The Machinery of the Universe: Mechanical Conceptions of Physical Phenomena

by A. E. Dolbear

THE ETHER IS NON-MAGNETIC.

A magnetic field manifests itself in a way that implies that the ether structure, if it may be said to have any, is deformed—deformed in such a sense that another magnet in it tends to set itself in the plane of the stress; that is, the magnet is twisted into a new position to accommodate itself to the condition

of the medium about it. The new position is the result of the reaction of the ether upon the magnet and ether pressure acting at right angles to the body that produced the stress. Such an action is so anomalous as to suggest the propriety of modifying the so-called third law of motion, viz., action and reaction are equal and opposite, adding that sometimes action and reaction are at right angles.

There is no condition or property exhibited by the ether itself which shows it to have any such characteristic as attraction, repulsion, or differences in stress, except where its condition is modified by the activities of matter in some way. The ether itself is not attracted or repelled by a magnet; that is, it is not a magnetic body in any such sense as matter in any of its forms is, and therefore cannot properly be called magnetic.

It has been a mechanical puzzle to understand how the vibratory motions called heat could set up light waves in the ether seeing that there is an absence of friction in the latter. In the endeavour to conceive it, the origin of sound-waves has been in mind, where longitudinal air-waves are produced by the vibrations of a sounding body, and molecular impact is the antecedent of the waves. The analogy does not apply. The following exposition may be helpful in grasping the idea of such transformation and change of energy from matter to the ether.

Consider a straight bar permanent magnet to be held in the hand. It has its north and south poles and its field, the latter extending in every direction to an indefinite distance. The field is to be considered as ether stress of such a sort as to tend to set other magnets in it in new positions. If at a distance of ten feet there were a delicately-poised magnet needle, every change in the position of the magnet held in the hand would bring about a change in the position of the needle. If the position of the hand magnet were completely reversed, so the south pole faced where the north pole faced before, the field would have been completely reversed, and the poised needle would have been pushed by the field into an opposite position. If the needle were a hundred feet away, the change would have been the same except in amount. The same might be said if the two were a mile apart, or the distance of the moon or any other distance, for there is no limit to an ether magnetic field. Suppose the hand magnet to have its direction completely reversed once in a second. The whole field, and the direction of the stress, would necessarily be reversed as often. But this kind of change in stress is known by experiment to travel with the speed of light, 186,000 miles a second; the disturbance due to the change of position of the magnet will therefore be felt in some degree

throughout space. In a second and a third of a second it will have reached the moon, and a magnet there will be in some measure affected by it. If there were an observer there with a delicate-enough magnet, he could be witness to its changes once a second for the same reason one in the room could. The only difference would be one of amount of swing. It is therefore theoretically possible to signal to the moon with a swinging magnet. Suppose again that the magnet should be swung twice a second, there would be formed two waves, each one half as long as the first. If it should swing ten times a second, then the waves would be one-tenth of 186,000 miles long. If in some mechanical way it could be rotated 186,000 times a second, the wave would be but one mile long. Artificial ways have been invented for changing this magnet field as many as 100 million times a second, and the corresponding wave is less than a foot long. The shape of a magnet does not necessarily make it weaker or stronger as a magnet, but if the poles are near together the magnetic field is denser between them than when they are separated. The ether stress is differently distributed for every change in the relative positions of the poles.

A common U-magnet, if struck, will vibrate like a tuning-fork, and gives out a definite pitch. Its

poles swing towards and away from each other at uniform rates, and the pitch of the magnet will depend upon its size, thickness, and the material it is made of.

Let ten or fifteen ohms of any convenient-sized wire be wound upon the bend of a commercial U-magnet. Let this wire be connected to a telephone in its circuit. When the magnet is made to sound like a tuning-fork, the pitch will be reproduced in the telephone very loudly. If another magnet with a different pitch be allowed to vibrate near the former, the pitch of the vibrating body will be heard in the telephone, and these show that the changing magnetic field reacts upon the quiescent magnet, and compels the latter to vibrate at the same rate. The action is an ether action, the waves are ether waves, but they are relatively very long. If the magnet makes 500 vibrations a second, the waves will be 372 miles long, the number of times 500 is contained in 186,000 miles. Imagine the magnet to become smaller and smaller until it was the size of an atom, the one-fifty-millionth of an inch. Its vibratory rate would be proportionally increased, and changes in its form will still bring about changes in its magnetic field. But its magnetic field is practically limitless, and the number of vibrations per second is to be reckoned as millions of millions; the waves are

correspondingly short, small fractions of an inch. When they are as short as the one-thirty-seven-thousandth of an inch, they are capable of affecting the retina of the eye, and then are said to be visible as red light. If the vibratory rate be still higher, and the corresponding waves be no more than one-sixty-thousandth of an inch long, they affect the retina as violet light, and between these limits there are all the waves that produce a complete spectrum. The atoms, then, shake the ether in this way because they all have a magnetic hold upon the ether, so that any disturbance of their own magnetism, such as necessarily comes when they collide, reacts upon the ether for the same reason that a large magnet acts thus upon it when its poles approach and recede from each other. It is not a phenomenon of mechanical impact or frictional resistance, since neither are possible in the ether.