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)

Actress Janina Gavankar attends OK! Magazine Pre-Oscar Party – Arrivals at Greystone Manor Supperclub on February 23, 2012 in West Hollywood, California. (Photo by Allen Berezovsky/Getty Images)

A general view shows smoke and volcanic ashes billowing from volcano Cotopaxi in Pedregal, Ecuador, late 07 October 2015. (Photo by Jose Jacome/EPA)

Seized plastic handguns which were created using 3D printing technology are displayed at Kanagawa police station in Yokohama, south of Tokyo, in this photo taken by Kyodo May 8, 2014. Yoshimoto Imura became the first man to be arrested in Japan for illegal possession of two guns he created himself using 3D printing technology, Japanese media said on Thursday. The 27-year-old, a college employee in the city of Kawasaki, was arrested after police found video online posted by Imura claiming to have produced his own guns. Gun possession is strictly regulated in Japan. Police raided Imura's home and found five guns, two of which could fire real bullets, Japanese media said. (Photo by Reuters/Kyodo)

Poznań is now Poland's fifth largest city. It is sometimes claimed to be the first capital of the kingdom of Poland. Poznań has many historic buildings and sights. The European Football Championship will take place in Poznan 2012.

Photo by: tiseb ; Source: Flickr

Kosovo- born British singer and actress Rita Ora performs in Pristina on February 17, 2018 on the occasion of the 10 th anniversary of Kosovo Independence. Kosovo celebrates 10 years since it declared independence, a moment of pride for its ethnic Albanian majority, although sovereignty remains fiercely contested by Serbia. (Photo by Armend Nimani/AFP Photo)

Stefan Sigmund, 29, from the Transylvanian city of Cluj, attempt to smoke 800 cigarettes through a self designed device in less than five minutes, in central Bucharest Tuesday, January 30, 1996, trying to enter the Guinness Book of Records. It is the last of his several attempts entering the record book which included eating 29 hard boiled eggs in four minutes and leaping into a lake from a height of 41 meters (135 feet) even if the Guinness Book of Records no longer rewards self damaging attempts. (Photo by AP Photo/Stringer)

“The Queen” painted fibreglass by artist John Humphreys is displayed backdropped by other works which feature in this year's Summer Exhibition on it's 250th year at the Royal Academy of Arts in London, Tuesday, June 5, 2018. The Summer Exhibition has been held since 1769, with around 1300 works on display this year and most of them available for purchase. It runs from June 12 until August 19. (Photo by Matt Dunham/AP Photo)