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 mother (2nd R) of missing firefighter Xue Ning is helped by other family members as she cries outside the venue of a news conference after trying to demand for more information from government officials, following the explosions on Wednesday night at Binhai new district in Tianjin, China, August 15, 2015. (Photo by Jason Lee/Reuters)

Hollywood actress Malin Akerman helps King Digital Entertainment set the Guinness World Record for the World's Largest Hammock to celebrate the launch of its new game Paradise Bay on Wednesday, September 2, 2015, in Jersey City, N.J. (Photo by Charles Sykes/Invision for King World Entertainment/AP Images)

A man helps a woman with blood on her face after security guards saw her looting in a hotel during a protest demanding the resignation of Haiti's Prime Minister Ariel Henry after weeks of shortages, in Port-au-Prince, Haiti on October 10, 2022. (Photo by Ralph Tedy Erol/Reuters)

A local helps a reveler with his costume made from beer and soda cans during the “Bloco da Latinha” street party Carnival parade in Madre de Deus, Brazil, Sunday, February 11, 2024. (Photo by Eraldo Peres/AP Photo)

Climate activists of the “Last Generation” covered with mud protest in front of the Senate building in Rome, Italy, Tuesday, May 23, 2023. Two bare breast activists have smeared the facade of the senate with mud, shouting the slogan: “Help us for the ecological transition”. (Photo by Cecilia Fabiano/LaPresse via EXPA)

Mates Jimi Hunt and Dan Drupstee dug the 650m slippery slide on a property at Helensville, northwest of Auckland and opened it this weekend as part of a festival to help combat depression.