In this Wednesday, March 18, 2015 photo, limestone quarry workers walk through a cloud of dust spewed into the air by rotor blades of the stone-cutting machinery in the desert of Minya, southern Egypt. Around 45,000 people, including children, work in an estimated 1,500 quarries, digging out stones that later will be used in construction or powdered to be used by pharmaceutical and ceramic companies. (Photo by Mosa'ab Elshamy/AP Photo)

Artist Heather Dewey-Hagborg's 'Stranger Visions', comprising of 3D printed faces extracted from DNA taken from discarded cigarette butts and chewing gum, is displayed at the Big Bang Data exhibition at Somerset House on December 2, 2015 in London, England. The show highlights the data explosion that's radically transforming our lives. It opens on December 3, 2015 and runs until February 28, 2016 at Somerset House. (Photo by Peter Macdiarmid/Getty Images for Somerset House)

In this Tuesday, June 4, 2019, photo, a Yamanote Line train travels above commuters walking across the crossing during evening rush hours in the Shinjuku district of Tokyo. Operated by the East Japan Railway Co., the Yamanote Line in Tokyo makes a loop around the center of the city, connecting 29 stations that include key stops such as Shinjuku, Shibuya and Ikebukuro. A complete loop of about an hour offers scenes of Japanese daily lives. (Photo by Jae C. Hong/AP Photo)

People ride a prototype of a driverless vehicle as it is moves through a pedestrian area in Greenwich, east London, February 11, 2015. Britain has begun testing driverless cars in four cities, launching the first official trials ahead of a series of planned rule reviews to accommodate the new technology. (Photo by Suzanne Plunkett/Reuters)

A pro-Russian armed man secures crash site wreckage of the Malaysia Airlines Boeing 777 plane (flight MH17) at the site of the plane crash near the settlement of Grabovo in the Donetsk region November 16, 2014. Local emergency services have begun collecting parts of the wreckage from its crash site in the middle of the conflict zone, Dutch air accident investigators said on Sunday. Dutch inspectors had hoped to collect the parts themselves, following the downing of the flight on July 17 that killed 298 people, two thirds of them Dutch citizens. But they remain concerned about the safety of their staff in the rebel-held conflict zone, and so have decided to work with local services following an initial focus on finding human remains and belongings. (Photo by Antonio Bronic/Reuters)

A Mai-Mai rebel soldier shows off his guns at a checkpoint near the Mugunga refugee camp in Zaire; 1996. (Photo by Carol Guzy/The Washington Post)

People stand along Aviation Blvd. as the space shuttle Endeavour lands at LAX in Los Angeles. (Photo by Wally Skalij/Los Angeles Times/MCT)

A cadet from the Interior Ministry with the word Fidel painted on her face attends a rally honoring the late Cuban leader at the Revolution Plaza in Havana, Cuba, Tuesday, November 29, 2016. Schools and government offices were closed Tuesday for a second day of homage to Fidel Castro, with the day ending in a rally on the wide plaza where the Cuban leader delivered fiery speeches to mammoth crowds in the years after he seized power.Fidel Castro passed away Friday Nov. 25. He was 90. (Photo by Ramon Espinosa/AP Photo)