, I suspect speed is just as good.

What do you use in French to distinguish these ideas?

The speeds of these frames of reference have to be so smooth that any people in them doing science would not feel that they are moving at all. So there wouldn't be any buoyancy or bumpiness.

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Originally Posted by cacian

Ouch that is too much information for me haha. :p
How about a simple drawing just to settle a picture in one's mind haha.

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I find it strange also, but I think the core of the strangeness has to do with finding a law of physics related to the maximum speed something can go.

In all these frames of reference, their relative speeds are supposed to be irrelevant in the verifications of the laws of physics done by someone in that frame of reference, but here is a law saying that there is a maximum possible speed. Here is a law about speed itself. Since it is a law of physics, I can verify it and I should come up with the same value no matter if I am moving toward the light source or away from the light source from the relative perspective of someone in a different frame of reference.

Of course, I don't think I'm moving at all in my own frame of reference. It is the other guy watching me who's moving and, oddly, getting the same value for the speed of light that I did.