Some persons predict that the world will end on December 21, 2012. Perhaps they are correct. For mathematical context, take a look back (perhaps the last look back any of us will have a chance to make!) at the 2011 Ig Nobel Prize winners in the field of mathematics:
MATHEMATICS PRIZE: Dorothy Martin of the USA (who predicted the world would end in 1954), Pat Robertson of the USA (who predicted the world would end in 1982), Elizabeth Clare Prophet of the USA (who predicted the world would end in 1990), Lee Jang Rim of KOREA (who predicted the world would end in 1992), Credonia Mwerinde of UGANDA (who predicted the world would end in 1999), and Harold Camping of the USA (who predicted the world would end on September 6, 1994 and later predicted that the world will end on October 21, 2011), for teaching the world to be careful when making mathematical assumptions and calculations.
BONUS: Dorothy Martin was the key figure in the formation of the psychological concept of “cognitive dissonance,” a process which itself involved some impressive psychological oddities.
BONUS (December 20, HT investigator Julia Lunetta): “More than 30 Michigan schools closed for the holidays two days early, in part because the Mayan calendar predicts the world will end on Friday, an official said“
BONUS VIDEO: The Guardian Guide to the End of the World (Part 1)
BONUS (only peripherally related, if at all): The Halting Problem, and “How Dr. Seuss would prove the halting problem undecidable” (details of the latter)