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

We can easily see the position of a car by looking at it. We can pretty easily measure the speed of a car by just watching how far it goes in a certain amount of time.

But looking at things requires bouncing photons off of it. That’s fine when it’s a car. But for something as small as an electron, a single photon can easily just yeet the electron to who knows where.

Edit: This is the observer effect. Check out the other replies explaining the uncertainty principle.