Dancers wait at backstage as they prepare for a dance performance during the Bali Arts Festival in Bali, Indonesia, Wednesday, June 21, 2017. The resort island of Bali is holding a month-long annual Bali Arts Festival from June 10 to July 8. (Photo by Firdia Lisnawati/AP Photo)

Mercury and Maia, fueled and overhauled, are waiting in the Tay at Dundee, for favorable weather to start the flight to the Cape, a distance of 6,370 miles. The composite machine moored in the Tay River, at Dundee, on September 23, 1938. (Photo by AP Photo)

Participants of the 79th edition of the annual Christmas swimming “Coupe de Noel” jump into the Lake Geneva, in Geneva, Switzerland, Sunday, December 17, 2017. More than 2000 men and women swam the 120 meters at the traditional Christmas swimming in Geneva where the water temperature was 6 degrees. (Photo by Martial Trezzini/EPA/EFE/Rex Features/Shutterstock)

Two and a half year-old Jennifer Martin in tears during a visit to Santa at Harrods department store in London, 10th December 1949. (Photo by William Vanderson/Fox Photos/Hulton Archive/Getty Images)

Tandem hair drying is possible with a new two-hood attachment for any electric hair dryer manufactured by Postcraft Co of Tucson, Ariz., shown in Chicago, January 27, 1965. A Y adapter permits two hoses to be attached to the dryer. (Photo by Edward Kitch/AP Photo)

A member of the Qinghai Acrobatic Troupe checks her hair with a smartphone during a media preview for the world premiere of cabaret show “Shanghai Mimi” as part of Sydney Festival in Chinatown, central Sydney, Australia, 08 January 2019. Sydney Festival 2019 runs from 09 to 27 January and will feature theatre, dance, circus, music, visual arts and talks from international and local artists. (Photo by Steven Saphore/EPA/EFE)

A young Sandinista guerrilla takes aim with his 45 pistol as he stands waiting to do combat with the Nicaraguan National Guard in Managua June 23, 1979. The guerrillas still occupy major parts of the Capitol City. (Photo by McLendon/AP Photo)

Poppy, a female Crowned sifaka, inspects a photographer's camera in the enclosure at the zoo of Mulhouse, eastern France, on March 5, 2019. The Crowned sifaka is a critically endangered species from Madagascar. (Photo by Sebastien Bozon/AFP Photo)