Flexi Says: One of the theories is that the expansion of the universe will continue forever. If so, then the universe will cool as it expands, eventually becoming too cold to sustain life. This is called Heat Death or Big Chill or Big Freeze. In the theory of Big Crunch, the gravitational attraction of stars and galaxies would one day start pulling the entire universe together again in which galactic clusters crash and merge, then stars and planets fusing together, and finally, everything in the universe would form a dense spot of infinitely small size once again.
