WHAT do red blood cells and skiers have in common? They both overcome friction by exploiting the unusual properties of porous surfaces, an idea that could help reduce friction between the moving parts of machines.
The idea that skiers and red blood cells move in a similar way occurred to Sheldon Weinbaum, a biomedical engineer at The City College of New York when he noticed that a skier made deeper tracks in powdered snow when she was standing still than when she was moving. He says that when she moves, the skier’s weight is supported not just by the particles…
