Wedges of an orange generate enough current and electrical juice – 3.5 volts – to power an LED. The fruit’s citric acid helps electrons flow from galvanized nails to copper wire in this 14-hour exposure. This image was published in September’s Visions of Earth, a trio of photos that appear in each issue of National Geographic. (Photo by Caleb Charland/National Geographic)

America in the 1970s: Texas. Motorcyclist loading his possessions onto a truck with the help of his friends in Leakey, May 1973. (Photo by Marc St. Gil/NARA via The Atlantic)

A stranded cat swims through flood water searching for dry land June 16, 2008 in Oakville, Iowa. (Photo by Scott Olson/Getty Images)

In this January 3, 2018 photo several female Gelada baboons, also known as bleeding-heart baboons, cuddle with their youngs in order to keep warm at the Wilhelma zoo in Stuttgart, Germany. (Photo by Sebastian Gollnow/DPA via AP Photo)

Rockhopper penguins live up to their name as they navigate the rugged coastline of Marion Island in the southern Indian Ocean. (Photo by Thomas P. Peschak)

A Sumatran Owl is seen in Palembang City, Indonesia on March 5, 2020. (Photo by Sigit Prasetya/Opn Images/Barcroft Media via Getty Images)

A nurse at St. Joseph's Hospital wears a unique mask as the hospital celebrates the release of a COVID-19 patient after 45 days in their care during the outbreak of the coronavirus disease (COVID-19) in Orange, California, U.S., May 5, 2020. (Photo by Mike Blake/Reuters)

Marta Garcia (R) of Spain loses the champgane bottle standing on the podium next to winner Jamie Chadwick of Great Britain after the first race of the W Series at Hockenheimring on May 04, 2019 in Hockenheim, Germany. W Series aims to give female drivers an opportunity in motorsport that hasn’t been available to them before. The first race of the series, which encompasses six rounds on the DTM support programme, is at the Hockenheimring on May 3rd and 4th. (Photo by Kai Pfaffenbach/Reuters)