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.

A wounded member of the Afghan police reaction force waits for treatment in Alingar, Laghman province, on April 30, 2012. A bomb exploded next to opium poppy fields during a poppy eradication campaign in, wounding two Afghan policemen, police officials said. (AP Photo/Rahmat Gul)

Intrigued by photographing time, Singapore-based photographer Fong Qi Wei created single, composite pictures from a sequence of images spanning 2-4 hours. He concentrated on capturing sunrises and sunsets as they evolved over different landscapes, seascapes, and cityscapes. He then digitally stitched the images together to get a snapshot of time passing over the scene for his series “Time is a Dimension”. “Most paintings and photographs are an instance of time”, Wei explained in his artist’s statement. “That’s not the way the world works. We experience a sequence of time, and that’s why a video is somehow more compelling than a freeze frame”. (Photo by Fong Qi Wei/Thoughtful Photography)

Rihanna holds the pregnant belly of Spc. Ariel Evans during an event promoting her Rogue Man cologne at Ft. Belvoir Exchange on Wednesday, November 12, 2014 in Ft. Belvoir, Va. (Photo by Kevin Wolf/AP Photo)

A man and a woman both wounded by what locals say was recent shelling by Ukrainian forces, react as they sit in an ambulance in Donetsk August 23, 2014. (Photo by Maxim Shemetov/Reuters)

Singer Halsey has her dress adjusted before she poses during the premiere of the film “The Huntsman: Winter's War” in Los Angeles, California, April 11, 2016. (Photo by Kevork Djansezian/Reuters)

Horse Racing – Crabbie's Grand National Festival – Aintree Racecourse April 10, 2015: Racegoers react during the 17.15 Weatherbys Wealth Management Champion Standard Open National Hunt Flat Race. (Photo by Andrew Boyers/Reuters)