A cadet lies on the grass after collapsing during a promotion ceremony at a police school in Bogota December 7, 2012. (Photo by John Vizcaino/Reuters)

In this April 7, 2015 photo, a tourist peers through the door of a jail cell inside the now empty Garcia Moreno prison during a guided tour for the public in Quito, Ecuador. According to tour guides, this cell was nicknamed “Los Polillas”, or “The Moths”. Here, in a room designed to hold two prisoners, about 15 inmates with drug addictions were locked in overnight by the prison gangs that controlled daily life. The locked-in prisoners were also known to prostitute themselves to get access to drugs. (Photo by Dolores Ochoa/AP Photo)

Tracy Sarita celebrates the sunrise during the Burning Man 2015 “Carnival of Mirrors” arts and music festival in the Black Rock Desert of Nevada, September 3, 2015. Approximately 70,000 people from all over the world are gathering at the sold-out festival to spend a week in the remote desert to experience art, music and the unique community that develops. (Photo by Jim Urquhart/Reuters)

A woman walks in front of an art installation made of artificial fruits and vegetables during the “Moscow Autumn” festival in central Moscow, September 14, 2015. (Photo by Maxim Zmeyev/Reuters)

Dog Xiaoniu dressed in clothes walks across a street with its owner (not pictured) in Shanghai, December 19, 2014. According to local media, Xiaoniu accompanies its owner to the food market everyday and is able to walk with its hind legs for up to about an hour. (Photo by Reuters/Stringer)

“Strike Through The Mothership”. Every May for the last 3 years I have driven down to Tornado Alley to capture some amazing storms. This supercell held so much promise to drop a tornado but one small shift in the atmosphere and all that it produced was an extreme lightning show. Photo location: Broken Bow, Nebraska. (Photo and caption by Vanessa Neufeld/National Geographic Photo Contest)

Mario Huettenhofer, chief of the German company 3D Fab, presents his own face as 3d print during the international fairs FabCon 3.D and Rapid.Tech in Erfurt, Germany, Thursday, May 15, 2014. 130 exhibitors from all over the world present the entire world of 3D printing. The trade fairs are accompanied by specialist programs featuring 80 scientists, practitioners and trend analysts from ten countries, who will explain the latest findings, trends and applications for additive processes in industry and for 3D printing in the private sector to newcomers, experts and consumers alike. (Photo by Jens Meyer/AP Photo)

Visitors look at a giant puppet of a grandmother sleeping on a bed inside St George's Hall in Liverpool, northern England July 23, 2014. The grandmother is one of two giant models made for a World War I commemorative event. (Photo by Nigel Roddis/Reuters)