Mostly out of curiosity, I downloaded the Sleep Time app for Android yesterday. It’s an alarm clock that uses the accelerometer in the phone (which has to be placed on the mattress) to determine one’s sleep phase. Based on that information, it wakes you up at a certain point during a 30-minute window, with the goal of not tearing you out of deep or REM sleep.
I set the alarm clock to 7 AM, but the app actually woke me up at 6:34 AM. Judging by the sleep cycle graph, that was probably the right call, I had been in light sleep for a while.
My sleep cycle graph is so pretty! Apparently I’m quite a normal sleeper.
Update:
OMG. When talking to guys at work, I realized what an evil genius would do with an app like this: Market the sleep cycle information to advertisers (or worse!), who will then play audio messages to the sleepers! Am I being brainwashed?