How the long-count Maya calendar will read on Dec. 21
(The end of the long-count cycle is similar to a car's odometer turning over when it reaches 100,000 miles.)
During the 2012 winter solstice, the sun and Earth will align with the center of the Milky Way galaxy. The gravitational pull from an enormous black hole in the galactic center will stress Earth to the extreme, creating massive earthquakes, volcanoes, and tsunamis that will destroy civilization. Reality
There are no planetary alignments on Dec. 21. The Earth, sun, and Milky Way alignment is an annual event of no consequence: The galactic center is too far away to stress our planet. Only the nearby moon and sun can affect tides.
The supposed enormous planet, allegedly discovered by the ancient Sumerians, was expected to collide with Earth in May 2003. When it didn't, the doomsday event was linked to the end of the long-count period of the Maya calendar. Other celestial objects have also been said to be on a collision course with Earth. Reality
If a planet or celestial object were on a collision course with Earth, the thousands of astronomers who scan the skies every night would have seen it.
A giant solar storm, with huge solar flares, will erupt into space and emit gamma rays so powerful they will knock out satellites that drive the world's financial, transportation, and communication systems. It's a doomsday prepper's nightmare: Some fear the ensuing pandemonium will shut down civilized society as survival instincts kick in and turn humans into the planet's most dangerous beasts. Reality
Solar storms generally follow solar cycles, which peak every 11 years. The next peak is predicted for mid-2013 and is expected to be mild. In addition, new satellites are being designed to protect electronics against most solar storms.
Earth's axis will do a 180 rotation around the core and cause a new Ice Age. Or Earth's magnetic north will flip suddenly and cause the planet's destruction. Reality
An axis shift would indeed affect our climate dramatically, but it won't happen: The orbit of the moon around Earth stabilizes it and prevents the shift. Magnetic field shifts occur slowly, with complete pole reversals about every 200,000 to 300,000 years. Geographic and fossil records on past reversals indicate no change in plant or animal life.
Before Dec. 21
Take a moment to consider what if it really were the end of the world. What would you do in these last days? With whom would you spend your time? Take the opportunity to appreciate and reflect.
On Dec. 21
Try not to look up. Hug the kids. Breathe a sign of relief when the day's over, even if you didn't entertain the thought, not even for a moment, that the world could end.
The day after
Celebrate the start of a new Maya long-count calendar with friends and family. Consider it a bonus New Year's event, and plan big: If you miss this one, you'll have to wait until 7137 for another chance.