Robot couple Xiaolan (L) and Xiaotao carry trays of food at a restaurant in Jinhua, Zhejiang province, China, May 18, 2015. The restaurant, which opened on Monday, has two robots delivering food for customers. The robots were designed as a couple, Xiaolan and Xiaotao, according to local media. (Photo by Reuters/Stringer)

People who fled the violence from Islamic State-controlled northern Syrian town of al-Bab arrive in the rebel-held outskirts of the town, Syria February 3, 2017. (Photo by Khalil Ashawi/Reuters)

A partial solar eclipse is seen in a break in the clouds during rush hour in downtown Wichita Kan., Thursday, October 23, 2014. A partial eclipse occurs when the moon covers a portion of the sun as seen from the Earth. (AP Photo/The Wichita Eagle, Travis Heying)

Egmont National Park in New Zealand with Mt. Taranaki at its center is seen in a Landsat 8 satellite image taken July 3, 2014 and released by NASA November 14, 2014. The image is from the book “Sanctuary: Exploring the World's Protected Areas from Space”, published by the Institute for Global Environmental Strategies with support from NASA, which was released this week. (Photo by Reuters/NASA/USGS)

In this July 12, 2007 file photo, a two-day-old piping plover runs along a beach in the Quonochontaug Conservation Area in Westerly, R.I. (Photo by Steven Senne/AP Photo)

A member of the “Castellers Minyons de Terrassa” adjusts her belt before forming a human tower or ÒcastellÓ during the festival of the patron saint of Barcelona “The Virgin of Mercy” at Sant Jaume square in Barcelona, Spain, September 20, 2015. The formation of human towers is a tradition in Catalonia dating back to the 18th century. (Photo by Susana Vera/Reuters)

David Bowie wears an eyepatch in red suit and guitar on blue background at Top Pop television studios in Holland while doing playback to his hit song Rebel Rebel in 1974. (Photo by Barry Schultz/Sunshine/REX Shutterstock)

The view at night from the Shanghai Tower in Shanghai, China on August 7, 2015. The tower is technically smaller than the Burj Khalifa in Dubai but, while the observation deck of Dubai’s mega-structure is at 556m, the Shanghai Tower’s is at 561m, meaning the view is a little higher. (Photo by Paul Reiffer/REX Shutterstock)