[homeslice (OP)]

You can pick this up on almost any youtube clip if you search his name and view of universe or whatever.

His general view appears to be that there was a universe before ours.  Then one before that.  Then one before that.  Not a "multiverse", with bubble universes going on all over the place, all at different times and the same time both, but just one after the other.  So far, so good, I can at least understand that.

But when he goes into more detail about his theory, he loses me.  He basically said our universe started out of the old one, which (according to him, but which I've heard others have said) will have in the far far future little or no mass left (he kind of hems on this point), and that when there is little or (presumably) no math left, time stops, because matter is a wave and you need waves to keep time, and when that happens the universe somehow goes from huge and with no matter anywhere to what we see as the big bang.  He claims that you don't need inflation in his model - indeed what we think of as inflation happens naturally in the "old" universe.  Something like that.

I can't even picture it.  On the time thing, if there is no mass, there are still photons/energy, which so far as I can tell have wave like properties, at least as much as mass, so why would time stop if there was no mass in the universe?  On the more general point about some huge, cold, no mass having universe somehow transitioning to one that is incredibly hot, expanding, etc. etc., he does not explain that, and I do not understand it.

Does anyone understand his proposal?

Thanks!

[Zer0]

I did watch a Utube video recently on this same Phenomenon...

I failed to Understand Mr Penrose, but somehow Understood it in the way You described it...hence Thanks Alot!

I did do a quick internet " Search " & saw his Model/Hypothesis was inconsistent with the Observable Evidence...did Not Understand that...but now when Someone in here answers/responds to your OP...i will get it, so Thanx Again!

P.S. - And Welcome to the Forum.
🙏

[evan_au]

Penrose's theory assumes that the universe has enough mass to slow down the expansion of the universe, so that it eventually contracts into a "Big Crunch" (or "Gnab Gib", as some palindromically express it).

This theory took a (possibly fatal) beating in the 1990s, when it was discovered that the universe is expanding at an accelerating rate.
- This suggests that Penrose's proposed contraction does not seem possible.
https://www.scientificamerican.com/article/the-2011-nobel-prize-in-prize-physics/

[geordief]

Penrose's theory assumes that the universe has enough mass to slow down the expansion of the universe, so that it eventually contracts into a "Big Crunch" (or "Gnab Gib", as some palindromically express it).

This theory took a (possibly fatal) beating in the 1990s, when it was discovered that the universe is expanding at an accelerating rate.
- This suggests that Penrose's proposed contraction does not seem possible.
https://www.scientificamerican.com/article/the-2011-nobel-prize-in-prize-physics/

Are you sure it is predicated on a Big Crunch?

I imagined it might be that the condition at the "end" of the universe (ie an absolutely total heat death) might provide a circumstance  where  the very large spatial distances were identical to the  very small distances (zero distances?) that may have prevailed before or just after the birth of the universe.

I have not looked into Penrose's idea apart from the one or two times I have heard it     mentioned but I thought it must surely be more than just a kind of Big Crunch.

[evan_au]

I stand corrected.
Penrose does talk about a continuously expanding universe, but assumes that by changing the coordinates of the universe, the near-zero density and near-zero temperature at the end of one universe becomes the near-infinite-density singularity and near-infinite temperatures at the start of the next universe.
https://en.wikipedia.org/wiki/Conformal_cyclic_cosmology

[geordief]

Well,here it is from the horse's mouth

He ends with what he thinks could be a way of measuring the effect whereby an old universe births a subsequent one.

It is just a short interview at under 20  minutes.

Not sure how recent it is (he seems quite youthful)

The salient points seem to me to be  to be that at the beginning and end of the process space and time  "forget"  their dimensions and the large is indistinguishable  from the small.

Edit:I see the  OP has largely explained the video (probably the same one)

I think I sort of "get it"   but maybe that is because I have so little math to  constrain me and I just like the idea (Penrose admits it is an outrageous conception but that it might one day be falsifiable)

[geordief]

why would time stop if there was no mass in the universe

I think he combines e=mc^2 with e =h*nu so that mc^2=h*nu and so mass is a frequency
So mass and time are connected (if I understood it right and if he is allowed to do that)

[Zer0]

This is the one i watched...
It has Visual Aids in the form of a monitor screen depicting Images..
But the video posted by geordief was Alot more easier for me to Grasp.

