Gyroscopic Grace

A lesson from your iPad or smartphone screen.

It's like magic, isn't it? No matter how many times you turn or twist that smartphone or tablet of yours, the screen turns and twists right along with you, keeping whatever it is you're looking at right-side-up, no matter what.

Chances are, the first time you encountered this feature -- now standard on just about every piece of mobile technology -- it made you smile, or maybe even laugh out loud. We're not used to things righting themselves. Typically, if something's out of whack in life, we notice it and try to make it right. Perhaps that's what makes the screen on your smartphone so charming. It's does the fixing itself.

Of course, it isn't magic that keeps our precious screens in sync with us. It's science. Inside your favorite device is a gyroscope, which -- when coupled with an accelerometer -- senses precise motion along six axes: up/down, left/right, forward/backward. It even keeps tabs on the speed with which you move. The result is a phone that not only keeps your pictures...