Members of the ice swimming club “Berliner Seehunde” (Berlin Seals) take a dip in the Orankesee lake as part of their traditional Christmas swimming session in Berlin, Germany, December 25, 2015. (Photo by Hannibal Hanschke/Reuters)

Members of a local winter swimming club photograph as they take part in festive bathing in the icy waters of Boyarskoye lake outside Tomsk, Russia, December 26, 2021. (Photo by Taisiya Vorontsova/Reuters)

Kyuta Kumagai, 10, wrestles with a boy the same age as him, during a training session at Buddy acL Ariake's wrestling club in Tokyo, Japan, August 22, 2020. (Photo by Kim Kyung-Hoon/Reuters)

A member of a winter swimming club wears flippers during the celebration of Maslenitsa, also known as Pancake Week, a pagan holiday, marking the end of the winter, in Novosibirsk, Russia. (Photo by Alexandr Kryazhev/Sputnik/Profimedia)

The London Cabaret Club on August 26, 2022 getting in the mood for Notting Hill carnival weekend will host to a Brazilian Fantasy Dance Company Festival ,with the colors and music of Carnival. (Photo by Paul Quezada-Neiman/Alamy Live News)

A Pug sleeps during the American Kennel Club's (AKC) Meet the Breeds event in New York, U.S., January 29, 2023. (Photo by Jeenah Moon/Reuters)

Katie Francis, a member of the Difficult Access Team from Wiss, Janney, Elstner Associates, inspects a gargoyle while rapelling down one of the north tower on the west front of the National Cathedral while looking for damage from August's magnitude 5.8 earthquake and high winds from Hurricane Irene October 17, 2011 in Washington, DC. DAT members used cameras, cell phones and iPad computers to record places on the cathedral's west front where damage was apparent. (Photo by Chip Somodevilla/Getty Images)

Luis Hernan was always curious about how wireless technologies like radio are transmitted through the air. So after finishing up his studies in architecture, computer science, and design, Hernan decided to research these invisible signals through a PhD at Newcastle University. Hernan set up a system that turned the wireless signals around him into colourful, ghostlike images using long-exposure photography, allowing people to see the strength of the signals around them. (Photo by Luis Hernan)