People watch a flock during the annual sheep parade, during which shepherds exercise their right to use traditional migration routes for their livestock from northern Spain to winter grazing pasture land in the southern areas of the country, on the streets of Madrid, Spain on October 23, 2022. (Photo by Violeta Santos Moura/Reuters)

A person dressed as a gorilla is seen in front of French police standing in position during a demonstration as part of the tenth day of nationwide strikes and protests against French government's pension reform in Paris, France on March 28, 2023. (Photo by Nacho Doce/Reuters)

Pilgrims ride their horses on their way to the shrine of El Rocio in Villamanrique, Spain, on Saturday, June 4, 2022, during the annual pilgrimage in which hundreds of thousands of devotees of the Virgin del Rocio converge in and around the shrine. (Photo by Joan Mateu Parra/AP Photo)

Members of a “Diablada” folk group dance during celebrations of the anniversary of Bolivia foundation, in Santiago, Chile on August 6, 2022. (Photo by Ivan Alvarado/Reuters)

Riders compete during the NETT sidecarcross championship in Middlesbrough, Britain on April 14, 2024. The daredevil sport is a branch of motocross racing in which bikes are designed to take the weight of two people. (Photo by Lee Smith/Reuters)

A model presents a creation for Irish-American designer Paul Costelloe during the catwalk show for his Autumn/Winter 2023 collection on the opening day of the London Fashion Week, in London, on February 17, 2023. (Photo by Niklas Halle'n/AFP Photo)

Rescuers attend an injured fan lying on the field of the Cuscatlan stadium in San Salvador, El Salvador, Saturday, May 20, 2023. At least nine people were killed and dozens more injured when stampeding fans pushed through one of the access gates at a quarterfinal Salvadoran league soccer match between Alianza and FAS. (Photo by Milton Flores/AP Photo)

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)