Ireland's Philip Mulpeter, left, is kicked by Brazilian Vitor Nobrega during their welterweight mixed martial arts bout of International Pro Combat at the Estoril Casino in Estoril, near Lisbon, Portugal, Monday, January 26, 2015. Nobrega defeated Mulpeter. (Photo by Francisco Seco/AP Photo)

Nick Franklin, in action during the FMX competition at the 23rd edition of Free4Style this Saturday, July 2, 2016 in Estavayer-le-Lac,Switzerland. (Photo by Jean-Christophe Bott/Keystone/APA)

People look at “The Fall” sculpture by Steve Cramb on display between Bondi and Tamarama beach as part of the Sculpture by the Sea exhibition in Sydney on October 21, 2022. (Photo by Muhammad Farooq/AFP Photo)

A man dressed in a condom costume walks at Caleta Portales beach, during a summer awareness campaign by the Chilean Corporation for the Prevention of AIDS in Valparaiso city, northwest of Santiago January 9, 2015. (Photo by Rodrigo Garrido/Reuters)

“Warming up”. This photo I capture in the early afternoon, the animal species of lemurs fly. Photo location: Sambas, West Kalimantan, Indonesia. (Photo and caption by Hendy Mp/National Geographic Photo Contest)

Cuban-American artist Jorge Rodriguez-Gerada's six-acre sand and soil “facescape” stretches across the JFK Hockey Field on the north side of the Reflecting Pool along the National Mall October 1, 2014 in Washington, DC. Titled “Out of Many, One” and composed of 2,500 tons of sand, 800 tons of top soil and eight miles of string, the piece is the artist's interpreative blending of 30 different men's faces. Rodriguez-Gereda used high-precision global positioning satellites to place 10,000 wood pegs as waypoints for the giant face. The piece will be open to the public beginning October 4 and will eventually be tilled back into the earth. (Photo by Chip Somodevilla/Getty Images)

Spain fans react during the penalty shootout during 2022 FIFA World Cup football match between Morocco v Spain in Qatar as they watch the match on a big screen in Barcelona, December 6, 2022. (Photo by Nacho Doce/Reuters)

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)