Chinese butchers catch a pig to slaughter on January 31, 2005 in Jinzhai County, Anhui Province, China. (Photo by Cancan Chu/GettyImages)

Caroline Wozniacki of Denmark serves in her match against Kaia Kanepi of Estonia during day four of the Toray Pan Pacific Open at Ariake Colosseum on September 28, 2011 in Tokyo, Japan. (Photo by Koji Watanabe/Getty Images)

13-year-old Emmanuel Festo from Tanzania poses for a portrait with a plush toy that he says makes him feel safe at night and that he sleeps with, in New York's Staten Island, September 21, 2015. Albino body parts are highly valued in witchcraft and can fetch a high price. Superstition leads many to believe albino children are ghosts who bring bad luck. Some believe the limbs are more potent if the victims scream during amputation, according to a 2013 United Nations report. (Photo by Carlo Allegri/Reuters)

An image produced by the Hubble telescope of the perfectly “edge-on” galaxy, or NGC 4013, March 1, 2001. This new Hubble picture reveals, with great detail, huge clouds of dust and gas extending along, as well as far above, the galaxy's main disk. NGC 4013 is a spiral galaxy, similar to the Milky Way, lying some 55 million light-years from Earth in the direction of the constellation Ursa Major. Viewed face-on, it would look like a nearly circular pinwheel, but NGC 4013 happens to be seen edge-on from our vantage point. Even at 55 million light-years, the galaxy is larger than Hubble's field of view, and the image shows only a little more than half of the object, albeit with unprecedented detail. (Photo Courtesy of NASA/Newsmakers)

Guests on the terrace of Shepheard's Hotel, Cairo, circa 1940. (Photo by Hulton Archive/Getty Images)

“The Boeing X-45 unmanned combat air vehicle is a concept demonstrator for a next generation of completely autonomous military aircraft, developed by Boeing's Phantom Works. Manufactured by Boeing Integrated Defense Systems, the X-45 was a part of DARPA's J-UCAS project”. – Wikipedia

Photo: Two X-45A Unmanned Combat Air Vehicles (UCAV) are shown to members of the news media July 11, 2002 at Edwards Air Force Base, California. The X-45A, developed by The Defense Advanced Research Projects Agency and the Boeing Company, is the first unmanned system designed from inception for combat missions. (Photo by David McNew/Getty Images)

Thousands of revelers continue to enjoy themselves throughout the night on Sunrise Beach on February 25, 2005 in Haadrian, Koh Phangan. (Photo by Shaul Schwarz/Getty Images)

Recreation time for the seminarists at St. Ignatius Loyala shrine at Azpeitia, Gipuzkoa (Guipúzcoa) in Spain. (Photo by Evans/Getty Images). 1955