Tao Xiangli gets out of his homemade submarine after operating it in a lake on the outskirts of Beijing September 3, 2009. Amateur inventor Tao, 34, made a fully functional submarine, which has a periscope, depth control tanks, electric motors, manometer, and two propellers, from old oil barrels and tools which he bought at a second-hand market. He took 2 years to invent and test the submarine which costs 30,000 yuan ($4,385). (Photo by Christina Hu/Reuters)

View of the “Sunset Lake” hot spring with it's unique colors caused by brown, orange and yellow algae-like bacteria called Thermophiles, that thrive in the cooling water turning the vivid aqua-blues to a murkier greenish brown, in the Yellowstone National Park, Wyoming on June 1, 2011. Yellowstone National Park, was established by the U.S. Congress and signed into law by President Grant on March 1, 1872. The park is located primarily in the U.S. state of Wyoming, though it also extends into Montana and Idaho and was the first national park in the world. It is known for its wildlife and its many geothermal features, especially the Old Faithful Geyser. (Photo by Mark Ralston/AFP Photo)

Young women wearing facemasks and traditional costumes of Song dynasty and Tang dynasty are seated on a bench in a park next to the East Lake in Wuhan, in China’s central Hubei province on May 17, 2020. The Guardian picture desk has chosen on December 17, 2020, the AFP photojournalist Hector Retamal as “Agency Photographer of the Year 2020” for his coverage of the novel coronavirus Covid-19 pandemic in Wuhan, China. (Photo by Hector Retamal/AFP Photo)

After some days with temperatures below freezing point, I was out skating at some lakes at the outskirts of Oslo in Norway. After a while I noticed something on the ice. To my astonishment it was a dead frozen frog.

A girl laughs while unloading her boat of produce at a market in Ganvie on January 6, 2012 in Cotonou, Benin. Often called the Venice of Africa, Ganvie is a stilted fishing village on Lake Nokoue, near Cotonou in Benin, the largest such village in Africa, and home to approximately 20,000 residents. (Photo by Dan Kitwood/Getty Images)

Sydney Truba, 11, of Melvindale, Michigan lies in a giant lake of mud during Wayne County's 2011 Mud Day event at Nankin Mills Park July 12, 2011 in Westland, Michigan. The annual event consists of 20,000 gallons of water mixed with 200 tons of topsoil. (Photo by Bill Pugliano/Getty Images)

A model poses during the annual World Bodypainting Festival in Poertschach, Austria, July 3, 2015. The event takes place from July 3 to 5 at lake Woerthersee in Austria's southern Carinthia province. (Photo by Heinz-Peter Bader/Reuters)

Historical reenactor Troy Kotz poses with a mug of wassail in the parlor of the Guyon-Lake-Tysen House during the annual Candlelight Tour of Historic Richmond Town, Saturday, December 13, 2014, in the Staten Island borough of New York. The annual event lets visitors experience an authentic Victorian Christmas. This image was made using the TinType by Hipstamatic iPhone app. (Photo by Chad Rachman/New York Post)