Members of the Coney Island Polar Bear Club warm up before swimming at the beach at Coney Island in New York, December 15, 2013. (Photo by Eric Thayer/Reuters)

A boy sleds through snow as he enjoys the snow in Bahcesaray district called as planet nine because of roads blocked by snow in winter, in Van province of Turkey on January 22, 2020. (Photo by Ozkan Bilgin/Anadolu Agency via Getty Images)

The sunken ferry Sewol sits on a semi-submersible ship during its salvage operations at the sea off Jindo, South Korea, in this handout picture provided by the Ministry of Oceans and Fisheries and released by Yonhap on March 26, 2017. (Photo by Reuters/Yonhap/The Ministry of Oceans and Fisheries)

Members of the contemporary circus company Cirk La Putyka perform in front of sculpture of Franz Kafka's head to entertain local residents in Prague, Czech Republic, 21 April 2020. The aim of the Cirk La Putyka events in the streets of Czech capital is to get live art back to people during the lockdown. According to them, when people can't go to the artists, to the theater, the actors go to the people. The Czech government has imposed a lockdown in an attempt to slow down the spread of the pandemic COVID-19 disease caused by the SARS-CoV-2 coronavirus. (Photo by Martin Divisek/EPA/EFE/Rex Features/Shutterstock)

Kieron Connolly’s new book of photographs of more than 100 once-busy and often elegant buildings gives an idea of how the world might look if humankind disappeared. Here: Bodie, Mono County, California. Gold was discovered at Bodie in 1859 (just after the initial California gold rush) and it went from mining camp to boomtown. Its decline began in 1880, when word spread of new boomtowns elsewhere. The Standard Consolidated Mine closed in 1913, and four years later the Bodie Railway was abandoned. By 1940 the population was down to 40. Today, Bodie is maintained in a state of arrested decay as a visitor attraction. (Photo by Alamy Stock Photo)

Two holidaymakers amuse themselves with a porter's trolley whilst waiting for their train at Euston Station, London, 5th August 1939. (Photo by A. J. O'Brien/Fox Photos/Getty Images)

In this June 29, 2016 file photo, boats docked at Central Marine in Stuart, Fla., are surrounded by blue green algae. The 153-mile-long Indian River Lagoon has been plagued by harmful algae blooms. Water quality testing data analyzed by the AP showed the average phosphorous level – a byproduct of fertilizers and human waste that algae thrive on, rose nearly 75 percent between 2000 and 2016. (Photo by Greg Lovett/The Palm Beach Post via AP Photo)

Fifty years ago, as France exploded in mass protests, words scrawled on the walls of the Sorbonne summed up the revolutionary zeal of the time: “Run free, comrade, we’ve left the old world behind!”. Sexual liberation, artistic creativity and anti-capitalism were the order of the day. For those who were there, it was an unforgettable time. Here: A wounded student is transported by first-aid workers during riots on the Boulevard Saint-Michel, Paris, France on May 6, 1968. (Photo by Gökşin Sipahioğlu/SIPA Press)