Tango instructor Fernando Waisberg (R) and Isabella Waisberg (L) pose for a photograph during a Tango lecture session in Taipei, Taiwan, 14 April 2019 (issued 18 April 2019). Taiwan has developed its own Tango, with a strong Japanese influence; the accompanying music features lyrics in Taiwanese and Mandarin, the pace slower and simpler than the original. Taiwanese Tango is now a popular phenomenon among people over 40, and is also a subject little studied inside and outside of the island. (Photo by Ritchie B. Tongo/EPA/EFE)

Students from CAS Ballet Theatre School stretch on the sidewalk Saturday, February 20, 2016, in Ann Arbor, Mich. (Photo by Junfu Han/The Ann Arbor News via AP Photo)

Sculptures entitled “The Rising Tide” by British sculptor Jason deCaires Taylor are seen beside the River Thames in front of the Houses of Parliament and the London Eye ferris wheel in London, September 3, 2015. The representations of four horses and riders are fully visible at low tide but become immersed underwater twice a day as the Thames rises to reach full tide. The installation will be on display throughout September as part of the annual Totally Thames festival. (Photo by Toby Melville/Reuters)

The Dynasphere, an electrically-driven wheel, invented by Mr. J. A. Purves of Taunton and his son. It had 2.5 horse power and once attained a speed of 25 mph. (Photo by Fox Photos/Getty Images). 1932

Women playing in the street as the snow falls on Johannesburg for the first time in seventeen years. (Photo by Keystone/Getty Images). 1st September 1962

Promotional models use their smartphones during their break at the Global Mobile Internet Conference in Beijing May 6, 2014. Mobile Internet industry executives, developers and investors from more than 30 countries took part in the Global Mobile Internet Conference in Beijing, the organiser said. (Photo by Kim Kyung-Hoon/Reuters)

The Eiffel Tour-the body language of balance. I came across this group of young adults from Sarajevo, Bosnia, having fun testing their balance two nights ago in on the Esplanade de Trocadero. (Photo and comment by Peter Turnley)

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)