The Enigma coding machine used by the Germans in WWII on display at Bletchley Park National Code Centre, November 25, 2004 in Bletchley, England. (Photo by Ian Waldie/Getty Images)

A demonstrator wears a message on a t-shirt in Tahrir Square on May 27, 2011 in Cairo, Egypt. The ruling Supreme Council of the Armed Forces said that there would be no use of violence against protests dubbed “the Second Revolution of Anger” taking place in Cairo and other cities in Egypt. (Photo by Peter Macdiarmid/Getty Images)

Adam Ghiggio from Australia poses next to mutant mannequins which are lined up to be used as displays for the new video game “Rage” at the Los Angeles Convention Center on June 5, 2011 in Los Angeles, California. The Electronic Entertainment Expo officially starts on Tuesday. (Photo by Kevork Djansezian/Getty Images)

Christie's employee Natalie McFarlane holds an armature model of King Kong used in the 1933 film at Christie's on November 19, 2009 in London. (Photo by Peter Macdiarmid/Getty Images)

Crocoite is a mineral consisting of lead chromate, and crystallizing in the monoclinic crystal system. It is identical in composition with the artificial product chrome yellow used as a paint pigment.

An exhibition at London’s Horniman Museum by three photographers from Brazil’s largest favela, Maré, shows us their unique vision of Rio de Janeiro. Here: Leisure day on the Avenida Brasil. (Photo by Elisângela Leite/Horniman Museum)