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)

Men stroll past roadside vendors as a painted truck makes its way through the busy street in Kabul, Afghanistan, November, 1961. (Photo by Henry S. Bradsher/AP Photo via The Atlantic)

British prime minister Winston Churchill (1874–1965) stops to pet a cat at Liverpool Street Station, 24th May 1952. (Photo by Keystone/Hulton Archive/Getty Images)

Gold medallist Rachelle Simpson of the U.S. celebrates after the women's 20m high dive competition during the Aquatics World Championships in Kazan, Russia August 4, 2015. (Photo by Hannibal Hanschke/Reuters)

Vivid colors and bizarre shapes come together in a false-color image that could be an illustration for a fantasy story. This labyrinth of exotic features winds its way along the edge of Russia’s Chaunskaya Bay in northeastern Siberia, seen as a vivid blue half-circle at the bottom of the image Two major rivers, the Chaun and Palyavaam, flow into the bay, which in turn opens into the Arctic Ocean. Ribbon lakes and bogs are present throughout the area, created by depressions left by receding glaciers. (Photo by USGS/NASA)

A caterpillar driven ferry with a 24 horsepower engine takes holidaymakers from the mainland at Bigbury in Devon to Burgh Island, a quarter of a mile away. (Photo by Reg Speller/Fox Photos/Getty Images). 4th April 1935

Gardener Peter Glazebrook poses for photographers with his world record breaking onion at The Harrogate Autumn Flower Show on September 16, 2011 in Harrogate, England. Peter Glazebrook from Newark, Nottinghamshire claimed a Guinness World Record with his giant onion weighing 8.150 kg. (Photo by Christopher Furlong/Getty Images)

Haitians pull a car atop a pushcart in Port-au-Prince, October 11, 1994. The price of gasoline has fallen to about $6 US per gallon since U.S. forces occupied Haiti. Before, gasoline had cost as much as $10 U.S. per gallon. (Photo by Eric Draper/AP Photo)