A demonstrator carries a placard reading “One more day of reflection” as she dances with others at Sol Square on May 21, 2011 in Madrid, Spain. A growing number of angry Spaniards have, encouraged by youth groups and social media campaigns, taken possession of the Sol square setting it up with tents and kitchens ahead of Sundays regional and municipal elections held in Spain. (Photo by Jasper Juinen/Getty Images)

“NASA's Pathfinder, Pathfinder Plus, Centurion and Helios Prototype were an evolutionary series of solar- and fuel-cell-system-powered unmanned aerial vehicles. AeroVironment, Inc. developed the vehicles under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. They were built to develop the technologies that would allow long-term, high-altitude aircraft to serve as “atmospheric satellites”, to perform atmospheric research tasks as well as serve as communications platforms”. – Wikipedia

Photo: The solar-electric Helios Prototype flying wing is flies over the Hawaiian islands of Niihau and Lehua during the first solar-powered test flight July 14, 2001 from the U.S. Navy's Pacific Missile Range Facility on Kauai, HI. The 18-hour flight was a functional checkout of the aircraft's systems and performance in preparation for an attempt to reach sustained flight at 100,000 feet altitude later in the summer. (Photo Courtesy of NASA/Getty Images)

A female participant armed with a bottle of ketchup attacks in the annual Vegetable Battle in Kreuzberg district near Oberbaumbruecke Bridge on August 28, 2011 in Berlin, Germany. The event pits Kreuzberg district residents againts Friedrichshain district residents for control of the Oberbaumbruecke, and the two sides pelt each other with rotten vegetables, other foods, ketchup, water guns and styrofoam bats until one side has pushed the other from the bridge. The event had originally been cancelled for today, but so many participants showed up anyway and began battling on the Kreuzberg side, where the situation escalated and began to threaten traffic, that police relented and let them later battle it out on the bridge. Kreuzberg claimed victory. (Photo by Sean Gallup/Getty Images)

“Douglas Fisher has worked in the photographic industry for more than 25 years, starting out at 19 as an assistant before establishing his own studio, just two years later. Here, Douglas would go on to be among the first to champion the emerging worlds of digital photography and CGI, identifying early the transformative impact they would bring to advertising and high end photography”. – Tim Mitchell

Photo: «Carlsberg Launch». (Photo by Douglas Fisher)

A cow, which escaped from a truck, attacks a farmer trying to catch it in Liangdun village of Nangang township, Anhui province December 15, 2013. The 700 kilogram (1,543 lb) cow attacked several farmers before being shot dead by policemen, local media reported. (Photo by Reuters/China Daily)

“Self-educated photographer, Quebec. I always impassioned myself for the animal world and natural spaces, in particular for the red squirrels and the titmouses. Having reached sixty and more, I am nothing any more has to prove but all has to show”. – Andre Villeneuve. Photo: “Eat and run”. (Photo by Andre Villeneuve)

School boys who attend Sri Lankan traditional dance training wait for their graduation ceremony at a Buddhist temple in Colombo, Sri Lanka January 23, 2017. (Photo by Dinuka Liyanawatte/Reuters)

A bull savar (jockey) jumps off his tray as he competes in a bull race in Pind Sultani, Pakistan January 31, 2017. (Photo by Caren Firouz/Reuters)