Magnet

Karen Luper

1. The Void
When the number zero had not been invented, when quantities themselves were represented by lines or by pebbles arranged in patterns like those found on dice or dominoes . . . when the composition of matter was thought variously to be based in water, air, or fire as the primary substance from which all things arise and to which they return, and, later, to consist of something else entirely, namely “atoms” of different sizes and shapes that come together “by chance” (for this idea, that matter is formed “by chance,” Dante has us visit Democritus in the first circle of hell) . . . Lucretius, representing Epicurus (of whose extensive writing little has survived, and who might have been forgotten had he not been championed two centuries later, in 55 BC) went to some trouble to lay out the nature of (among other things) the void, which is essential to an early understanding of how the magnet draws iron to itself.

(These “whens” are, in fact, many “whens,” taking place over hundreds, even thousands of years; Pythagoras, around 530 BC, was the first to name the void and thought it was air; a hundred years later, Parmenides was insisting that there could be no identity assigned to nothing.)

Lucretius tells us, because it couldn’t be taken for granted:

. . . there doth exist pure space, or void . . .
for if there were no void, no thing could move . . .
since naught would be the first to yield its place. (Book 1, 338-44)

We must be patient, he continues, and assemble the facts with great care in order to arrive at a logical explanation of the magnet’s action. Illustrating the inevitability of the void from many angles—water finding its way through rock, sustenance through the passages of the body and through the roots of plants, out to leaves and fruits . . . none of this movement is possible without a pathway of emptiness, of void . . . he finally takes as example the relative densities of different kinds of matter, wondering:

Why is it that we see one thing outweigh
Another, though its bulk is nowhit more?
For if an equal store of matter lay
In ball of wool and lead, ’twere reasonable
That they should weigh the same, since ’tis the task
Of body to press downward every thing,
Whereas to nature of the void no weight
Is given. That body, then, of equal bulk,
But which is seen to be of lesser weight
Doth clearly show it holdeth in itself
The more of void, and in manner opposite
The heavier doth attest it harboreth more
Of body, less of space. (Book 1, 360-72)

Once the existence of the void and matter (also called “body,” “atoms,” “first beginnings”) is established beyond a doubt (there is struggle even at this late date, with the concept itself and with language that was being stretched to accommodate new ideas—“the far too slender store / of this my country’s tongue / doth hold me back”), Lucretius describes how all things, by virtue of their characteristic compositions of body and void, give off particles—visible, or scented, or audible, or endowed with taste . . . all, however, endowed with the ability to touch, for it is, in the Epicurean system, through physical contact alone that all the senses function. These particles find their way into appropriate passages (some can pass through stone walls—particles of sound or heat, for example—others, like the “idols,” or streaming particle-images associated with sight, require unimpeded air through which to travel) and into the “range of varied senses” in animals and humans.

Lucretius recognizes that sense impressions vary, from human to human and human to animal (“while mud to us doth seem the foulest filth, this very thing is seen / to be to swine a pleasure, that therein / they wallow without stint, nor e’re are filled”), and he makes the essential point that giving off and taking in particles requires a partnership of sorts—the receiver must contain appropriate passages through which the sent particles can enter. Which is why sun hardens earth but softens ice, and the magnet attracts iron but not wood.

The magnet, then, by virtue of its own makeup, emits

. . . a draft, which by its thrust doth part the tract of air [between the stone and iron]
And when this space between is emptied, and much room midway is changed
To void, straightway will forward leap a throng
Of first beginnings of the iron.” (Book 6, lines 1011-16)

So the magnet creates something like a wake around itself, of emptiness, of void, and into that wake, by virtue of its own nature and in response to the void, rush particles (the “first beginnings”) of iron.

More recent understanding has the axes of electrons spinning in the outer orbitals of iron atoms aligned in domains, like schools of barracuda, with each other and with the magnetic core of the earth, and that this alignment creates passages through which the loosely bound electrons of some metals can move, into which they are drawn or attracted.

It is said that if a bar of unmagnetized iron (for not all iron is a magnet) is placed in a strong magnetic field and hammered gently to jar or jolt the atoms in their crystalline structure, and a stethoscope is placed against the iron bar, one can hear the billions of atoms aligning themselves in domains. Clicking.

“A stone dark and heavy, of an iron colour and livid, mingled with indigo or sky-blue, so that it is like unto polished iron tarnished by foul air: such a stone I have never seen without great power,” wrote the crusader Petrus Peregrinus of Maricourt, to his soldier friend Sygerus of Foncaucourt in 1269, “Secure one of this description if you can.”

