It wasn't just the Mayans who predicted it, apparently other prophets did as well.
The "I Ching" is an old Chinese text, which means "book of changes". It's mostly used for personal fortune telling. How you do it is ask a question, toss 3 coins and depending on the outcome of coins, you draw various lines. When it's mostly tails, you draw a straight line, if it's mostly heads, a broken one. Repeat 6 times, and you'll end up with something called a "hexagram". In the "I Ching", there's 64 different variations, each giving a different outlook on the future based on which hexagram you receive. Surprisingly, the answer the text gives you is "astoundingly appropriate to the question you asked". Problem is the "I Ching" is very generalized, which is like "appealing" to everyone.
Now how this plays into 2012 is a "controversial researcher" noticed a unrecognized pattern in the hexagrams in the I Ching. He plotted them on a timeline graph, starting when the "I Ching" was created. The weird thing is, this graph shows the highs and lows of civilization, like world wars and such. But, the graph just ends at it's farthest and last point, Dec. 20th 2012.
It's odd how the Mayans, I Ching and other prophets all seemed to conclude that 2012 was the year of downfall. It's not like the world would end, but they seem to think something will happen.
Personally, I'm not sure I believe it, but it's intriguing.
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