An artist shows her hands after working on a wall as part of a campaign to call for coexistence and the renouncement of violence through the painting of walls in Sanaa, Yemen March 15, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

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 Tonight Show” host Jimmy Fallon, center, exits the water during the Chicago Polar Plunge, Sunday, March 2, 2014, in Chicago. Fallon joined Chicago Mayor Rahm Emanuel in the event. (Photo by Andrew A. Nelles/AP Photo)

Sjinkie Knegt of Netherlands, left, and Park Se-Yeong of South Korea crash out as they compete in a men's 1500m short track speedskating final at the Iceberg Skating Palace during the 2014 Winter Olympics, Monday, February 10, 2014, in Sochi, Russia. (Photo by Bernat Armangue/AP Photo)

Nine year old girl Barsati reacts while walking on a tightrope in Mumbai on February 11, 2014. Barsati, and her younger brother Rajababu, (4) earn an average of around 2000 rupees (32 dollars) per day from pedestrians and tourists performing various acts on the tightrope near the city's iconic landmark Gateway of India. (Photo by Indranil Mukherjee/AFP Photo)

A frog sits on a leaf and instead of seeing a reflection of itself in the water below, it sees a snail, attached to the bottom of the leaf, in a fish tank in Vietnam. (Photo by Duong Quoc Dinh/Solent Ne/SIPA Press)

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)

West Berliners crowd in front of the Berlin Wall as they watch East German border guards demolish a section of the wall on November 11, 1989. (Photo by Gerard Malie/AFP Photo)