Reference: Essays on Substance
Space and Medium of Light
A question was asked:
“Why is space not considered to be the medium of light when its properties determine the speed of light?”
In 1873, Maxwell’s effort to determine the relationship between electromagnetic theories and the Newton’s theory of motion resulted in the amazing discovery that light was an electromagnetic phenomenon.
Maxwell wrote in the preface to the first edition of his book A TREATISE ON ELECTRICITY AND MAGNETISM:
“The most important aspect of any phenomenon from a mathematical point of view is that of a measurable quantity… I have therefore thought that a treatise would be useful which should have for its principal object to take up the whole subject in a methodical manner, and which should also indicate how each part of the subject is brought within the reach of methods of verification by actual measurement… before I began the study of electricity I resolved to read no mathematics on the subject till I had first read through Faraday’s Experimental Researches in Electricity.
“As I proceeded with the study of Faraday, I perceived that his method of conceiving the phenomena was also a mathematical one, though not exhibited in the conventional form of mathematical symbols. I also found that these methods were capable of being expressed in the ordinary mathematical forms, and thus compared with those of the professed mathematicians.
“For instance, Faraday, in his mind’s eye, saw lines of force traversing all space where the mathematicians saw centres of force attracting at a distance: Faraday saw a medium where they saw nothing but distance: Faraday sought the seat of the phenomena in real actions going on in the medium, they were satisfied that they had found it in a power of action at a distance impressed on the electric fluids.
“When I had translated what I considered to be Faraday’s ideas into a mathematical form, I found that in general the results of the two methods coincided, so that the same phenomena were accounted for, and the same laws of action deduced by both methods, but that Faraday’s methods resembled those in which we begin with the whole and arrive at the parts by analysis, while the ordinary mathematical methods were founded on the principle of beginning with the parts and building up the whole by synthesis.”
It is interesting to note that Maxwell finds Faraday’s “lines of force traversing all space” to be mathematically equivalent to other mathematician’s “centers of force attracting at a distance”. Maxwell notes, “Faraday saw a medium where they [other mathematicians] saw nothing but distance”.
Space is not “nothing” because it has the electromagnetic properties of permittivity and permeability. These properties of space determine the speed of light per Maxwell’s equations. This fact alone should be enough to convince that space is the medium through which light travels.
Why is space not considered to be the medium of light? Why can’t the mysterious ether be space itself?
This thinking led to the theory of Substance.
.
