Measurement

Heisenberg's uncertainty principle in quantum mechanics is sometimes described, somewhat inaccurately I'm told, as establishing that the precise measurement of the position of a particle necessarily disturbs a particle's momentum. Therefore you cannot measure with precision both a particle's position and momentum. It's a law of nature (though as an interesting aside Einstein didn't like it. This was the source of his famous quote "God does not play dice"). Believe it or not, I don't have a lot of need to precisely measure the position and momentum of particles. Still, I do find this sort of thing fascinating. And I love a good physics joke. Like these two uncertainty principle jokes -

A quantum physicist is stopped on the highway by a police officer who asks "Do you know how fast you were going, sir?", to which the physicist responds, "No, but I know exactly where I am!"

Physics building graffiti - "Heisenberg may have been here."

The characterization of the uncertainty principle that most interests me, whether it is accurate or not in a purely scientific sense, is that "observation of an event changes the event." A true statement if ever there was one. When I have a camera, I sometimes get so lost in recording the moment that I neglect to experience the moment. In some ways, I was so involved with trying to "capture" this sunrise on our recent Boundary Waters trip that I didn't experience it as well as I might. Of course, I can reexperience it in some small way later. And that is part of the charm and joy of canoe trips for me. So I take my camera along. But there is no doubt that the "observation of the event changes the event."



What made me think about the uncertainty principle lately is the speedometer I bought for my bicycle. I've avoided this purchase for years. Not for cost reasons. Just because I was afraid that if I had a speedometer I would be so busy tracking my time and speed that I would forget to enjoy the ride itself. And I was somewhat right. I am now sometimes overcome with a strange compulsion to check my time at particular spots along my ride. To feel good when I'm going 16 miles an hour where I "normally" go 14. Notwithstanding the fact that the reason I am going faster is the tail wind that is pushing me along. For a few days I took the speedometer off my bike. But then I decided that for my personal growth I needed to learn how to ride without paying excessive attention to the speedometer. So if you see some idiot riding between downtown Minneapolis and St. Paul who is paying too much attention to his speedometer, it's probably me. I won't know where I am, but I'll know exactly how fast I am going.