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)

A medical worker wearing a full protective outfit tests a man for Covid-19 symptoms in a street in Wuhan, China, 01 April 2020. Wuhan, the epicenter of the coronavirus outbreak, partly lifted the lockdown allowing people to enter the city after more than two months. According to Chinese government figures over 2,500 people have died of Covid-19 in Wuhan since the outbreak began. (Photo by Roman Pilipey/EPA/EFE)

Competitors gather backstage as they prepare to take part in the All Ireland Irish Dancing Championships on November 2, 2016 in Belfast, Northern Ireland. The championships take place at the Waterfront Hall over the course of six days with winners qualifying for the World Irish Dancing Finals which will take place in Dublin next year. (Photo by Charles McQuillan/Getty Images)

Chrissy Teigen and daughter Luna Stephens seen on the streets of Manhattan on June 24, 2019 in New York City. (Photo by James Devaney/GC Images)

American model Emily Ratajkowski attends Game 5 of the NBA Playoffs, New York Knicks v Atlanta Hawks at Madison Square Garden in New York, USA on June 2, 2021. (Photo by Startraks Photo/Rex Features/Shutterstock)

German model Lorena Rae arrives for the screening of the film “Tout s'est Bien Passe” (Everything Went Fine) at the 74th edition of the Cannes Film Festival in Cannes, southern France, on July 7, 2021. (Photo by Johanna Geron/Reuters)

The singer Ciara attends ELLE's 27th Annual Women In Hollywood Celebration, presented by Ralph Lauren and Lexus, at Academy Museum of Motion Pictures on October 19, 2021 in Los Angeles, California. (Photo by Emma McIntyre/Getty Images for ELLE)