More on the idea of 'before' the Big Bang

[Btodd]

Okay, so I was listening to the audiobook version of Bill Bryson's 'A Short History of Nearly Everything', and very early in the book, he says something to the effect of 'The Big Bang came from nothing'. Other than the usual attempts by Creationists to frame it in a derisive manner when confronting atheists (like myself), I've never heard anyone put it in that manner. The last person I heard use that was Sean Hannity, who said it takes more faith to be an atheist, because you had to believe that 'the universe came from nothing'.

So, what is your understanding of this issue? Was all matter, space and time created at the Big Bang? Does that mean that 'before' it was 'nothing'? My understanding is that we simply don't know what came before the Big Bang, and it may not be possible to know, since the laws of physics appear to break down when we get back to that moment.

In my limited mind, it would seem that something 'has always been', which is paradoxical to me. If something 'always was', whether the pre-Big Bang state, or a God (which I think creates even more problems)....and this ties in with my thread about infinity....that would mean that 'time' stretches back forever, with no beginning.

But if that's the case, if the regress backward is infinite, wouldn't it mean that we could never get to this point, because there are an infinite number of 'steps' or moments that precede it, which logically could not be traversed?

Does that make sense to anyone, or am I mixed up here?

 

[sol invictus]

My understanding is that we simply don't know what came before the Big Bang, and it may not be possible to know, since the laws of physics appear to break down when we get back to that moment.

That is correct.

In my limited mind, it would seem that something 'has always been', which is paradoxical to me. If something 'always was', whether the pre-Big Bang state, or a God (which I think creates even more problems)....and this ties in with my thread about infinity....that would mean that 'time' stretches back forever, with no beginning.

But if that's the case, if the regress backward is infinite, wouldn't it mean that we could never get to this point, because there are an infinite number of 'steps' or moments that precede it, which logically could not be traversed?

Does that make sense to anyone, or am I mixed up here?

I don't see the problem. You might find this thread interesting.

 

[Btodd]

I don't see the problem. You might find this thread interesting.

Thanks, I'm going to read it now.

You don't see the problem with the concept of infinite time? If 'what came before now' stretches back into the past infinitely, then isn't it impossible to get to this current point in time? There would also be an infinite number of 'days', or whatever unit of time you use, that preceded today.....hence, logically, you could never reach today or you would have traversed an infinite number of steps.

To me, that's a logical paradox.

 

[LarianLeQuella]

Is it really that big a deal to just admit "I don't know."? Sure, that shouldn't stop us from trying to find out, but I just see some sort of human distain for saying I don't Know that they go to great lenths not to admit a lack of knowledge. Hence we get a lot of made up fairytales like the bronze age creation myth that so many people buy into. I guess even a non-sensical BAD answer is better than saying "I don't know"?

 

[sol invictus]

You don't see the problem with the concept of infinite time? If 'what came before now' stretches back into the past infinitely, then isn't it impossible to get to this current point in time?

What do you mean, "get to"? There are an infinite number of integers less than zero. Is it therefore impossible for a number to be zero, or to have zero of something, or to count starting from zero?

There are an infinite number of intervals between 0 and 1, for example (0,1/2), (1/2,3/4), (3/4,7/8), etc. Does that mean you can never walk 1 mile (Xeno's "paradox")? Of course it doesn't.

There would also be an infinite number of 'days', or whatever unit of time you use, that preceded today.....hence, logically, you could never reach today or you would have traversed an infinite number of steps.

To me, that's a logical paradox.

It's certainly not a logical paradox. Think about it - what do you mean when you say "you could never reach today"? Who is "you" in that phrase? What do you mean by "reach"?

 

[Roboramma]

There would also be an infinite number of 'days', or whatever unit of time you use, that preceded today.....hence, logically, you could never reach today or you would have traversed an infinite number of steps.

Well, "you" would never reach today in a finite amount of time, anyway. But since "you" would have traversed those infinite number of steps in an infinite amount of time. I don't see the problem...

 

[Tim Thompson]

Pre Big Bang Cosmology Redux

To me, that's a logical paradox.

