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)

Two men try to load their just purchased Samsung 55" TV into a car, at a Best Buy store in Fairfax, Virginia on November 26, 2015, on a Black Friday sale that started a day earlier during Thanksgiving evening. The US holiday shopping season kicks off with "Black Friday" – the day after the Thanksgiving holiday – with a frenzy expected at stores around the country as retailers slash prices. (Photo by Paul J. Richards/AFP Photo)

At least 43 people have been killed and more than 200 others wounded in an attack by Somali Islamist militants on a Nairobi shopping mall, the Kenyan Red Cross said on Sunday. The Somali Islamist group al Shabaab claimed responsibility for Saturday’s attack on the Kenyan capital’s Westgate mall, which is frequented by Westerners as well as Kenyans. Several foreigners, including a Canadian diplomat, were among the dead. Photo: Security officers secure an area inside the Westgate Shopping Centre. (Photo by Siegfried Modola/Reuters)

Mystical Forest. Tracey Jennings photographed this seven-gill shark in a kelp forest just off the shore of Simon's Town near Cape Town, South Africa. You don't need to travel far from cities to visit Narnia. This 7 gill shark was photographed in a kelp forest just off the shore of Simonstown near Cape Town, South Africa. (Photo by Tracey Jennings/National Geographic Travel Photographer of the Year Contest)

Two brave contestants take part in the World Gravy Wrestling Championships at the Rose 'n Bowl in Stacksteads, Lancashire, England on August 27 2018. Contestants must wrestle in the gravy for 2 minutes, points are scored for fancy dress, comedy effect, entertainment and wrestling ability. The event is held to raise funds for the East Lancashire Hospice and competitors nominated charities. (Photo by The Mercury Press)

Participants run through the streets of the Back Bay during the 16th annual Santa Speedo Run in Boston, Massachusetts, December 12, 2015. (Photo by Brian Snyder/Reuters)

The galactic centre of the Milky Way glows brightly in the clear night sky above the lighthouse at Portland Bill on the Dorset Jurassic Coast, United Kingdom on April 13, 2021. (Photo by Graham Hunt/Alamy Live News)

Cheerleaders wearing face masks due to the outbreak of the coronavirus disease (COVID-19) are seen at the first professional baseball league game of the season at Taoyuan International baseball stadium in Taoyuan city, Taiwan, April 11, 2020. (Photo by Ann Wang/Reuters)