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

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

#11

Post by djsumdog »

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.

But the trouble with the South Pole and Shuttlecock metaphors is that you assume those objects are literally everything; all matter. If you define the Universe as Everything there is (seen and unseen; where what we see is the "Observable Universe") there is no outside location from which to observe it in entirety.

That's where the analogy really breaks down, but I guess it's still a useful thought experiment so long as you realize the limits to the domain.

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

#12

Post by djsumdog »

SketchySeaBeast wrote: post #6
kumarvvr wrote: post #2

Curiously,Indian philosophy also propounds that the universe has neither a beginning nor an end.

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…

Some of our best fictional stories are in cycles. The "Hero's Journey" is often a circle with growth, where you end up where you started from. Every season of The Wire pretty much ends in a circle.

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

#14

Post by eyeundersand »

omarchowdhury wrote: post #7
kumarvvr wrote: post #2

Curiously,Indian philosophy also propounds that the universe has neither a beginning nor an end.

What of Indian philosophy can you cite regarding this? From what I gather, it's seen as cyclic.

I would imagine the OP meant the cycles are never-ending, as opposed to one iteration of the cycle.

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

#15

Post by pavel_lishin »

sp332 wrote: post #13
SomeOldThrow wrote: post #3

What does it even mean to ask “what happened before time”? The question seems nonsensical to me.

You can still have causality.

Can you expand on this? How can you have causality - cause and effect - that's divorced from some sort of flow of time?

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

#16

Post by quotemstr »

sp332 wrote: post #13
SomeOldThrow wrote: post #3

What does it even mean to ask “what happened before time”? The question seems nonsensical to me.

You can still have causality.

Causality without time makes no sense. Even if you don't have a ticking clock, you can define "time" with a counter and a Lamport clock. Any time you have state, you have time. A timeless universe is hard to grasp.

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

#17

Post by abtinf »

The explanation I've found most persuasive is to take a purely philosophical approach: the universe had no beginning and will have no end because those concepts do not apply. The universe is everything. If there was something that "caused" the universe, it would just be part of the universe. If there is something after the universe ends, it would just be part of the universe. There is nothing outside the universe, if there was it would be part of the universe.

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

#18

Post by quotemstr »

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 effect.

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

#19

Post by [deleted] »

djsumdog wrote: post #10

This seems different than the concept of infinite time, where prior to the big band there was something the collapsed into a ball of energy and maybe someday our universe will collapse back again (which has lost merit since we've seen matter in the universe isn't slowing down in spreading apart, but accelerating .. meaning in a few trillion years, atoms may be so far apart that light can't reach anything .. the event…

[deleted]

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

#20

Post by abtinf »

quotemstr wrote: post #16
sp332 wrote: post #13

Earlier quoted context omitted.

You can still have causality.

Causality without time makes no sense. Even if you don't have a ticking clock, you can define "time" with a counter and a Lamport clock. Any time you have state, you have time. A timeless universe is hard to grasp.

Time without causality makes no sense. Time is an identification that entities move and change. The entities themselves cause all actions. The nature of those actions is determined by the nature of the entities.
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