A woman wearing cut-off jeans and a halter-neck sun top in St Tropez, 1972. (Photo by Roy Jones)

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)

Members of the Al-Baraa bin Malek batallion, part of the Free Syria Army's Al-Fatah brigade, duck to the ground as they pull a man (R) who was shot by a sniper twice in the Bustan al-Basha district of the northern city of Aleppo on October 20, 2012. (Photo by Javier Manzano/AFP Photo)

General Augusto Pinochet, the President of Chile, with the Argentinian President, Maria Estela Martinez De Peron, at a dinner given in his honour in Buenos Aires. (Photo by Keystone/Getty Images). 22nd April 1975

Castro's soldiers at Playa de Giron, Cuba, after thwarting the ill-fated US backed 'Bay of Pigs' invasion. (Photo by Graf/Getty Images). April, 1961

Nora Muaid stands in Zawraa Park on December 2, 2011 in Baghdad, Iraq. The park's 180-foot tall Ferris wheel opened earlier this year and is the second largest in the Middle East. (Photo by Mario Tama/Getty Images)

U.S. Army soldiers from the 2-82 Field Artillery, 3rd Brigade, 1st Cavalry Division, wait to load onto their armored vehicles as they prepare to convoy to Kuwait from Camp Adder in Iraq on December 7, 2011 at Camp Adder, near Nasiriyah, Iraq. (Photo by Joe Raedle/Getty Images)

Ivan Shamyanok, 90, shaves in his house in the village of Tulgovichi, near the exclusion zone around the Chernobyl nuclear reactor, Belarus March 15, 2016. “My sister lived here with her husband. They decided to leave and soon enough they were in the ground ... They died from anxiety. I'm not anxious. I sing a little, take a turn in the yard, take things slowly like this and I live”, he said. (Photo by Vasily Fedosenko/Reuters)