Big Bounce vs Big Bang

[Alex K]

I haven't read this article yet, sorry. But if this universe contracts and bounces back would the universe play out the exact same when bouncing back?

Well, according to the article the Big Bounce theory was suggested in the early 1900s, but the scientists haven't been able to prove it until recently. The universe right now is expanding. It is also accelerating in expansion. It is not contracting. I don't know the laws that govern whether or not it will stop expanding and

It still isn't proven. To "prove" it, bounce scenarios would have to provide observable phenomena distinct from inflation that are visible in the microwave background. If there are such predictions, they haven't been observed yet. What we have is a proof of principle that big bounce has a chance of working mathematically, at least in a simplified version of reality. The big bounce we discuss here is also not the same as a cyclical universe that recollapses again and again. Turok's paper on which the article is based only concerns the nature of the big *** in our past and whether it could have come from a previous collapse if I understand it correctly.

Currently there is no evidence that dark energy is anything other than a cosmological constant, and a cosmo constant by itself leads to eternal exponential expansion. But - dark energy could come from something more complicated such as quintessence models, and in those the dark energy can in principle become smaller, facilitating a recollapse - there is just no evidence for that as of today...