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Physicists Debate Hawking’s Idea That the Universe Had No Beginning

quantamagazine.org

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Re: Physicists Debate Hawking’s Idea That the Universe Had No Beginning

#41

Post by syn0byte »

umvi wrote: post #24
quotemstr wrote: post #18

Cosmology is deeply disturbing if you think about it too long. Why should the universe exist? What is a causeless cause? How can something come from nothing? Regardless of the precise mechanisms involved, at some scale, some kind of steady-state cyclic model seems unavoidable --- the whole idea of existence not existing is bizarre and puzzling. The only way out of the causeless effect problem is to nop out of the eff…

> the whole idea of existence not existing is bizarre and puzzling The alternative is that matter has always existed, which is equally bizarre and puzzling, though things make more sense that way.

While everyone else wonders about the nature of time. I wonder about the nature of "sense." What is "sense"? How do some things 'make' sense and others don't? Is "sense" universal? If not, why?

Re: Physicists Debate Hawking’s Idea That the Universe Had No Beginning

#42

Post by SketchySeaBeast »

roland00 wrote: post #35
SketchySeaBeast wrote: post #6

Earlier quoted context omitted.

I think it might actually be more unique for western philosophy/religion to be building a narrative with a beginning, middle, and end - a lot of other ancient cultures seemed to see things as a cycle - for instance, we see in the Mayans that they saw the world as a series of cycles. It makes sense in early traditions to not have a beginning and end - if there's no track of "progress" in a historical fashion, it would…

It was Aristotle's Unmoved Mover being incorporated into Christian Thought around AD 50 via Philo of Alexandria that changed Monotheistic religion of God being the Organizer of All Things from Chaos into the Creator of All Things out of Nothing, Ex Nihilo. Beforehand Monotheistic Religions believed God was a creator but he created out of chaos and imbued the formless with a specific form. Likewise simultaneously arou…

Zoroastrianism had to concept of a universe that starts with nothing and comes to an end as far back as the 6th century BCE.

But I agree, adding a concrete understanding of time really helps to cement the linear narrative.

Re: Physicists Debate Hawking’s Idea That the Universe Had No Beginning

#44

Post by [deleted] »

roland00 wrote: post #35
SketchySeaBeast wrote: post #6

Earlier quoted context omitted.

I think it might actually be more unique for western philosophy/religion to be building a narrative with a beginning, middle, and end - a lot of other ancient cultures seemed to see things as a cycle - for instance, we see in the Mayans that they saw the world as a series of cycles. It makes sense in early traditions to not have a beginning and end - if there's no track of "progress" in a historical fashion, it would…

It was Aristotle's Unmoved Mover being incorporated into Christian Thought around AD 50 via Philo of Alexandria that changed Monotheistic religion of God being the Organizer of All Things from Chaos into the Creator of All Things out of Nothing, Ex Nihilo. Beforehand Monotheistic Religions believed God was a creator but he created out of chaos and imbued the formless with a specific form. Likewise simultaneously arou…

[deleted]

Re: Physicists Debate Hawking’s Idea That the Universe Had No Beginning

#45

Post by dmix »

The linked 1981 source document "Astrophysical Cosmology" proceedings from the Vatican look's interesting (Hawking's raw talk is at page 575 in the PDF):

http://www.pas.va/content/dam/accademia/pdf/sv48pas.pdf

The preface mentions the academy was from 1603 and Galileo Galilei was a member.

Re: Physicists Debate Hawking’s Idea That the Universe Had No Beginning

#46

Post by logicchains »

quotemstr wrote: post #18

Cosmology is deeply disturbing if you think about it too long. Why should the universe exist? What is a causeless cause? How can something come from nothing? Regardless of the precise mechanisms involved, at some scale, some kind of steady-state cyclic model seems unavoidable --- the whole idea of existence not existing is bizarre and puzzling. The only way out of the causeless effect problem is to nop out of the eff…

From a probabilistic point of view, we're observing with extreme selection bias: we only see the universe in which we do exist, not all the ones in which we don't, so no matter how incredibly unlikely existence is, from the perspective of existing consciousness it is guaranteed. This means it's possible for consciousness to arise from pure entropy: https://en.wikipedia.org/wiki/Boltzmann_brain.

Re: Physicists Debate Hawking’s Idea That the Universe Had No Beginning

#48

Post by gavanwoolery »

I have very little knowledge of astrophysics, but I thought it would be an interesting idea if the universe constantly recycled itself. That is, every so often it collapsed in on itself and produced another big bang. Theoretically some parts of the universe would have already achieved escape velocity, but the rest of it is gradually gravitating towards some center of mass. Is such a thing even feasible?

Re: Physicists Debate Hawking’s Idea That the Universe Had No Beginning

#49

Post by TheOtherHobbes »

wuliwong wrote: post #38
kowdermeister wrote: post #22

Earlier quoted context omitted.

If I turn on a very simple computer, then the clock starts at zero. From the computers perspective that's all there is, it doesn't know the cause. From my point of view there absolutely is a case, me pushing a button. This is not a god argument, there might be natural processes that can trigger such events.

I don't think this is an accurate analogy. The computer's space-time and your space-time are the same in this analogy. The space-time that our universe exists in would not be the same as the space-time that some extra-universe process would be inside if the big bang theory is accurate. This isn't an analogy for causality without time, this is causality for the creation of our universe if the big bang theory is wrong…

If the computer is simulating a spacetime, they're not the same.

You could - hypothetically - pause the computer, check its state, change a few variables, and the simulation would experience instant modifications.

A slow simulator could take many "real" time units to calculate each in-simulation time frame - and this would be invisible in-simulation.

And so on.

You have a fully causal system, but the simulation is ruled by its own independent emulation of causality.

Of course a computer implies a conscious user. But let's attempt some wild speculation and suggest that a "simulation" could also be a completely natural process - something that happens in a much bigger causal substrate: a kind of causal symmetry breaking, where a subset of possible relationships crystallises out of a bigger set of possibilities and then continues independently, losing some degrees of freedom.

A simple two level topology is the simplest possible model. But "causality physics" could allow all kinds of topologies - nested, circular, fractal, etc.

Re: Physicists Debate Hawking’s Idea That the Universe Had No Beginning

#50

Post by BurningFrog »

weego wrote: post #8
hirundo wrote: post #4

> “Asking what came before the Big Bang is meaningless ... It would be like asking what lies south of the South Pole.” Isn't Polaris Australis south of the South Pole? Was Hawking imagining an Earth-shaped space that isn't embedded in a larger space?

A stars position can't be defined as being south of somewhere. South exists as a logical construct of our magnetic poles. Once you lose that you have no relative measure to work with. The same is possibly true of time.

Nitpick: North/south exist due to the planet's rotation, not the magnetic poles.

The magnetic poles happen to be near the rotational poles, but that's incidental.

Sorry to be That Guy today :(

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