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)

Iraqi paramilitary troops fire towards Islamic State militants during a battle with Islamic State militants on the outskirts of the ancient city of Hatra near Mosul,Iraq April 26, 2017. (Photo by Reuters/Stringer)

N.C. Dezendorf, wife of the general manager of the Electro-Motive division of General Motors, christens the new lightweight “Aerotrain” at the company's locomotive works in La Grange, Ill. on August 22, 1955. (Photo by Edward Kitch/AP Photo)

Migrant children run away from clashes with Mexican National Guards after their group crossed the Suchiate River on foot from Guatemala to Mexico, on the riverbank near Ciudad Hidalgo, Mexico, Monday, January 20, 2020. More than a thousand Central American migrants hoping to reach the United States marooned in Guatemala are walking en masse across a river leading to Mexico in an attempt to convince authorities there to allow them passage through the country. (Photo by Santiago Billy/AP Photo)

A Vietnamese woman collects dried incense sticks at a courtyard in Quang Phu Cau village on the outskirts of Hanoi on January 9, 2020 ahead of the upcoming Lunar New Year celebrations, referred to in Vietnam as Tet. (Photo by Manan Vatsyayana/AFP Photo)

A person stands next to the skyline of lower Manhattan on the opening day the Edge NYC, an outdoor observation deck on the 100th floor of 30 Hudson Yards on March 11, 2020 in New York City. (Photo by Gary Hershorn/Getty Images)

Joseph Fons holding a Pride Flag, runs in front of the U.S. Supreme Court building after the court ruled that a federal law banning workplace discrimination also covers sexual orientation, in Washington, D.C., U.S., June 15, 2020. (Photo by Tom Brenner/Reuters)

People stand in the rain as they wait to enter the Martyrs' Mausoleum during a ceremony for Martyrs' Day in Yangon on July 19, 2020. Myanmar observed the 73rd anniversary of Martyrs' Day on July 19, marking the assassination of independence heroes including Aung San Suu Kyi's father, who helped end British colonial rule. (Photo by Sai Aung Main/AFP Photo)