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)

A Sri Lankan activist, who wrapped himself with fire crackers, walks in Colombo on July 23, 2014 to symbolically demonstrate against people burned during Anti-Tamil riots on the island thirty-one years ago. Official accounts placed the death toll at 400 while human rights activists put the toll at thousands. (Photo by Ishara S.Kodikara/AFP Photo)

Visitors hold ice blocks to cool themselves in hot weather at a water park on June 23, 2016 in Chongqing, China. Citizens and visitors escaped high temperature at a water park in Yangren Jie (also known as Foreigner Street), Nan'an District of south China's Chongqing. (Photo by VCG/VCG via Getty Images)

Vendors selling candied haws wait for customers at the Harbin Ice and Snow Festival in Harbin, China, January 4, 2016. The festival is open from Jan. 5 till Feb. 5, 2016, and is aimed at attracting both foreign and local visitors to experience the beauty of the ice and snow. (Photo by Wang Zhao/AFP Photo)

Female police officers from Istanbul's Motorcycled Police Unit wait to search vehicles during a roadside checkpoint operation on March 7, 2017 in Istanbul, Turkey. The rapid response unit nicknamed Dolphins is used primarily in crime prevention operations and has 25 female officers. 6% of Turkey's 250,000 strong police force are women, March 8 marks International Women's Day. (Photo by Chris McGrath/Getty Images)

Dinosaur robots acting as receptionist greet a hotel employee demonstrating how to check-in to the hotel during a press preview for the newly-opening Henn na Hotel Maihama Tokyo Bay in Urayasu, east of Tokyo, Japan March 15, 2017. The reception desk is handled by robots that speak Japanese, English, Chinese and Korean, as well as porter robots that help guests carry luggage to their rooms. Tasks such as window-cleaning and vacuuming are also handled by robots. Japan's second robot-run hotel Henn na Hotel (“strange hotel” in Japanese) opened on March 15, 2017 as the robot-staffed hotel near Tokyo, operating company H.I.S. Co. said. (Photo by Issei Kato/Reuters)

Members of a propaganda troupe perform in a public square in Pyongyang on April 12, 2017. (Photo by Ed Jones/AFP Photo)