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)

Artist Emiliano Paolini (R), and his partner Marianela Perelli, show their “Ken” doll that they have re-designed into the religious figure of Jesus Christ at their workshop in Rosario, north of Buenos Aires September 23, 2014. Paolini and Perelli have adapted religious figures such as Jesus Christ, Moses and the Virgin of Guadalupe to Mattel's line of Barbie and Ken dolls and are working on more religious figures, although they say they will not be using the Prophet Muhammad to avoid controversy. They plan to have a gallery show in Buenos Aires next October. (Photo by Enrique Marcarian/Reuters)

Athlets run during the women's 3000 meter steeplechase at the International Athletics Meeting in Lucerne, Switzerland, 14 June 2016. (Photo by Alexandra Wey/EPA)

A female Kurdistan Workers Party (PKK) fighter stands near a security position in Sinjar, March 13, 2015. Women fighters at a Kurdistan Workers Party (PKK) base on Mount Sinjar in northwest Iraq, just like their male counterparts, have to be ready for action at any time. Smoke from the front line, marking their battle against Islamic State, which launched an assault on northern Iraq last summer, is visible from the base. Many of the women have cut links with their families back home; the fighters come from all corners of the Kurdish region. (Photo by Asmaa Waguih /Reuters)

A visitor poses for a photo with a Crayon Shin-chan model during an exhibition at Joy City in Beijing May 5, 2015. The exhibition, which showcased fifty models of the Japanese cartoon character in different poses and expressions, will run from April 18 to June 22. (Photo by Jason Lee/Reuters)

Wounded people walk after clashes with riot police in central Kiev February 18, 2014. Ukrainian riot police advanced on the heart of 12-week-old protests against President Viktor Yanukovich on Tuesday and security forces set a deadline to end disturbances after at least five protesters were reported killed in a day of clashes. (Photo by Vlad Sode/Reuters)

Riot police stand guard behind a fire as refinery workers hold a blockade of the oil depot of Douchy-Les-Mines to protest against the government's proposed labour reforms, on May 25, 2016. Refinery workers stepped up strikes that threaten to paralyse France weeks ahead of the Euro 2016 tournament as the government moved to break their blockades, escalating a three-month tug-of-war over labour reforms. (Photo by François L.O./AFP Photo)

Chacha, the male chimp, screams at a worker in Sendai, northern Japan, Thursday, April 14, 2016 after fleeing from a zoo. The chimpangzee tried desperately to avoid being captured by climbing an electric pole. Chacha was on the loose nearly two hours Thursday after it disappeared from the Yagiyama Zoological Park in Sendai, the city that's hosting finance ministers from the Group of Seven industrialized nations in May. (Photo by Kyodo News via AP Photo)