A woman reacts during the annual tomato fight fiesta called “Tomatina”, tomato fight fiesta, in the village of Bunol near Valencia, Spain, Wednesday, August 30, 2023. Thousands gather in this eastern Spanish town for the annual street tomato battle that leaves the streets and participants drenched in red pulp from 120,000 kilos of tomatoes. (Photo by Alberto Saiz/AP Photo)

Bystanders look at the wreckage of a bus in Noshki town of Balochistan province on March 17, 2025, a day after an explosives laden car hit one of the seven buses of a convoy, a bombing carried out allegedly by the separatist group Baloch Liberation Army (BLA). Separatists in southwest Pakistan killed at least five paramilitaries and wounded more than 30 on March 16, police told AFP, days after an attack on a train in Balochistan province left dozens dead. (Photo by AFP Photo)

Members of the Guard of Honor of the Presidential Regiment from Russia perform during the “Spasskaya Tower” international military music festival at Moscow's Red Square, Russia, September 10, 2015. The festival runs until 13 Sepember. (Photo by Maxim Shemetov/Reuters)

An injured Iraqi Emergency Response Division (ERD) soldier hit by a mortar is held by another officer as they wait for medics to arrive at the Islamic State occupied Mosul Airport in west Mosul, part of the offensive to retake the city some two years after it fell to the hardline jihadist group, February 23, 2017. Iraqi forces encountered stiff resistance with improvised explosives, heavy mortar fire and snipers hampering their advance before they successfully took the airport. (Photo by Martyn Aim/Getty Images)

A guard stands at Dityatki checkpoint, marking a 30 km (18-mile) zone around the Chernobyl nuclear power plant April 23, 2013. Ukraine will mark the 27th anniversary of the Chernobyl disaster, the world's worst civil nuclear accident, on April 26. (Photo by Gleb Garanich/Reuters)

Professor Xie Yong works on an art installation of a beaver, which is made out of plastic and around 300,000 needles, in Shenyang, Liaoning province, July 23, 2013. The needles, according to Xie, represent the pain felt by animals when their fur is taken off to produce clothing. (Photo by Reuters/Stringer)

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)