Children wearing uniforms hold toy guns during a military parade game on China's National Day, at Beyou World, a centre children where can experience different kinds of professions, in Beijing, October 1, 2015. (Photo by Reuters/Stringer)

Miniature spring-wound 35-mm film camera in a modified cigarette pack. The Tessina’s small size and quiet operation provided more options for concealment than most commercially available models. (Photo by Central Intelligence Agency)

“The Northrop Grumman (formerly Ryan Aeronautical) RQ-4 Global Hawk (known as Tier II+ during development) is an unmanned aerial vehicle (UAV) used by the United States Air Force and Navy as a surveillance aircraft”. – Wikipedia

Photo: A full-scale model of The RQ-4 Global Hawk unmanned plane is displayed during a presentation at PiO Exhibition Center on March 24, 2010 in Tokyo, Japan. (Photo by Koichi Kamoshida/Getty Images)

This October 25, 2014 photo provided by the U.S. Geological Survey shows lava flow advancing across the pasture between the Pahoa cemetery and Apa'a Street, engulfing a barbed wire fence, near the town of Pahoa on the Big Island of Hawaii. Dozens of residents in this rural area of Hawaii were placed on alert as flowing lava continued to advance. Authorities on Sunday, October 26, 2014 said lava had advanced about 250 yards since Saturday morning and was moving at the rate of about 10 to 15 yards an hour, consistent with its advancement in recent days. The flow front passed through a predominantly Buddhist cemetery, covering grave sites in the mostly rural region of Puna, and was roughly a half-mile from Pahoa Village Road, the main street of Pahoa. (Photo by AP Photo/U.S. Geological Survey)

The Y-40 Deep Joy is the worlds deepest pool. Y-40 is projected by Architect Emanuele Boaretto and supported by the “Boaretto Group Hotel and Resort”. The name Y-40 is inspired by mathematical symbols. “Y” is the ordinate axis of the Cartesian system and “–40” means the world's record depth or our pool- that is 40 meters underground. (Photo by Courtesy Y40 Deep Joy)

A rider demonstrates Lighting artist Bruce Munro latest installation “Star-Turn” at a one-night event in front of the Holburne Museum on December 21, 2011 in Bath, England. (Photo by Matt Cardy/Getty Images)

“The Lockheed Martin X-33 is an unmanned, sub-scale technology demonstrator suborbital spaceplane developed in the 1990s under the U.S. government-funded Space Launch Initiative program”. – Wikipedia

Photo: An Artist's Rendering Shows How Nasa's X-33 Technology Demonstrator, A Cost-Cutting Fully Reusable Single-Stage-To-Orbit Space Vehicle, Will Look Upon Completion. The 67 Foot-Long, 278,600 Pound, Twin Engine Space Vehicle, Capable Of Reaching Speeds In Excess Of Mach 15, Will Lead To The Construction Of A 127 Foot-Long, 2,186,000 Pound Version With Seven Engines And A 50,000 Pound Payload Capacity Called The “Venturestar”. (Photo By Nasa/Getty Images)

Emily Ratajkowski sun bathes at Paradise Cove in Malibu, CA on March 9, 2017. Emily showed off her stunning figure in a white bikini and large sunhat. She sipped beer as she relaxed with her boyfriend Jeff Magid. (Photo by Splash News and Pictures)