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)

Rosanna Davison attends the “Lambertz Monday Night” at Alter Wartesaal on February 1, 2012 in Cologne, Germany. (Photo by Andreas Rentz/Getty Images)

(L-R) Ozzy Osbourne and son, producer Jack Osbourne visit the Tribeca Film Festival 2011 portrait studio on April 25, 2011 in New York City. (Photo by Larry Busacca/Getty Images for Tribeca Film Festival)

Silver medalist Vivian Jepkemoi Cheruiyot of Kenya and gold medalist Almaz Ayana (R) of Ethiopia during the medal ceremony for the women's 10000m final of the Rio 2016 Olympic Games Athletics, Track and Field events at the Olympic Stadium in Rio de Janeiro, Brazil, 12 August 2016. (Photo by Sergei Ilnitsky/EPA)

A mahout rides on an elephant in the city of Amritsar, India, 08 November 2015. Such elephants are often accompanied by their caretakers who ask for alms from people in the streets. (Photo by Raminder Pal Singh/EPA)

A three-seater Toyota Kikai concept car is displayed during the 2016 CES trade show in Las Vegas, Nevada January 8, 2016. (Photo by Steve Marcus/Reuters)

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)

Residents (R to L) Luiza, Janubie, Leiticia and Lucas sit beneath an overpass near their houses in an impoverished area in the unpacified Complexo da Mare slum complex, one of the largest “favela” complexes in Rio, on March 18, 2014 in Rio de Janeiro, Brazil. (Photo by Mario Tama/Getty Images)