Scary sledding. (Physical News).

The skeleton may be the scariest event at the 2002 Olympic Winter Games. Sliders scream belly first down an icy track banked with 15 hair-raising curves at speeds up to 137 km (85 mi) per hour. Named for the sled's bony framework (see picture, right), the event makes its first Olympic comeback in 54 years!

For 27-year-old Austrian Martin Rettl, extreme sledding is a perfect match for an extreme hairdo: his spiked coif is dyed red, purple, and blue--Rettl claims his "do" helped him become the 2001 skeleton world champion.

But more than his hair, Rettl thanks his speedy sled for his victories. To start a race, he sprints on spiked shoes, then dives headfirst onto a glass-fiber frame. Underneath, two solid steel runners slice into the ice to create friction, a rubbing force between objects, which helps Rettl control his ride. Runners are the most critical sled part, says U.S. skeleton team coach Ryan Davenport. "Differences in runners' grooves and shape" can change the speed of the sled, he says.

Once Rettl plants his chest on the sled's saddle, he streamlines his body into a human torpedo. With help from gravity, coupled with a sleek bodysuit and helmet Rettl picks up speed. "You want to cut neatly through the air," says physicist Louise Bloomfield at the University of Virginia. "Air resistance will slow your momentum [mass x speed]." More than a bad hair day?