A couple shares a light moment in a Mass Transit Railway (MTR) subway train in Hong Kong, China on August 28, 2019. (Photo by Anushree Fadnavis/Reuters)

Michael Read, director of Flight Operations from New Zealand-based Martin Aircraft Company, flies a Martin Jetpack during a demonstration at a water park in Shenzhen, China December 6, 2015. KuangChi Science Ltd, a Hong Kong-listed Chinese company and investor of Martin Aircraft, will sell the flying machine in mainland China for 1.6 million yuan ($249,902), according to the company. (Photo by Bobby Yip/Reuters)

In modern Russia there are no free elections, therefore the political elite is almost constant.

Photo: Valentina Matvienko, Mayor of St. Petersburg, attends the St. Petersburg International Economic Forum (SPIEF) on June 17, 2011 in St. Petersburg, Russia. Global business leaders have gathered in Russia for the three-day conference. (Photo by Alexander Aleshkin/Epsilon/Getty Images)

“A small British company with a dream of building a re-usable space plane has won an important endorsement from the European Space Agency (ESA) after completing key tests on its novel engine technology. Reaction Engines Ltd believes its Sabre engine, which would operate like a jet engine in the atmosphere and a rocket in space, could displace rockets for space access and transform air travel by bringing any destination on Earth to no more than four hours away”. – Chris Wickham via Reuters. Photo: Artist's impression of Skylon. (Photo by Reaction Engines Ltd)

A Panasonic Toughpad is displayed during a press event at The Venetian for the 2012 International Consumer Electronics Show (CES) January 9, 2012 in Las Vegas, Nevada. CES, the world's largest annual consumer technology trade show, runs from January 10-13 and is expected to feature 2,700 exhibitors showing off their latest products and services to about 140,000 attendees. (Photo by Ethan Miller/Getty Images)

Chinelos (traditional costumed dancers) perform in front of San Andres Ocotlan church as part of continuing festivities to welcome the new year in Calimaya, Mexico on January 4, 2016. (Photo by Arturo Hernandez/Demotix/Corbis)

A Porcupine on display during the PBS portion of the 2010 Summer TCA Press Tour at the Beverly Hilton Hotel on August 5, 2010 in Beverly Hills, California. (Photo by Frederick M. Brown/Getty Images)

A postman walks past an art work titled “Alphabetti Spaghett” by artist Alex Chinneck on Norborough Road in Sheffield, Yorkshire, England on September 26, 2019. (Photo by Danny Lawson/PA Images via Getty Images)