Showing an adiabatic invariance with a macroscopic harmonic oscillator is v. difficult, because of dissipation. For another reason I’ve been changing the effective g of an E-M clock driven pendulum. The magnet attached to the bottom of the bob completes the clock drive and serves to change the effective g using a solenoid waxed beneath the sense and drive coils of the Fedchenko type drive. After many trials, I thought, perhaps a driven pendulum WRT adiabatic invariance would be the same as a dissipation-less pendulum. So I tried changing the “g” using an RC supply to the solenoid (L ~ 190 mH) The measured TC is ~ 93s (R ~ 2K Ohm; C ~ 16K microFd calc’d 32s). Nada! Tho the g increase is ~ 35% (TC ~ 96s and the period is ~ 1s) By a stroke of luck I thought, well, how about the extreme of my previous trials (TC < 1s!). Wow! The product Omega * Amplitude is the same once equilibrium obtained. (W/ and W/O the added g within ~ 1/2%) While the ”supposedly" adiabatic trial has a difference of ~ 5%