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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

#61
I misinterpreted the direct idea of 'Big Bang' at a very young age and thought that the nature of time changed over time, ergo, 'the beginning' could never be achieved (even if you could travel backwards in time), i.e. it's 'infinitely far back' similar to how time changes for traveller/observer as one approaches the speed of light.

Only in any given time frame could one mark 'the start', but that would be a misinterpretation.

So time did have a 'start' but it was 'infinity ago'.

I realized at some point this has nothing really to do with 'Big Bang', but later I've come back to the idea as at least novel!

It's fun to see smart people contemplating alternative things.

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

#62
post #54

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…

Wikipedia's 'Timeline of the Far Future' is a great article on the posibilities of our universe's fate [0]. Of note are the entries near the end of the list. Year 10^(10^(50)) : Estimated time for a Boltzmann brain to appear in the vacuum via a spontaneous entropy decrease [1] Year 10^(10^(120)) : High estimate for the time for the universe to reach its final energy state, even in the presence of a false vacuum. Year…

This kind of discussion always reminds me of the Asimov story "The Last Question"

https://www.multivax.com/last_question.html

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

#63
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Re: Physicists Debate Hawking’s Idea That the Universe Had No Beginning

#64

Am I wrong, or are they arguing on matters of belief rather than evidence?

The word is 'speculation' not 'belief' that that's pretty much what all science is. The evidence usually comes later.

There I was thinking that the scientific method involved falsifiable hypotheses - so how are they going to prove or disprove their respective beliefs? I'm getting string theory flashbacks where half of the physics community is into it, the other half is not, and no-one can prove anything, but they still have a grand old time arguing about it anyway.

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

#65

Am I wrong, or are they arguing on matters of belief rather than evidence?

The word is 'speculation' not 'belief' that that's pretty much what all science is. The evidence usually comes later.

Agreed that is where science starts. Speculation leads to generating testable hypotheses and experiments.

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

#66
post #31
post #21

Earlier quoted context omitted.

That's only disturbing if you believe everything is simple enough that humans could comprehend it straight away. If you accept that some stuff is beyond our understanding, and will be for quite a while yet, everything is much less bothersome. Accept that you are fallible and the universe is fine. I'm not saying this is easy though.

> If you accept that some stuff is beyond our understanding isn't that just an elaborate way to say 'give up'? I asked religious friends of mine about what god _is_, and the common answer is that it's beyond human understanding. I don't believe that people should take things on faith, and accept that anything is beyond understanding.

He only said it was beyond our understanding "for some unknown amount of time", or that it might end up being too complicated/incompatible with our existence.

His comment wasn't at all about giving up, honestly the exact opposite. It was about avoiding/managing the disturbed/dreadful feelings that commonly accompany the thoughts and work in this domain.

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

#67

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…

Although it raises an interesting question, because physics has a lot of issues with time. Just as in the computer example, why could we not imagine that our universe exists inside the space and time of larger superuniverse, and perhaps the phenomena that explain times arrow is easily observable in that universe, but not in ours.

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

#68

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…

> There is also a theory there could be many other big bangs and universes next to our own, but they are all accelerating away from each other.

I speculate that there is. And I assert that for our universe to be meaningful, it must birth a sentience into life in the fourth dimension. That probably sounds very wishy washy but does anyone get what I mean and agree with me on this? I’ve never told anyone about this postulation before but I doubt that I am alone in thinking this.

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

#69

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

It might be phrased differently. Like this. Is there something more universal than time. Look at spacetime from an outsider's perspective. Suppose it is 2D+1D, then one way time can be represented is as frames where each frame is slightly different. The interesting part is that those consecutive frames have very strong constraints. But what are those constraints? One of them is that energy is conserved. One other might be that it's Markovian: you only need to have the last frame for the next. If there exist (entangled) histories this seems to be wrong. The quest for (moderately) consistent frameworks that all have their own emergent nature of time might be a very fruitful one. It's rather a "beyond" time than a "before" time.

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

#70
post #51

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…

> what, if anything, is outside the observable universe The answer is similar to the time. Remember, in cosmology there's no really separate space and time, there's only space-time. So when you're looking at the edge of the observable universe, you really looking back in time. So the answer to the question "what is outside" is the same as "what was before". Or, in simpler words, the question is meaningless, as there'…

If you are restricted to the typical 3 dimensions of movement (and 1 through which we are non-optionally traveling) - you should either get to a physical boundary, or you end up in a loop, right? I mean, you won't travel so far you end up in Tuesday.
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