Watch HDToday. Hans Thirring, a theoretical physicist at the University of Vienna, is skiing down a mountain slope wearing cape-like attire. The cape, designed by Thirring and called the Thirring mantel, is made of parachute silk and acts somewhat like a parachute to provide its wearer reduced speed while shushing down the slopes. But it also provides lift so that the skier is lighter on his skis, almost weightless. This "flight" somewhat mimics the experience felt by those participating in the relatively new sport of ski-flying (also known as ski jumping), which must have exacting conditions (i.e. little wind, hard packed snow) to ensure safety. Even in ideal conditions, ski-flying is a dangerous sport, especially if the landing is not executed properly.