The Mayan Calendar2012 gained the patina of doom with the best-selling 1966 book "The Maya" by Harvard archeologist Michael D. Coe. He noted that the Mayan culture's famously complex "Long Count" calendar simply ends on 12/21/12, speculating that civilization might come crashing down on that date. Other scholars argue, however, that the Mayan calendar would merely flip over like an odometer that reached 100,000 miles.
Galactic Alignment
Astrologers have also pointed out that during the winter solstice of 2012, the orbital planes of the solar system and the twelve Zodiacal constellations will intersect with the "Dark Rift" -- a black bit of the Milky Way located next to Sagittarius. Some argue this intersection is precisely why the Mayans -- who were brilliant astronomers -- ended their calendar when they did. But other astrologers believe that this conjunction will usher in a great shift in consciousness.
Timewave Zero
And then there's counterculture thinker Terence McKenna, whose Timewave Zero theory -- drawing off of elements from the "I-Ching," the teachings of philosopher Alfred North Whitehead, and modern fractal mathematics -- determined that 12/21/12 is, you guessed it, the exact date of a profound change in world. Roughly speaking, the Mayans, astrologers and McKenna are all predicting global doom or the dawning of the Age of Aquarius.
[yahoo movie talk - june 17, 2009, jonathan crow, author]