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)

Qiandao Lake (Chinese: 千島湖, lit. Thousand Island Lake), a man-made lake located in Chun'an County, Zhejiang, China, formed after the completion of the Xin'an River hydroelectric station in 1959. 1,078 large islands dot the lake and a few thousand smaller ones are scattered across it. The lake covers an area of 573 km² and has a storage capacity of 17.8 km³. The islands in the lake cover about 86 km²

The Kingdom of Pagan (also commonly known as the Pagan Dynasty and the Pagan Empire) was the first kingdom to unify the regions that would later constitute modern-day Burma (Myanmar). Pagan's 250-year rule over the Irrawaddy valley and its periphery laid the foundation for the ascent of Burmese language and culture, the spread of Burman ethnicity in Upper Burma, and the growth of Theravada Buddhism in Burma and in mainland Southeast Asia.

“John Constables's «The Hay Wein» meets «Bender» from «Futurama»”. (Photo and caption by Dave Pollot/Caters News)

“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)

Watercolorist Shin Jong Sik is famous for expressing clean, transparent colors and his still life paintings express colorful, dignified and deep feeling. Taking flowers, dishes and hemp cloth as materials, he does not compose as they are seen but recomposes with new ideas.

An Afghan National Army (ANA) soldier assigned to the Mobile Strike Force Kandak fires a RPG-7 rocket-propelled grenade launcher during a live-fire exercise supervised by the Marines with the Mobile Strike Force Advisor Team on Camp Shorabak, Helmand province, Afghanistan, May 20, 2013. The Marines with the Mobile Strike Force Advisor Team instructed and mentored their ANA counterparts on how to properly utilize their weapons systems. (Photo by SSgt Ezekiel R. Kitandwe/RCT 7)

Aerial view of flower fields near the Keukenhof park, also known as the Garden of Europe, in Lisse April 9, 2014. Keukenhof, employing some 30 gardeners, is considered to be the world's largest flower garden displaying millions of flowers every year. (Photo by Yves Herman/Reuters)