WHAT MAKES MATERIALS MAGNETIC? Magnetism comes from the constant movement of charged electrons in atoms. As electrons swirl around an atom, they create an electrical current, and whenever electricity moves in a current, a magnetic field is created. So magnetism is a force between electric currents: two currents flowing in the same direction attract, while those pulling in opposite directions repel. The reason some materials are magnetic, while others are not, has to do with how the electrons are ordered. A magnet is an object made of magnetic materials; naturally occurring magnets are known as lodestones. Every magnet has at least one north pole and one south pole. In fact, if you take a bar magnet and break it into two pieces, each of the smaller pieces will still have a north and south pole. The Earth itself is a giant magnet with a north and south pole, which is why a magnetic compass's needle always points north/south.
WHAT ARE STENTS? A stent is essentially a small piece of metal "scaffolding" that pushes arterial plaque to the side and provides a framework to keep the blood vessel open so that the blood can flow freely through it. Stents have been used for many years to clear blockages in the arteries of the heart and neck.
The American Physical Society, AVS, the Science and Technology Society and the Materials Research Society contributed to the information contained in the TV portion of this report.