A Hindu pilgrim feeds biscuits to an ox to seek blessing before heading for an annual trip to Sagar Island for the one-day festival of “Makar Sankranti”, in Kolkata, India January 10, 2017. (Photo by Rupak De Chowdhuri/Reuters)

Workers attach a hat to a pinata depicting the drug lord Joaquin “El Chapo” Guzman at a workshop in Reynosa, July 21, 2015. Guzman broke out of Mexico's top maximum security prison through a tunnel built into his cell earlier this month. (Photo by Daniel Becerril/Reuters)

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)

Winner. “I took this vertical image in the Quarry Bay district of Hong Kong during the dusk ‘blue hour’, when there was a perfect balance between the ambient light in the sky and the artificial lights of the high-rise residential buildings”. (Photo by Jatinder Heer/The Guardian)

Cropped shot of a woman flirtatiously touching leg of man in a suit with her foot under the table. (Photo by LightField Studios/Skyfish Digital Media/Getty Images)

These “snapcats” have found their bunny doppelgängers in a series of sweet photo shoots. Animal photographer Mark Taylor, from Surrey, England, and his assistants have scoured the U.K. to bring together carbon-copy rabbits and cats. Here: Chocolate Birman-cross kitten with chocolate Lop rabbit. (Photo by Mark Taylor/Warren Photographic/Caters News Agency)

A man walks on the road between Nouahibou and Nouakchott, where three Spanish aid workers were abducted in Mauritania, December 3, 2009. (Photo by Rafael Marchante/Reuters)

This photo taken on October 20, 2018 shows tourists posing for a photo on a middle of a railway track passing through an old residential district in central Hanoi. (Photo by Nhac Nguyen/AFP Photo)