Eli5 Why can’t we “know” the speed and position of an electron simultaneously? Why can we only measure one of these properties at a time?

Question

This always confuses me and I’m not sure how it works. Please explain…

In: 252

Answer 1

Lets say I give you a camera and tell you to take a picture of a baseball, and to find the ball’s speed and position after five seconds.

You have a few options. If you use a high-speed camera you will get the EXACT position of the the ball at five seconds, with absolutely no blur or distortion. But the ball just looks like it’s hanging there,so it’s impossible to guess the speed.

Or you could take a standard picture where the ball just looks like a smudge. You don’t know exactly where the ball was at five seconds, but you know the smudge is 10 feet long and the camera takes half a second to take a picture. From there you can tell the ball was traveling at 20 ft/s.

Now imagine every time you take a picture, a giant fan turns on and blows the ball in a totally random direction at a random speed.

Same general principle with electrons. There’s obviously a LOT more to it, but at a base level it comes down to the amount of information we can gather at one time. Every test and observation we make of that election changes its speed and trajectory.