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)

A Rafale fighter jet flies over France's Charles de Gaulle aircraft carrier as it makes its way in the Gulf, January 28, 2016. (Photo by Philippe Wojazer/Reuters)

A model takes part in the Necropolis – Tanexpo 2021 international exhibition of funeral accessories, services and commemorative art at Moscow's Expocentre in Moscow, Russia on October 26, 2021. (Photo by Sergei Karpukhin/TASS)

A home-made steam train, designed by Pavel Chilin, rides on a make-shift railway across country house neighborhood in the settlement of Ulyanovka in Leningrad region, Russia on November 4, 2019. (Photo by Anton Vaganov/Reuters)

A dramatic rise in owning exotic pets in China is fuelling global demand for threatened species. The growing trade in alligators, snakes, monkeys, crocodiles and spiders is directly linked to species loss in some of the world’s most threatened ecosystems. Here: A fennec fox (Vulpes zerda) is groomed in a pet store in central Beijing. Native to the Sahara in North Africa, the species became a popular pet after being depicted as a character in Disney’s 2016 animated movie Zootopia. Individuals can cost between $2,000–$3,000. (Photo by Sean Gallagher/The Guardian)

People pause at a memorial set up for victims of a mass shooting in Las Vegas, Nev., on Tuesday, October 3, 2017. A gunman opened fire on an outdoor music concert on Sunday. It was the deadliest mass shooting in modern U.S. history, with dozens of people killed and hundreds injured, some by gunfire, some during the chaotic escape. (Photo by John Locher/AP Photo)

Believers bathe in the icy water during a traditional Epiphany at the Church of the Holy Trinity in Ostankino near TV Tower in Moscow, Russia, Wednesday, January 18, 2023. Across Russia, the devout and the daring are observing the Orthodox Christian feast day of Epiphany by immersing themselves in frigid water through holes cut through the ice of lakes and rivers. Epiphany celebrates the revelation of Jesus Christ as the incarnation of God through his baptism in the River Jordan. (Photo by Alexander Zemlianichenko/AP Photo)

Russia's figure skater Alexandra Trusova performs in a show at the CSKA arena in Moscow on February 14, 2023. (Photo by Kirill Kudryavtsev/AFP Photo)