The velocity of "light" in an imaginary medium

Imagine for a moment, if you will, that you are William of Ockham, and some one has given you the address of this web-site:


You will find no simplification - no attempt, even, at simplification - but rather the opposite, a successful attempt at obfuscation. A photon, we read, is a certain species of particle (we are told that the concept was invented by Herr Einstein, but we are not told whether, and in what respects, one photon may differ from another photon in the way that one grain of sand may differ from another; for that information we must go back to Herr Leibniz). Then in the next paragraph we read that it lacks the essential properties of a particle, "mass" for example - but is affected by, and indeed generates, "gravitation"!

But a photon is not a real particle we are told, it is a disturbance, a kind of rustle of Spring, a temporal oscillation. But we are in the same breath assured there is no ether to be disturbed.

Then in the paragraph after that a photon becomes a "radiation" which (not being a particle in that sense) does not move at all but merely "beams" in "rays" [see footnote].

And the remainder of the article descends into mathematical tautology scribbled by bewildered Northern Americans. As I said, no clarification. The wilder and essentially lawless fringes of reification imagined as "forces" of Nature. What nonsense it all is!

So, back to Dr. Johnson:
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SPEED. n. s. [spoed, Dutch.]

Quickness; celerity.

Earth receives
As tribute, such a sumless journey brought
Of incorporeal speed, her warmth and light;
Speed! to describe whose swiftness number fails.
- Milton.

We observe the horse's patient service at the plough, his speed upon the highway, his docibleness, and desire of glory.
- More.
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VELOCITY. n.s. [velocitas, Latin]

Speed; swiftness; quick motion.

Had the velocities of the several planets been greater or less than they are now, at the same distances from the sun; or had their distances from the sun, or the quantity of the sun's matter, and consequently his attractive power, been greater or less than they are now, with the same velocities; they would not have revolved in concentric circles, but moved in hyperbolas, or parabolas, or in ellipses, very eccentric.
- Bentley.
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[We should in particular note there that the "velocity" of something is measured relatively to some other thing.]

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Footnote: The independent word "radio" was unknown until, in 1910, it was without legitimacy derived from "radio-telegraphy" by Mr. de Forest, a Northern American. I recommend that in future if it is used at all it be spelled "radi-o," as for example "B.B.C. Radi-o Four."

All this "photon" business seems to be the modern-day equivalent of jolly old Ptolemy's epicycles. If one is going to discuss the velocity of something one must first have a clear and distinct of what that something is must one not. Perhaps light is neither particle, nor vibration, nor beam, nor simple time-lapse; perhaps it is velocity itself made visible. Until it is clearly stated once and for all to be something and not something else we are at liberty to say that it is anything. Clean-limbed Englishmen will have no truck with ambiguity.

In general I find scientists oddly unimaginative. For example, it is only in the past twenty years or so that they seem to have become aware of the possibility of "dark matter." Before that, it was ignored because they could not see it!