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Roger Penrose claims our Universe has been through multiple Big Bangs

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Re: Roger Penrose claims our Universe has been through multiple Big Bangs

#131

Post by wswope »

truculent wrote: post #14

IANAP - why are these ideas so controversial? The article seems to suggest he has some (potentially) supporting evidence, and I don't have an intuition for how damning the counter-argument is ("This would necessitate making all particles lose mass as the universe gets old." Again, IANAP and physics can get weird).

Since I haven’t seen anyone else mention this bit of context elsewhere in the thread: Penrose gets a bit of side-eye in the physics community because of his metaphysical beliefs on consciousness. (Specifically, that quantum effects in tubule proteins of the brain produce special nondeterministic effects that constitute our conscious essence, and true consciousness is impossible without this nondeterministic fount of spiritual essence.)

https://en.wikipedia.org/wiki/Roger_Penrose#Consciousness

He’s clearly a smart guy… but also has some hot takes.

(Zero judgement intended; only bringing this up as background context.)

Re: Roger Penrose claims our Universe has been through multiple Big Bangs

#132

Post by Chris2048 »

some_other_time wrote: post #106

This reminds me of something I read some time back. It was about hypervelocity stars, stars with escape velocity. These are stars that are moving fast enough to escape the gravitational pull of their galaxy. If they are escaping their galaxy and moving away from the galactic center, they may also be beyond the pull of any retraction. This, in turn, would mean the subsequent post-retraction Big Bang contains less matt…

hypervelocity stars only escape their galaxies. I'd assume to escape the big-bang they would need to escape the "universe" aka most of the matter in the universe.

Re: Roger Penrose claims our Universe has been through multiple Big Bangs

#134

Post by throwaway290 »

likeabbas wrote: post #129
mr_mitm wrote: post #19

> What proof does the physicist have for this theory he dubbed “conformal cyclic cosmology” (CCC) that goes against the current Big Bang dogma? It doesn't go against the current "dogma", as the Big Bang theory only covers history up until a fraction of a second after the big bang. Anything before that is basically fair game, even though some ideas are further out there than others. Penrose admits it's a "crazy idea o…

> Hossenfelder's thoughts about FTL travel in her video from yesterday I didn't watch said video, but we have theories rooted in GR and Quantum Mechanics that would allow for FTL travel already using negative energy/pressure. We know there exists mechanisms to create negative pressure, like the Casimir effect. We know the universe is non-local, as per the Nobel prize awarded last year. And we are beginning to see exp…

What experiments violate causality?

Re: Roger Penrose claims our Universe has been through multiple Big Bangs

#135

Post by what-no-tests »

neom wrote: post #123
_448 wrote: post #86

Here is Dr. Carl Sagan describing this in his Cosmos series (Episode 10, start at 36mins 30secs into the episode): https://www.youtube.com/watch?v=FcpJj4g8IxM

FYI: I needed to VPN over to Mexico to watch this. Worth it though, super interesting/terrifying. Thanks for sharing!

Enjoy that now, before the "RESTRICT" Act gets passed!

Re: Roger Penrose claims our Universe has been through multiple Big Bangs

#136

Post by [deleted] »

elashri wrote: post #87
mr_mitm wrote: post #42

Earlier quoted context omitted.

Another user in this thread mentioned it and it's described in the wikipedia article about crazy nobel laureates linked elsewhere here. Basically, Pauling believed high doses of vitamin C could prolong the lives of cancer patients and cure schizophrenia, despite being out of his field of expertise and lack of evidence.

But Penrose's field of expertise is Cosmology. So I don't think I get the analogy? I understand that this is a speculation because it is very hard to collect evidence for that claim but it is still within the wide umbrella of what Penrose devoted his career.

[deleted]

Re: Roger Penrose claims our Universe has been through multiple Big Bangs

#137

Post by bawolff »

_a_a_a_ wrote: post #78
rdtsc wrote: post #72

Earlier quoted context omitted.

Just wanted to commend you for sharing your experience. It's not something that's popular on HN and, as expected, was immediately followed with "you probably have a brain tumor for doing it" comments. So wanted to counter-balance that and let you know that not everyone is as hostile and mean-spirited.

I'd say this kind of thing is not popular on HN because it had very little useful information content, and if he knew it was not going to be popular here because of religion, well he posted it anyway didn't he… > was immediately followed with "you probably have a brain tumor for doing it" comments Actually most comments weren't of this nature, but you climbed over those to find the one you could plant your flag of ma…

To be fair, the brain tumour thing used to be much higher up (i guess it got downvoted), and i agree that it is an incredibly condescending and offensive thing to say.

Like sheesh, imagine saying that in any other context. e.g. someone likes emacs, must be a brain tumour.

Re: Roger Penrose claims our Universe has been through multiple Big Bangs

#138

Post by likeabbas »

throwaway290 wrote: post #134
likeabbas wrote: post #129

Earlier quoted context omitted.

> Hossenfelder's thoughts about FTL travel in her video from yesterday I didn't watch said video, but we have theories rooted in GR and Quantum Mechanics that would allow for FTL travel already using negative energy/pressure. We know there exists mechanisms to create negative pressure, like the Casimir effect. We know the universe is non-local, as per the Nobel prize awarded last year. And we are beginning to see exp…

What experiments violate causality?

https://phys.org/news/2017-04-physicists-violate-local-causa... is one

Re: Roger Penrose claims our Universe has been through multiple Big Bangs

#139

Post by DangitBobby »

m3kw9 wrote: post #22

Then how did the first one came about? What was there before it, pls don’t tell me nothing because it was nothing for a long time and then something must have triggered the first one. Or was there no first one because of infinity?

Either something can come from nothing, or something has always been. Neither make sense from our understanding of causality, but one of them must be true.

Re: Roger Penrose claims our Universe has been through multiple Big Bangs

#140

Post by slenk »

what-no-tests wrote: post #135
neom wrote: post #123

Earlier quoted context omitted.

FYI: I needed to VPN over to Mexico to watch this. Worth it though, super interesting/terrifying. Thanks for sharing!

Enjoy that now, before the "RESTRICT" Act gets passed!

VPNs are illegal in China, but that doesn't stop a lot of them
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