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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

#242
Watching his Gresham talk (link in someone else's post) he represents the multiple cycles of the universe as cylinders connected at the round ends with time going along the central axis. He also represents the Big Bang universe as an upsidedown bell shape starting from a tiny radius, undergoing inflation and then later accelerating expansion shown by the outward flare of the bell. Not quite sure how he gets from multiple consecutive bell shapes to the cylinder representation. Seems like it should be more like a string of sausages with a big crunch before the next big bang.

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

#243

Watching his Gresham talk (link in someone else's post) he represents the multiple cycles of the universe as cylinders connected at the round ends with time going along the central axis. He also represents the Big Bang universe as an upsidedown bell shape starting from a tiny radius, undergoing inflation and then later accelerating expansion shown by the outward flare of the bell. Not quite sure how he gets from mult…

On second listening, he stretches the base of the bell (the big bang phase) out and compresses the flare of the bell down using some mathematical transforms and makes the argument that mass is irrelevant at both ends. In the far future it is mostly massless photons and in the big bang things are so hot and fast that all the energy is kinetic and rest mass can be ignored. I still don't understand how the next cycle big bang originates.

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

#244

Earlier quoted context omitted.

If you're happy for mathematical structures to be infinite, why can't our universe (including ourselves) just be one infinite mathematical structure? Yes, it's very complex, but there's plenty of room in infinity. It doesn't need to have a "real" physical instantiation anywhere. It's like the simulation hypothesis, except you don't need the simulation. We're just the inside of an infinite self-experiencing mathematic…

Because universe is a physical structure, not mathematical, e.g. you can't define things into existence.

This is exactly the position I'm trying to argue against.

What does it mean for something to be a physical structure? That you perceive it to be physical? But aren't your perceptions part of the universe? So how would you know if it actually "exists" anywhere?

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

#245

Earlier quoted context omitted.

But it can’t NOT be infinite! If space were three dimensionally finite, then there must be a boundary. But if there were a boundary, then there must be something beyond that boundary. And now we have a paradox that infinitely regresses. Same goes for time. Same goes for distance. How can there be both a finite distance, as well as an infinite number of points between two distinct points? To me, infinity seems to be e…

> If space were three dimensionally finite, then there must be a boundary. Not true, space might just repeat in all directions - a finite volume but with no boundaries. Maybe if you go far enough you always end up back where you came from.

That may be true. But if that we’re the case, then a fourth spatial must exist for the entire 3rd dimension to wrap in on itself. And then we find ourselves in the same infinite regression, wondering about the boundaries of the parent dimension.

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

#246
post #196

Earlier quoted context omitted.

Oh this is super cool, thanks for sharing. I have strong (admittedly mostly irrational) inclinations against determinism, seeing something like this is exciting. Definitely going to have to give it a read. Sapolski's take on determinism was really a low blow for me, and I've since seen several other intellectuals I respect very highly espouse similar views, and there was a point where I would have agreed in my adoles…

The problem with arguing quantum non-determinism gives rise to consciousness is that it doesn't really give you free will, it just implies the consciousness is an unpredictable process. But a quantum physicist would then ask "to what degree?" because quantum mechanics is very deterministic over large sample sizes (and a few trillion proteins in the brain would be a very large sample). More importantly though, free wi…

Sure, but are we not precluding that the forces which gave rise to the genesis and evolution of life were able to search and select for functional quantum phenomena? We're talking about processes that can turn a pile of water, salt, sugar, nitrogen, and some vitamins into an obscenely complex, highly adaptable, self-replicating, self-regulating machine which can produce a variety of different micro and macromolecules in a baffling concert of physics and chemistry at scales and complexity humans can hardly work at, and certainly not so majestically.

And we've also got eyes, which in principal means that many life forms already have quantum-sensitive apparati, right? Magnetoreceptors as well, and they're also found in "lower lifeforms" in various different forms from the basest phototaxis to extraordinarily refined lens systems which can numerous wavelengths.

And then I suppose when talking in scale — what does it actually mean — to flip that coin when you've only got an N of one in reality.

Of course I would have to concede that I accept an element, even a large one of determinacy, but my experience also precludes the idea of it existing exclusively. I'm really just pattering away right now, frankly I know very little of quantum physics (nothing, really) it's just nice to know someone is willing to furnish a hypothesis contrary to what I believe is the consensus on the topic.

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

#247

Earlier quoted context omitted.

Because universe is a physical structure, not mathematical, e.g. you can't define things into existence.

This is exactly the position I'm trying to argue against. What does it mean for something to be a physical structure? That you perceive it to be physical? But aren't your perceptions part of the universe? So how would you know if it actually "exists" anywhere?

Physical structure works by its own rules, mathematical structures work by our rules. For example, in mathematics you can complete an infinite process, because there's no time in mathematics, it can just be assumed out of existence. It can't be done with physics, because physics isn't affected by our assumptions.

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

#248

Earlier quoted context omitted.

This is exactly the position I'm trying to argue against. What does it mean for something to be a physical structure? That you perceive it to be physical? But aren't your perceptions part of the universe? So how would you know if it actually "exists" anywhere?

Physical structure works by its own rules, mathematical structures work by our rules. For example, in mathematics you can complete an infinite process, because there's no time in mathematics, it can just be assumed out of existence. It can't be done with physics, because physics isn't affected by our assumptions.

Time and physics are just things you experience. They're parts of the universe, they're within the universe. The mathematical universe itself can quite easily be infinite in both space and time, you just can't experience all of it.
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