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)

Egyptian President Hosni Mubarak speaks to the media after talks with German Chancellor Angela Merkel at the Chancellery on April 23, 2008 in Berlin, Germany. (Photo by Sean Gallup/Getty Images)

A model presents a creation by DB Berdan during the Mercedes-Benz Fashion Week in Istanbul, Turkey March 28, 2018. (Photo by Osman Orsal/Reuters)

Dancers pose after performing “El Macho Raton”, “El Toro Huaco” and “El Gueguense” traditional dances during San Sebastian festivity in Diriamba, province of Carazo, some 50 km south of Managua on January 19, 2016. Devotees of Saint Sebastian dance in traditional costumes between the cities of Diriamba and Dolores, which are some three kilometers away. (Photo by Inti Ocon/AFP Photo)

Dancers Daisy Kerry (R) and Alice Rathbone pose as characters from The Nutcracker, for the annual Christmas event at Chatsworth House near Bakewell in Britain November 4, 2016. (Photo by Darren Staples/Reuters)

Models and Caroline Scheufele, Artistic Director and Co-President of Chopard (C) pose during a photocall ahead of the Chopard Gold Party during the 68th Cannes Film Festival in Cannes, southern France, May 18, 2015. (Photo by Yves Herman/Reuters)

Vatican Swiss Guards stand attention at the St. Damaso courtyard on the occasion of the swearing-in ceremony at the Vatican, Sunday, October 4, 2020. The ceremony is held to commemorate the day in 1527 when 147 Swiss Guards died protecting Pope Clement VII during the Sack of Rome. (Photo by Gregorio Borgia/AP Photo)

Police officers remove Extinction Rebellion activists blocking a main street outside the Health Ministry, during a protest demanding actions against climate change, in Madrid, on March 26, 2021. (Photo by Gabriel Bouys/AFP Photo)