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)

People are reflected on a soap bubble lying on a road during the evening in New Delhi, India, June 23, 2015. (Photo by Anindito Mukherjee/Reuters)

October 25, 2009; London,UK; The mascot for the Tampa Bay Buccaneers watches a cheerleader during the NFL International Series game against the New England Patriots at Wembley Stadium. (Photo by David Wilkinson/Offside Sports)

British model Jean Shrimpton at London Airport (now Heathrow), 5th June 1967. (Photo by Dove/Express/Getty Images)

Jordan Matter showcases their athletic prowess in everyday situations such as a martial artist shaving with a samurai sword, an ice hockey goalie shopping and a gymnast balancing from a street sign. Photo: “River View” – Jacob Jonas & Jill Wilson – Acro Yoga Specialists. (Photo by Jordan Matter)

It wasn’t exactly the Westminster Dog Show, but it was serious stuff. Photo: five-month-old Carly LeRolls Gottesman, at Pooch Prom at Downtown at the Gardens on Saturday, April 26, 2014. Carly was crowned the 2014 Pooch Prom queen. (Photo by Thomas Cordy/The Palm Beach Post)

A Sotheby's employee holds a rare 52.82-carat white diamond ring at Sotheby's auction house on April 12, 2010 in London, England. Price: 7 million USD. (Photo by Dan Kitwood/Getty Images)

Turkana tribesmen walk with guns to protect their cattle from rival tribes near Baragoy, Kenya August 4, 2017. (Photo by Goran Tomasevic/Reuters)