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)

An officer reviews members of the honor guard as they line up before a welcoming ceremony for visiting Mozambique's President Filipe Jacinto Nyusi at the Great Hall of the People in Beijing, Wednesday, May 18, 2016. (Photo by Mark Schiefelbein/AP Photo)

Paramilitary policemen carry tyres as they take part in a training session in Zhangye, Gansu Province, China, March 1, 2016. (Photo by Reuters/Stringer)

Music student Daniele Gonzalez, (centre row, L), and Australian musician Susie Park from the Minnesota Orchestra (centre row, 2nd L), react during a rehearsal in Havana, May 15, 2015. The Minnesota Orchestra will offer two concerts in Havana and is the first major U.S. orchestra to play in Cuba since 1999. The trip cost nearly $1 million. It was underwritten by Marilyn Carlson Nelson, an heir to the Carlson hotel company fortune, and her husband Glen. The U.S. government gave special permission for a direct charter flight from Minneapolis to Havana for the event, putting 4 tons of equipment and 160 people on an Airbus 330. (Photo by Alexandre Meneghini/Reuters)

Morocco's Romain Saiss, right, reacts after teammate Abdelhamid Sabiri, not visible, scored a goal on Belgium's goalkeeper Thibaut Courtois, left, during the World Cup group F soccer match between Belgium and Morocco, at the Al Thumama Stadium in Doha, Qatar, Sunday, November 27, 2022. (Photo by Frank Augstein/AP Photo)

North Korean leader Kim Jong Un (3rd R) and wife Ri Sol Ju (4th L) enjoy an art performance given by the Chongbong Band to mark the 70th anniversary of the founding of the Workers' Party of Korea (WPK) in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on October 19, 2015. (Photo by Reuters/KCNA)

English actor Emma Corrin attends the “My Policeman” Premiere during the 2022 Toronto International Film Festival at Princess of Wales Theatre on September 11, 2022 in Toronto, Ontario. (Photo by Amy Sussman/Getty Images)

In this photo taken on January 20, 2024 a tourist poses in front of incense sticks drying in a courtyard in the village of Quang Phu Cau on the outskirts of Hanoi. Families living and working in the “incense village” of Quang Phu Cau now also make sticks in yellow, blue and green, catering to visitors eager to snap shots for Instagram. (Photo by Nhac Nguyen/AFP Photo)