Soap Bubble Structures by Kym Cox. Bubbles optimise space and minimise their surface area for a given volume of air. This phenomenon makes them a useful tool in many areas of research, in particular, materials science and “packing” – how things fit together. Bubble walls drain under gravity, thin at the top, thick at the bottom, which interferes with travelling lightwaves to create bands of colour. Black spots show the wall is too thin for interference colours, indicating the bubble is about to burst. (Photo by Kym Cox/2019 Science Photographer of the Year/RPS)

In this November 28, 1966 file photo, one of the 10 beagles involved in the first test of the Veterans Administration Hospital in East Orange, N.J. smokes a cigarette through a machine linked to its windpipe by a plastic tube to test any link between smoking and emphysema. (Photo by AP Photo)

A visitor passes behind the sculpture “Puma-Dentist” made with plastic, wax and original heads of a puma and a hind by Austrian artist Deborah Sengl during an exhibition at the art gallery Deschler in Berlin April 15, 2008. (Photo by Fabrizio Bensch/Reuters)

Ukrainian servicemen of the 28th Separate Mechanised Brigade fires a 122mm mortar towards Russian positions at the front line, near Bakhmut, Donetsk region, Ukraine, Sunday, March 3, 2024. (Photo by Efrem Lukatsky/AP Photo)

People look at a skeleton couple kissing installation dubbed “Till Death Do Us Part” during a Valentine's Day event in Bucharest, Romania, Tuesday, February 13, 2024. (Photo by Vadim Ghirda/AP Photo)

British singer-songwriter Rita Ora early May 2024 makes an eye-catching face as she promotes “The Masked Singer”, where she’s a judge. (Photo by Rita Ora/Instagram)

This photo provided by Jiji Press shows a Japan Airlines plane on fire on a runway of Tokyo's Haneda Airport on January 2, 2024. A Japan Airlines plane was in flames on the runway of Tokyo's Haneda Airport on January 2 after apparently colliding with a coast guard aircraft, television reports said. (Photo by JIJI Press/AFP Photo)

A girl feeds a squirrel in Bolivar Square, in Caracas, Venezuela on June 4, 2024. (Photo by Gaby Oraa/Reuters)