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)

Models smoke during a break at Sevilla de Boda (Seville Wedding) fashion show in the Andalusian capital of Seville November 27, 2015. (Photo by Marcelo del Pozo/Reuters)

A man dressed as the “Star Wars” character Darth Vader sits on a bench in central Lviv, Ukraine, November 24, 2016. (Photo by Gleb Garanich/Reuters)

Teenage girls are all steamed up these days about straight hair. The steam iron is replacing the huge rollers on which countless teens slept every night to achieve the height and curls fashionable until. The same girls endure having their hair stretched to absolute straightness on the ironing board, and then ironed to keep it that way. Unlike the roller setting, this takes teamwork. Gay Stilley, 14, goes through an ironing session with a couple of her friends at the Stilley Home in Glen Oaks, Queens, New York City on December 23, 1964. With a wary eye, Gay tries to watch the straightening process as one friend stretches her hair with a comb and another does the ironing, in the Stilley kitchen. (Photo by Marty Zimmerman/AP Photo)

U.S. Army soldiers carry an injured soldier who was shot in the leg, through a poppy field on April 24, 2011 in the Arghandab River Valley, Kandahar Province, Afghanistan. The injured was evacuated to a waiting Blackhawk UH-60A helicopter by Task Force Thunder Brigade, Charlie company 1st of the 52nd Aviation regiment from Fairbanks, Alaska. It is feared that as weather improves with the approaching summer that the casualty toll will rise. (Photo by Paula Bronstein/Getty Images)

Afghan women attend a rally to support Afghan security forces and demand peace in the country in Herat, Afghanistan, 08 February 2021. Hamdullah Mohib, Afghanistan's National Security Advisor told a press conference in Kabul on 06 February, the Afghan government was ready for war after successive setbacks in recent weeks to peace talks with the Taliban, who have refused to return to discussions that began in September in Doha. (Photo by Jalil Rezayee/EPA/EFE)

A military helicopter flies over people during the Afghan Security Forces Exhibition, at the Darul Aman Palace in Kabul, Afghanistan, Wednesday, March 3, 2021. The three-day military exhibition in Kabul allowed civilians to have a first hand view and take pictures of weaponry used by Afghan Security forces. (Photo by Rahmat Gul/AP Photo)

In this Monday, July 20, 2015 photo, Bill Lattin, the Southern California Timing Association president and Speed Week race director, stands in the Bonneville Salt Flats in Utah. A small city of tents, trailers and thousands of visitors appears almost every August in the Utah desert to watch cars, motorcycles and anything with wheels rocket across gleaming white sheets of salt at speeds of 400 mph. But wet weather has forced the cancellation of Speed Week for the second straight year and revived a debate about whether nearby mining is depleting the Bonneville Salt Flats of their precious resource. (Photo by Rick Bowmer/AP Photo)