Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

“The knight and his steed”. This picture was taken in a natural but controlled environment. There are pictures that can not be done in nature or that would imply a very high cost of both time and money, thats why photography workshops are run conducted at strategic locations and bringing EVERYONE who is interested, the basic notions (lighting, camera handling, composition, etc...) or the specimens, and afford them the opportunity to take pictures like this. Although controlled, this shot was not prepared at all, I was performing a workshop with the agalychnis callidryas treefrog from Costa Rica when the frog managed to jump to the branch where this huge titan was sleeping... I had my gear ready so I only had to change a few settings and shoot... the rest is history. (Photo and caption by Nicolas Reusens Boden (Sweden)/2014 Sony World Photography Awards)

Skeleton involves a person riding a small sled down a frozen track while lying face down. The sport is a more intense form of luge because skeleton competitors leap onto the sled and slide downhill head first. Skeleton athletes can reach up to 80 mph on straightaways, causing forces up to 5g, so the helmet is a critical component for attitude as well as safety.

The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its sixth year and has received over 2,500 entries. Photo: Centre of the Heart Nebula by Ivan Eder (Hungary). Situated 7500 light years away in the “W”-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation. (Photo by Ivan Eder)

A mass pillow fight in Trafalgar Square in central London on April 5, 2014 on International Pillow Fight Day. (Photo by Jane Scanlan)

A woman reacts as anti-government protesters place a dead body on a stretcher after violence erupted in the Independence Square in Kiev, in this February 20, 2014 file photo. (Photo by Vasily Fedosenko/Reuters)

“Warming up”. This photo I capture in the early afternoon, the animal species of lemurs fly. Photo location: Sambas, West Kalimantan, Indonesia. (Photo and caption by Hendy Mp/National Geographic Photo Contest)

The annual Sculpture by the Sea exhibition in Sydney features dozens of sculptures on Bondi and Tamarama beaches and along the coastal path between them. The free outdoor exhibition, now in its 18th year, stretches for 2km along the coastline and includes work by artists from 16 countries. It runs from 23 October to 9 November 2014. Here: “Breaching” by Michael Greve is displayed during the 2014 Sculptures by the Sea exhibition at Marks Park on October 23, 2014 in Sydney, Australia. (Photo by Cameron Spencer/Getty Images)