Hindu devotees play with coloured powders during Holi celebrations at the Bankey Bihari Temple on March 21, 2011 in Vrindavan, India. Holi, the spring festival of colours, is celebrated by Hindus around the world in an explosion of colour to mark the end of the winter. (Photo by Majid Saeedi/Getty Images)

An orphaned 11 month old cougar cub plays at Six Flags Discovery Kingdom on April 26, 2007 in Vallejo, California. Three cougar cubs were given to the park from the Idaho Fish & Game in March after they were found motherless in the wild and it was determined that they would not survive in the wild. (Photo by David Paul Morris/Getty Images)

Cathryn Shrimpton, 4, prepares to play the Angle Gabriel during a traditional Christmas Nativity on December 18, 2011, at St Mary's Church, Myton Village, England. In schools and churches around the country children busy preparing and performing in the telling of the traditional nativity story. (Photo by Bethany Clarke/Getty Images)

Baraa Melhem plays on her sisters bike at her mothers house on February 2, 2012 in Qalandia, near Ramallah, West Bank. Baraa Melhem was held in captivity in a bathroom by her father for over nine years, and was finally rescued by Palestinian security forces after a family member notified police. (Photo by Ilia Yefimovich/Getty Images)

These photographs of hundreds of ducks following their leader down a river are truly mesmerizing. Rafeur Rahman of Bangladesh climbed a high bridge and saw hundreds of ducks apparently playing a game of follow the leader. More than 500 ducks live on the river, where the mosses and snails provide the perfect habitat. Here: Ducks in the river Baral in Bangladesh. (Photo by Rafeur Rahman/Caters News Agency)

“Igor Sikorsky (May 25, 1889 – October 26, 1972), born Igor Ivanovich Sikorsky was a Russian American pioneer of aviation in both helicopters and fixed-wing aircraft. He designed and flew the world's first multi-engine fixed-wing aircraft, the Russky Vityaz in 1913, and the first airliner, Ilya Muromets, in 1914. After immigrating to the United States in 1919, Sikorsky founded the Sikorsky Aircraft Corporation in 1923, and developed the first of Pan American Airways' ocean-conquering flying boats in the 1930s. In 1939 Sikorsky designed and flew the Vought-Sikorsky VS-300, the first viable American helicopter, which pioneered the rotor configuration used by most helicopters today. Sikorsky would modify the design into the Sikorsky R-4, which became the world's first mass-produced helicopter in 1942”. – Wikipedia

Photo: Westland Sikorsky H-5's, used by British European Airways Helicopters, which fly between London and Birmingham. The Sikorsky H-5, (aka R-5, S-51, HO3S-1, or Horse) (R-5 until 1948; company designation VS-327) is a helicopter built by Sikorsky Aircraft Corporation, formerly used by the United States Air Force, and its predecessor, the United States Army Air Forces, as well as the United States Navy and United States Coast Guard (with the designations HO2S and HO3S). (Photo by Harrison /Topical Press Agency/Getty Images). 22nd May 1951

A child plays in front of “Etnias”, a large graffiti wall by Brazilian graffiti artist Eduardo Kobra created ahead of the Rio 2016 Olympic Games at Porto Maravilha in Rio de Janeiro, Brazil, 30 July 2016. The Olympics start on 05 August. Eduardo Kobra hopes to set a Guinness World Record for the largest graffiti created by a single artist. (Photo by Lukas Coch/EPA)

These stunning images document the everyday lives of the men, women and children of the Mentawai tribe. The Mentawai people, a native population in Indonesia, are famous for their decorative tattoos and for living a semi-nomadic life on the Mentawai Islands in West Sumatra. Shot by professional photographer Mohammed Saleh Bin Dollah, the series captures a glimpse of life on the island as the Mentawai men smoke and hunt for food and the children play in the river. Here: A young boy helps a woman to prepare food taken on July 19, 2014 on the Mentawai Islands, Indonesia. (Photo by Muhamad Saleh Dollah/Barcroft Media)