Light Velocity Obeys Galilean Principle of Relativity

Scientific Paper
Title	Light Velocity Obeys Galilean Principle of Relativity
Read in full	Link to paper
Author(s)	Qing Zeng
Keywords	light velocity, radiation, vector, vector superposition principle, Galilean principle of relativity
Published	2010
No. of pages	10

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Abstract

Article 1 and article 6 point out that principle of constancy of the light velocity is deficient. The conclusion of this paper is that light velocity has superposition feature: in the vacuum, light wave has no oscillating medium to propagate, and the mass of light field is zero, motion of field does not need the action of force, so the motion of light is a radiation, and it is a vector c₀ which is relative to the radiation velocity of light source, this is a relative velocity which is relative to the radiation source, but not the absolute velocity, and it obeys superposition principle of velocity vector, when the relative velocity v exists between light source and observer, the relative light velocity that observer measures is c = c₀ + v, and such conclusion indicates: light velocity obeys Galilean principle of relativity.

Overview

Prof. Zeng Qingping of the Air Force Radar Academy of the Chinese People's Liberation Army argues here for an emission (ballistic) theory of light: the vacuum speed c₀ is a velocity relative to the emitting source, so that an observer in relative motion v measures the vector sum c = c₀ + v. The paper is part of a long series by the same author, listed in his references, attacking Maxwell's electromagnetic theory, the Lorentz transformation and relativistic mass in mass spectrometers.

The argument is built from what Zeng calls the "rigidity" of field waves. Because a light wave has no oscillating medium and "the mass of light field is zero," it is a pure radiation and cannot be compressed, dragged or left behind. From this he draws two consequences: longitudinal rigidity — the wavelength is fixed by the source frequency, λ = c₀/f, and never changes with source motion — and horizontal (transverse) rigidity — an emitted beam is carried sideways with its source "like a rigid stick," never being blown backward. The departure from the mainstream is direct: he rejects both the ether and the constancy of c, keeping instead Galilean velocity addition for light. His practical warrant is radar engineering, where, he says, the classical Doppler relation Δf = v/λ is what reconnaissance receivers actually measure.

The argument

Objection to the relativistic Doppler treatment

Zeng opens by claiming an inconsistency in the relativistic account. If a stationary source of wavelength λ is observed by a measurer moving at v, and the measured light speed is still c₀, then from the identity f′λ′ = c₀ "frequency deviation does not exist." He regards relativity's derivation of a Doppler shift by adding "period = time that light source moves + time that light wave propagates" as a patch: the λ′ it produces conflicts with relativity's own length-contraction λ′, and the period conflicts with its own T′. His own account is simpler: λ is rigid, c varies, and the shift is

f = (c₀ ± v)/λ = f₀ ± v/λ,

with the last term the Doppler frequency f_d, which he says a great deal of military reconnaissance equipment confirms.

Longitudinal rigidity

The evidence offered is a sequence of thought experiments about fields carried by moving sources. A magnet on a train carries its field lines with it; the pattern does not flatten into a disc, and the Earth's own motion does not distort its magnetic field. A time-varying source I dl radiating B(r) = K(t) on the ground produces the same B(r) on a moving train, with r measured from the source and "not the distance to the railway station." A triangular or sinusoidal current pulse puts its wave crest at the same distance from the source whether the source is at rest or moving. Hence, he concludes, crest-to-crest spacing is unaffected by source motion: the wavelength is rigid.

He contrasts this with mechanical waves. Sound and water waves propagate by force acting on an oscillating medium, so a moving source compresses the medium at the crest and the wavelength changes. Field waves have no medium and no compressive force, so λ = c₀/f is fixed once the frequency is fixed. His everyday illustrations: a fluorescent lamp on the moving Earth emits the same wavelength east and west; a "laser bullet will not be blocked because laser gun moves forward, and it will not stay in the laser-bore"; an automobile headlamp is not dragged back by ether; and airborne radar waveguides, whose spacings are cut in wavelengths, would fail if motion compressed the wavelength.

Transverse rigidity and the denial of the ether

The same reasoning is applied sideways. The field of a capacitor or an inductor moves with its source; the iron-filing ring of an Ampère's-law demonstration is still a ring on a high-speed train. Therefore a beam launched perpendicular to the motion is carried along with the emitter, as a stage laser sweeps with its projector. Zeng's figure 7 contrasts this (a) with the ether-dragged alternative (b), and he takes the absence of any backward drift as evidence that "Ether does not exist" — the same conclusion he draws from Michelson–Morley and from Trouton–Noble. He allows that a real medium does drag light, citing the Fizeau experiment as the case where "longitudinal rigidity will also be dragged by medium."

