Children in Hiroshima, Japan, wearing masks to combat the odour of death after the city was destroyed by the first atom bomb. (Photo by Keystone/Getty Images). 1945

Pigs race around the track at the Pig Racing and Diving display at the Sydney Royal Easter Show on April 10, 2009 in Sydney, Australia. (Photo by Mark Kolbe/Getty Images)

Recording artist Lady Gaga performs during a stop of The Monster Ball Tour at the MGM Grand Garden Arena March 25, 2011 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)

The Ray and Maria Stata Center is shown on the campus of the Massachusetts Institute of Technology February 22, 2006 in Cambridge, Massachusetts. The Institute admitted its first students in 1865 and continues with the mission to advance knowledge and educate students in science, technology, and other areas of scholarship. (Photo by Joe Raedle/Getty Images)

146 West End Stars hold a flashmob in support of the non-profit organistation Love 146, which campaigns to end child s*x slavery and exploitation, at Trafalgar Sqaure on April 11, 2011 in London, England. (Photo by Tim Whitby/Getty Images)

Afghan police recruits undergo training at the Afghan Police Academy October 5, 2010 in Kabul, Afghanistan. (Photo by Majid Saeedi/Getty Images)

Castro's soldiers at Playa de Giron, Cuba, after thwarting the ill-fated US backed 'Bay of Pigs' invasion. (Photo by Graf/Getty Images). April, 1961

Opera singers perform in the pool “AquAria PALAOA” during a rehearsal at the swimming pool Neukoelln on April 27, 2011 in Berlin, Germany. The premiere of the underwater opera AquAria PALAOA is on May 1st. (Photo by Andreas Rentz/Getty Images)