Dropping a Knowledge Bomb

Today's KB is all about 3D...

NASA- Most human beings use what is known as binocular vision to perceive depth and see the world in 3D. The binocular vision system relies on the fact that we have two eyes, which are approximately 3 in apart. This separation causes each eye to see the world from a slightly different perspective. The brain fuses these two views together. It understands the differences and uses them to calculate distance creating our sense of depth and ability to gauge distance.

A simple way to understand this principle is to hold your thumb up at arms length and close one eye. Then try closing the other eye. As you switch between open eyes you should see your thumb "jumping" back and forth against the background. To see how much of a difference the binocular vision system makes, have a friend throw you a ball and try to catch it while keeping one eye closed.