I think that, like Zeno's Paradoxes, it only looks like a paradox, but really isn't.

My understanding is that we simply don't know what came before the Big Bang, and it may not be possible to know, since the laws of physics appear to break down when we get back to that moment.

I'm sure that's quite correct, but I seem to have a more liberal attitude towards the idea of pre big bang cosmology than does Sol Invictus.

Surely the idea that the universe came from "nothing", in the truly logical sense of "nothing" is absurd. But of course the physicist's "nothing", unlike the mathematician's "nothing", is full of essentially undetectable, quantum mechanical departures from "nothing", under the protection of Heisenberg's ubiquitous umbrella of probability. So one must be careful about what "nothing" is really supposed to mean.

In the meantime, simply put, general relativity by itself, as the sole theory of spacetime, does not allow the initial conditions of the big bang universe to be defined. So you can pretty much make up anything you like, as long as it winds up consistent with the physics we expect when the universe reaches the ripe old age of about 10^-43 seconds or so. But of course "make up anything you like" is about as unsatisfactory as it gets. Fortunately, a more satisfying alternative is available.

We seek a quantum mechanical theory of gravity. We don't actually know that it is possible to achieve a quantum mechanical theory of gravity, but we seek one any way, because it seems like the right thing to do, and the results so far are at least encouraging. A quantum mechanical theory of gravity is a quantum mechanical version of general relativity (we hope), and as such should eliminate the undefined nature of the initial conditions of the big bang universe, without resorting to the undisciplined "make up anything you like". There is no such theory at present, but the proto-theories or pre-theories or hypotheses we have certainly appear to allow for pre big bang cosmology, which I have discussed elsewhere.

I think it is at least fair to say that asking what happened before the big bang is not unreasonable. And I think that a quantum mechanical version of general relativity, or whatever a quantum mechanical theory of gravity turns out to be, once we have one, will allow us to explore the answer to that question seriously.

 

[Btodd]

What do you mean, "get to"? There are an infinite number of integers less than zero. Is it therefore impossible for a number to be zero, or to have zero of something, or to count starting from zero?

There are an infinite number of intervals between 0 and 1, for example (0,1/2), (1/2,3/4), (3/4,7/8), etc. Does that mean you can never walk 1 mile (Xeno's "paradox")? Of course it doesn't.

Perhaps my problem is in thinking of time as a straight-line concept. I'm starting at this point, going backward, and thinking.....at no point will I reach a beginning. If any given point in the timeline has an infinite number of steps that precede it, then it seems like you could never get anywhere, because what does it mean to 'reach infinity'? I promise, I'm not just 'mystery mongering' here, like an undercover theist would....and then later propose that God solves the problem. I really can't understand this.

But your points are good ones, and make me reflect on my misunderstanding. Thank you.

It's certainly not a logical paradox. Think about it - what do you mean when you say "you could never reach today"? Who is "you" in that phrase? What do you mean by "reach"?

'You' doesn't mean a person, it's a placeholder. Think of something that doesn't die, any inanimate object if you wish. I think 'reach' is a reasonable word.....if time passes, each 'day' or increment of time in which an object exists was 'reached' by the passage of time. And in my limited mind, you can't 'reach' an infinite number, hence why I keep thinking it's a paradox.

Oh, and @ the poster above who said, 'Why not just say you don't know'? I do say, 'I don't know', but I also like to think about things instead of just throwing my hands in the air. That's a good thing, I think.

 

[MetalPig]

There are an infinite number of integers less than zero. Is it therefore impossible for a number to be zero, or to have zero of something, or to count starting from zero?

No, but what if you want to count up toward zero? There's no starting point, so how do you get anyhere? I think that's what Btodd is asking.

 

[Skeptic Ginger]

Re-listening to the discovery of the formation of Earth's Moon recently the math also 'broke down' as one calculated the orbit back to the time the Moon formed. It almost reached the Earth but the math failed at the point of actually merging with the Earth. The solution was the Moon formed from a collision and once that was added to the calculations the math worked.

