Alternative to the big bang singularity?

[Jimmy_C]

I was just thinking. From what I understand, the current Big Bang model suggests that the universe was originally in a single point, space got "bigger" as the universe got bigger.

But what if space was always infinite? However, when the universe got "bigger", space got bigger at the same rate, thinning out the universe the same was as a point would. Different parts would still go past our light cone, never to return. However, this avoids the "no space" thing.

It still has the universe starting with infinite density and pressure; however, the "singularity" is now not really a singularity, is it? Just like the gravity inside a spherical shell is zero, wouldn't the gravity of a point with infinite density also be canceled out by the gravity of the other infinite density points around it?

 

[Jimmy_C]

This is just a guess. I'm sure I'm wrong, and would like to know the reason!

 

[PurpleBuddha]

I wouldn't mind entertaining the idea, but I have few questions about it first.

How does infinite space get bigger? And when you said "this avoids the no space thing", I get the impression you find that aspect of the big bang as we know it problematic. If so, why?

 

[Jimmy_C]

Just because it is infinite doesn't mean it can't expand. Is not known if the universe is infinite or bounded. We can probably never know, since we can only see the "observable universe" and not the entire universe.

I find having a point where space just BEGINS to be problematic; because, you can't define what happens at that point that. Physics doesn't make sense without space as a dimension. So I want there to still be space at the big bang.

 

[FordSVT]

Physics doesn't make sense without space as a dimension. So I want there to still be space at the big bang.

Physics says the interior of a black holes doesn't make sense either but no amount of wishing is going to make their reality go away.

That's why they're still working on a Grand Unified Theory, so they can reconcile the incredibly small (singularity) with the large.

The problem a lot of people seem to have coming to grips with the big bang theory and many other theories (especially in quantum mechanics) is that reality doesn't always jive with common sense and human senses. Sometimes you have to think beyond what's logical or what is common sense because the human reference point is inferior.

 

[bryce]

Space-time always in infinite?

Do you mean something like the old Steady State Theory???

That was disproven long ago - because there is a ton of reasons besides cosmic expansion that point to a Big Bang having happened ~ 14by ago...plenty of evidence for a Big Bang, and things that can only be accounted for it -- such as the 3 degree K microwave cosmic background radiation, just to name *one*.

And sure - physicists wrestle with how to handle the problem of the singularity (but it's still *there*)...and a more complete /higher understanding of physics can help us better understand it, or redefine it.

M-theory, for example, sorta does away with the singularity at the Big Bang, by redefining it (in some way I don't have the knowledge to really explain)...some say even allowing us to progress *back* through the singularity and to before it. (Something to do with time, of a sorts, existing before it...and our "universe" just being one "membrane" floating in 11-D hyperspace-time, and the Big Bang being caused by the collision of our "brane" with another floating in this 11th dimension...)

 

[bryce]

^I can't figure out how to embed video (mods?) - but here's a link to excerpts of a BBC documentary (called "Parallel Universes") - that discusses some of the ideas.

http://www.youtube.com/watch?v=HOkAagw6iug

NOTE: As per the video's disclaimer - these hypotheses are new, controversial, and currently untestable - so still mainly conjecture.

But so was Bing Bang cosmology once upon a time...

 

[Jimmy_C]

I don't mean steady state, just that maybe space wasn't at one "point" at the big bang. Maybe it was still infinite, it just "got bigger." Anyway, I don't think this idea is true anymore. I was just speculating.

 

[USS Triumphant]

I don't mean steady state, just that maybe space wasn't at one "point" at the big bang. Maybe it was still infinite, it just "got bigger." Anyway, I don't think this idea is true anymore. I was just speculating.

I don't really see any problem, per se, with the theory you outlined in the initial post - except that there is no evidence for it, and probably, there can't be. If none of the matter and energy of the universe was "out there", then there's no way for anything (and no "anything" for that matter) to communicate information back to us.