There its a long post in Apologetics Press on the Big Bang theory and its evolution. Worth reading.
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There its a long post in Apologetics Press on the Big Bang theory and its evolution. Worth reading.
I have little interest in astronomy, nor do I pay much attention to videos about aliens and other juvenile concepts such as those that appear on YouTube where conspiracy theories abound.
There's a lot of uninformed chatter about the moon landings for example and then there's this:
https://youtu.be/tHJUVDL68iw
Edit: with apologies for the juvenile comments that are also a major feature of YouTube.
I find it hard to believe that the Apollo missions to the Moon were manned. I loved the juvenile comments in the video.Quote:
Originally Posted by Emil Miller
Why do we need to send humans that far into space anyway? Isn't that what "artificial intelligent" robots are for? I suppose if we put advanced telescopes at a Lagrangian point which would be further than the Moon, we may need to have a human be able to make repairs.
Much of this is confirmed by Peter Coles' "Cosmology A Very Short Introduction" that I am also reading to get an overview. I liked this Berlinski quote from the link:Quote:
Originally Posted by Dreamwoven
Contemporary cosmologists feel free to say anything that pops into their heads.
I agree with this (and Emil). All the dithering over 'going to Mars' is unnecessary, and I don't think it will happen. As YesNo says, This is exactly what "artificial intelligent" robots are for, and we can see the results on Mars very well from that. They take samples, analyse them, and range pretty freely across the planet, filming as they go.Quote:
Originally Posted by YesNo
There is an astronomical radio source at the center of our galaxy called Sagittarius A* which some believe to be a black hole. https://en.wikipedia.org/wiki/Sagitt...cretion_course
There was also supposed to be an event where a gas cloud, G2, was to collide with this alleged black hole last year. However, G2 survived the encounter with the black hole. Does that mean the radio source Sgr A* is not the location of a black hole?
Perhaps when we get more reliable information about the astronomical radio source at the centre of our galaxy called Sagittarius A* we may be in a position to draw conclusions?
Yes, Sagittarius A* does represent something so far unknown. Only a few days ago, I thought black holes existed. Now, I am ready to doubt that they even can exist.
However, if I doubt that such singularities exist, then whatever the universe was at the Big Bang, it could not have been like a black hole. To remove the idea from my mind that there was a beginning some 14 billion years ago, one would have to find something in the universe older than 14 billion years.
Another dwarf planet has been found in the sun's orbit far out in the Kuiper Belt: http://www.space.com/31100-most-dist...net-found.html. Two or three time further out than Pluto (and smaller), it hasn't yet had its orbit plotted, as has been done for Eris.
In checking that link about the new dwarf planet, there was one about Vesta, the brightest asteroid: http://www.space.com/12097-vesta-ast...ar-system.html
There were two things I found interesting about it: (1) Supposedly Vesta can at times be seen without binoculars and (2) Gauss calculated its orbit in 10 hours without computers.
That second thing made me wonder how he did that? What were his input values and the formulas he used?
I think we still have not had the closet pass by Dawn to this asteroid. Or have we? This film sequence of a really close pass is quite stunning: http://www.space.com/17389-take-a-to...aft-video.html.
Gauss' work has a good page on this: https://www.math.rutgers.edu/~cherli...999/weiss.html
The use of the cubesats in the coming mission sounds interesting: http://www.space.com/29489-marco-cub...ding-2016.html
Thanks for the link describing how Gauss found the orbit of Vesta. He only had a set of observations which contained time and two degree measurements to pinpoint the asteroid.
I had missed that, YesNo: cubesats in the next Mars lander. i am really glad that NASA is spending so much effort in exploring the next nearest neighbour to Earth (Venus beats Mars but is far more difficult to explore).
This post was a good way of trying to imagine the vast distances of space: http://earthsky.org/astronomy-essent...-a-light-year?
Discovery of the furthest known galaxy: http://earthsky.org/space/scientists...ant-galaxy-yet. 13.8 billion years old.
I think that would be about 13 billion years old with the universe itself at 13.8 billion years. It is interesting that these objects are so faint that spectroscopy may not work. It looks like we need bigger telescopes.
This from EarthSky:
Many universes? Until recent decades, most astronomers would have told you that, by definition, the word universe means all there is. That word was used to describe all space, time, matter, physical laws and constants. But now a new word – multiverse – has entered the language of scientists.
Not all scientists agree, but some – including Stephen Hawking, for example, and Alan Guth of MIT – believe there’s scientific justification for a multiverse, many universes springing into being, possibly existing simultaneously, each possibly with its own physics. If true, then our universe of stars and galaxies is just a small part of this vast assemblage of many universes.
There is a growing interest in parallel universes, rather than just one universe, and not just one big bang, but several. This is discussed in http://earthsky.org/space/bumping-up...llel-universe?
