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

It is a confusing concept, but here is how I think of it. Velocity is the change in position over time – to measure the speed of a car, you have to know where it is at time 1, then time 2. We do this with a car by counting the turns of the wheels – it turns x rotations a second, the wheel has a diameter of y, so it is going xy per second. If you stop the car to check the wheel’s position, can you know how fast it was going? By definition, speed requires that the thing whose speed you are measuring is changing position – and every time it changes position, it’s speed can change – so at some level of super accurate precision, even for a car, you cannot know both its position and its velocity. An electron is so small that everything about it is at a supremely high level of precision.

I realize that probably is not the explanation- but that’s how I think about it. The physicists can now commence downvoting.