A stone dark and heavy that drew the iron tip of a shepherd’s staff, or an iron nail in a boot, when boots came to include nails in their making . . . or a tool of iron, a blade or an ax head, laid on the ground and strangely hard to pick up . . . or that drew even other stones, chips of itself, as a magnet passed by a child over a dry river bed will catch whiskers of iron until it bristles with them. Shepherds, who might have had time during warm afternoons for such observations, make a pleasing beginning. What persisted through speculations of its discovery was that the stone was plentiful in the ancient province of Magnesia, off the Aegean coast; or, conversely, that the shepherd who found it was named Magnes.

It began with the observation of attraction, of stone for stone or stone for iron. By the time of Thales, around 650 BC, these properties had been demonstrated and documented: a piece of stone could hold a ring of iron to itself and to that ring another could be attached “by invisible forces,” writes Lucretius, until a long chain hung suspended from the stone. Although repulsion had been observed (iron filings in a bronze dish jumping in frenzy when a lodestone was held underneath), the discovery of polarity—that one end or side of a stone attracts or repels the end or side of another, and then of that polarity’s relationship to the stars in the sky and to the cardinal directions on earth, came later.

In China, by 400 BC, the stone was being carved into the graceful shape of a ladle which, when placed on a surface of polished wood and allowed to turn, would align itself with the dipper in the heavens. This instrument was used to direct the placement of doors, windows, and furnishings in a house in a way that was pleasing to the gods, and there is evidence that the Olmec, as early as 1400 BC, used thin, carved bars of lodestone, suspended so that they could turn, to direct the placement of graves in burial sites.

“Have the stone rounded with a tool with which crystals and other stones are rounded,” instructs Petrus Peregrinus, and “afterwards let a bar of iron, slender after the fashion of a needle, be placed over the stone, and along the iron needle let a line be marked out dividing the stone along the middle. . . . ” Careful repetition of this exercise at several positions of the sphere results in a series of lines that converge at the poles.

Next, he directs the friend to whom his letter is addressed to place the stone (rounded and with its poles marked) into a wooden vessel, “then place that vessel, with the stone within it, in another vessel, a large one, filled with water, so that the stone may be in the first vessel like a sailor in a ship.” In this manner may be observed two things: one, that another stone, similarly carved and with its poles marked, when held out to the floating stone, will either draw the floating stone to itself or drive it away, depending on which pole is offered to which; and two, that taken out of doors, the stone in the boat “will turn its small vessel until the North pole stands in the direction of the Northern part of the sky, and the South pole in the direction of the Southern part. And if this stone be moved aside a thousand times, a thousand times will it return to its place by direction of God.” (A different translation reads: “as if by instinct.”)

 

2. Anima, Animate
To Thales of Miletus, who flourished in 650 BC, are attributed three ideas: one, that the primary substance from which all things are derived and to which they return, is water; two, that all things are full of gods; and three, that the magnet has a soul because it can move iron. Thales does not seem to have rejected the divine, though it’s true that these early thinkers were seeking to dispel the power of superstition in their lives, as represented by the deceitful, capricious, vengeful gods of myth.

The magnet has a soul because it can move iron.

Epicurus was unswerving in his materialism; everything, in his view, was composed of atoms and void, in characteristic proportions, from all that is perceptible in the physical world to the workings of the five senses and to actions of memory and will. Even the soul, even the gods. Atoms and void, only. Democritus, around 430 BC, had proposed, in addition to the various hooked or jagged, rough, or smooth or slippery shapes of atoms (all with the purpose of cohering with or moving among other atoms) the existence of “soul-atoms,” smoother and rounder and smaller than any other kind of atom, because they had to fit in everywhere and were responsible for movement in the body. Epicurus took the idea of tiny atoms to its limit, relegating the gods to outer space from where they might emit particles so fine as to be perceptible to humans only in their dreams but otherwise having no interest or influence in their worldly lives. For his more crucial point, we meet him in the sixth circle of hell, “with all his friends, who say the soul dies with the body.”

Only five senses: to account for everything. (This idea, unlike concepts of soul and void, didn’t need to be argued.)

What of a single chord in Schubert’s Piano Sonata in A that sounds like breaking glass but is really the sound of a heart breaking?

What of a rabbit flung bloody against the bricks (exulting dogs race by) at the moment when a motorcycle hits a cow on a Mexican road and the rider lies smashed on the pavement, and she who lifts the broken rabbit to lay it under a juniper knows of the other death, knows . . . something.

What of the magnet in the cells of pigeon brains that allows them to find their way, unerring, over thousands of miles.

What of plants, and what of animals? What of rocks, and water? Their souls.

What of dreams.

What of Earth’s iron core, molten and swirling, solid in the center, where unimaginable pressure overcomes unimaginable heat: solid, and a magnet.

 

Work cited
Lucretius. Trans. by Charles E. Bennett. On the Nature of Things. New York: Walter J. Black, 1946.

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