the BF showed me a natural phenomenon at a local state park that he calls a vortex. I don't know much on vortexes but this is flippin cool and freaky at the same time!! The pendulum literally hangs from the string at about a 25 degree angle instead of perpendicular to the ground. How wierd is that?! I think there is some iron oar there, but the BF is convensed it is a vortex...a mighty powerful one at that.