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)

“Shortly after he arrived, Van Agtmael witnessed the aftermath of this suicide bombing at a cafe that soldiers frequented in Mosul. Nine people died and 23 were wounded”. (Photo and caption by Van Agtmael/Harrison Jacobs/Magnum Photos)

Philippine President Rodrigo Duterte looks at Miss Universe candidates at the presidential palace in Manila, Philippines January 23, 2017. (Photo by Erik De Castro/Reuters)

This image obtained January 31, 2017 from the US Geological Survey's Hawaiian Volcano Observatory showing a lava stream, pouring out of the lava tube on the sea cliff at the Kamokuna ocean entry from the Kilauea Volcano on January 29. (Photo by AFP Photo/USGS)

Bonnie Morgan arrives at the LA Premiere of “Rings” at the Regal LA LIVE Stadium 14 on Thursday, February 2, 2017, in Los Angeles. (Photo by Willy Sanjuan/Invision/AP Photo)

In this February 19, 2017 photo, a statue of the Death Saint stands inside Mercy Church as Juan Carlos Avila Mercado gives a service, on the edge of Mexico City's Tepito neighborhood. “She chooses them and has always been with us”, said Avila, who says he is a Catholic priest, but who is not listed among the archdiocese's priests. “We are born and we die with death”. (Photo by Marco Ugarte/AP Photo)

A woman promotes a go-go dance bar in Pattaya, Thailand March 25, 2017. With mascots dressed as smiling fish and a police rock band, Thai authorities launched a “Happy Zone” at the weekend to improve the image of a city notorious for sеx tourism. Stung by foreign headlines portraying the seaside resort of Pattaya as “Sin City” and “The World’s Sеx Capital”, Thailand’s junta has begun a new effort to re-brand it. Businesses in the Happy Zone are asked to make the area feel safer, there are increased security patrols, police launched a mobile phone app for visitors to summon them if an emergency occurs. (Photo by Jorge Silva/Reuters)

TV and radio host Lizzie Cundy, 46, attends the World Premiere of “The Hatton Garden Job” at The Curzon Soho on April 11, 2017 in London, England. (Photo by Fame Flynet)