The following is a Letter to the Editor of the IEE journal 'Electronics and Power' published in the March, 1967 issue at p. 95.
Dear Sir - R. A. Waldron, in a reply to a previous letter (Jan. 1967 Electronic and Power, p. 22) [1967a], states that he cannot understand my comments about conduction electrons in metals reacting to screen magnetic fields; and he
states that the null result of the Trouton-Noble experiment is only surprising in the light of aether theory.
To clarify the first point, consider electrons in motion in a steady magnetic field. It is well known that they are deflected into a helical path, and always move to produce a magnetomotive force opposing the field. If there are free conduction electrons in random thermal motion in a metal, the metal should, on
electron theory, act as a screen against steady magnetic fields. Quantitatively, the reaction magnetic moment is the kinetic energy of the reacting electrons, calculated from their component velocities normal to the field direction, divided by the magnitude of the resultant field (Aug. 1966 Electronic and Power, p. 288) [1966c]. For example, 1022 electrons per cm3 at 104 cm/s would develop a reaction field of 4000 oersted for a 1 oersted resultant field. A strong applied field would, therefore, be heavily screened by a
good nonferromagnetic metal conductor at room temperature.
The fact that this event does not happen presents an anomaly in magnetic theory. It can be explained by theorising, as I did in the letter mentioned above, that the kinetic energy of the reacting charge maximises, and is, in fact, the magnetic-field energy inside the conductor. Then the density of free electrons
is determined by the magnetic-field strength, in accordance with the thermal-velocity state. Also the reaction effect exactly cancels half the applied field.
To keep our units correct, the actual field produced by any motion of charge has to be doubled, which then explains the observed
gyromagnetic-ratio factor of 2, whether determined from reversing magnetism in a pivotally mounted ferromagnetic rod or from magnetic-resonance experiments; and the explanation requires only orbital motion of charge. Whatever is meant by 'spin' in physical theory is not relevant to the observations. Indeed, spin might be a kind of motion in a minor orbit, but this does not matter.
The Trouton-Noble experiment proved that two charges of opposite polarity, moving in parallel at the same velocity and in any direction relative to the line joining the charges, develop electrodynamic interaction forces only along the line joining the charges. This fact is contrary to the usual electrical engineering teaching about magnetic fields set up by a charge in motion and the forces on a charge in motion in a magnetic field. The experiment was founded on such theories, and a suspended capacitor should have turned about the suspension by an amount proportional to the velocity of the apparatus. It did not turn, proving either
that our laws of electrodynamics were wrong, that the aether could develop a reaction couple on the charges, or that the electrodynamic reference frame or aether moves with the apparatus.
If one ignores the aether, the laws of electrodynamics need modification. The empirical law is presented as equation (2) in an earlier letter (April 1965 Electronics and Power, p. 137) [1965a]. This law is consistent with the null result of the Trouton-Noble experiment and all other
observations. However, as applied between charges in nonparallel motion without an aether to complete the system, Newton's
Third Law of Motion is defied.
To avoid the problem, radiation momentum is added to the momentum of matter to satisfy this law. The system of the charges is thus completed by energy somewhere in space. Such energy is mixed up with energy from millions of other such systems, and surely forms the metric of space-time otherwise known as the aether. The aether is a medium permeating all space. It is primed with energy, and is able to take up the balance forces in electrodynamic interactions. Our difficulty is that there is reluctance in appreciating that energy has been dispersed into the aether for so long that it has become uniformly distributed, and become a medium well worth studying in its own right.
IBM United Kingdom Laboratories
Hursley, Winchester, Hants.
3rd January 1967