A member of the German wireless police picks up signals on the radio equipment he carries on his back, while his colleague takes notes. (Photo by General Photographic Agency/Getty Images). Circa 1925

Benfica's Turkish midfielder #10 Orkun Kokcu celebrates after scoring their third goal during the UEFA Champions League knockout phase play-off second leg football match between SL Benfica and AS Monaco at Luz stadium in Lisbon on February 18, 2025. (Photo by Filipe Amorim/AFP Photo)

A child who learns is a teacher who teaches.

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)

Young couples compete in Rock' n'Roll & Co, an all- Russian acrobatic rock' n'roll competition in Kazan, Russia on November 4, 2017. Acrobatic rock’n’roll is a discipline for couples combining energetic dancing with acrobatic moves. (Photo by Yegor Aleyev/TASS via Getty Images)

A group of colorful row houses are reflected on to the top of a black car parked on 3600 block of N street in the Georgetown section of Washington DC, February 16, 2017. (Photo by John McDonnell/The Washington Post)

American social media personality, golf instructor and former professional golfer Paige Spiranac attends MAXIM Hot 100 Experience at Hyde Beach at SLS South Beach on July 16, 2022 in Miami Beach, Florida. (Photo by @_paige.renee/Instagram)

Demonstrators march on a Slutwalk on June 4, 2011 in Glasgow, Scotland. Glasgow's first ever sl*t walk made its way through the town center streets in a bid to raise awareness about commonly-held attitudes towards rape and sexual assault. (Photo by Jeff J Mitchell/Getty Images)