Evidence for the Cyclic Model?

[Mitbulls]

Is there any sound scientific evidence for the cyclic model of cosmology? I've heard alot of evidence against it (if it were true, the universe would lose energy each cycle and would eventually not expand at all, if the Big Crunch actually happened a black hole should form, distant supernovas show that the universe expansion is actually speeding up, etc.) but very little for it. Why do people still believe in it?

[technomage]

Why do people still believe in it?

Not sure anyone believes it outside of Marvel Comic Books. Have you come across a recent publication that posits a "Big Crunch?"

Justin

[George Murphy]

Is there any sound scientific evidence for the cyclic model of cosmology? I've heard alot of evidence against it (if it were true, the universe would lose energy each cycle and would eventually not expand at all, if the Big Crunch actually happened a black hole should form, distant supernovas show that the universe expansion is actually speeding up, etc.) but very little for it. Why do people still believe in it?

The brief answer to your 1st question is "No." Present observations indicate that the universe will continue to expand. & even in a closed universe which "bounces" there won't be a recurrence of the earlier state of expansion. Instead, such a universe will grow to greater and greater size in each cycle and may eventually "take off" & never re-contract. This is in contrast to the intuitive idea you suggest, that it should eventually not expand at all. This topic was discussed recently on the "Deep Theistic Evolution" thread by Glenn Morton and myself - posts 430 & 432.

That's for classical general relativity. Recently there has been a proposal (the ekpyrotic universe - there was a thread on this awhile ago) invoking string theory & extra dimensions. It may be that the same thermodynamic considerations that apply in classical GRT also rule out strict recurrence here.

Shalom,
George

[Sacrificial Ram]

Is there any sound scientific evidence for the cyclic model of cosmology? I've heard alot of evidence against it (if it were true, the universe would lose energy each cycle and would eventually not expand at all, if the Big Crunch actually happened a black hole should form, distant supernovas show that the universe expansion is actually speeding up, etc.) but very little for it. Why do people still believe in it?

There is some slight evidence... the older concepts of it have been disproven,
but the latest incarnation of it (The ekpyrotic universe model) has some interesting possiblities. I think it is highly speculative, and I would not be surpised that when it's predictions are able to be tested it gets falsified. It is interesting because it DOES make some testable predictions that distinguish it from the currently accepted model of the big bang... we just don't have the techology yet to do testing.

Here is a small article about the current theory

http://www.space.com/scienceastronomy/astronomy/bigbang_alternative_010413-3.html

[shunyadragon]

There is some slight evidence... the older concepts of it have been disproven,
but the latest incarnation of it (The ekpyrotic universe model) has some interesting possiblities. I think it is highly speculative, and I would not be surpised that when it's predictions are able to be tested it gets falsified. It is interesting because it DOES make some testable predictions that distinguish it from the currently accepted model of the big bang... we just don't have the techology yet to do testing.

Here is a small article about the current theory

http://www.space.com/scienceastronomy/astronomy/bigbang_alternative_010413-3.html

I believe that our observations of the present nature of existence reveals everything appears cyclic. At present our knowledge of what lies beyond is highly speculative. It is true that our universe was a singular event in it self with a beginning and will not likely collapse again to it's original beginning, but in the greater picture I believe there is the potential of a multiverse model for existence. The conditions that brought about the beginning of our universe are likely not unique. There is a tendency of egocentric thinking in religion as well as science concerning our uniqueness as a planet, solar system and universe, but I think it is more realistic to assume that we are not unique, maybe not very common, but not unique.

Recent evidence indicates the beginning of the universe was rather explosive and the intial growth was rapid, with galaxies forming very quickly. On a grander scale in the matrix of existence, other universes could very well form and reform from the collapsing debri of older universes. I believe some form of an ekpyrotic universe model would fit this view.

[grmorton]

There is some slight evidence... the older concepts of it have been disproven,
but the latest incarnation of it (The ekpyrotic universe model) has some interesting possiblities. I think it is highly speculative, and I would not be surpised that when it's predictions are able to be tested it gets falsified. It is interesting because it DOES make some testable predictions that distinguish it from the currently accepted model of the big bang... we just don't have the techology yet to do testing.

Here is a small article about the current theory

http://www.space.com/scienceastronomy/astronomy/bigbang_alternative_010413-3.html


But don't forget that it has failed observational tests. We should see different energy distributions in supernova if that theory were true and we don't see it. That theory depends upon higher dimensions and so far the supernova data says they don't exist. I made mention of this. Search this forum for my name and ekpyrotic and you should find the post.

[shunyadragon]

But don't forget that it has failed observational tests. We should see different energy distributions in supernova if that theory were true and we don't see it. That theory depends upon higher dimensions and so far the supernova data says they don't exist. I made mention of this. Search this forum for my name and ekpyrotic and you should find the post.

I agree, the current ekpyrotic model lacks the observational evidence, but I do believe some form of multiverse model will evolve from this.

[grmorton]

I agree, the current ekpyrotic model lacks the observational evidence, but I do believe some form of multiverse model will evolve from this.


I would like the YECs to note that this is the way to handle issues when one's religious apologetic has difficulties. Note that he didn't call me names, he didn't tell me that I was a compromising churchian (or christadelphian). He didn't deny that there was a problem. He acknowledged the difficulty and stated what he believed would happen. Time will tell if he is right or wrong.