A subway worker walks away after a train departed the station in central Pyongyang, North Korea May 7, 2016. (Photo by Damir Sagolj/Reuters)

A protester is taken away by policewomen after storming into the government headquarters in Hong Kong September 27, 2014. (Photo by Bobby Yip/Reuters)

A vendor sells fruits and nuts at the Green Bazaar in Almaty January 23, 2015. Kazakhstan is spending billions of dollars of its reserves to keep devaluation of its currency gradual and reduce inflationary risks of the sort thrown up in Russia by the rouble's slide, analysts and former central bank officials say. Kazakhstan, Central Asia's largest economy, is closely tied to Russia through trade and, like other ex-Soviet states, has been feeling the pain of the crisis which has driven the rouble down 50 percent against the dollar since the start of 2014. (Photo by Shamil Zhumatov/Reuters)

Fans of Chris Mazdzer of the United States including his girlfriend Mara Marian (C) react following his third run during the Luge Men's Singles on day two of the PyeongChang 2018 Winter Olympic Games at Olympic Sliding Centre on February 11, 2018 in Pyeongchang-gun, South Korea. (Photo by Alexander Hassenstein/Getty Images)

Skeleton involves a person riding a small sled down a frozen track while lying face down. The sport is a more intense form of luge because skeleton competitors leap onto the sled and slide downhill head first. Skeleton athletes can reach up to 80 mph on straightaways, causing forces up to 5g, so the helmet is a critical component for attitude as well as safety.

Do tears of joy look the same as ones of woe—or ones from chopping onions? In “The Topography of Tears,” the Los Angeles-based photographer Rose-Lynn Fisher explores the physical terrain of one hundred tears emitted during a range of emotional states and physical reactions. Using a Zeiss microscope with an attached digital camera, she captures the composition of tears enclosed in glass slides, magnified between 10x and 40x. “There are many factors that determine the look of each tear image, including the viscosity of the tear, the chemistry of the weeper, the settings of the microscope, and the way I process the images afterwards,” she says.

A model in Mongolia costumes prepares backstage in Xiangshawan Desert, also called Sounding Sand Desert on July 18, 2013 in Ordos of Inner Mongolia Autonomous Region, China. Xiangshawan is China's famous tourist resort in the desert. It is located along the middle section of Kubuqi Desert on the south tip of Dalate League under Ordos City. Sliding down from the 110-metre-high, 45-degree sand hill, running a course of 200 metres, the sands produce the sound of automobile engines, a natural phenomenon that nobody can explain. (Photo by Feng Li)

Photographer David Lazar captured photos of native Dessana tribe, nearly 3,000 miles away from Brazil's capital. Tribe is only accessible by boat from city of Manaus. Surrounded by trees, waterfalls and tropical wildlife, this Amazon tribe is a world away from the beaches of Rio.