1: Dubai's Burj Khalifa is the tallest building in the world, but perhaps not for long. Saudi Arabia has announced plans to build a 1 kilometer (3,280 foot) tower into the sky, to be named the Jeddah Tower, scheduled for completion in 2020. The Burj Khallifa currently stands at 2,716 ft. (Photo by Matthias Seifert/Reuters)

In this December 23, 2013 photo, Indian army soldiers patrol near one of their forward post at the Line of Control (LOC), that divides Kashmir between India and Pakistan, at Krishna Ghati (KG Sector) in Poonch, 290 kilometers (180 miles) from Jammu, India. The military commanders of longtime rivals India and Pakistan met on Tuesday in a bid to stop frequent cross-border attacks in disputed Kashmir which escalated tensions in the region in recent months. (Photo by Channi Anand/AP Photo)

This image provided by NASA shows parts of Europe and Africa very easily recognizable in this night time image shot by one of the Expedition 25 crew members aboard the International Space Station flying 220 miles above Earth on Thursday October 28, 2010. The view “looks” northward over Sicily and the “boot” of Italy, with the Mediterranean Sea representing most of the visible water in the view and the Adriatic Sea to the right of center. Tunisia is partially visible at left. Part of a docked Russian spacecraft and other components of the ISS are in the foreground. (Photo by AP Photo/NASA)

Leaves and forest foliage claim abandoned motors at makeshift car graveyards. German photographer Dieter Klein travels the world to find vintage automobiles left to rust in leafy forests and fields. Here: Seemingly camouflaged cars are stacked on top of each other causing them to blend in with the landscape, in 2013, France. (Photo by Dieter Klein/Barcroft Media)

People board a passenger bus during rush hour at a bus terminal, amidst the coronavirus disease (COVID-19) outbreak, in Mumbai, India, September 9, 2020. (Photo by Niharika Kulkarni/Reuters)

King Abdullah of Jordan and Queen Rania who holds Princess Salma in her arms, pose for a portrait November 20, 2000 in Amman, Jordan

A Chinese girl touches the gun of a relievo featuring Chinese soldiers fighting with Japanese troops during World War II at an exhibition at the Anti-Japan War Museum to mark the 60th Anniversary of the Victory of the Chinese People's War of Resistance Against Japan on August 18, 2005 in Beijing, China. (Photo by Cancan Chu/Getty Images)

Skeleton involves a person riding a small sled down a frozen track while lying face down. The sport is a more intense form of luge because skeleton competitors leap onto the sled and slide downhill head first. Skeleton athletes can reach up to 80 mph on straightaways, causing forces up to 5g, so the helmet is a critical component for attitude as well as safety.