Craig Packard, age 13, of Jersey Shore, Pennsylvania, for his question:

Why do magnets have north and south voles?

Magnetism is one of the mighty cosmic forces that hold the universe in shape and govern its moving parts. Its behavior in small natural magnets has mystified mankind since the dawn of history, yet scientists only began to understand haw it works during the last century. Even now, they cannot explain. all its secrets. For example, all known magnets have two opposite poles. But some researchers suspect that a magnet with only one pole just might be a possibility.

So far as we know, the great cosmic forces that span the universe also operate in the invisibly small realm of atoms and molecules. This is true of magnetism, though ft reveals itself only in certain forms of matter. The most common natural magnets are iron, for two reasons. The structure of its basic atom can be modified to reveal itsrA3gnetic properties and iron is our second most plentiful metal.

The secret lies in the electrons that orbit the nuclei of all normal atoms. An electron is a negatively charged particle of matter and as it whirls around its orbital shell it creates a miniature breeze, comparable to an infinitesimal current, like a one

way traffic lane of electrical energy. In most atoms, electrons orbit in various directions, which cancels out the energies of individual traffic lanes. In this state, a substance reveals no outside evidence of magnetism.

However, the traffic inside iron, nickel and other magnetic materials tends to be more orderly. In the average iron atom, the majority of electrons orbit in the same direction. What's more, iron atoms tend to congregate in domains in which most electrons whirl in parallel lanes. Though a domain may contain 1,000 million million atoms, it is no bigger than a pinhead. In a small bar of ordinary iron, the many domains are tilted so that their traffic breezes blow in various directions and cancel each other.

However, they may be aligned by some outside force, such as heat, impact or the field of another magnet. Then uncountable electrons in uncountable domains breeze around in the same direction. Their parallel energies combine and boost the ordinary iron into a magnet. Its force forms a pattern of lines that loop through and outside the solid metal to surround it in an invisible magnetic field. These flux lines of magnetic force loop between the two ends of the solid magnet. We know that they create the north and south poles of a magnet, but scientists can merely guess how they do it.

Magnetic lines mirror the looping orbits of the breezy electrons. Possibly they make a sort of U turn at each end of the solid magnet, creating two opposite swerves in the pattern. But nobody can prove this or any other suggestion. So far as we know, every magnetic field has a north and south pole and each attracts the opposite pole of all other magnets. Two north poles repel each other and so do two south poles. But magnets seem determined to keep their innermost secrets.