what if the big bang isn't the beginning of the universe?

The Big crunch is a dead theory now but for a while it was widely touted so it's not surprising to still hear people referring to it.

It held sway back in the 90s until Saul Perlmutter and his Supernova Cosmology Project made the shock discovery that rather than slowing down as the big crunch theory predicted, the expansion of the cosmos was continuing to accelerate. This was not at all the result the physics community expected and the question of why the universe is going into a runaway expansion has not been answered. This extra expansion has been labelled "dark energy" which basically means "we don't know what it is but it's got us by the balls." Guaranteed Nobel prizes for whoever works it out!

There are two prospective fates for this current universe. Either it will just go on expanding forever until all free energy is utterly exhausted and entropy reaches maximum. OR the expansion will continue to accelerate until gravity is overwhelmed even at a local level and all matter in the cosmos is torn apart. Respectively these potential futures are known as "The Big Freeze" and "The Big Rip" Current observations of the cosmos favour the big freeze outcome but the prediction is far from settled.

What I think can be said fairly succinctly is that the Big Bang is the beginning of THIS universe. Whether the big bang was preceded by another universe or some form of pre-existing cosmological state is a matter of much conjecture but with no good answers. Because the big bang is our absolute event horizon on reality it is impossible to reach back in time to a point before time as we understand it even existed. Answers to this question could be a long time in coming.

It is quite possible that there were many big bangs and big crunches before the existence of our universe, but for whatever reason, this universe will not repeat the pattern. If we thought that was the case then the question to ask would be "what's changed this time around?"

We're feeling about at the edge of understanding on questions like this and it's without doubt one of the most exciting frontiers in science.

So far, nobody has been able to come up with a believable "what if" answer for this question. In order words: if the BB is just an event in the cycle of the universe ==> we would see everything the way we do.

And if the BB is NOT just an event in the cycle of the universe ==> we would STILL see everything the way we do.

One thing that we do see is the accelerating expansion of the universe. So if there is a cycle, it would have to be much much longer than the time since the BB. Not just 1000 times longer, or a billion times longer, more like 10^80 times longer.

one of the problems with the cyclic universe medel is that the previous universe that collapsed is ASSUMED to have the same laws of physics and thermodynamics as this Universe currently has. There is no logical reason why this assumption as to true. A universe CAN have different laws of physics and thermodynamics. so different we might not even recognize it as being a universe.. An atom can be universe. with this universe.

Was this a question or a statement? what about the "big Freeze' or "heat death " end of the Universe. Entropy becomes infinite and all molecular and atomic motion ceases No collapse., no black hole era.

The Theory of the Big Crunch is just that. Eventually, things will start to slow down, and the "Dark Gravity" will pull the universe back into the Singularity, where things will start all over gains.

But since EVERYTHING is pulled back into a singularity. nothing is left, no information is saved, and so there is NO WAY to know IF this is happening, and more importantly there is no way to know if it EVERY happened before.

With no possible way of obtaining "proof", this will remain just a theory, and can NEVER be considered a FASCT.

We don't know. That could be so, as what we call the universe is part of a bigger one. An idea floating around is that we're from a 4d black hole.

That's called the Big Crunch - and it was theory for a couple of years... Today, we see the expansion *accelerating* - so, it's thought that the 'Big Crunch' may not happen.

That is the general consensus. The Big Bang, the Big Crunch are repeat for some indeterminate period of time.

We would not know, that's what.

it wasn't God made the world in 12 days