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)

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)

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)

Renowned aerobatic pilots Sean D. Tucker, flying the Oracle Challenger III, and Jeff Boerboon, flying the Jack Link's Screamin' Sasquatch, take to the skies over EAA's 2015 AirVenture Oshkosh, on Monday, July 20, 2015 in Oshkosh, Wis. (Photo by Matt Ludtke/AP Images for Jack Link's)

A young fan watches as Green Bay Packers running back AJ Dillon (28) tries his best to ride her bicycle to training camp on Monday, August 1, 2022, at Ray Nitschke Field in Green Bay, Wis. (Photo by Dan Powers/USA TODAY Sports)

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.

Steam rises from Lake Superior as the ship St. Clair comes to harbor during some of the coldest temps of the year, Sunday, December 31, 2017, at Canal Park in Duluth, Minn. The St. Clair is a self-unloader built in 1976 at Sturgeon Bay, Wis., and is 770 feet long and has 26 hatches that open into 5 cargo holds, providing a load capacity of 45,000 tons. (Photo by David Joles/Star Tribune via AP Photo)