The waning moon sets behind leafless sumac trees on a crisp, clear morning, Thursday, December 15, 2016, in Portland, Maine. Much of the northern Mid-Atlantic and Northeast will stay cold for the next couple of days as the arctic air remains stuck over the northern Appalachians, the National Weather Service said. (Photo by Robert F. Bukaty/AP Photo)

A model poses for a photograph backstage during Moscow Fashion Week in Moscow, Russia, Monday, October 7, 2024. (Photo by Pavel Bednyakov/AP Photo)

An Egyptian passenger sits on the locomotive of a train as it leaves Cairo train station in Egypt, Wednesday, October 14, 2015. (Photo by Amr Nabil/AP Photo)

Maria Sakkara of Greece in action against Ann Li of the United States in her second round match at the Qatar TotalEnergies Open at the Khalifa International Tennis & Squash Complex on February 22, 2022 in Doha, Qatar (Photo by Robert Prange/Getty Images)

A Land Rover Discovery has been crashed and abandoned inside a canal lock in Tipton, United Kingdom on Monday morning, November 14, 2022. There were no reported injuries and the car is expected to be removed on Tuesday. (Photo by Katie Stewart/Alamy Live News)

A Houthi follower with fake blood on his clothes lies on the ground to represent a victim as others perform a war dance during a ceremony marking the first anniversary of the Houthi movement's takeover of Yemen's capital Sanaa September 21, 2015. (Photo by Khaled Abdullah/Reuters)

Faithful wearing face mask pray during the Arafah prayer ceremony ahead of Eid al-Adha, at the Tehran university’s mosque in Tehran, Iran, 30 July 2020. Iran will not hold the Eid al-Adha prayers and ceremonies over the coronavirus (COVID-19) crisis in the country. (Photo by Abedin Taherkenareh/EPA/EFE)

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)