Either the world will end on Dec. 21, or it won't. Your view depends on whether you believe in a much-publicized but debunked interpretation of the Mayan calendar, or you don't. Here are 10 facts so amazing they may crack the time-space continuum:

1 One in five Americans believes the world will end in his or her lifetime, according to an Ipsos survey conducted earlier this year. In the poll of more than 16,000 adults in 21 countries, only Turkey and South Africa are similarly pessimistic about the future. As for the Mayan calendar issue, 12 percent of Americans believe it does indeed mark the end of the world. Interestingly, just 9 percent report being anxious about that.