You may not believe the world will end on Oct 21 , or with the Mayan calendar or that mankind will simply make the planet uninhabitable, but if popular movies and books are any indication, there must be a lot of people who believe the world is ready for its final bow. You may subscribe to a religious End of Days doctrine, but when it comes to the planet's fate, only one thing is for certain: All good things must come to an end.
There’s little agreement on exactly how this will happen, but there are plenty of theories. Here’s a look at 12 of the most popular ones and the science — or lack of it — behind them.
