Why world is said to end on December 21, 2012 ?

 December 21, 2012; the day, which many erroneously believe, the ancient Mayans predicted the end of the world. But, on this date, the sun aligns with the centre of the spiral galaxy — the Milky Way. This happens roughly every 25,920 years, and the phenomenon is known as precession of the equinoxes.

 

With every precessional process, the earth passes through the 12 constellations of the Zodiac. The latter is a small band of the sky about 8° on either side of the ecliptic; the narrow path followed by the sun, the moon and the planets in the solar system.

Every 2,160 years on the spring equinox (March 21), the sun rises against the background of a different constellation of the Zodiac. In other words, if on the spring equinox, about an hour before dawn, you were to gaze due East, you come across one of the 12 constellations of the Zodiac. These days, the sun rises between Pisces and Aquarius, suggesting that we live in the transitional period between the Age of Pisces and Aquarius.

The ancient Egyptians knew about precession of the equinoxes. The circular Zodiac found in the temple of Hathor at Dendera in Egypt sheds more light on precession of the equinoxes. Incidentally, the Mayans, who regularly tracked the movement of stars across the sky, also measured precession of the equinoxes, but from the winter solstice rather than the spring equinox. Their Long Count calendar, which began in 3114 BC, was set to end precisely on a winter solstice — December 21, 2012.

The ancient Mayans interpreted time as being cyclical in nature. Their Long Count calendar began at the onset of the current cycle (known as the 5{+t}{+h}Sun) on August 13, 3114 BC. December 21, 2012 the day when their Long Count calendar ends, could well be sort of a marker in time which the Mayans used to point the end of one cycle and the beginning of a new one.