I'm not suggesting something hit the singularity necessarily and started the BB. But there has to be something that occurred which we have yet to discover that will make the math work when we do.

 

[Akhenaten]

ssssssssssssst . . .

 

[sol invictus]

I'm sure that's quite correct, but I seem to have a more liberal attitude towards the idea of pre big bang cosmology than does Sol Invictus.

I'm not sure about that - I agree with what you wrote in that post. In another thread here I listed 4 or 5 possibilities for what could have come before the big bang, or how it might be resolved. I could try to dig it up.

I'm starting at this point, going backward, and thinking.....at no point will I reach a beginning. If any given point in the timeline has an infinite number of steps that precede it, then it seems like you could never get anywhere, because what does it mean to 'reach infinity'?

Those two statements are not equivalent, nor does the second follow from the first. Start somewhere and go backwards. Now it's true, at no point do you reach a beginning. But how does it follow from that that you could never get anywhere? On the contrary - given any place (or time), if you go for long enough you'll arrive. So it's just the opposite.

No, but what if you want to count up toward zero? There's no starting point, so how do you get anyhere? I think that's what Btodd is asking.

It's only a paradox if you start from infinity. But it doesn't make sense to start from infinity, because infinity isn't a place - so you've put the paradox in by hand. If instead you start from any finite point, there's no difficulty - and that's all one can do in physics anyway (measure conditions at some time or place and then use equations of motion to extrapolate forward or backwards).

 

[sol invictus]

Here it is:

Here's what we know: the universe is expanding in such a way that about 13.7 billion years ago all the matter we see in it today was crunched up in one point - or at least in a very small region. Those observations together with our current understanding of physics are not precise enough to tell us it was really a point with zero size or precisely what happened there. In particular general relativity (Einstein's theory of gravity) goes haywire there - it encounters a singularity, meaning it gives back infinity for physical quantities (which presumably shouldn't happen).

Resolving the singularity has proven to be extremely difficult - string theory doesn't seem to do it in general, and neither does any other credible theory. However there are some ideas. Here's a rough list of not necessarily mutually exclusive options:

1) the big bang was a true singularity, and time began there. There was no "before".

2) the big bang was actually a bounce - a previous universe collapsed towards a crunch, but just before it hit some very powerful repulsive force came into play and forced it to "bounce" and expand. We live in the expanding phase. The universe before could have been there forever (gradually contracting, going back to infinite size long ago) or the bouncing could be cyclic.

3) classical spacetime ceases to exist near the singularity. Quantum gravity effects put space and time into a quantum state with large fluctuations. Questions about "before" become meaningless.

4) the universe originated in a Hartle-Hawking instanton (i.e. time went from being a spatial coordinate to a time coordinate, and the universe appeared in a de Sitter phase).

5) our patch of the universe is expanding because it is inside a bubble of true vacuum in a larger space. In that case the big bang was non-singular, but you could still ask where the larger space came from.

6) the world is balanced on the back of a giant turtle. Before you ask, it's turtles all the way down.


The final answer to your question: we don't know.

 

[Perpetual Student]

Surely the idea that the universe came from "nothing", in the truly logical sense of "nothing" is absurd. But of course the physicist's "nothing", unlike the mathematician's "nothing", is full of essentially undetectable, quantum mechanical departures from "nothing", under the protection of Heisenberg's ubiquitous umbrella of probability. So one must be careful about what "nothing" is really supposed to mean.
__________Tim Thompson

If the 'physicist's "nothing"' is not really nothing, then it must be something; consequently, the big bang came from something, which would would appear to deprive the universe of a real beginning. Something had to be for the universe to be.

 

[Belz...]

Perhaps my problem is in thinking of time as a straight-line concept. I'm starting at this point, going backward, and thinking.....at no point will I reach a beginning.

Why would that be a problem ? Other than the fact that you wouldn't get a first cause by doing so.

If any given point in the timeline has an infinite number of steps that precede it, then it seems like you could never get anywhere, because what does it mean to 'reach infinity'?

It doesn't follow. If you can't get to B, you may still be able to get to A.

 

[quarky]

illusion, same as now.