Ke$ha performs live on stage during the second day of the Wireless Festival at Hyde Park on July 2, 2011 in London, England. (Photo by Jim Dyson/Getty Images)

Prints of R$ 50 Brazilian reais bills sit on a table for inspection at at the Casa da Moeda, the national mint, in the Santa Cruz suburb of Rio de Janeiro, Brazil, on Tuesday, March 5, 2013. Brazil is likely to keep its key interest rate at a record low for the third straight meeting, as policy makers are caught between a fragile economic recovery and faster-than-expected inflation. (Photo by Dado Galdieri/Bloomberg)

A Chinese future bride has her friends playing with her dress during a pre-wedding photoshoot in front of the Eiffel tower in Paris, France, August 28, 2015. As young Chinese become wealthier, they take abroad the tradition of taking their wedding photos days before they are married, rather than on their wedding day. (Photo by Philippe Wojazer/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)

Festival goers in Finsbury Park ahead of the Wireless Festival at Finsbury Park in London, United Kingdom on Friday, July 8, 2022. (Photo by James Manning/PA Wire Press Association)

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

A visitor relaxes in a sleeping module at Tokyo's tube Hotel “Capsule Inn Akihabara” on February 6, 2007 in Tokyo, Japan. The two-square-meter sleep modules are equipped with a TV, Radio and Wireless LAN and are priced at 3500 yen per night. Uptil recently it has mainly been the office workers who stay at such tube hotels when they cannot go home, but recently they are attracting many foreign travellers due to their Japanese style. (Photo by Koichi Kamoshida/Getty Images)