A man steers with his legs while riding a motorcycle on a road in Vietnam's northern Hoa Binh province, outside Hanoi, October 15, 2015. (Photo by Reuters/Kham)

In this March 22, 1975 file photo, a refugee clutches a baby as a government helicopter gunship carries them away near Tuy Hoa, Vietnam, 235 miles northeast of Saigon. They were among thousands fleeing from Communist advances. AP Photographer Nick Ut will be retiring from the AP in March 2017 after 51 years of taking photographs from the front lines of the Vietnam War to the red carpets of Hollywood. (Photo by Nick Ut/AP Photo)

Performers Roni, Liv and Becky behind the scenes at Great Yarmouth Hippodrome Circus, England. (Photo by Nick Warner/The Guardian)

“Unexpected humour”. The Dog and the Faucet, in Kolkata, India on January 2017. (Photo by Pau Buscató/The Guardian)

A newborn grey seal pup is tended by its mother at Donna Nook, a nature reserve on the county’s coastline managed by Lincolnshire Wildlife Trust in Lincolnshire, UK on November 23, 2015. (Photo by David Tipling/Rex Shutterstock)

Teeming with images of spectacular underwater scenes from around the world, Call of the Blue is the culmination of a five-year project by the photographer and ocean conservationist Philip Hamilton. This groundbreaking book includes contributions from acclaimed scientists and ocean “guardians”, who reveal what drove them to answer the call of the blue. (Photo by Philip Hamilton/The Guardian)

Stefania and Mariah play with a hose in South Norwood, United Kingdom on June 1, 2021. (Photo by Joe Plimmer/The Guardian)

An incredible clear-air lightning display from storms to the east of Noonamah, just outside Darwin on April 6, 2015. (Photo by Jacci Ingham/The Guardian)