>It's a question of relative strengths. The >earth's magnetic field is really very weak while >the forces holding the earth together are >enormous.
>Roger

This what Joe Kirschvink http://www.gps.caltech.edu/users/jkirschvink/ said was the problem with humans and being able to pick up these very weak fields. He did mention that he thought it was possible that very early man had the capability but that it was rarely used and hence lost.
Now...Dr. Jon Dobson http://www.pd.uwa.edu.au/~dobson/Jon.html shared a whole bunch of his research papers with me, as he was interested in the possibility of some folks with iron overload, or even with excessive magnetite to be ultra senstive to small changes in the EM field. Jons work carried him in that direction... and he did find what he considered meaningful quantities of magnetite in the brain, however his work stopped at that point. He did say that he thought it still possible, but the one thing they never came upon was the mechanism.
In some of his research he noticed a "pooling" of magnetite near the adrenal gland. This perked my ears, as most of what I consider sensitivity is in my nervous system and affects my adrenaline..So this might answer the question as to what to look for in sensitivity to those long wave changes.

• Pinpoint