A young arab boy, armed with a rifle and a knife, in the Aden Protectorate near Yemen. (Photo by Richards/Fox Photos/Getty Images). February 1938

A woman looks out of a dusty window after boarding a bus to be transported to see the casket of Nelson Mandela at the Union Buildings in Pretoria, South Africa, Wednesday December 11, 2013. On Thursday, December 5, 2013, Mandela died at the age of 95. (Photo by Markus Schreiber/AP Photo)

Finding just the right spot above the clouds at Camp 1 on Ama Dablam, Danuru Sherpa uses his iPhone to catch up with friends and family. Even at 18,500 feet (5,654 meters), climbers here can check their email and other dispatches from the world below. (Photo by Aaron Huey/National Geographic)

An area of vegetation can be seen amongst drought effected farmland in South Australia, November 12, 2015. A pioneering Australian scheme to improve the management of water in the world's driest inhabited continent is facing its first real test as an intensifying El Nino threatens crops and builds tensions between farmers and environmentalists. An El Nino, a warming of sea-surface temperatures in the Pacific, is already causing drought and other extreme weather, affecting millions of people across parts of the world, and experts warn that the intensifying weather pattern could emerge as one of the strongest on record. (Photo by David Gray/Reuters)

Radio City Music Hall Rockettes perform after days of rehearsal and routine polished to perfection at the Radio City Music Hall in New York City on July 26, 1949. (Photo by Ivan Dmitri/Getty Images)

A devotee sits with lighted oil lamps while offering prayers during the “Dashain”, Hinduism's biggest religious festival in Bhaktapur October 3, 2014. Hindus in Nepal celebrate victory over evil during the festival by flying kites, feasting, playing swings, sacrificing animals and worshipping the Goddess Durga as well as other gods and goddess as part of celebrations held throughout the country. (Photo by Navesh Chitrakar/Reuters)

The Komodo dragon (Varanus komodoensis) was the most popular species overall based on English language Wikipedia page views. It is the world’s largest lizard, living on the islands of Komodo, Rinca and other smaller islands, and on Flores island in Indonesia. (Photo by Eric Nathan/Alamy)

Lightning strikes near Jacobsdorf at the Oder-Spree district in eastern Germany, September 1, 2015. (Photo by Patrick Pleul/AFP Photo)