Who can help me call BS on the physics of something I just watched on TV. Ok let me clarify that statement, of course 90% + of what's on TV is BS but this particular show is a documentary style that so far seemed reasonably well grounded in fact (though at times somewhat contrived). The show is called "man versus wild" and it's a survival style documentary where this ex-commando style guy gets dropped by helicopter into some remote wilderness and demonstrates various survival skills as he makes his way back to civilization, usually over several days. In this weeks episode he was hiking out of some remote canyon in Mexico and at one point he camped overnight in a cave that had signs of previously being used as a campsite by native Indians (and possibly others). He searched around for anything useful for survival and found a small piece of steel wire. Ok that part was probably contrived but I don't care about that. What does concern me is what he did next. He wanted to make a simple compass by magnetizing the wire and placing it on a floating leaf in a very still puddle of water. Ok no problems with that I've done it many times before myself and it works as expected. But get this part, he magnetized the wire by rubbing it vigorously against the hair on the side of his head. I know of no physical explanation of how this would work? Though it's not my area I've heard there is some bio-magnetism in the human body, but surely not enough to magnetize a wire by rubbing it on the side of your head. Can anyone explain this one or is it just plain BS.