Some say the world will end in fire, some say in ice. Others say the universe may tear it apart before either of those options.
If the thought of the universe ending with the eventual cooling of everything until there's nothing but darkness bums you out, don’t worry—the Big Rip theory is gaining steam, and the event may be getting closer.
Scientists are still trying to understand the gravitationally repulsive force known as dark energy, which accounts for 70 percent of the current content of the universe. But as the universe gets older, dark energy pushes galaxies farther apart from each other at an accelerating rate, and physicists now believe this will culminate in an explosive tear that will cause galaxies to separate, then planets, then, eventually, individual atoms, leaving the universe devoid of any structure.
Some new estimates are even moving that tear date up on our calendar by several billion years. Of course, the estimates remain hugely variable—somewhere between 16.7 and over 100 billion years from now.
Video by Jim Festante.