Police officers display their AI-powered smart glasses in Luoyang, Henan province, China on April 4, 2018. (Photo by Reuters/China Stringer Network)

Lizzy Huggler, 20 ,wears blue ties on her legs on the third day of the Firefly Music Festival in Dover, Delaware U.S., June 16, 2018. (Photo by Mark Makela/Reuters)

In this Thursday, June 14, 2018, file photo, students wear virtual reality goggles during a science class at Pyongyang Teachers' University, a teacher training college, in Pyongyang, North Korea. (Photo by Dita Alangkara/AP Photo)

British band Florence and the Machine performs at the Bilbao BBK Live festival in Bilbao, Spain, early 13 July 2018. Bilbao BBK Live festival runs from 12 July to 14 July 2018. (Photo by Miguel Tona/EPA/EFE)

Tightrope walker Tatian-Mosio Bongonga hangs from a tightrope as she pauses while scaling the Monmartre hill towards the Sacre Coeur Basilica (not pictured) in Paris, France, July 20, 2018. (Photo by Philippe Wojazer/Reuters)

Dancers perform inside of transparent balls during the Botanical Night at Botanical Garden in Berlin, Germany, 20 July 2018. During the Botanical Night a 16 kilometre long path along the flower beds and several themed gardens are illuminated and guide to many attractions. (Photo by Hayoung Jeon/EPA/EFE)

A picture shows the full moon during a “blood moon” eclipse over the temple of Apollo in Corinth on July 27, 2018. The longest “blood moon” eclipse this century began on July 27, coinciding with Mars' closest approach in 15 years to treat skygazers across the globe to a thrilling celestial spectacle. (Photo by Valerie Gache/AFP Photo)

Performers line up during the closing ceremony of the 2014 Winter Olympics, Sunday, February 23, 2014, in Sochi, Russia. (Photo by Darron Cummings/AP Photo)