The experiment. It is a necessary step to get a truth. In magnetic-time relations. It is like that too. There was a reverse magnetic area near Hami city in xingjiang China(ÖÐ¹úÐÂ½®¹þÃÜ»ÆÉ½Í_Äø¿ó) In this area, the magnetic direction reverse 180 degree. Naturely, it is useful for magnetic time relation experiment. If you have some interest about that to do something. I hope you get your way in this naturely area. Sorry, as the deposits under that ground, it isn't long in time perhaps.