A man walks along an El Paso road while observing a large ash column from the Cumbre Vieja volcano on the Canary Island of La Palma, Spain, October 4, 2021. (Photo by Borja Suarez/Reuters)

Police officers block a road as lava rises following the eruption of a volcano on the Island of La Palma, in Tacande, Spain on September 22, 2021. (Photo by Borja Suarez/Reuters)

Peasants celebrate a traditional festival “Corpus Cristhi” since the time of the conquest, in Anolaima in the department of Cundinamarca, Colombia on June 29, 2022. Peasants collect all kinds of fruits and assemble great representative figures in gratitude to God for this festival. (Photo by Yair Suarez/Anadolu Agency via Getty Images)

In 2013, the United Nations General Assembly officially designated November 19 as World Toilet Day, which is coordinated by UN-Water in collaboration with governments and partners. Here: An open-air toilet and a hot spring shower are seen in the middle of nowhere on the road to the Krafla geothermal power station and lava fields, near Reykjahlid and Lake Myvatn in northeastern Iceland, on August 19, 2012. (Photo by Mariana Suarez/AFP Photo)

Tourists look at would-be immigrants at the Maspalomas beach, on Gran Canaria in Spain's Canary Islands, after some 21 would-be immigrants arrived in a fishing boat on their way to European soil from Africa, November 5, 2014. (Photo by Borja Suarez/Reuters)

Several soldiers from the Spanish Air Force observe a Eurofighter EF-2000 fighter aircraft of the Spanish Air Force, as it flies during the Ocean Sky 2023 Military Exercise for advanced air-to-air training in the southern airspace of the Canary Islands, Spain on October 25, 2023. (Photo by Borja Suarez/Reuters)

A couple chats at a park during sunset in Chihuahua November 15, 2014. (Photo by Jose Luis Gonzalez/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)