Video Infoblog: I was wrong about the Heisenberg Uncertainty Principle
0:00 You've probably heard the Heisenberg Uncertainty Principle described like this. Measurements knock 0:05 the state of a particle and disturb it, and that's why you can't know the position and 0:10 the momentum at the same time. So for example, if I wanted to know where this electron was, 0:16 then I'd have to bombard it with high energy gamma rays. 0:20 But when I do that Even though it will give me a pretty accurate representation of its position, 0:26 it will have knocked this state so badly that now I have no idea 0:30 what speed it's going at. But as some of you may already know, this is completely and 0:34 utterly wrong. Heisenberg uncertainty isn't about measurement, it's about the spread of a particle. 0:42 Or at least, that was the version of the Heisenberg Uncertainty Principle that I 0:46 was taught when I went to university. But ...