New York City policemen tangled with demonstrators at a subway station on the opening day of the New York World's Fair, April 22, 1964. Youths attempted to stall the train, which was headed from the city to the fairgrounds, as a form of protest on behalf of civil rights for blacks. (Photo by Charles Gorry/AP Photo)

The British Breitling Wingwalkers, Danielle Hughes and Emily Guilding, soar above the Palm Jumeirah in Dubai at 1,500 feet (460 meters) in excess of 100mp/h, ahead of their Dubai debut performance at the 2014 UIM Skydive Dubai XCAT World Powerboating Series, on Saturday, 13th December 2014. The British team is the only aerobatic formation display team who employ full time wingwalkers and fly their two Breitling-liveried 1930's Boeing Stearman bi-planes at Air Shows and major sporting events around the world. (Photo by Katsuhiko Tokunaga/Breitling via AP Images)

Russian artist Maria Gazanova (L) works on her "The Alive Painting" art work during the Art Krasnoyarsk annual festival in Siberian city of Krasnoyarsk, Russia November 4, 2015. (Photo by Ilya Naymushin/Reuters)

Artist Kong Ning wears a wedding dress made from respirators to highlight concerns about air quality and pollution in Beijing, China on December 1, 2015. (Photo by Luo Xiaoguang/Xinhua Press/Corbis)

Undated handout photo of Buckbeak, a Hippogriff that lived with Rubeus Hagrid in the Harry Potter series, has his feathers preened and replenished by featherologist Val Jones, as he will feature in the the Feathers and Flight event at Warner Bros. Studio Tour London. This is the first make-over Buckbeak has received since the hugely popular Harry Potter film series was made. His intricate coat is created from thousands of individually airbrushed chicken and goose feathers that Val will carefully clean and replenish in time for the start of Feathers and Flight. Val will lead an expert team to demonstrate the techniques that made winged wonders such as Buckbeak and Fawkes the Phoenix a reality on screen. (Photo by Tim Anderson/PA Wire)

Actress Kerry Washington, Harvard University's Hasty Pudding Theatricals' Woman of the Year, throws wine in the face of an actor playing Republican presidential candidate Donald Trump, Thursday, January 28, 2016, as she is roasted in Cambridge, Mass. (Photo by Elise Amendola/AP Photo)

A man presents a self-made robot that local media reported is able to carry a person, in Heihe, Heilongjiang province, China, April 5, 2017. (Photo by Reuters/China Daily)

A woman looks towards part of an artwork called “Lichen! Libido! (London!) Chastity!” by Anthea Hamilton, one of the four artists shortlisted for the Turner Prize 2016, as it is displayed at the Tate Britain gallery in London, Monday, September 26, 2016. The Turner Prize aims to promote public debate around new developments in contemporary British art. (Photo by Kirsty Wigglesworth/AP Photo)