I read that the Heisenberg uncertainty principle arises for stuff like electrons simply because the observer affects the observed . That is,because photons (or what ever the observer uses to detect the position) will affect the trajectory of the particle... That doesn't make much sense to me.. (SURPRISE!!). Does that mean, that if no one "looks" at the electron , it will keep moving in a regular, predictable orbit? That doesn't seem likely, what will all of Schrodinger's work... So I think I've got it mixed up. Let's see... I'll try to sum up my understanding of this subject and I hope you guys will be able to correct me. 1 The electron is fizzing around the nucleus. 2. If someone tries to look at it, then it's path is altered by incoming photons. (uncertainty principle) 3. Schrodinger came up with the wave function of electrons to predict where they will most probably be. Now, to me, step 2 and 3 seem to be contradictory. If nobody looks at it the electron would move in it's regular (predictable) orbit...and shrodingers equations would seem to be wrong. One the other hand, if shrodinger's equation are right, that would mean that whether you looked or not the electrons wouldn't move in a predictable manner... (please feel free to say so if you think I'm in a hopeless muddle. ) Please help me clear this up.