The Big Crunch theory proposes that the universe, that began expanding with the Big Bang, will collapse in on itself with increasing speed. According to the theory, this collapse of the universe will continue until the universe has lost all its mass and turned into a single point of infinite density.
It is also believed that the contracting universe will end in a fierce heat and contraction known as the "Big Crunch." This would lead to the end of all forms of life as we know them. Renata Kallosh and Andrei Linde, professors of physics from Stanford University, made the following statements on the subject:
The universe may be doomed to collapse and disappear. Everything we see now, and at a much larger distance that we cannot see, will collapse into a point smaller than a proton. Locally, it will be the same as if you were inside a black hole... We have found that some of the best attempts to describe dark energy predict that it will gradually become negative, which will cause the universe to become unstable, then collapse... Physicists have known that dark energy could become negative and the universe could collapse sometime in the very distant future... but now we see that we might be, not in the beginning, but in the middle of the life cycle of our universe.4
This is how this scientific hypothesis of the Big Crunch is indicated in the Qur'an:
That Day We will fold up heaven like folding up the pages of a book. As We originated the first creation so We will regenerate it. It is a promise binding on Us. That is what We will do. (Qur'an, 21:104)
In another verse, this state of the heavens is described thus:
They do not measure Allah with His true measure. The whole Earth will be a mere handful for Him on the Day of Resurrection the heavens folded up in His right hand. Glory be to Him! He is exalted above the partners they ascribe! (Qur'an, 39:67)
According to the Big Crunch theory, the universe will begin to collapse slowly and will then increasingly pick up speed. At the end of the process the universe will have infinite density and be infinitely hot and small. This scientific theory runs parallel to the Qur'anic explanation of this particular scientific concept. (Allah knows best)