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)

Philippe Marquis of Canada during the FIS Freestyle Ski World Cup Dual Moguls on December 20, 2011 in Meribel, France. (Photo by Alain Grosclaude/Agence Zoom/Getty Images)

The first solar-powered station designed to look like a tree provides users with a free Wi-Fi spot charging station, seating and cool drinking water.

A cat jumps from a shelf to catch a light beam at the “Kis-Kis” Cat Cafe in the Siberian city of Krasnoyarsk, Russia, July 6, 2015. A local animals rights group founded the shelter for dozen of homeless cats and combined it with the cafe, where visitors can communicate with animals for hourly fee in addition to drinks, table games, books and WI-FI. (Photo by Ilya Naymushin/Reuters)

The Cobra JoyRide car charger by Cobra Electronics is displayed during a press event at The Venetian for the 2012 International Consumer Electronics Show (CES) January 8, 2012 in Las Vegas, Nevada. The JoyRide works with Android phones and can automatically trigger preset phone functions like enabling GPS or disabling Wi-Fi with the press of a single button. It will be available for USD 39 in the second quarter of 2012. (Photo by Ethan Miller/Getty Images)

Apple Senior VP of Worldwide Marketing Phil Schiller talks about the display on the new iPad during an Apple product launch event at Yerba Buena Center for the Arts on March 7, 2012 in San Francisco, California. In the first product release following the death of Steve Jobs, Apple Inc. introduced the third version of the iPad (iOS 5.1; Processor is an Apple A5X ARM-based unit; Display 2048 x 1536 pixels; Camera is set at 5 megapixels and has a 5-element lens plus auto face-detection, auto focus lock and image stabilisation for video; Wi-Fi + 4G) and an updated Apple TV. (Photo by Kevork Djansezian/Getty Images)

Green Bay Packers' Johnathan Calvin rides a bike to NFL football training camp on July 27, 2017, in Green Bay, Wis. (Photo by Morry Gash/AP Photo)

In this September 17, 2010 file photo a little brown bat is photographed in La Crosse Wis. Researchers for the first time found that little brown bats appear to be showing resistance to white-nose syndrome, which has killed millions of bats across North America. (Photo by Peter Thomson/La Crosse Tribune via AP Photo)