An Egyptian university student drives a hybrid racing car he built with his team to compete at the Global Hybrid-Electric Challenge in Cairo, Egypt September 2, 2016. (Photo by Mohamed Abd El Ghany/Reuters)

A recruitment drive during the First World War at Trafalgar Square, London. (Photo by Central Press/Getty Images)

Labourers who work nearby nap on a road as cars drive past in Chongqing Municipality, July 23, 2013. (Photo by Reuters/Stringer)

Cars drive under a rainbow near Bad Langensalza, Germany, Wednesday, November 2, 2016. (Photo by Jens Meyer/AP Photo)

A car drives between trees in a small park in Frankfurt, Germany, Monday, April 8, 2024. (Photo by Michael Probst/AP Photo)

Cars drive on an alley between rape fields in the outskirts of Frankfurt, Germany, Monday, April 22, 2024. (Photo by Michael Probst/AP Photo)

Supporters celebrate as they watch official results from the Union Election Commission on an LED screen in front of the National League for Democracy Party (NLD) head office in Yangon, November 9, 2015. Myanmar's ruling party conceded defeat in the country's general election on Monday, as the opposition led by democracy figurehead Aung San Suu Kyi appeared on course for a landslide victory that would ensure it can form the next government. "We lost," Union Solidarity and Development Party (USDP) acting chairman Htay Oo told Reuters in an interview a day after the Southeast Asian country's first free nationwide election in a quarter of a century. (Photo by Soe Zeya Tun/Reuters)

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)