[SmG Blade]

Taking about finite and Infinite, it is not possible that universe can be finite.

Ya know Energy can never be created nor be destroyed. It can only be transferred.

According to thermodynamics, no system can achieve true isolation. Either it be microscopic or macroscopic. So if we consider the universe as a system, it is ever increasing (the energy is coming into the universe, hence explaining the expansion of it).

So we kinda can say it's infinite.

Explaining the Big Crunch, take example of tea or coffee cup. We provide heat to it and after keeping it away, it gets cold. So Universe will take up so much energy that at one time it will give away energy like a teacup. And this process will repeat itself. Over and over again. It's just it will take a lot of time.