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)

A Saudi police officer receives emergency calls at a call center, ahead of the Hajj pilgrimage in the Muslim holy city of Mecca, Saudi Arabia, Tuesday, August 6, 2019. The hajj occurs once a year during the Islamic lunar month of Dhul-Hijja, the 12th and final month of the Islamic calendar year. (Photo by Amr Nabil/AP Photo)

American swimmer Lydia Jacoby poses for a portrait during the Team USA media summit ahead of the Paris Olympics and Paralympics, at an event in New York, U.S., April 17, 2024. (Photo by Andrew Kelly/Reuters)

Tourists feed freshly picked grapes to 40-year-old elephant Boonruen, a long-term resident of the Hua Hin Hills vineyard, that used to be an elephant corral in Hua Hin, about 200km southwest of Bangkok, Thailand, 08 March 2016. The winery is among a handful of companies producing new latitude wines in non-traditional wine areas of the world near the equator. Harvest is only once a year in Thailand, this year in March. (Photo by Barbara Walton/EPA)

An injured woman is pictured near the Blue Parrot nightclub in Playa del Carmen, Quintana Ro state, Mexico where 5 people were killed, three of them foreigners, during a music festival on January 16, 2017. A shooting erupted at an electronic music festival in the Mexican resort of Playa del Carmen early Monday, leaving at least five people dead and sparking a stampede, the mayor said. Fifteen people were injured, some in the stampede, after at least one shooter opened fire before dawn at the Blue Parrot nightclub during the BPM festival. (Photo by Victor Vargas/AFP Photo)

“Diver in Magic Kingdom”. Green Lake (Grüner See) is located Tragöss Austria. In spring snowmelt raises the lake level about 10 meters. This phenomenon, which lasts only a few weeks covering the hiking trails, meadows, trees. The result is magical to watch diving landscapes. Photo location: Grüner See at Tragöss, Austria. (Photo and caption by Marc Henauer/National Geographic Photo Contest)

Passengers take photos at a wildfire while traveling on a train in Zamora, Spain, Monday, July 18, 2022. When Francisco Seoane's train unexpectedly stopped in Spanish countryside that was being engulfed by a wildfire, he and other passengers got a fright when they looked out at flames encroaching on both sides of the track. The Spaniard told The Associated Press it was scary to see how quickly the fire spread. Video of the unscheduled – and unnerving – stop shows about a dozen passengers in Seoane's railcar appearing alarmed as they look out of the windows Monday. (Photo by Francisco Seoane Perez/AP Photo)

A reveller dances next to a police officer at Notting Hill Carnival in London, Britain on August 28, 2022. (Photo by Henry Nicholls/Reuters)