Contorsionist Rich Miteku performs during the opening of the 41st Monte-Carlo International Circus Festival in Monaco on January 19, 2017. (Photo by Valery Hache/AFP Photo)

Lilly Caron, 8, of Bridgeton, Maine, Jason Homchick, of San Diego, and Lilly's father Jason Caron, (obscured), ride the Sky Swing at Seacoast Adventure, Thursday, July 14, 2016, in Wyndham, Maine. The 100-foot-tall swing gives riders the combined thrills of sky diving and hang gliding. (Photo by Robert F. Bukaty/AP Photo)

A Naga sadhu, or naked Hindu holy man, performs a ritual inside his tent during Kumbh Mela, or Pitcher festival, at Trimbakeshwar, India, Friday, August 28, 2015. Hindus believe taking a dip in the waters of a holy river during the festival will cleanse them of their sins. The festival is held four times every 12 years. (Photo by Rajanish Kakade/AP Photo)

Dinosaur robots acting as receptionist greet a hotel employee demonstrating how to check-in to the hotel during a press preview for the newly-opening Henn na Hotel Maihama Tokyo Bay in Urayasu, east of Tokyo, Japan March 15, 2017. The reception desk is handled by robots that speak Japanese, English, Chinese and Korean, as well as porter robots that help guests carry luggage to their rooms. Tasks such as window-cleaning and vacuuming are also handled by robots. Japan's second robot-run hotel Henn na Hotel (“strange hotel” in Japanese) opened on March 15, 2017 as the robot-staffed hotel near Tokyo, operating company H.I.S. Co. said. (Photo by Issei Kato/Reuters)

A woman holds an elderly woman on her back to cross a flooded street after a heavy rain in Shenyang, Liaoning province on July 14, 2017. (Photo by Fred Dufour/AFP Photo)

Tourists gather to watch Mount Agung at Amed beach in Karangasem on Indonesia' s resort island of Bali on November 30, 2017. Thousands of foreign tourists were expected to leave Bali by plane on November 30 following a nearly three- day airport shutdown sparked by a rumbling volcano on the Indonesian holiday island. (Photo by Juni Kriswanto/AFP Photo)

People walk passed sculptures by Chinese artist Minjun Yue on a street outside a museum in Beijing, China on July 5, 2018. (Photo by Nicolas Asfouri/AFP Photo)

A hot air balloon in the shape of children's comic Rupert Bear is seen tethered before a tethered flight at the Bristol International Balloon fiesta in south west England, Britain, August 10, 2018. (Photo by Adrian Sherratt/The Guardian)