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)

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

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)

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

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)

A car rests on a fence after it was carried there by floodwater on March 06, 2022 in Tumbulgum, Australia. Residents of southeast Queensland and northern New South Wales are still cleaning up following unprecedented storms and the worst flooding in a decade. (Photo by Dan Peled/Getty Images)

School students attend a pioneer induction ceremony in Moscow's Red Square in Moscow, Russia on May 22, 2022. Pro-Communist Russians are trying to preserve the Young Pioneers, which used to be the Communist league for pre-teens in the Soviet Union. (Photo by Sergei Karpukhin/TASS)

Russian policemen detain a participant taking part in an unauthorized protest against Russia's partial military mobilization due to the conflict in Ukraine, in downtown of Moscow, Russia, 24 September 2022. Russian President Putin announced in a televised address to the nation on 21 September, that he signed a decree on partial mobilization in the Russian Federation. Russian citizens who are in the reserve will be called up for military service. On 24 February 2022 Russian troops entered the Ukrainian territory in what the Russian president declared a “Special Military Operation”, starting an armed conflict that has provoked destruction and a humanitarian crisis. (Photo by Maxim Shipenkov/EPA/EFE)