Hello All, I want to understand uncertainty principle. I understand that when we measure x accurately we cannot measure p with that accuracy. The process of measuring x accurately might like this: some detector fires high energy photon to that small particle, and we can know x accurately. But the high energy photon can change momentum of the particle. But, when we fires low energy photon to that particle we get fuzzy region of probability for that particle. Now, I want to understand how can we get accurate momentum by getting fuzzy region of the particle? What might be the process to get it?