Hi all I was just looking through my notes from my first year of my degree, and I couldn't find a missing bit. I know that Planck's postulate states that the allowed energies of a quantum simple harmonic oscillator are 0, hf, 2hf etc and that by the Schroedinger equation, you get E(n)=(n+1/2) hbar omega, but I can't explain why each of these give different answers. A quick google didn't bring up anything not password protected, and I don't have my textbooks with me at the moment. Anything to clear this up would be much appreciated! Many thanks.