‘Cartilage is remarkable, too. It is many times smoother than glass: it has a friction coefficient five times less than ice. Imagine playing ice hockey on a surface so smooth that the skaters went sixteen times as fast. That’s cartilage. But unlike ice, it isn’t brittle. It doesn’t crack under pressure as ice would. And you grow it yourself. It’s a living thing. None of this has been equalled in engineering or science. Most of the best technology that exists on Earth is right here inside us. And everybody takes it almost completely for granted.’
