Greg Moshos, age 12, of Lancaster, Pennsylvania, for his question:

What causes the force of magnetism?

The astonishing force of magnetism was recognized by the ancient Greeks. For ages, small natural magnets were regarded as novelty toys and later man learned to create them. But the force of magnetism was a mystery until the 19th century and some of its mysteries are still unsolved.

Mankind learned how to use electrical power before he grasped the true nature of electricity. The Chinese learned to use slivers of magnet centuries before scientists grasped the nature of magnetic force. The first glimmerings of understanding came in the 19th century, when the best brains were busy sorting and studying the various atoms. These researchers learned that each atom contains infinitesimal allotments of both electrical and magnetic energies. Like large magnets, each atom is a dipole with two opposite magnetic poles.

It seemed logical to relate this bit of information to magnetic force on a grand scale. Certain 19th century scientists suggested that the force in a large magnet occurs when all its little magnetic atoms are lined up in the same direction. This would mean that all the north poles of the zillions of metallic atoms were arranged to point the same way, with their south poles, naturally, pointing the other way. It was believed that the combined teamwork of this magnetic energy caused the strange force that reaches out beyond a solid magnet and surrounds it with the looping lines of its invisible force field.

This theory was a start in the right direction. But later investigations proved it to be an oversimplification of the facts. We now know that magnetic force is indeed caused by the dipole energy of zillions of tiny atoms. But the teamwork that provides the magnetic force is parceled out in sections.

These colony units are called "domains." There may be 1000 million million atoms in a domain    the figure one with a tail of 15 zeros. The poles of most of these atoms are aligned in the same direction. The average domain may be only as wide as a pinhead, but the energy of all the tiny teammates pulling in the same direction does create a small measure of magnetic force. A small magnet contains a vast number of these organized domains. When most of the domains are aligned in the same north south direction, their teamwork  divides enough energy to reach o   and surround the metal with an invisible magnetic force field. Heat or hammering blows tend to weaken the force of a magnet by jostling the domains out of alignment. When they point in different directions, the teams of atoms pull against each other and the magnet loses its magic.

The basis of magnetic force is within the tiny atom itself. Its dipole nature was not explained until the 20th century. Its magnetic energy is provided by the tiny electron particles that orbit the atomic nucleus. In a magnet, the swarming electrons in each domain are spinning at their fantastic speeds in the same direction. They are aligned with their orbits parallel to each other. This orderly drill formation provides the energy in each domain, and countless parallel domains combine their teamwork to endow a magnet with its quota of magical magnetism.

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