Does Roger Penrose's Big Bang cyclic-universe thing make sense?

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In summary, the conversation discusses a theory proposed by Penrose about the origin of our universe. According to Penrose, our universe is just one in a series of prior universes and the big bang was a result of the prior universe reaching a state of no matter and time essentially stopping. However, this theory is questioned as it does not explain why time would stop if there are still photons acting as waves. Additionally, there is confusion about how our universe is a continuation of the prior one rather than other universes potentially arising from it. A specific reference to a paper where Penrose presents this model is requested but the conversation ends with a disagreement over the validity of sources.
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HomesliceMMA
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Does it make sense to anyone? He says our universe is just one in a long line of prior universes. But the big bang was not so much starting from a very small area, but instead results out of a prior universe that had gotten so old that essentially it has no matter, and when there is no matter time essentially stops, and it is out of this that essentially our universe was borne, with that state at the end of the prior universe making it look like there was inflation. I'm not saying it as eloquently as he is, but something like that.

This really makes no sense to me. First of all, he says matter is at its core waves, so once there is no matter (or essentially no matter, he seems to hem on this point a bit), and waves are used to keep time. Once there is no matter, there are no waves, nothing to keep time, so there is no time. Again, something like that. But that piece of it makes no sense to me - because as wavelike as matter is, photons are at least as wavelike. Why on earth would time stop if there are still photons that act as waves? Seems very silly to me.

Then I don't get his point about the end of the prior universe looking like the beginning our our universe (complete with what looks like inflation). I mean, if his point is that our universe sprang out of prior one, I would understand that - but then theoretically many universes could have sprang from the prior universe given that our (obervable) universe seems to have started very small, presumably many other very small universes would or could have sprang out if an insanely large prior one. But he seems to be saying no, our universe is somehow a continuation of that prior one. So single universe before, single one now. But how? I just don't get the picture he is trying to describe.

Anyone follow him better than I or have thoughts?

Thanks!
 
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Please give a specific reference to a paper where Penrose presents the model you are asking about.
 
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PeterDonis said:
Please give a specific reference to a paper where Penrose presents the model you are asking about.

Nah, its all over youtube. I'm confident you can find it, it will take any intelligent person about half a second
 
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HomesliceMMA said:
Nah, its all over youtube. I'm confident you can find it, it will take any intelligent person about half a second
Are you TRYING to get banned from PF?
 
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HomesliceMMA said:
You are unreal

Did you even read the rules you agreed to obey?
 
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HomesliceMMA said:
Nah, its all over youtube.
And none of those sources are valid references for a PF discussion. You need to find a textbook or peer-reviewed paper. If you find one, you can start a new thread with it.

This thread is closed.
 
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1. What is Roger Penrose's Big Bang cyclic-universe theory?

Roger Penrose's theory proposes that the universe undergoes cycles of expansion and contraction, with each cycle starting with a Big Bang and ending with a Big Crunch. This theory suggests that the universe has existed for an infinite amount of time and will continue to do so in an endless cycle.

2. How does this theory differ from the traditional Big Bang theory?

The traditional Big Bang theory suggests that the universe began with a single event, the Big Bang, and has been expanding ever since. Penrose's theory, on the other hand, suggests that the universe has been through multiple cycles of expansion and contraction.

3. Is there evidence to support this theory?

There is currently no concrete evidence to support Penrose's theory. However, some scientists believe that the presence of dark energy, which is thought to be responsible for the accelerating expansion of the universe, could potentially be explained by the cyclic nature of the universe.

4. What are some potential criticisms of this theory?

One criticism of Penrose's theory is that it relies on the assumption that the universe will eventually collapse in a Big Crunch, which is not supported by current observations. Additionally, there is no known mechanism that could cause the universe to undergo cycles of expansion and contraction.

5. How does this theory impact our understanding of the universe?

If Penrose's theory were to be proven correct, it would significantly change our understanding of the universe and its origins. It would also raise new questions about the nature of time and the ultimate fate of the universe.

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