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

What is Roger Penrose's cyclic universe theory?

Roger Penrose's cyclic universe theory, also known as Conformal Cyclic Cosmology (CCC), proposes that the universe undergoes infinite cycles of Big Bangs and subsequent expansions. Each cycle, or "aeon," starts with a Big Bang and ends in a conformally stretched, smooth state that serves as the starting point for the next Big Bang. This theory suggests that the universe's ultimate fate is not a singular, final state but rather an eternal series of cycles.

How does Conformal Cyclic Cosmology differ from the traditional Big Bang theory?

While the traditional Big Bang theory posits a single beginning of the universe followed by continuous expansion, CCC suggests that the universe goes through infinite cycles of expansion and smoothening out. In CCC, the end of one universe (when it becomes smooth and featureless) transitions into the beginning of the next through a conformal transformation, effectively linking the end of one aeon to the start of another.

What evidence supports Penrose's cyclic universe theory?

Penrose and his collaborators have pointed to certain anomalies in the Cosmic Microwave Background (CMB) radiation, such as concentric circles and low-variance regions, as potential evidence for CCC. They argue that these features could be remnants or "signals" from previous aeons. However, this interpretation is controversial and not widely accepted in the cosmological community, with many scientists arguing that these features can be explained by other means or are not statistically significant.

What are the main criticisms of Conformal Cyclic Cosmology?

Critics of CCC argue that the theory lacks empirical evidence and that the supposed features in the CMB can be explained by other, more conventional models. Additionally, some scientists question the mathematical and physical plausibility of the conformal transformations that link one aeon to the next. The theory also faces challenges in explaining how entropy resets between cycles, given the second law of thermodynamics.

Is Conformal Cyclic Cosmology widely accepted in the scientific community?

As of now, Conformal Cyclic Cosmology is not widely accepted in the scientific community. While it is an intriguing and mathematically sophisticated theory, it remains speculative and lacks robust empirical support. Most cosmologists continue to favor the traditional Big Bang model and its extensions, such as inflationary theory, which have more substantial observational backing.

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