A prototype Rollkers transportation device is displayed during a press event at the Mandalay Bay Convention Center for the 2015 International CES on January 4, 2015 in Las Vegas, Nevada. The product is not a skate; it balances for you and when you place it on the bottom of your shoe, it gives you the ability for faster transportation based on walking. The balance CES, the world's largest annual consumer technology trade show, runs from January 6-9 and is expected to feature 3,600 exhibitors showing off their latest products and services to about 150,000 attendees. (Photo by Ethan Miller/Getty Images)

A girl dances in front of the digital art installation “Light in Dark” created by teamLab, a collaborative of Japanese digital artists, during a special exhibition of “Shake! Art Exhibition! and Learn and Play! teamLab Future Park” at National Museum of Emerging Science and Innovation (or Miraikan) in Tokyo, Japan, 19 January 2015. The exhibition is held through 01 March 2015. (Photo by Kimimasa Mayama/EPA)

A volcanic eruption at Mount Etna’s Vorgaine crater in Sicily, Italy on December 3, 2015. (Photo by Marco Restivo/Barcroft Media)

A farmer rides a truck in a village near Nong Khai, Thailand, September 16, 2015. (Photo by Jorge Silva/Reuters)

An Iraqi army cadet performs “the leap of faith” from a bridge in Baghdad, September 22, 2015. (Photo by Ahmed Saad/Reuters)

A portrait of Kazakh historical figure Ablai Khan is projected on a building in downtown Astana, Kazakhstan, October 8, 2015. (Photo by Shamil Zhumatov/Reuters)

Students play in their school yard on the first day of the new school term at a primary school in Baghdad, October 18, 2015. (Photo by Ahmed Saad/Reuters)

Revellers take part in a zombie parade to celebrate Halloween in Vina del Mar, October 31, 2015. (Photo by Rodrigo Garrido/Reuters)