American Journal of Physics
Adiabatic Invariance in Simple Harmonic Motion
Leonard Parker
Abstract
We show, in an elementary but apparently new way, that the ratio of the energy to the frequency of a simple harmonic oscillator is an adiabatic invariant. The adiabatic invariance is a consequence of the conservation of angular momentum in the two-dimensional system, of which the one-dimensional harmonic oscillator is the projection. We also briefly discuss the connection between the quantization of angular momentum and the quantization of the oscillator's energy.