Magnetism is one of a few fundamental phenomena in the universe. As we move a magnet slowly toward a metal surface the attraction between the magnetand the metal can suddenly become very great. With a very strong magnet, themagnet and the metal may leap toward each other and be very difficult toseparate. But the strangest effect is felt when two magnets are moved closetogether. Sometimes we feel the attraction, and sometimes there is an evenstranger repulsion. When two ends of the magnets repel each other, it almostfeels as if there is something between the magnets, pushing them apart. If weslowly move the repelling ends together, that mysterious repulsion gets strongerand can even push the magnets sideways rather than allow the magnets to touch.There is a force on the magnets, even though their surfaces never touch. This wascalled “action at a distance” in the 1600s and was a very unsettling to manyphysicists including Newton.