Magnetism is an invisible force that comes from objects called magnets that can push or pull other objects. The area around the magnet is called the magnetic field. A magnet has two points, called a north pole and a south pole, where the magnetism is strongest. When two magnets are placed pole to pole, a force acts between them. A north and south pole pull each other. This is called attraction. Two north poles or two south poles push each other away. This is called repulsion. When placed within a magnetic field, some materials turn into magnets themselves, sometimes briefly or sometimes permanently. These materials are then attracted or repulsed by a magnet. These materials are magnetic. Iron and some other metals are examples. The Earth itself acts like a giant magnet with a magnetic field and two magnetic poles. These poles are found near the Earth’s geographical north and south poles. Scientists think the Earth’s magnetism is caused by the movement of molten iron at the Earth’s core. A compass is a navigational device that uses a small magnet called a needle. The needle is attracted and repulsed by Earth’s magnetism. The needle moves so that one end points to Earth’s north pole and the other end points to Earth’s south pole. You can make your own compass by rubbing a sewing needle on a magnet, then letting it float in water. If the sewing needle is made of steel, it will stay permanently magnetized. Did You Know? The rocky mineral magnetite, which contains iron, is naturally magnetic. Early sailors used magnetite tied to and hung from a string as a magnetic compass. attraction repulsion A maglev train, or magnetic levitation train, hovers above the track, supported by a strong force of repulsion between magnets on the train and the track. Other magnets are attracted to the train and pull it along the track.
