The Big Crunch Is Cosmos fated to collapse?

Ever wonder how this gigantic Universe of ours will come to an end? One possible theory, amongst many, is the Big Crunch theory. And it states that one day in the future, our Universe will not only stop expanding, but also reverse due to the immense pull of gravity and eventually will collapse into itself and eventually will turn into a super-hot, super-dense singularity. Some scientists even conjecture that this collapse into an imaginably big black hole would eventually trigger another Big Bang (BB).

The Universe is all about the struggle between the momentum of expansion caused by BB and the pull of gravity that came into being after the BB itself. The rate of expansion is measured by the Hubble Constant (a ratio expressing the rate of apparent expansion of the universe, equal to the velocity at which a typical galaxy is receding from Earth divided by its distance from Earth) whereas the strength of the gravity depends on the density (the solidity aspect of an object) and pressure of matter in the Universe. And if the pressure of matter is low which is the case with most forms of matter we know of today, then, the fate of the Universe is governed by its density. And where does the Big Crunch fit in all of these? Well, if the density of the Universe is greater than the critical density (the mass density of the universe which just stops the expansion of space, after infinite cosmic time has elapsed), then gravity will eventually win in its struggle with expansion and the Universe will collapse back onto itself--the Big Crunch. But if the density of the Universe is less than the critical density, then, chances are the Universe will expand forever and ever, where gravity might just be able slow the rate of expansion. However there won't be any reverse pull like that of Big Crunch, instead, there will a Big Chill or Big Freeze where the Universe will slowly cool down as it expands until everything within it becomes absolutely barren and lifeless.

And when will all these apocalyptic phases take place? No one is sure. But for the moment, it seems we are safe. Recent studies of the Cosmos and the extensive mapping of the Cosmic Microwave Background (the cooled remnant of the hot big bang) have led to this conclusion that out Universe is not being slowed down by gravity but rather accelerating. And this is because of the Dark Energy, a form of energy hypothesized to reside in the very structure of space itself, responsible for the accelerating expansion of the universe. So, our empty Universe is not so empty after all. But there is another theory that predicts how the Universe will come to an end. It states that with such expansion, guided by the dark energy, there is a possibility of the Big Rip, where, being unable to bear such a rate of expansion, everything in this cosmos will be violently ripped apart in such a way as if it never existed.