Did the universe have a beginning?

Brian-M

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Brian-M
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A question for people far more knowledgeable in this area than I am, is it both possible and plausible that the universe had no beginning? And if so, how?

My entirely baseless hypothesis (uneducated guess) is that universe began as an infinitely small point and has been expanding forever, with the universe as we know it only forming as it grew large enough for current physical laws to apply.

Is this in any way plausible? What exactly do we know about the universe before Planck temperature fell below 1? Do other theories/hypothesis such as the oscillating universe theory have any merit?
 
I think I would say "we don't know but for all practical purposes it did".
 
Did the universe have a beginning?

Does knowing the definitive answer really matter?
 
Yesish*


*I think
 
It may have had a beginning but we cannot know what happened before that as the question itself is meaningless, is how I understand Stephen Hawking's explanation of the Big Bang.
 
Brian-M said:
A question for people far more knowledgeable in this area than I am, is it both possible and plausible that the universe had no beginning? And if so, how?
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Yes. You might study Alfven's concept of a "big bang". It was more of a cyclical event rather than a "creation event".
http://www.thesurfaceofthesun.com/Alfven/CosmologyAlfven.pdf

His theory more or less begins with equal amounts (equal numbers of galaxies) composed of matter and antimatter that are drawn together by gravity. As they get close, they begin to annihilate each other and that annihilation process leads to an expansion cycle. Theoretically it could result in cyclical contraction cycles followed by cyclical expansion cycles. I suppose if one added an external, all pervasive EM field into the process, one could even explain an accelerating expansion. An accelerating expansion process however would tend to rule out cyclical events in favor of a "one time" event.
 
Dancing David said:
We can't say what was befor eth BBE, maybe someday, but not at this time.
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Just for clarification, I'm not asking for someone to step forward and say x, y and z happened. What I'm looking for is an understanding of the different ideas of what may and may not have happened, and how plausible/implausible each idea may be.

commandlinegamer said:
It may have had a beginning but we cannot know what happened before that as the question itself is meaningless, is how I understand Stephen Hawking's explanation of the Big Bang.
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I know we cannot know for sure, I'm looking for scientifically plausible hypothesis. As for the Big Bang, the idea I put forward is that maybe the "Big Bang" is infinite and has always been expanding (and always will be, if you count the current expansion of the universe as a continuation of it). Since the Planck limit prevents us from finding out what happened before a certain point, an exponential proportional expansion from an infinitely small point might give the appearance of the sudden expansion we observe today, without actually having a beginning.

Or I could just be talking complete nonsense, which is why I'm asking. :)

Michael Mozina said:
Yes. You might study Alfven's concept of a "big bang". It was more of a cyclical event rather than a "creation event".
http://www.thesurfaceofthesun.com/Alfven/CosmologyAlfven.pdf
Click to expand...


That's similar to what I meant with my mention of the oscillating universe theory.
 
Here's are a few threads on similar topics:

http://www.internationalskeptics.com/forums/showthread.php?t=143090
http://www.internationalskeptics.com/forums/showthread.php?t=134077
http://www.internationalskeptics.com/forums/showthread.php?p=4512662

And here's an old post of mine:

sol invictus said:
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.
Click to expand...
 
Michael Mozina said:
Yes. You might study Alfven's concept of a "big bang".
Click to expand...

Don't bother with this one, Brian. It's already been falsified. Michael just clings to it because he doesn't understand the standard cosmological model and so thinks it must be wrong.
 
Youtube: A universe from nothing, a lecture by Lawrence Krauss from the Richard Dawkins Foundation (I can't post URLs yet).

My summary of the lecture or at least the bits that rocked my world.

The universe is 13.72 billion years old and we are all stardust.

I also liked how well he explained how we know the universe is expanding (red shift), how we weighed the universe (and dark matter).

If the universe is flat (which it appears to be), then it has an energy of zero (negative energy of gravity balances out the positive energy of matter), and the laws of physics allow it to be created from nothing, quantum fluctuations can produce the universe.

If you have nothing in quantum mechanics, you always have something. 70% of the energy in the universe resides in empty space, or nothing, and we don't know what it is for. The other 30% is dark matter, and all of what we can see, the galaxies, stars, etc, is irrelevant.

The big bang happened as there is energy left from it, cosmic microwave background (the afterglow of the big bang), 1% of the static on a blank TV screen is this.

The conclusion, the universe is big and mysterious, and rare events happen all the time.
 
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