The Cathedral in Your Hand

Hold your hand up and spread your fingers. You are looking at twenty-seven bones, thirty-four muscles, and over one hundred twenty ligaments, all packed into a space smaller than a paperback novel. Robotics engineers have spent decades and millions of dollars trying to replicate the human hand. Their best prototypes still cannot peel a ripe peach without crushing it. Yet your hand can thread a needle, crack an egg with just enough pressure, play a Rachmaninoff chord stretching a tenth on the piano, and cradle a newborn's skull with precisely calibrated tenderness — all in the same afternoon.…