An undercover police officer, who had been marching with anti-police demonstrators, aims his gun at protesters after some in the crowd attacked him and his partner in Oakland, California December 10, 2014. Police said more than 100 demonstrators marched in Berkeley, California, which has a history of social activism. Under cloudy skies, turnout was smaller than earlier in the week, when demonstrators in the area threw rocks at police and shut down a major freeway. (Photo by Noah Berger/Reuters)

A woman browses through kimonos for sale at Boroichi flea market in Tokyo December 15, 2014. In the 16th century, Boroichi was a place for farmers to buy and sell rags, known as boro, for mending clothes and weaving sandals. Now in its 436th year, the original spirit lingers, with about 700 stands hawking fabric, used clothes and piles of rags. Others sell kitchen tools, pottery, seaweed and spices. About 200,000 people flock to the market, which is only open for four mid-winter days a year – two in December and two in January. (Photo by Thomas Peter/Reuters)

“Maeklong Railway Market, located in Samut Songkhram, Thailand, around 37 miles west of Bangkok, looks like any other open-air market in Asia. HOWEVER...”. – Kaushik via Amusing Planet. Photo: Maeklong Railway Market (Photo by Trent Strohm)

Two Bulgarian tourists pose in front of the Eiffel Tower in Paris on their last day in the capital on March 24, 2014. (Photo by Franck Fife/AFP Photo)

Students pose for a pictures taken by their friends during spring break on the beach in the resort city of Cancun, Mexico, February 27, 2009. (Photo by Israel Leal/AP Photo)

Members of the Bolivarian National Guard who joined Venezuelan opposition leader and self-proclaimed acting president Juan Guaido fire into the air to repel forces loyal to President Nicolas Maduro who arrived to disperse a demonstration near La Carlota military base in Caracas on April 30, 2019. Guaido – accused by the government of attempting a coup Tuesday – said there was “no turning back” in his attempt to oust President Nicolas Maduro from power. (Photo by Federico Parra/AFP Photo)

Two dogs sent into outer space by the Soviet Union after their safe return to earth. They spent 22 days in orbit. (Photo by Central Press/Getty Images). 22nd March 1966

Crew members work to secure a hot air balloon after landing during the 2015 Albuquerque International Balloon Fiesta in Albuquerque, New Mexico, October 4, 2015. (Photo by Lucas Jackson/Reuters)