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

Electrons don’t always behave like particles. Sometimes they behave like waves. Rather than the Bohr model of an atom, where the electron orbits the nucleus like a planet around a star, Schrodinger’s equation gives orbitals as regions of high probability of the electron existing. The means the electron could be found in multiple places, based on that equation (which is related to its motion – so if we know the motion we can’t know the location).

If we combine multiple equations for motion (meaning we no longer know which one is the true motion) then these probable locations combine through interference (constructive and destructive, the way light does through diffraction) and this can result in one area of 100% probability – so we know where it is but as above we no longer know its motion.