While it's undoubtedly true that opening than can of tinned peaches you yearn for would have been practically impossible without your opposable thumb, it turns out that there are other ways to get a good grip! Scientists have created a robotic arm that can do everything from serve drinks to draw pictures even though it has no digits.

Fingers and thumbs work perfectly well for humans. But on a robot they can be clumsy. They slip, or they grip too hard and break whatever they're trying to hold. And sometimes they don't grasp it at all. Then there are the complexities of manipulating 20-odd joints with a computer.So physicist Eric Brown and his research colleagues at the University of Chicago took a different track.

Their robotic hand is a thin rubber sack filled with coffee grains or small glass spheres. When this hand comes in contact with an object, a small pipe sucks air from the sack, causing it to contract and mold to the object's shape. The contraction is small--a mere 1% change in volume-but was enough to grab most objects. "It's very simple to control," notes Brown. "You don't have all these joints."