On December 21 2012, a comet won’t hit the earth, a pole shift won’t happen instantly and a massive gravity burst won’t happen either. The only thing you can fear is a pole shift and it takes 5,000 years to complete. I’m pretty sure you won’t survive that long.

"The world will not end on 12-21-2012, at least not according to the Mayans, who knew about as much about our planet's future demise as Gordon-Michael Scallion, St. Malachy, Edgar Cayce, or Nostradamus, namely, nothing."

The Mayan Doomsday Prophecy is purely based on a calendar which we believe hasn't been designed to calculate dates beyond 2012.