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)

Thai Buddhist monks wear face shields to protect themselves from new coronavirus as they walk to collect alms from devotees in Bangkok, Thailand, Tuesday, March 31, 2020. (Photo by Sakchai Lalit/AP Photo)

A cosplayer dressed as Domino attends 2019 Comic-Con International on July 20, 2019 in San Diego, California. (Photo by Quinn P. Smith/Getty Images)

“Cassowaries are large, flightless birds related to emus and (more distantly) to ostriches, rheas, and kiwis”, writes Olivia Judson in the September issue of National Geographic magazine. How large? People-size: Adult males stand well over five foot five and top 110 pounds. Females are even taller, and can weigh more than 160 pounds. Dangerous when roused, they’re shy and peaceable when left alone. But even birds this big and tough are prey to habitat loss. The dense New Guinea and Australia rain forests where they live have dwindled. Today cassowaries might number 1,500 to 2,000. And because they help shape those same forests – by moving seeds from one place to another – “if they vanish”, Judson writes, “the structure of the forest would gradually change” too. (Photo by Christian Ziegler/National Geographic)

UK “Ex On The Beach” star Ashley Cain celebrates his birthday with girlfriend and ex “Big Brother” star Chloe Khan at Gallery Nightclub in Maidstone, England, UK on September 25, 2016. (Photo by FameFlynet UK)

Miranda Kerr going back to her hotel during Paris fashion week Paris,France on October 04th 2016. (Photo by KCS Presse/Splash News and Pictures)

Kendall Jenner seen at Universal, NBC, Focus Features, E! Entertainment Golden Globes After Party Sponsored by Chrysler on Sunday, January 8, 2017, in Beverly Hills, Calif. (Photo by Eric Charbonneau/Invision for Focus Features/AP Images)