KALTENBERG, GERMANY - JULY 08: Actors dressed as knights perform during the traditional Kaltenberg knight tournament on July 8, 2007 in Kaltenberg, Germany. With around 120,000 visitors each year, the festival including knight tournaments, medieval styled markets and a variety of music performances, the event is one of the biggest of its kind. (Photo by Johannes Simon/Getty Images)

Starlings come home to roost on Brighton's Old Pier as the sun sets on December 21, 2011 in Brighton, England. December 21 marks the winter solstice, the shortest day of the year. (Photo by Dan Kitwood/Getty Images)

Ultra Orthodox Jews celebrate the Jewish holiday of Purim on March 8, 2012 in Benei Brak, Israel. The carnival-like Purim holiday is celebrated with parades and costume parties to commemorate the deliverance of the Jewish people from a plot to exterminate them in the ancient Persian empire 2,500 years ago, as described in the Book of Esther. (Photo by Uriel Sinai/Getty Images)

Encyclopedia Britannica editions are seen at the New York Public Library on March 14, 2012 in New York City. Encyclopedia Britannica announced it will be ceasing its print edition of reference books for the first time in its 244-year history to focus solely on digital versions. (Photo by Mario Tama/Getty Images)