Coloured X-ray of a barn owl. A physicist has used X-ray to create an extraordinary collection of artwork. Arie van't Riets pictures reveal birds, fish, monkeys and flowers in an incredible new light. The 66-year-old, from Bathmen in the Netherlands, began X-raying flowers as a means to teach radiographers and physicians how the machine worked. But after adding a bit of colour to the pictures, the retired medical physicist realised the potential for an exciting new collection of art. (Photo by Arie van't Riet/Barcroft Media)

A member of security personnel stands on duty on an empty train platform inside a station on the Subway Line Number 1 on the eve of the Chinese Lunar New Year, in Beijing, China, February 7, 2016. According to local media, traffic in Beijing has seen a rare relief from its usual heavy pressure after 15 million people have left the city, heading for family reunions in their hometowns on the eve of the Chinese Lunar New Year of Monkey. (Photo by Jason Lee/Reuters)

This picture taken on June 20, 2020 shows longtail macaques chasing a woman on a scooter in the town of Lopburi, some 155km north of Bangkok. Residents barricaded indoors, rival gang fights and no-go zones for humans. Welcome to Lopburi, an ancient Thai city overrun by monkeys super-charged on junk food, whose population is growing out of control. (Photo by Mladen Antonov/AFP Photo)

A toque macaque is eating flowers in the water at the pilgrimage site in Polonnaruwa, Sri Lanka, on January 13, 2024. The toque macaque (Macaca sinica), a reddish-brown-colored Old World monkey, is endemic to Sri Lanka, where it is known as the rilewa or rilawa. It is named for the whorl of hair at the crown of its head, which resembles a brimless toque cap. (Photo by Thilina Kaluthotage/NurPhoto/Rex Features/Shutterstock)

A young chimpanzee reacts on a pirogue with Rohmay Ndoulek, from the Papaye International association, during an outing in the Douala-Edea Natural Park in Marienberg on December 15, 2024. In the heart of Douala-Edea Natural Park, dedicated Cameroonian caretakers tend to and rehabilitate chimpanzees, victims of poaching and deforestation, at Papaye International, a sanctuary dubbed a “monkey paradise”. Founded in 2001, the association funded by 30 million friends and the Brigitte Bardot Foundation regularly receives eco-volunteers from all over the world. (Photo by Daniel Beloumou Olomo/AFP Photo)

A jaguar (Panthera onca) growls at the Mata Ciliar association, an organization for the conservation of biodiversity, in Jundiai, Sao Paulo state, Brazil on May 29, 2025. Twenty-five pumas and ten jaguars are currently recovering at the Brazilian Center for the Conservation of Neotropical Felines at Mata Ciliar, a site as large as 40 football fields where monkeys, wild dogs, maned wolves, ocelots, and other regional animals are also rehabilitated. (Photo by Nelson Almeida/AFP Photo)

Female members of police commando march during a ceremony on International Women's Day, at the police headquarters in Islamabad, Pakistan March 8, 2018. (Photo by Faisal Mahmood/Reuters)

Police officers take cover as they clash with protesters after an officer shot and killed a black man in Brooklyn Center, Minneapolis, Minnesota on April 11,2021. Protests broke out April 11, 2021 night after US police fatally shot a young Black man in a suburb of Minneapolis – where a former police officer is currently on trial for the murder of George Floyd. Hundreds of people gathered outside the police station in Brooklyn Center, northwest of Minneapolis. Police fired teargas and flash bangs at the demonstrators, according to an AFP videojournalist at the scene. (Photo by Kerem Yucel/AFP Photo)