Finally, I give the blow by blow account of making the Einstein de Hass pendulum, which is one of the three practical project challenges out there. The ferrite core twists to the beat of a magnetic field that flips trillions of electron gyros that then kicks the ferrite on its way. I really wasn't expecting such instant success, I am used to months chasing phantom low signal and sneaking up on some really obscure effects. You may find it interesting to hear the struggle with simple things that were one by one won over to the cause. Note to self: don't hang your glasses next to your lapel mike while walking. MP4 recording     MP3 recording -- -- Your browser does not support the audio element.