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)

“A Little Monkey on the Cliff”. “A cold front hit the Nagano prefecture. I saw a little monkey enduring the cold in Jigokudani Monkey Park. This little monkey is really cute”. (Photo by Hidetoshi Ogata/Smithsonian Photo Contest)

Monkeys climb onto tourists during the annual Monkey Festival in Lopburi province, Thailand on November 26, 2023. (Photo by Chalinee Thirasupa/Reuters)

A monkey licks ice during the annual “monkey buffet” in Lopburi province, some 150 kms north of Bangkok on November 24, 2013. More than 2,000 kilos of fruits and vegetables were offered to the monkeys during the annual festival to help promote tourism in the area. (Photo by Pornchai Kittiwongsakul/AFP Photo)

Monkeys climb on top of tourists during the Lopburi Monkey Festival on November 27, 2022 in Lop Buri, Thailand. Lopburi holds its annual Monkey Festival where local citizens and tourists gather to provide a banquet to the thousands of long-tailed macaques that live in central Lopburi. (Photo by Lauren DeCicca/Getty Images)

A Pakistani monkey handler Naseer Khan plays flute to attract passers by for a monkey show to earn his living in Islamabad, Pakistan, Monday, September 7, 2015. (Photo by B. K. Bangash/AP Photo)

A monkey grabs the face of a tourist during the Lopburi Monkey Festival on November 27, 2022 in Lop Buri, Thailand. Lopburi holds its annual Monkey Festival where local citizens and tourists gather to provide a banquet to the thousands of long-tailed macaques that live in central Lopburi. (Photo by Lauren DeCicca/Getty Images)