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)

Hotel guides jump as they pose for pictures outside the Great Hall of the People during the opening session of the National People's Congress (NPC) in Beijing, China, March 5, 2016. (Photo by Aly Song/Reuters)

A cadet lies on the grass after collapsing during a promotion ceremony at a police school in Bogota December 7, 2012. (Photo by John Vizcaino/Reuters)

In this Sunday, March 5, 2017, photo, hospitality staff take souvenir photos in front of the Great Hall of the People where the National People's Congress is held in Beijing. (Photo by Andy Wong/AP Photo)

A Filipino dancer performs with fire to mark the Chinese Lunar New Year in Manila's Chinatown, Philippines, 28 January 2017. Chinese around the world celebrate the Lunar New Year on 28 January 2017, the first day of the year of rooster. (Photo by Francis R. Malasig/EPA)

Two girls in cosplay dresses walk in the street in Beijing on March 27, 2017. (Photo by Fred Dufour/AFP Photo)

People react as the body of a relative is retrieved from the ruin of a building at an area affected by an earthquake in Mamuju, West Sulawesi, Indonesia, Friday, January 15, 2021. A strong, shallow earthquake shook Indonesia's Sulawesi island just after midnight Friday, toppling homes and buildings, triggering landslides and killing a number of people. (Photo by Yusuf Wahil/AP Photo)

A farmer runs behind a police officer during a protest against farm laws introduced by the government, in New Delhi, India, January 26, 2021. Tens of thousands of farmers drove a convoy of tractors into the Indian capital as the nation celebrated Republic Day on Tuesday in the backdrop of agricultural protests that have grown into a rebellion and rattled the government. (Photo by Adnan Abidi/Reuters)