On this page we will examine in more detail how Maxwell came to his physical conclusions about electromagnetism and light, many of which are supported by the analysis of this site, and how and where he went wrong.
The Maxwell model
Towards the start of his famous ‘Treatise on Electricity and Magnetism’, Maxwell wrote:
‘The theory I propose assumes that in that space there is matter in motion by which the observed electromagnetic phenomena are produced.’i
He identified, in the 1860s, ‘reason to believe, from the phenomena of heat and light, that there is an ethereal medium filling space and permeating bodies, capable of being set in motion and of transmitting that motion from one part to another, and of communicating that motion to gross matter so as to heat it and affect it in various ways.’ii
‘We may therefore receive,’ he concluded later, ‘as a datum derived from a branch of science independent of that with which we have to deal, the existence of a pervading medium, of small but real density, capable of being set in motion, and of transmitting motion from one part to another with great, but not infinite, velocity.’iii
‘It appears therefore’, reasoned Maxwell, ‘that certain phenomena in electricity and magnetism lead to the same conclusion as those of optics, namely, that there is an ethereal medium pervading all bodies, and modified only in degree by their presence; that the parts of this medium are capable of being set in motion by electric currents and magnets; that this force is communicated from one part of the medium to another by the forces arising from the connections of those parts; that under the action of these forces there is a certain yielding depending on the elasticity of those connections; and that therefore energy in two different forms may exist in the medium, the one form being the actual energy of motion of its parts, and the other being the potential energy stored up in its connections, in virtue of their elasticity.’iv
This allowed Maxwell to conclude: ‘Now Professor W. Thomson has pointed out that no distribution of forces acting between the parts of a medium whose only motion is that of the luminous vibrations, is sufficient to account for the phenomena, but that we must admit the existence of a motion in the medium depending on the magnetisation, in addition to the vibratory motion which constitutes light.
It is true that the rotation by magnetism of the plane of polarization has been observed only in media of considerable density; but the properties of the magnetic field are not so much altered by the substitution of one medium for another, or for a vacuum, as to allow us to suppose that the dense medium does anything more than merely modify the motion of the ether. We have therefore warrantable grounds for inquiring whether there may not be a motion of the ethereal medium going on wherever magnetic effects are observed, and we have some reason to suppose that this motion is one of rotation, having the direction of the magnetic force as its axis.’v
The ‘elasticity’ that Maxwell identified is the concept that caused all the problems then and perhaps now. It was the breakthrough in the mathematical modelling of electromagnetism, creating the ‘displacement current’ term that made the whole thing work, but it destroyed the aether as a background for physical processes.
It seemed to require a solid ether (his spelling) and fitted with his calculations of transverse vibratory motion that he identified as light. And a solid aether is incompatible with the fluidic medium that Maxwell had described, detailed and required up to that point. Maxwell, one of the greatest minds of his day, had constructed a theoretical aether that simply didn’t work.
It is this contradiction that killed the aether, legitimated the principle of relativity and opened the door to a disastrous century of abysmally poor science.
Maxwell’s failure was readily recognised. This encouraged Hertz to state, somewhat baldly, that ‘Maxwell’s theory is Maxwell’s system of equations’vi, dismissing the painfully detailed reasoning that created them.
And its resolution
As far as I am aware, Maxwell did not revisit that contradiction. It is only when the nature of the medium is made central to our enquiry that we identify that both elasticity and transverse vibrations can indeed occur in a fluid if they are seen purely in relation to rotational structures (vortices). This frees us to accept a fluidic aether together with much of Maxwell’s rotational analysis, and to suggest pressure waves, longitudinal waves for light.
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i. James Clerk Maxwell (1831 – 1879), Treatise on Electricity and Magnetism (Clarendon Press, Macmillan & Co), 1873, p34, point (3). Also found in: A Dynamical Theory of the Magnetic Field, edited by TF Torrance (Scottish Academic Press, Edinburgh, 1982).
ii. Maxwell, p34, point (4). In his ‘Treatise’, Maxwell brought together ideas from earlier publications.
iii. Maxwell, p34, point (6)
iv. Maxwell, p39, entire point (15)
v. Maxwell, p36, point (8)
vi. Heinrich Hertz, Electric Waves (Macmillan, 1983) page 21