Did you know your face actually turns slightly red each time your heart beats, when fresh blood pumps through it? Neither did I, and that’s because it’s so slight that our visual perception system doesn’t pick up on it. Ah, but what if you could use a computer program to magnify the changes so they become visible? That’s just what computer scientists at MIT did, and the result is fascinating: watch the video above (starting at 1:25) and see how with every heartbeat, a man’s face turns tomato red, then fades to a pallid yellow. The program is so precise that it can accurately calculate a person’s heart rate from the color changes.
[via Technology Review]