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)

A general view shows smoke and volcanic ashes billowing from volcano Cotopaxi in Pedregal, Ecuador, late 07 October 2015. (Photo by Jose Jacome/EPA)

A monkey drinks water from a tap on a hot afternoon in Jammu, the winter capital Kashmir, India, 17 May 2016. Temperatures of around 42 degrees Celsius were forecast in the region. According to the news reports the Indian government decided to divert water by its river interlinking plans from rivers like Brahmaputra and the Ganges towards those rivers facing the drought likesituation . Many Indian states have been affected by drought and have been hit hard by water scarcity. (Photo by Jaipal Singh/EPA)

In this Wednesday, September 12, 2018, file photo, vendors carry banana on their heads at a fruit and vegetable market in Peshawar, Pakistan. Pakistan says it will seek a bailout loan from the International Monetary Fund to address a mounting balance of payments crisis, Finance Minister Asad Umar said Monday. (Photo by Muhammad Sajjad/AP Photo)

Xiren Wang, Lili Wat, and Sitong Chen join the pageant’s opening routine, dancing to “The Boys”, a song by K-Pop group «Girls’ Generation». While the women come from a range of professional backgrounds – including economics, nursing, and acting – every contestant is looking for her big break into the entertainment industry. Most contestants said they would prefer to have a career in the U.S. but would go wherever the opportunity lies. (Photo and caption by John Brecher/Sahra Vang Nguyen/NBC News)

A woman raises her fist during events to mark Juneteenth, which commemorates the end of slavery in Texas, two years after the 1863 Emancipation Proclamation freed slaves elsewhere in the United States, amid nationwide protests against racial inequality, in the Harlem neighbourhood of Manhattan, in New York City, New York, June 19, 2020. (Photo by Andrew Kelly/Reuters)

A cosplayer poses during Day 2 of London MCM Comic Con 2019 at ExCel on May 25, 2019 in London, England. (Photo by Jack Dredd/Rex Features/Shutterstock)

“Sangoma” initiate Dipuo Banda (C) is led out of her teachers shack while she remains in a trance like state prior to dancing during her 3 day initiation ceremony with her teacher, family, friends and students in the Alexandra Township in Johannesburg, South Africa, 14 May 2021. Sangomas, the Zulu term for Medicine Women or traditional healers, fulfill different social and political roles in the community, including divination, physical healing, emotional and spiritual illnesses, directing birth or death rituals and finding lost cattle. (Photo by Kim Ludbrook/EPA/EFE)