Since the beginning of space time - or at least the space year 2005, as I recall, I have been hearing prediction after prediction about how the APOCALYPSE IS NIGH, especially on one particular day.
December 21st, 2012.
The world is going to end that day, is it? Well, let's look at it scientifically. The various theories are as follows
The Mayan Calender
The main argument is the Mayan Calender. What is the Long Count? Well, it's a part of the Mayan Calender that goes on and on, well beyond their death. It has been around for millennium, and has always ended on the same day. It just happens to predict the end on that exact day. But here's the the thing. The Mayan Long Count doesn't mark that day as the end! The Mayan calender simply stops on that day. And what happens when one of our calenders end? Does the world end, or do we just get a new one? Even the philosopher who predicted the Mayan Long Counts in sections of 20 years didn't even say the Long Count ended then. It just restarts, as all calenders do.
All that said, how exactly does a really good calender prove the Mayans are smarter then us? Even if it did predict the end of the world. If New Horizons finds a Mayan Probe on Pluto, then I'll listen to what doom sayers have to say.
Nibiru
Okay, let's talk about this. For those of you unacquainted with this particular theory, it goes something like this. Our sun just happens to have a companion star that is so far away, no one can see it except the conspiracy nutters. So, this companion star (or Brown Dwarf, which isn't much better) has its own planetary system. Said Planetary system has intelligence giant beings on it called the Enichey or something, and they have a planet called Nibiru. Niburu is actually a battle station that they launch their evil Alien Invasions of EVIL from. Apparently the asteroid belt used to be a planet, but Niburu destroyed it for the lulz. Anyway, the evil aliens are finally fed up with us and have sent their entire evil planet into our solar orbit. Nibiru is slowly approaching the Earth and is going to destroy it.
Most of the pictures of Nibiru are actually things like Mars, Mercury, and the like. I've actually had some Nibiru-fanatic-tards send me coordinates to use on public telescopes claiming that said object is Nibiru. Each and every one is just a regular object, like a galaxy. Come on guys, 10 minutes with hyperleda is all it takes!
While it is true that most stars live out their lives in Binary Pairs, (our sun is the freak here, but only by a little. It's somewhere around 54% of all stars have a companion), no noted star has a companion star that far away. In fact, some physicists would say it's impossible because of how gravity works - it draws heavy elements to its center. You know, like, stars. Its why those gravitational monsters, Super Massive Black Holes are in the center of just about every galaxy. If Evil Nibiru really was making its way towards the Earth, we would see it perturbing the orbits of the outer Gas Planets at this point. So yes. Evil Nibiru is not on its way. Shut the hell up.
Nostradamus
I could spend hours telling you how much of a problem Nostradamus' prophecies are. But instead I will just go over it in brief. Nostradamus had his prophecies, and all of them were vague. They could have applied to anyone or everyone. And what's more, some people even make shit up and say he wrote it! The biggest example I have here is that one about the twin towers. That one was actually written as a way of proving how vague a prophecy needs to be by a college student emulating his style. Poor Nostradamus, I guess. Anyway, this guy had his prophecies, and while some of them were surprisingly accurate, when you shoot 25 arrows one of them is gonna hit the mark, especially when the mark happens to be 40 feet large. Either way, Nostradamus never specified this era as the end of anything.
Other Fortune Tellers
Have the same damn problem. They're either too vague, too inaccurate, too silly, or just plain weird. And now more and more people know about the 2012, more and more can predict disasters in that era. Old time fortune tellers are unreliable - there was even one that never existed, but was said to exist by some man who was the only person in the world to contact her. No other proof.
LHC
No. Just no.
Armageddon
I'm not going to alienate people by proving the Bible is a wrong - even though that is seriously up for debate. I will, however, say that people have been 'waiting for the lord to come back in about...5 minutes' since he died. He himself said "Only He knows the time. Not the Son nor the Spirit." So stop shouting about how the world's gonna end and just live your life.
Magnetic Pole Reversal
These events happen. We are indeed due for one in the relative near future. However, life is easily capable of enduring these events.
Conclusion
The only reason the world will end on Dec. 21st, 2012 is because humans are a bunch of superstitious idiots who will end it themselves because they're all so upset.