What is the Big Crunch and the Big Yawn?
Big Crunch: Similar in theory as to how the Sun keeps it self from collapsing in on it self, through the massive amounts of energy release via Nuclear Fusion: In the Universe, if all of the energy is used up, there would be no force driving the expansion or to sustain the structure of the Universe and thus it would collapse back in on it self. Big Yawn: I believe means the Universe will just keep expanding over time, eventually the density will become extremely low due to expanding space and then nothing would really happen except for objects just getting further apart. Eventually, life may not be sustainable anywhere.
