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)

Only the most intrepid urban explorers cross the tattered ruins of the old Iron Curtain to endure the excessive bureaucracy, military paranoia and freezing winds of the East to hunt for the ghosts of an empire. Rebecca Litchfield is one who couldn’t resist the haunting allure of the ruins of the Soviet Union.

Barcelona's Caroline Graham Hansen, center, in action during the women's Champions League quarterfinals, second leg, soccer match between FC Barcelona and SK Brann Kvinner at the Estadi Johan Cruyff in Barcelona, Spain, Thursday, March 28, 2024. (Photo by Joan Monfort/AP Photo)

Texas state troopers in riot gear try to break up a pro-Palestinian protest at the University of Texas, during the ongoing conflict between Israel and the Palestinian Islamist group Hamas, in Austin, Texas, April 24, 2024. (Photo by Jay Janner/USA Today Network via Reuters)

Jaime Munguia lands a left to Canelo Alvarez in a super middleweight title fight Saturday, May 4, 2024, in Las Vegas. (Photo by John Locher/AP Photo)

Stiliana Nikolova of Bulgaria performs her ball exercise in the final of the individual competition of the 40th European Rhytmic Gymanstics Championships in Budapest, Hungary, 25 May 2024. (Photo by Tibor Illyes/EPA)

Sunisa Lee competes on the beam during the U.S. Gymnastics Championships, Sunday, June 2, 2024, in Fort Worth, Texas. (Photo by Julio Cortez/AP Photo)

Netherlands and England fans arrive at the city ahead of a semi final match between Netherlands and England at the Euro 2024 soccer tournament in Dortmund, Germany, Wednesday, July 10, 2024. (Photo by Markus Schreiber/AP Photo)