Muslims pray at the top of Mount Al-Noor during their Umrah Mawlid al-Nabawi “Birthday of Prophet Mohammad” in the holy city of Mecca, Saudi Arabia January 16, 2016. Muslims believe Prophet Mohammad received the first words of the Koran through Gabriel, at the top of Mount Al-Noor in the holy city of Mecca. (Photo by Amr Abdallah Dalsh/Reuters)

March 11, 2008 Swiss car manufacturer Rinspeed made quite the splash at the Geneva Motor Show with its innovative sQuba, a fully functional submersible concept car that cost $1.5 million to build. (Photo by Rinspeed)

A motor taxi driver gets his hands washed at an Ebola screening station on the road between Butembo and Goma on July 16, 2019 in Goma. The first patient to be diagnosed with Ebola in the eastern DR Congo city of Goma has died, the governor of North Kivu province said on July 16, 2019. The case – the first in a major urban hub in the region's nearly year-old epidemic of the disease – has sparked deep concern in neighbouring Rwanda and at the UN. (Photo by John Wessels/AFP Photo)

An older model Ford Mustang sits on cinder blocks with missing wheels near an abandoned apartment building in Detroit, Michigan January 7, 2015. Detroit, also known as the Motor City, is the historic hub of automobile manufacturing in the United States. A federal judge in December 2013 formally declared the city bankrupt but it won court approval to exit bankruptcy last November. Once the proud symbol of U.S. industrial strength, Detroit fell on hard times after decades of population loss, rampant debt and financial mismanagement left it struggling to provide basic services to residents. (Photo by Joshua Lott/Reuters)

“Izhevsk Machinebuilding Plant (Russian: Ижевский Mашиностроительный Завод) or IZHMASH (ИЖМАШ) is a weapons and motor vehicle manufacturer based in Izhevsk, founded in 1807 at the decree of Tsar Alexander I, and is now one of the largest corporations in its field. It manufactures the famous Kalashnikov series of assault rifle, along with a host of other Russian arms, including medium cannons, missiles, and guided shells”. – Wikipedia. (Photo by Pismoshnaya.ru, 2012)

Tao Xiangli gets out of his homemade submarine after operating it in a lake on the outskirts of Beijing September 3, 2009. Amateur inventor Tao, 34, made a fully functional submarine, which has a periscope, depth control tanks, electric motors, manometer, and two propellers, from old oil barrels and tools which he bought at a second-hand market. He took 2 years to invent and test the submarine which costs 30,000 yuan ($4,385). (Photo by Christina Hu/Reuters)

In this October 21, 2015, file photo, a young man rides a hoverboard along a Manhattan street toward the Empire State Building in New York. More than 500,000 hoverboards are being recalled after reports that they can burst into flames. The Consumer Product Safety Commission said Wednesday, July 6, 2016, it has received 99 reports of battery packs in the two-wheel motorized scooters catching fire or exploding that causing burns or property damage. The recalled hoverboards were made by eight companies. (Photo by Kathy Willens/AP Photo)

In a photo taken on September 11, 2019, North Korean students pose for photos in Chonji lake, or “Heaven lake”, as they visit the crater of Mount Paektu, near Samjiyon. Mount Paektu has long been considered the spiritual birthplace of the Korean nation and is a place of pilgrimage for tens of thousands of North Koreans every year, who are trained from birth to revere their leaders. (Photo by Ed Jones/AFP Photo)