Revellers at the Chin Chin music festival in Amsterdam, Netherlands on July 3, 2021. The festival season has started with a QR code, one can enter, corona proof or vaccination proof in the corona check app. (Photo by Robin Utrecht/Rex Features/Shutterstock)

A displaced Iraqi girl, who fled her home, cries during a battle between Iraqi forces and Islamic State militants, near Badush, Iraq, March 16, 2017. (Photo by Reuters/Stringer)

Two girls run through the heavy rain as people head out to Wind Street in Swansea, Wales to celebrate Halloween on Monday, October 31, 2022. (Photo by Robert Melen)

Mary Pickford takes a picture of husband Douglas Fairbanks, Sr., who is executing a handstand on the roof of a building on December 19, 1920. (Photo by Bettmann Archive/Getty Images)

An Egyptian boy rides his donkey in front of a cafeteria with a picture of former Barcelona's forward player Lionel Messi at a village, near Giza, on the outskirts of Cairo, Egypt, February 7, 2022. (Photo by Amr Abdallah Dalsh/Reuters)

National Geographic photographer Steve Winter has spent most of his adult life shooting wild cats. Photo: A 14-month-old cub, cooling off in a pond, is riveted by a deer that appeared near the shore. Tigers are powerful swimmers; they can easily cross rivers four to five miles wide and have been known to swim distances of up to 18 miles. (Photo by Steve Winter/National Geographic)

A participant rests while people take part in the Mermaid Parade at Coney Island, in Brooklyn, New York, June 20, 2015. The annual parade, founded in 1983, seeks to bring mythology to life for residents, create confidence in the district and to allow artistic self-expression in public, according to the parade's website. (Photo by Eduardo Munoz/Reuters)

Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)