Dancers at the Windmill Theatre in London, England practice a routine wearing gas masks and hard-hats with their costumes, 1940. (Photo by Hulton Archive/Getty Images)

Hamish the polar bear tries out his new enclosure at the Yorkshire Wildlife Park at Branton, Doncaster on November 6, 2020, after moving from the Highland Wildlife Park in Scotland. Hamish was the first polar bear to be born in the UK. (Photo by Danny Lawson/PA Wire Press Association)

Director Taro Kambe directs as he watches acting with VR headset during a rehearsal for ROCKET's 3D virtual reality adult film at the company's studio in Tokyo, Japan, July 31, 2017. Japan is the world's second biggest virtual reality market after the United States and the adult entertainment industry and gaming sector are turning to VR as a new way to distribute content. (Photo by Kim Kyung-Hoon/Reuters)

In this January 29, 2017 photo, musicians perform for dancers on the shores of Lake Titicaca, as they practice before their presentation for the Virgin of Candelaria celebrations in Puno, Peru. Dancers in colorful masks and elaborate costume celebrate the Virgin of Candelaria, patron saint of communities along the shore of Lake Titicaca, in what's considered the largest Catholic festival in the Andes. (Photo by Rodrigo Abd/AP Photo)

Parts of the Royal Chariot, which will be used during the late King Bhumibol Adulyadej's funeral later this year is seen at the National Museum in Bangkok, Thailand, February 6, 2017. (Photo by Chaiwat Subprasom/Reuters)

Two men using an electric power saw to fell a tree circa 1940's. (Photo by Keystone View/FPG/Getty Images)

A history enthusiast, dressed as a soldier, marches before the re-enactment of Napoleon's famous battle of Austerlitz near the southern Moravian town of Slavkov u Brna, Czech Republic December 3, 2016. (Photo by David W. Cerny/Reuters)

Two young women embrace in bed together, both wearing white lace underwear. (Photo by Popperfoto/Getty Images)