In Charles Lawrence's talk on the Planck mission results he claimed there wasn't any evidence in the data for multiverses. He also didn't even know what to measure in the data that would show a multiverse. See the part toward the end about 1:30 and following for this discussion: https://www.youtube.com/watch?v=ZCZdrfDHwgU
That makes me think there isn't any "scientific justification" for a multiverse. However, if one needs certain metaphysical assumptions about the universe to be true then there might be philosophical justifications that could save those assumptions by invoking a random multiverse. All we would have to go on are whether the justifications are rational or not. There is no data, hence no scientific justification.
The main problem is that the cosmic microwave background is evidence that our universe had a beginning. It is not eternal. Did something conscious start the universe? If so, then one has theism. So the basic metaphysical assumption underlying these multiverse theories is the need to avoid theism. This is done by assuming there must be a random multiverse. This would restore the eternal and unconscious nature of the universe. However, it does not help explain the existence of our own consciousness.
My personal view is that there is a non-random, intentional multiverse. If the big bang happened once, it happened many times. There is a consciousness that started all of these universes and they are all able to support life.
Another question that arose is where in the universe did the big bang take place and so provide the centre of the universe out of which it expanded? Presumably the heart of the universe can be identified, by measuring the distance from this "centre". Where, for example is our own galaxy the Milky Way in this pattern of explosion?
I am thinking there should be a center as well, but I understand that space and time started with the big bang. If that is the case, the big bang happened everywhere in our space and time. However, it is hard for me to think of space and time having a beginning.
One thing Lawrence mentioned in his talk was that someone looking at the cosmic microwave background from a different part of the universe would see something different.
I was thinking about the multiverse a bit more. It seems that life requires that the universe be finite based on Olber's paradox: https://en.wikipedia.org/wiki/Olbers%27_paradox If there were infinitely many stars, the night sky would be black and too hot for life to survive. So each universe is finite and this allows us to exist.
"Scientists capture a black hole swallowing a star for the first time ever" - http://releases.jhu.edu/2015/11/26/s...speed-flare-2/
Ta ! (short for tarradiddle),
tailor STATELY
I searched for ASASSN-14li which I assume is the name associated with this along with "tidal disruption event". I wonder what Mersini-Houghton thinks of that event.
The multiverse theory: https://en.wikipedia.org/wiki/Laura_Mersini-Houghton. Sorry, not checked my mail for some days...
She may be wrong about the cosmic microwave background showing evidence for a multiverse. I understand the Planck data does not show enough variability that something besides randomness cannot account for it. Also I don't understand why another universe would have a gravitational effect on our universe. They are in separate spaces. They shouldn't touch.
It seems she is also interested in many worlds. This is different from a multiverse. Each universe would have multiple versions of itself to account for quantum indeterminacy. I don't think that's a coherent interpretation of quantum physics.
So maybe she is wrong about the black holes as well. According to the link, "She claimed that Hawking radiation causes the star to shed mass at a rate such that it no longer has the density sufficient to create a black hole." In her favor there isn't much evidence to go on. The ASASSN-14li might be explainable in other ways than a black hole consuming a star. It is after all in another galaxy and the predicted collision in our galaxy's center did not happen.
An astronomy thread?
Why didn't someone tell me?
Serious amateur astronomer for about 40 years. I'll be checking back to see what's been going on.
Welcome to the astronomy thread!
Yes, welcome back. There's also a cosmology thread you might be interested in.
I was hoping to see the moon and Venus this morning, but the sky was overcast.
The Atheist - you are probably far ahead of us - or at least of me. I was inspired to start this thread because of the recent discoveries in our own solar system, New Horizons, the explorations of Mars (which shows just how unnecessary it will be to send astronauts to Mars). And this is just the beginning. The future is clearly with unmanned exploration, I think.
It would be interested to learn more about what kind of amateur astronomy you have been involved in. I have no equipment to speak of, only a 7x50 binoculars - asaklitt, decent quality but better for birdwatching than stargazing...There is not even a local astro club near me...So I follow space.com and EarthSky.org on a regular basis, and am a member of the British popular astronomy society. Read the Swedish equivelent, too, at local libraries - populär astronomi.
SPA: Electronic News Bulletin No. 411 2015 December 6
A team of astronomers using the Very Large Telescope (VLT) has captured detailed images of the hypergiant star VY Canis Majoris. The observations show how the unexpectedly large size of the particles of dust surrounding the star enable it to lose an enormous amount of mass as it begins to die. That process, understood now for the first time, is necessary to prepare such gigantic stars to meet their explosive demise as supernovae. VY CMa is a stellar goliath, a red hypergiant, one of the largest stars known in the Milky Way. It is 30 or 40 times the mass of the Sun and 300,000 times (nearly 14 magnitudes) more luminous. In its current state, the star would encompass the orbit of Jupiter, having expanded tremendously as it entered the final stages of its existence. The new observations of the star were made with the SPHERE instrument on the VLT. The adaptive-optics system of that instrument corrects images to a higher degree than earlier systems. It allows features very close to bright sources of light to be seen in great detail. SPHERE clearly revealed how the brilliant light of VY CMa was lighting up clouds of material surrounding it. The team could not only see into the heart of the cloud of gas and dust around the star, but could also see how the starlight was scattered and polarised by the surrounding material. Those measurements were key to discovering the properties of the dust, and revealed the grains of dust to be comparatively large particles, half a micron across, which may seem small, but it is about 50 times larger than the dust normally found in interstellar space.
