A winter swimmer, wearing a Santa Claus hat to celebrate the upcoming Christmas, reacts as he plays on a frozen lake at a park in Shenyang, Liaoning province, December 22, 2014. The characters on the hat read: “Shenyang Winter Swimming”. (Photo by Reuters/Stringer)

Jessica Chastain arrives at the 72nd annual Golden Globe Awards at the Beverly Hilton Hotel on Sunday, January 11, 2015, in Beverly Hills, Calif. (Photo by Jordan Strauss/Invision/AP Photo)

Participants costumed as zombies try to catch hobby runners during the so-called Zombie-Run at the harness racing track Karlshorst in Berlin, Germany, 18 May 2014. The runners carry small flags in their belts which they have to get safely across the finishing line while the zombies try to steal them. The sporting event is based on the US television series “The Walking Dead”. (Photo by Soeren Stache/DPA)

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)

The anthropomorphic robot named hitchBOT sits on the shoulder of Highway 102 to begin its 6000 kilometer cross country journey outside of Halifax, Nova Scotia, July 27, 2014. The hitch hiking robot is part of a social experiment to see if drivers will pick up and drop off the robot in one piece to an art gallery in Victoria, British Columbia. (Photo by Paul Darrow/Reuters)

A group of youngsters dressed as ghouls and zombies for Halloween parade in downtown Lisbon, Portugal, Friday, October 31, 2014. (Photo by Francisco Seco/AP Photo)

Participants prepare backstage before the 5th “Strongo Cup” open amateur bodybuilding tournament at the State Opera and Ballet Theatre in Russia's Siberian city of Krasnoyarsk, November 1, 2014. Participants from all over Russia took part in the tournament competing in bodybuilding, body fitness and bikini fitness disciplines. (Photo by Ilya Naymushin/Reuters)

Model Yasmine Petty arrives on the Life Ball plane on May 15, 2015 in Vienna, Austria. The Life Ball, an annual charity ball raising funds for HIV & AIDS projects, will take place on May 16, 2015 at the city hall in Vienna. (Photo by Monika Fellner/Getty Images)