U.S. Army soldiers with the 1st Battalion, 501st Infantry Regiment deployed to Combat Outpost Sabari, Afghanistan scan their area as they begin a multi-day air assault mission near the Pakistani border of eastern Afghanistan's Khost province May 2, 2012. (Photo by Staff Sgt. Joshua L. DeMotts/U.S. Air Force)

Promotional models use their smartphones during their break at the Global Mobile Internet Conference in Beijing May 6, 2014. Mobile Internet industry executives, developers and investors from more than 30 countries took part in the Global Mobile Internet Conference in Beijing, the organiser said. (Photo by Kim Kyung-Hoon/Reuters)

“Slow”. A calm cow in the messy streets of Jodhpur. Photo location: India. (Photo and caption by Matthias Troeger/National Geographic Photo Contest)

“The Challenge!” Young boy relishes in a game of tug of war before school. Photo location: Lake Titicaca, Peru. (Photo and caption by Paul Heyman/National Geographic Photo Contest)

Fishermen prepare marlin and sailfish, destined for Jakarta, for auction at a fish market in Tegal, Central Java November 26, 2014 in this photo taken by Antara Foto. (Photo by Oky Lukmansyah/Reuters/Antara Foto)

Spencer Slate, costumed as a scuba-diving Easter bunny, is shown in this handout photo provided by the Florida Keys News Bureau as he hides eggs amid eel grass, in the Florida Keys National Marine Sanctuary off Key Largo, Florida March 31, 2013. About 80 adults and children participated in an Underwater Easter Egg Hunt, seeking real hard-boiled eggs painted with non-toxic food coloring to avoid adverse effects on the marine ecosystem. (Photo by Bob Care/Reuters/Florida Keys News Bureau)

Humanoid robot bartender “Carl” interacts with guests at the Robots Bar and Lounge in the eastern German town of Ilmenau, July 26, 2013. “Carl”, developed and built by mechatronics engineer Ben Schaefer who runs a company for humanoid robots, prepares spirits for the mixing of cocktails and is able to interact with customers in small conversations. (Photo by Fabrizio Bensch/Reuters)

“Zeybeks”. That's Dance, Sunward and Zeybeks. (Photo by Hasan Baglar/2014 Sony World Photography Awards)