The surprising science of why ice is so slippery

(via Vox) Winter Olympic ice sports are possible due to this one fact: Ice is slippery. The low friction of ice is why speedskaters can reach 35 mph, why figure skaters can twirl in dizzying circles, and why a 40-pound curling stone can glide and accomplish whatever the heck the point of curling is. But for much of the past two centuries, scientists have struggled to explain why, exactly, ice is slippery — and why skates can glide atop it so well.