Kris: What Was There Before the Big Bang?
>> Monday, June 22, 2009
Kris asked (a long time ago): What was out in space before the Big Bang?
Kris, I'm so sorry. You sent this to me some time ago and I missed it.
The answer is, I haven't the faintest idea.
The Big Bang is a current theory, but it's hardly the only one. Many think it is the definitive one, the one in best agreement with available data, I don't know, it's not my area of expertise.
However, when it comes to what came before the "Big Bang," I think there is absolutely no evidence at all. Most speculate that there was nothing but a point of hot energetic matter in one spot that blasted out during the Big Bang (or their variation of choice) and it's been expanding into the nothingness ever since.
That could be true.
For me, it's pure speculation and, personally, I think your guess is as good as mine.
I like the notion that the world as we know it regenerates in cycles and that the universe might do the same. Perhaps there were worlds and a universe before the beginning of time as we know it and it was all scooped up cataclysmically like a handful of jacks before being scattered again. That this has happened time and again.
I don't know, but I'll tell you, what you or I believe doesn't really change whatever really happened. And I won't lose sleep on it either way.
that's a really hrd question to answer.
The classic "religion" conundrum--why is there something instead of nothing?
I have heard a nifty string theory idea that a big-bang type cataclysm could have happened if two "branes" or two multiverses ran into each other.
Plus there's the big crunch theory, that the universe will stop expanding, start shrinking, and eventually shrink to the size of an atom (which is unstable), and big bang all over again.
Interesting, but completely unprovable. EVER.
All kinds of cool theories, the current most accepted is the big bang. As for what existed before, absolutely nothing, in an instant time and matter came into being, how wild is that?
My old man always told me that right before the big bang was the big grunt. Of course, he's dead now, so what the hell did he know?
Could it be quantum mechanics?
Imagine shuffling a deck of card and spreading them out, they will be basically random, but once in a while, they will be in order. That is out universe, our universe is the rare time where a random process produced an ordered system.
Hey, I was browsing through Stephanie's last answers - and I'd like to take a stab at Kris question. I am a physicist, so I know a bit about what I am talking about; but then again, I am a plasma physicist and not an astrophysicist, so take this answer with a grain of salt.
Your question is a very common one, and it's based on two misconceptions. Still, the truest answer would probably be the one Stephanie gave you: "We don't know."
Yet we physicists like to hear ourselves talk, so here follows a small digression in cosmology.
Our universe expands. This is something that many people know, but what does it mean? If our universe expands, does that mean I get fatter?
That our universe expands was first noticed by astronomers who looked at the light of distant stars, and noticed that the light coming from them was too red. Too red in a spectrographic sense - it does not mean that all the stars look reddish (which they don't), but that the spectral lines in the light were shifted to longer wavelengths. In the visible spectrum the longest wavelength belongs to red, hence the word "redshift". The only explanation that makes sense (if we postulate that physics works the same way in the whole universe, and this makes sense in absence of evidence to the contrary) is that those stars move away from us very fast, so the wavelength of their light gets elongated, kind of like the sound of the horn of a car that passes you. Furthermore, more distant stars have light that is even stronger shifted to the red, so they have to move away even faster. Since for a variety of reasons we can be pretty sure that we are not the center of the universe, this must mean that every star is moving away from every other star - that is space itself must expand.
You can imagine this as the stars being little dots on the surface of a balloon. When you inflate the balloon, it's surface gets stretched, and every dot will move away from every other dot. If those dots can move, then dot's whose force of attraction to each other (what we call gravity) will keep some dots close to each other. This is why we don't move away from the sun, or from the stars in our galaxy. Gravity keeps us together. The atoms in your body have an even stronger force of attraction than gravity, the electromagnetic force, which is why you and I don't expand ;)
But if the universe expands, what does it expand into? And here the analogy with the balloon breaks down, because the balloon expands into the space around it. Our universe doesn't, because it is space itself. There is no "outside", not even (as far as we know) an outside we can't get to. (You can show this with some fairly complicated mathematics, becuase an outside, i.e. another dimension, would, even if we couldn't get "to" it, have an impact on how our world works, and we don't see that)
So, to answer part of your question: There was not even nothing out in space before the big bang, because all space was included in the tiny, tiny universe that started to expand (or explode, if you like). And here a wag of my finger to you, Stephanie: The universe doesn't expand into nothingness, it expands, full stop!
But still, part of the question remains: What was there before the Big Bang? And again, the answer given with our current understanding (or at least, with my probably skewed version of that understanding) is, that there was no before.
This, you will say, makes no sense. And I agree, but in fundamental physics stuff like this always happens; you get used to it after a while. You see, the Big Bang created not only space, but space-time. If you create time, then there can be no "before", because "before" is a concept that needs time to work in. So no before the Big Bang.
Grr, stupod 4096-character-limit! Here is the rest of my post:
But our understanding of the Big Bang has a serious weakness: The theories we no cannot describe it. We can describe what happenen right up to 10^-43 seconds after - but before that, we don't have the right theories. General relativity predicts a singularity, but we know that general relativity fails near singularities. What we need is a theory we call quantum gravitation, but we don't have that (yet).
And here we are, right back at the beginning: we don't know what happened before the Big Bang (there might not have been a before, though). We don't even know what happened at the Big Bang!
I hope that answered your question,
Boris
Boris, before you go wagging your finger at me, define "nothingness"?
But I appreciate the expanded explanation. I'm not of the opinion that just because an explanation is the only one we can think of doesn't mean it's the answer. But I find the redshift fascinating.
Actually, I should have wagged my finger at you for "into", not for "nothingness". Nothingness is not well enough defined to object to, but the universe is not expanding "into" anything, because that would mean something exists outside the universe. And nothing does, by definition. As far as we know.