In this Monday, October 8, 2018 photo, Colombia's BMX freestyle athlete Sebastian Martinez practices at the Urban Park, at the Youth Olympic Games in Buenos Aires, Argentina. (Photo by Ian Walton/OIS/IOC via AP Photo)

A woman looks on while a horse-drawn carriage passes by Italian artist Emilio Ferro's artwork installation “Portal of Light” at the Giza pyramids necropolis during the second edition of the Art D’Égypte exhibition “Forever is Now” on October 27, 2022. (Photo by Khaled Desouki/AFP Photo)

Coaches of the North-East Express passenger train that derailed late Wednesday near Raghunathpur railroad station in Buxar district of Bihar state, India, Thursday, October 12, 2023. The train was on its way to Assam state from New Delhi. (Photo by Aftab Alam Siddiqui/AP Photo)

Contestant of the Muslimah World 2013, Obabiyi Aishah Ajibola (C) of Nigeria, is reflected in a mirror checking her make-up while contestants wait for a grand final during the Muslimah World competition in Jakarta on September 18, 2013. (Photo by Adek Berry/AFP Photo)

In this handout image provided by Red Bull, Artem Silchenko of Russia dives from the 27 metre platform at training on Hong Island in the Andaman Sea during the final stop of the 2013 Red Bull Cliff Diving World Series on October 25, 2013 at Krabi, Thailand. (Photo by Romina Amato/Red Bull via Getty Images)

This picture taken on December 17, 2013 shows people taking photos of a pole dancer (R) practising after it snowed in Tianjin during a promotional event by members of China's national pole dancing team and students of the sport. China set up its first national pole dancing team in Tianjin in 2012 in order to compete in the World Pole Dancing Championships. (Photo by AFP Photo)

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)

The hot air balloon “Hopper T Frog” from Park City, Utah, peeks over the red rock cliffs during the 23nd Annual Red Rock Balloon Rally at Red Rock State Park December 6, 2003 near Gallup, New Mexico. (Photo By Douglas Tesner/Getty Images)