A soldier poses with a Hythe Mk III Gun Camera during training activities at Ellington Field, Houston, Texas in April of 1918. The Mk III, built to match the size, handling, and weight of a Lewis Gun, was used to train aerial gunners, recording a photograph when the trigger was pulled, for later review, when an instructor could coach trainees on better aiming strategies. (Photo by Harry Kidd/WWI Army Signal Corps Photograph Collection via The Atlantic)

In this March 13, 2015 photo, Yohan, 4, from left, Cristian, 7, and Angelo, 6, playfully toss coca leaves into the air, singing: “I have a lot of money, look at all the money I have”, in La Mar, province of Ayacucho, Peru. Hauling cocaine out of the remote valley is about the only way to earn decent cash in this region where a farmhand earns less than $10 a day. Beyond extinguishing young lives, the practice has packed Peru's highland prisons with cocaine backpackers while their bosses evade incarceration. (Photo by Rodrigo Abd/AP Photo)

A model falls while displaying a design from Wu Xuewei and Wu Xuekai, winners of the Asahi Kasei China Fashion Designer Award during China Fashion Week held in Beijing, China, Friday, October 29, 2010. (Photo by Ng Han Guan/AP Photo)

People at a Czech Stop look at a cloud of smoke rising from the explosion in West, Texas, April 17, 2013. (Photo by Andy Bartee via Dallas Morning News/MCT)

Three members of English pop group The Tremeloes; Chip Hawkes, Alan Blakley and Dave Munden, kissing their brides; Carol Dilworth, Lyn Stevens and Andree Wittenberg, in Trafalgar Square, London. (Photo by Wesley/Getty Images). 1967

A painting of a Trabant car bursting through a wall in post unification Berlin, August 1993. (Photo by Steve Eason/Hulton Archive/Getty Images)

Models pose backstage ahead of the Gary Bigeni show during Rosemount Australian Fashion Week Spring/Summer 2011/12 at Overseas Passenger Terminal on May 4, 2011 in Sydney, Australia. (Photo by Matt King/Getty Images)

A woman dancing on the Sphinx. A pyramid can be seen in the background. (Photo by Fox Photos/Getty Images). 1928