Centuries ago, it was discovered that certain types of mineral rock possessed unusual properties of attraction to the metal iron. One particular mineral, called lodestone, or magnetite, is found mentioned in very old historical records (about 2500 years ago in Europe, and much earlier in the Far East) as a subject of curiosity.

Later, it was employed in the aid of navigation, as it was found that a piece of this unusual rock would tend to orient itself in a north-south direction if left free to rotate (suspended on a string or on a float in water). A scientific study undertaken in 1269 by Peter Peregrinus revealed that steel could be similarly “charged” with this unusual property after being rubbed against one of the “poles” of a piece of lodestone.

Unlike electric charges (such as those observed when amber is rubbed against cloth), magnetic objects possessed two poles of opposite effect, denoted “north” and “south” after their self-orientation to the earth. As Peregrinus found, it was impossible to isolate one of these poles by itself by cutting a piece of lodestone in half: each resulting piece possessed its own pair of poles

Magnetism is the force generated by any moving charged particle or charged particles. A magnetic field is the result of the motion of a charged particle or charged particles, and this field is generated in no other way. Any time a charged particle moves, it creates a magnetic field around its path of travel. There are no exceptions that we know of. Magnetism is the phenomena associated with a magnetic field and with its action on other things.

The creation of a magnetic field by a moving charge or moving charges is this fundamental concept that is behind the term electromagnetic force, which is one of the four fundamental forces in the universe. Electricity and magnetism are tied together inextricably because of this.

If enough electrons are moving in a uniform way in a group of atoms, it will give rise to an “external” magnetic field, and we call this a magnetic domain. It could be one atom or, as suggested, a group of them, but the key is the uniform motion of “enough” electrons to create the domain.

This phenomena, that of magnetic domains, appears in ferromagnetic materials like iron. The domains are there. And if we perform some kind of operation to align a gross quantity of these domains, it will permit us to have a magnet.

 

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