- #1
betelgeuse91
- 32
- 0
According to one of the postulates of quantum mechanics, every measured observable q is an eigenvalue of a corresponding linear Hermitian operator Q. Which means, that q must satisfy the equation Qψ = qψ. But according to Griffiths chapter 3, this equation can only be followed from σ_{Q = 0. It makes no sense to me because not every observable has zero standard deviation. Can someone explain this?}