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)

A regional train passes fog-covered fields in Wehrheim near Frankfurt, Germany, early Friday, October 7, 2022. (Photo by Michael Probst/AP Photo)

A painting of Chinese President Xi Jinping holding an umbrella is seen on the toilet wall in a guesthouse in Hong Kong December 30, 2014. Set up in a small apartment in the Causeway Bay shopping district, the guesthouse that gives what it calls “Umbrella Revolution Occupation Experience” charges guest HK$100 (US$13) a night to stay in a tent surrounded by pro-democracy banners, a cardboard cutout of President Xi Jinping holding a yellow umbrella, and serve toilet paper printed with the face of embattled leader of Hong Kong chief executive Leung Chun-ying. (Photo by Tyrone Siu/Reuters)

Flames from the Falls Fire burn on a hillside along South Main Divide Road in the Cleveland National Forest as firefighters drive through the area on Monday, August 5, 2013. (Photo by Kurt Miller/AP Photo/The Press-Enterprise)

Labourers who work nearby nap on a road as cars drive past in Chongqing Municipality, July 23, 2013. (Photo by Reuters/Stringer)

Youth category winner: Symphony No 5 by Giacomo Redaelli (Italy). (Photo by Giacomo Redaelli/2019 Nature Photographer of the Year)

Goats wait to get unloaded from a vehicle at a livestock market during Dashain, the biggest religious festival for Hindus in Nepal, in Kathmandu, Nepal October 4, 2016. (Photo by Navesh Chitrakar/Reuters)

People take part in the “The Burial of the Sardine” funeral procession, which marks the end of carnival festivities, in Madrid, Spain, February 10, 2016. “Mourners” carry a coffin with a mock sardine through the streets to celebrate the countdown to Lent. Spanish painter Francisco de Goya's painting “El entierro de la sardina” (The Burial of the Sardine) was inspired by this tradition, which started in Madrid in the 18th century, around the time of Spanish King Carlos III. (Photo by Juan Medina/Reuters)