Carol Johnson, age 10, of Omaha, Nebraska, for her question:

What makes a magnet magnetic?

The magic within a magnet may be a cousin of the magic in an electric current. We say may be, because the problem still seems to be in the study stage. The force of magnetism has puzzled the best brains for many centuries. We still do not know all there is to be known about it, nor do we know all there is to know about electricity.

We know that electric current is caused by tiny electrons. Electrons are small particles of electricity. They cause an electric current in a wire when they all march in the same direction, like soldiers on parade. Strange to say, an electric current acts like a magnet. This electric current magnet is certainly caused by countless electrons on parade.

The parade ground is a copper wire, a double copper wire which runs to and from a generator. The double wire is called the circuit. The generator provides the power voltage which keeps the electrons on parades. The electrons‑in the magnet work without a generator. They have no copper wire along which to parade. They use another trick to keep themselves on parade.

Electrons belong to atoms. About two billion atoms have room to dance on the head of a pin. And each electron is only a tiny, tiny part of an atom. Electrons, however, are full of energy and very busy. They whirl around the core, or nucleus of an atom like planets going around the sun. Their parade ground is round, or oval.

There are countless atoms in a small magnet and far more electrons. The magnetic force is caused by those whirling electrons. There are, of course, countless electrons in a bar of metal which is not necessarily a magnet. These electrons are also whirling around in the atoms. However, in the non‑magnetic metal, about half the electrons whirl in one direction and half in the opposite direction. The little electric currents they make cancel each other out.

In a magnet, the majority of the electrons are whirling in the same direction. More than half of them are pulling in the same direction. This causes a current of force to whiz through the magnet.

We can make magnets only from certain substances. Iron, steel, cobalt and nickel are good materials for making magnets. Mixtures, or alloys, of certain metals make good magnets. In these materials more than half the electrons already are traveling in one direction. They need only to be lined up to create the magnetic force, This happens when the metal comes into a magnetic field from another magnet.

The magnetic field reaches out from the solid magnet in invisible lines of force. This force, or power gives the magnet its magic. The modern idea is that this magnetic force is caused by busy electrons, the same little fellows that give us electricity. Each one whirling around in an atom creates a tiny electric breeze. When trillions of them whirl in the same direction, the breezes form magnetic force.