Signs

One funny part in the movie signs was the part when Mel Gibson walks into the kids' room and they are in there sitting on the bed with the aluminum foil helmets. Morgan says they are wearing them so that the aliens can't read their minds. I thought it was silly at first but then I remembered something I learned in AP Physics B last year. That idea does have some merit to it, even though what the kids were doing wouldn't have exactly worked. The problem is that the aluminum foil didnt entirely enclose they're brain. If you've ever seen a spy movie, their suitcases are usually made out of a magnetic metal if their is any electronic information inside. That is because if it is totally enclosed there is no magnetic field inside, making it impossible for the information inside to be picked up or intercepted. So if I remember last years lessons correctly: if aliens from the movie signs are trying to to electronically read your mind you can stop them by totally enclosing yourself in a magnetic metal?