Two robotic legged squad support system (LS3) machines by the Defense Advanced Research Project Agency follow a technician during a demonstration at Joint Base Myer-Henderson Hall, Virginia, on September 10, 2012. (U.S. Marine Corps photo by Sgt. Mallory S. VanderSchans via The Atlantic)

Toyota Motor unveils a concept car the “PM”, is on display at a press preview for the Tokyo Motor Show in Makuhari, east of Tokyo October 23, 2003. PM is a single seater personal vehicle whose cabin posture changes from upright to reclined as speed increases. (Photo by Koichi Kamoshida/Getty Images)

Two guards perform an execution in China, one holding the gun, the other holding a mask over the victim's face. (Photo by General Photographic Agency/Getty Images). Circa 1925

People wearing costumes attend the annual water-splashing festival to mark the New Year of the Dai minority in Jinghong, Yunnan province, April 13, 2015. (Photo by Reuters/China Daily)

A young Indian girl dressed as Hindu goddess Laxmi participates in a procession to mark “Gudi Padwa”, or Maharashtrian New Year, in Mumbai, in the Indian state of Maharashtra, Friday, April 8, 2016. (Photo by Rajanish Kakade/AP Photo)

Dancers perform on their way to attend a rally with former President Luiz Inacio Lula da Silva, “Lula”, supporting President Dilma Rousseff in the historic Lapa neighborhood on April 11, 2016 in Rio de Janeiro, Brazil. Brazil's congressional impeachment committee approved the motion to proceed with President Dilma Rousseff's impeachment process today. A full vote by the lower house of Congress on the impeachment is scheduled for Sunday to decide whether she will face trial. (Photo by Mario Tama/Getty Images)

Nick Franklin, in action during the FMX competition at the 23rd edition of Free4Style this Saturday, July 2, 2016 in Estavayer-le-Lac,Switzerland. (Photo by Jean-Christophe Bott/Keystone/APA)

Principle Ballet Dancer, Ekaterina Bulgutova, of the Russian State Ballet, with the Nutcracker part of Christmas Ballet Season in Cardiff which starts at St Davids Hall on December 20, 2016 in Cardiff, England. (Photo by Kiran Ridley/Barcroft Images)