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)

Bikini-clad women ski as they are led by a car during a performance on the frozen Yenisei River outside Krasnoyarsk, Siberia, Russia, March 20, 2016. The performance, entitled “Siberian Spring's Strings” and created with the participation of artist Vasily Slonov, marked the day of spring equinox (vernal equinox), according to organizers. (Photo by Ilya Naymushin/Reuters)

People watch a forest fire in Funchal, Madeira Island, Portugal, 09 August 2016. The fire has led to the evacuation of 400 people. Portugal remains on high alert as a wave of wildfires has swept the country with around 350 isolated fires affecting swathes of the countryside. (Photo by Gregório Cunha/EPA)

An injured young woman is led away after an incident at Parsons Green underground tube station in west London on September 15, 2017. Police and ambulance services said they were responding to an “incident” at Parsons Green underground station in west London on Friday, following media reports of an explosion. A Metro. co. uk reporter at the scene was quoted by the paper as saying that a white container exploded on the train and passengers had suffered facial burns. (Photo by Luke MacGregor/Reuters)

Clowns Perlita and Tapetito, wearing protective gear amid the new coronavirus pandemic, speak with resident Enrique Zeballos as they arrive to disinfect his home free of charge, in El Alto, Bolivia, Friday, September 11, 2020. The lack of traditional employment for the clowns due to the pandemic has led them towards other avenues of making money. But for people with limited income they provide their disinfection services free of charge. (Photo by Juan Karita/AP Photo)

A man treats a woman affected by pepper spray as Washington Metropolitan Police officers clash with demonstrators trying to pull down the statue of U.S. President Andrew Jackson in the middle of Lafayette Park in front of the White House during racial inequality protests in Washington, D.C., U.S., June 22, 2020. Dozens of law enforcement officers, led by U.S. Park Police, stormed into the square, swinging batons and firing chemical agents to scatter protesters. By dark, police had taken control and outnumbered demonstrators in the immediate area. (Photo by Tom Brenner/Reuters)

An Indian man stands near his house as waves caused by high tide hits the huts on the shore of the Arabian Sea in Mumbai, India, Wednesday, July 3, 2019. Heavy monsoon rains in Maharashtra have led to more than 30 deaths since Monday night, from collapsed walls, drownings and other causes. Dozens of others have been injured. (Photo by Rafiq Maqbool/AP Photo)

A couple kisses in a central Barcelona street during the first night without the state of alarm, on 9 May, 2021 in Barcelona, Catalonia, Spain. The state of alarm that the Government decreed for the second time six months ago ended at 00.00 hours this Sunday, May 9. In Catalonia this has led to the fall of the curfew and the perimeter confinement of the Community. (Photo By Lorena Sopena via Getty Images)