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)

Law enforcement officers stand, with some turning their backs, as New York City Mayor Bill de Blasio speaks on a monitor outside the funeral for NYPD officer Wenjian Liu in the Brooklyn borough of New York January 4, 2015. Tens of thousands of law enforcement officers from across the country gathered on Sunday for the funeral of the second of two New York City policemen killed last month in an ambush that galvanized critics of Mayor de Blasio. (Photo by Shannon Stapleton/Reuters)

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)

A Sri Lankan child uses an inflatable tube to wade through floodwaters after heavy rains in Biyagama suburb of Colombo, Sri Lanka, 06 June 2021. Many parts of the island have been inundated due to heavy monsoon rains. According to the Sri Lanka Disaster Management Center, at least 14 people have been killed so far and more than 245,212 people affected across the country. (Photo by Chamila Karunarathne/EPA/EFE)

A motorway bridge crosses the icy Hunhe River in Shenyang, China on December 12, 2019. (Photo by Costfoto/Barcroft Media)

A pigeon sits on the cap of an Indonesian military personnel during a ceremony marking the country's 80th Independence Day, at the Presidential Palace in Jakarta, Indonesia, on August 17, 2025. (Photo by Ajeng Dinar Ulfiana/Reuters)

A woman falls while slipping on ice during freezing rain on Roosevelt Island, a borough of Manhattan, in New York January 5, 2014. New York City was hit on Friday by the first severe winter storm of 2014 and was still in the grip of sub-freezing weather on Sunday morning. The woman got up and walked away from the fall. (Photo by Zoran Milich/Reuters)

A young Iraqi shepherdess cools down buffaloes in wastewater filling the dried-up Diyala river which was a tributary of the Tigris, in the Al-Fadiliyah district east of Baghdad, on June 26, 2022. Iraq's drought reflects a decline in the level of waterways due to the lack of rain and lower flows from upstream neighboring countries Iran and Turkey. (Photo by Ahmad Al-Rubaye/AFP Photo)