Upon a measurement of the position, the wavefunction collapses to a spike centered at x0 https://farside.ph.utexas.edu/teaching/315/Waveshtml/img3240.png I encounter similar spike pictures numerous times, but there is an uncertainty in position , it can't be a spike right. First thing I see on google: In quantum mechanics, wave function collapse is said to occur when a wave function—initially in a superposition of several eigenstates—appears to reduce to a single eigenstate (by "observation"). I thought position was not an eigenstate? See similar thread now: https://www.physicsforums.com/threads/position-eigenstates.764912/ Pls explain, thanks in advance. I have a lot of other questions but I don't want to cram them all in on thread, BUT I don't want to spam either, I'll just do it one by one.