In this photo taken Friday, September 4, 2015, tourists Sarah and John Scott from Worcester, England, take a step back as a male silverback mountain gorilla from the family of mountain gorillas named Amahoro, which means “peace” in the Rwandan language, unexpectedly steps out from the bush to cross their path in the dense forest on the slopes of Mount Bisoke volcano in Volcanoes National Park, northern Rwanda. Deep in Rwanda's steep-sloped forest, increasing numbers of tourists are heading to see the mountain gorillas, a subspecies whose total population is an estimated 900 and who also live in neighboring Uganda and Congo, fueling an industry seen as key to the welfare of the critically endangered species as well as Rwanda's economy. (Photo by Ben Curtis/AP Photo)

Pornstar Asa Akira made an appearance at the new Pornhub shop in New York, USA on Friday, November 25, 2017. Pornhub is a pornographic video sharing website and the largest pоrnography site on the Internet. The new pop-up will be open in New York's SoHo until 20 December. (Photo by Curtis Means/ACE Pictures/Rex Features/Shutterstock)

Developed for the British American Ambulance Corps, this new motorcycle ambulance is capable of speeding wounded soldiers 90 miles an hour from the front lines to field hospitals. Its springs are synchronized with the patient's heartbeat to avoid increasing fever when traveling over various Terrain. Viewing it in New York August 27, 1941, are left to right: constable Herbert Scott of England, driver; William E. Detlor, whose firm developed the vehicle; M. W. Stand, inspector-general of Civilian Defense, and Maj. Edward Riekert, also. (Photo by AP Photo)

Kenyan women protest for the right to wear whichever clothes they want, at a demonstration in downtown Nairobi, Kenya Monday, November 17, 2014. A recent incident in which a mob of men surrounded a woman and tore her clothes off, leaving her naked on the street in front of a bus stop after alleging that she was improperly dressed, is one of several such videos that have surfaced online in recent days leading to a groundswell of anger that on Monday prompted around 1000 demonstrators, including a number of men supporting the women's cause, to march through the capital and protest online using the hashtag #MyDressMyChoice. (Photo by Ben Curtis/AP Photo)

“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)

Lava erupts from the Piton de la Fournaise “Peak of the Furnace” volcano, on the southeastern corner of the Indian Ocean island of Reunion Saturday, August 1, 2015. Spewing red-hot lava, one of the most active volcanoes in the world is currently erupting on this Indian Ocean island, where the world's attention has been focused since a wing fragment believed to be from the missing Malaysian jet was discovered washed up on a beach. The lava fountains are shooting as high as 40 meters (44 yards) and are creating cones that are about 20 meters high after only one day of eruption, said Peltier. The volcano is in the Reunion National Park – a world heritage site. The volcano is not seen as dangerous because the lava flows down the east side of the mountain through an uninhabited area called the Grand Brule, or the Big Burned, toward the sea. The last times the volcano threatened the population was in 1977 and 1986. (Photo by Ben Curtis/AP Photo)

“Bear Grylls, (born Edward Michael Grylls, 7 June 1974) is an English adventurer, writer and television presenter. He is best known for his television series Man vs. Wild, known as Born Survivor in the United Kingdom. He was the youngest Briton to climb Mount Everest, doing so at age 23. In July 2009, Grylls was appointed the youngest ever Chief Scout at the age of 35”. – Wikipedia

Photos: Passer inspects “Camelot”, a replica camel carcass simulating that used by adventurer Bear Grylls to shelter in the Sahara desert during an episode of the Discovery Channel's “Man Vs. Wild”, in Wynyard Park on March 1, 2010 in Sydney, Australia. (Photo by Discovery Channel via Getty Images)

Polar Bear club swimmers take their annual swim in the sea at Coney Island in New York City on January 1, 2014. (Photo by Curtis Means/ACE/INFphoto.com)