Google Lady_Di! ...but you can start with the mayan calendar... ...and as for prophecy, I have always founnd this one intriguing: http://en.wikipedia.org/wiki/Prophecy_of_the_Popes
Regarding 2012, it's not just a mayan thing. There is some scientific basis that the world will end in 2012. Google 2012 and polar shifts...
Well... every 200,000 years or so, the magnetic polarity of the planet flips. You can see it in magnetic rock strata. And in fact, we are due for a shift. But the models, even the best, most recent models, cannot predict the exact year of the next flip, or exactly how many years it will take. Most of the models I've seen have the magnetic field weaken, wobble for 100 years or more, and then shift N<--->S. If anyone's interested, I can link you to some cool computational work on this. Amazing how little we know for sure about the innards of the earth. Anyway, any scientist telling you 2012 is predictable is, well, not smoking crack... but disagreeing with most of her or his colleagues. Let's put it that way.
Okay, so maybe it won't happen in 2012... but we are due for a shift soon right? And when it comes.. what... mass extinction?
Yes, soon, but soon in geological time. Great question! And now I'm realizing we may be talking about different things. I'm talking about Geomagnetic reversal, which is pretty well-accepted. It's still scary, because the planet gets bombarded by intense charge particles from the sun once we don't have a magnetic field. (e.g. see the movie, THE CORE. ) While you may be talking about rotational pole shift!. To me, that's kind of unphysical, or at least very controversial. As if the earth would violate the conservation of angular momentum and choose a new axis of rotation? Anyway, if we're worried about big-time natural earth-wide disasters, I'd go with asteroids (edit: see KingCheetah's thread), and the magnetic pole shift! Have at it!