Many Thanks/Credits/Source -
Sir Roger Penrose/The Institute of Art and Ideas Channel/YouTube.

On the Internet it says his Idea was Debunked, his Model(imagination) did not match up with the Observable Evidence.(reality)

Any Explanations?

[geordief]

This is the one i watched...
It has Visual Aids in the form of a monitor screen depicting Images..
But the video posted by geordief was Alot more easier for me to Grasp.

Many Thanks/Credits/Source -
Sir Roger Penrose/The Institute of Art and Ideas Channel/YouTube.

On the Internet it says his Idea was Debunked, his Model(imagination) did not match up with the Observable Evidence.(reality)

Any Explanations?

Where does it say that?Does it spell out how it was debunked?

[Zer0]

When i Goggle the Keywords...
" Roger Penrose Cyclical Universe "

The first link is Obviously
" Wikipedia "
https://en.m.wikipedia.org/wiki/Conformal_cyclic_cosmology
In there it says the CCC has not been yet proven to be true due to lack of data/information.

Then a PopSci article appears at the No 2 spot.
https://www.forbes.com/sites/startswithabang/2020/10/08/no-roger-penrose-we-see-no-evidence-of-a-universe-before-the-big-bang/
Which claims He was Wrong.

Then bypassing a few Utube video links...No 3 is this.
https://physicsworld.com/a/new-evidence-for-cyclic-universe-claimed-by-roger-penrose-and-colleagues/
It does not speak up in any confidence supporting CCC n saying it's true.

I was just Skeptical about All the sources mentioned above, hence asked for further Explanations.

So CCC isn't completely dead, is it still alive, a possibility?

[geordief]

I am not well enough informed to get a  feel for how reliable those articles are.

The flavour of them is certainly  that CCC seems very unlikely to become a successful theory as all the supposed data supporting it seems to be contested for now and stronger data seems a  far distance away.

To have a better idea I think one might need there to be a debate between a strong advocate for and a strong  advocate against  CCC.

Perhaps such a debate exists out there on the internet

It might be interesting if it was  discovered and dug up.

[Zer0]

Yep!
Exactly my point.

I failed to find any consensus or agreement Online on the CCC Topic.

The ones against it pop up at top spots in the Goggle search engine.

The only ones i could find in favour of CCC were Sir Roger Penrose's own videos on Utube.

Thou, there is one thing i wish to ask here...
In his video He draws the shape of the Universe like a pointy conical.
(it begins n slowly spreads out)
The images/diagrams i've seen of the Universe show a large bloating right at the beginning.
(possibly showcasing Inflation)

So, where does the CCC stand on Inflation?
Is Inflation also embedded into & is a part of the CCC Model?

[geordief]

Yep!
Exactly my point.

I failed to find any consensus or agreement Online on the CCC Topic.

The ones against it pop up at top spots in the Goggle search engine.

The only ones i could find in favour of CCC were Sir Roger Penrose's own videos on Utube.

Thou, there is one thing i wish to ask here...
In his video He draws the shape of the Universe like a pointy conical.
(it begins n slowly spreads out)
The images/diagrams i've seen of the Universe show a large bloating right at the beginning.
(possibly showcasing Inflation)

So, where does the CCC stand on Inflation?
Is Inflation also embedded into & is a part of the CCC Model?

Do you want to take a look at this fairly recent discussion?

https://www.reddit.com/r/cosmology/comments/jfu7mm/is_conformal_cyclic_cosmology_really_debunked/

I have only read the first few contributions  so far  and am not sure yet of the overall flavour .

[Zer0]

Aha!
That Link was Spot On.
👍
(thumbs up emoji)

It mentions the same ' Forbes ' article which Claims Sir Penrose was " Wrong ".

I'll have to read more stuff on CCC now.
Comments on Reddit talk n discuss about Entropy & Inflation.

What I've learnt from here & there is that...
The 2nd Law of Thermodynamics is Unbreakable.
Inflation is Based on Evidence by WMAP & Planck satellites.

If CCC is Against both, then it's gonna be very very tough for it to Survive, not Impossible, but Improbable.

I Personally would Love to have a Theory that is of utmost Simplicity to understand.
(layman expectations)
But as They say, the Universe is under no obligation to make sense to Us
(boss music)
🎶
(musical notes emoji)