Cheers!
A couple of bits that may already be under discussion:
The Japan probe to Venus is finally in orbit - 5 years late.
and the LISA Pathfinder, about to prove gravitational theories.
My telescope is one of these.
Fully motorised, with many thousands of pre-programmed positions that work off a GPS. It means you don't have to waste too much time looking for what you want to see. Excellent for planets & nebulae.
The astronomy comes in handy at times, like when we saw a bolide a few months ago. In 40 years of watching the sky I've never seen anything remotely as impressive as that. The thing that struck me - and probably as a result of being in a very quiet place - was the sound! It was an amazing hissing that made us look at the sky, only to see it bursting through the atmosphere. No question it was an outer solar system rock; it was much, much faster than any meteor I've seen.
Out of this world, you might say!
A fellow-Londoner, and with a decent telescope! The link to The Guardian article was interesting. And the Japanese Venus probe. It seems that different countries are specialising in different planets to investigate further, like NASA on Mars. Good to specialise, especially when each planet poses its own problems. There is an article on this in Scace.com today: http://www.space.com/31300-japan-aka...orbit-try.html
Venus has been very prominent in the skies in recent months, bright and clear. Feel free to publish any pictures on this website.
Almost!Quote:
Originally Posted by Dreamwoven
Well, almost exactly opposite London on the globe. I'm down t'other end. NZ.
The gravitational wave observatory is interesting.
What do you view with your telescope, Atheist? I have only 7x50 binoculars which are most useful when I am in Wisconsin where the sky is dark.
Nebulae and planets, mostly. The prettiest bits, which is all any shop-bought amateur scope is good for. The moon is really cool through a good 'scope as well.
I'm inheriting $350,000,000 from Nigeria in a couple of weeks' time and I've decided I'm going to buy the Mt John observatory! One of the darkest places on the planet which is easily accessible.
That would be amazing, to own an entire space observatory. Look forward to learning more.
From SPA (Society for Popular Astronomy) Newsletter 40
New planet, or even planets?
Papers just published* suggest that there could be a hitherto undiscovered planet or even a brown dwarf star in the outer Solar System – or, more likely, it is just a smaller asteroid much closer. One object, dubbed Gna, has appeared on observations of the variable star W Aquilae made using ALMA, the Atacama Large Millimeter/submillimeter Array (above) on three occasions in March, April and May 2014. It had apparently moved between the first two observations, but was absent on the third. This could simply be because it is a fairly close object, a Centaur asteroid of maximum size 880 km, and had moved out of the field of view.
But the Swedish authors of the paper speculate that the movement is also consistent with a very remote planet or even a brown dwarf on the outskirts of the Solar System, though it would have to be highly variable to account for its disappearance in the third observation. However, in another paper, ALMA observers say that they have found a source close to the star Alpha Centauri, also moving over a ten-month period, which had not been previously detected. They rule out a new member of the Alpha Centauri system, but instead claim that it belongs to the Solar System, either a distant brown dwarf or a ‘super Earth’ in the Kuiper Belt.
The claims have been dismissed by other astronomers. Planetary scientist Mike Brown points out that ‘if it is true that ALMA accidentally discovered a massive outer solar system object in its tiny tiny tiny field of view that would suggest that there are something like 200,000 Earth sized planets in the outer solar system.’ This, he says, would destabilise the whole Solar System – which clearly isn’t the case.
* Technically minded readers can decide for themselves by reading the (as yet unrefereed) papers:
http://arxiv.org/pdf/1512.02650v1.pdf
http://arxiv.org/pdf/1512.02652v1.pdf
Just the idea that there could be a dwarf brown star in our solar system is something I didn't even consider.
I heard, and mentioned earlier, that there could be 200 planets like Pluto that are still undiscovered. All of this lack of knowledge about objects so close to us make me wonder about the accuracy of data claimed to come from other galaxies. Although I understand that our current knowledge about the cosmic microwave background is better than our knowledge of the universe about us. That might be because there is not much left to know about it.
Yes, it underlines how limited our knowledge is of our own galaxy. Even more so of our own solar system.
In Swedish the Milky Way is called The Winter Road (Vintergatan), which is an interesting reflection of the different cultural viewpoints...
There is an interesting piece in EarthSky on Ceres, including the comment by Y. Whateley. It seems the composition of the ice on Ceres suggest its origins lie in the Kuiper Belt.
So those bright spots are believed to be magnesium salts rather than an alien structure. Maybe Velikovsky was partly right as Whateley hints. I wonder what a possible set of orbits could have been for Ceres that would take it from the Kuiper belt to the Asteroid Belt.