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)

“The Tonight Show” host Jimmy Fallon, center, exits the water during the Chicago Polar Plunge, Sunday, March 2, 2014, in Chicago. Fallon joined Chicago Mayor Rahm Emanuel in the event. (Photo by Andrew A. Nelles/AP Photo)

Beachgoers watch the detonation of a 500 pound British bomb on the beach on May 19, 2014 in Wassenaar, Netherlands. The bomb was dropped by the British allied forces during the second world war over nearby Leiden where it was found on a building site. (Photo by Michel Porro/Getty Images)

Participants climb over a wall at the “Tough Mudder” endurance event series in Arnsberg September 6, 2014. Competitors who took part in the endurance event saw themselves having to overcome various military style obstacles. (Photo by Ina Fassbender/Reuters)

A dirty thunderstorm occurs over Mount Sakurajima as the volcano erupts violently at 12:03 am on July 26, 2016 in Tarumizu, Kagoshima, Japan. The eruption occurred at the mountain's Showa crater. This is the first time that the active volcano in southern Kyushu has spewed out a smokestack that high since an eruption on August 18, 2013, according to the Kagoshima Meteorological Office. (Photo by The Asahi Shimbun via Getty Images)

A woman hands flowers to a member of the Wisconsin National Guard standing by as people gather for a vigil, following the police shooting of Jacob Blake, a Black man, in Kenosha, Wisconsin, U.S., August 28, 2020. (Photo by Brendan McDermid/Reuters)

John Pfaff lays on a fallen tree Thursday, September 10, 2020, in Salt Lake City. Two days after a windstorm wreaked havoc in Utah, many schools remain closed and tens of thousands are still without power. (Photo by Rick Bowmer/AP Photo)

School cheerleaders wearing protective masks pose for a photo as fellow students arrive for classes on the first day of school in Miami-Dade County at Barbara Goleman Senior High School, in Miami, Florida, August 23, 2021. (Photo by Marco Bello/Reuters)