K try it yourself make yourself a pendulum or buy one and go to your nearest stone circle and try it out see how it swings see how it sparks but don't say i did not warn you if you get a shock!!!
Snap
buy one and go to your nearest stone circle and try it out see how it swings
Tell you what, next time you go take two. Stick one on a stick and stick the stick in the ground and see if it swings the same as the one in your hand.