The superposition construction

The quantitative core is figure 8. A laser on a train moving at v fires perpendicular to the track at t = 0. The passenger sees only the longitudinal component; the ground observer sees components c_y = c₀ and c_x = v, so

c = c₀j + v''i (1), c = c₀ + v (2).

The transit time to a target at distance d is t = d/c₀ (longitudinal rigidity); the sideways displacement is a′b′ = vt (transverse rigidity); the slant path is ob′ = t√(c₀² + v²). The resultant speed is therefore √(c₀² + v²), tilted from the perpendicular by α = arcsin(v/√(c₀² + v²)).

For a general launch angle θ measured from the perpendicular to the track (figure 9), the parallelogram rule gives

c = √(c₀² + v² + 2c₀v sinθ) (3).

The conclusion restates the abstract: the radiation speed c₀ is relative to the source, not absolute, and light "obeys Galilean principle of relativity."

Assessment

The paper's virtues are its directness and its concreteness. Zeng states a single, falsifiable proposition — c = c₀ + v — and works it out geometrically rather than hiding behind formalism. He is also right about a point often blurred in textbooks: the transverse case does produce a tilted beam in the ground frame, and both his theory and relativity agree that the beam is carried sideways. The distinction between a bound field that travels with its source and a wave that has left it is exactly the right place to look, even though he resolves it the wrong way.

The vector algebra is correct as far as it goes. The slant path t√(c₀²+v²), the aberration angle arcsin(v/√(c₀²+v²)) and equation (3) all follow from the stated premises without error. There is, however, one clear internal slip: immediately after equation (3) Zeng writes "if θ = 90°, there is c = c₀ + v, which is the case in figure 8." With θ measured from the perpendicular, as he defines it, θ = 90° is the beam fired along the track, whereas figure 8 is the θ = 0 case giving √(c₀² + v²). The two results differ at first order in v/c; the sentence attaches the wrong figure to the formula.

The central inference — from the rigidity of a magnet's field to the rigidity of a radiated beam — is asserted, not derived. A magnetostatic field is a bound near field, permanently attached to its source; a radiated wave is a disturbance that has separated from the source and thereafter propagates on its own. That a comoving magnet carries its field lines says nothing about a pulse already in flight, and Zeng's inference silently identifies the two.

The decisive difficulty is experimental, and it is not the experiments Zeng cites. Michelson–Morley used a source at rest with respect to its own mirrors, so v = 0 in his own formula and a null result is expected under both theories; the same is true of Trouton–Noble. These are consistent with his proposal but cannot confirm it. Fizeau's experiment is worse for him than he allows: there the source is at rest in the laboratory and only the water moves, so his own rule predicts no shift at all, yet a shift is observed and matches the Fresnel drag coefficient 1 − 1/n² — the classic result that ballistic emission theory cannot produce and that relativistic velocity addition reproduces exactly.

Emission theory of precisely this form has been measured against directly. Alväger and co-workers at CERN in 1964 timed gamma rays emitted by neutral pions moving at 0.99975c and found their speed equal to c to about one part in 10⁴ — where c₀ + v predicts nearly 2c. Brecher's 1977 analysis of X-ray binaries bounds the source-velocity dependence at k < 2×10⁻⁹. De Sitter's much older argument stands too: if light from a binary star travelled at c ± v_orbital, the approaching and receding phases would arrive out of order and the observed orbits would be grossly distorted, which they are not.

Testing the paper against itself sharpens the point. Zeng holds the wavelength rigid and lets the speed vary, so the observed frequency is f = c/λ. Apply that to a source moving purely transverse to the line of sight: equation (3) with θ = 0 gives c = √(c₀²+v²) ≈ c₀(1 + v²/2c₀²), hence a transverse blueshift of +v²/2c². The transverse Doppler shift is measured — Ives and Stilwell in 1938, and modern lithium-ion storage-ring versions to parts in 10⁹ — and it is a redshift of −v²/2c². Same magnitude, opposite sign. The paper's own construction thus makes a second-order prediction that the cleanest available experiment reverses.

Two smaller points. The claim that "the mass of light field is zero" and so "motion of field does not need the action of force" treats zero rest mass as zero inertia; light carries momentum E/c, as radiation pressure measurements from Nichols and Hull (1901) to solar sails demonstrate. And the first-order radar relation Δf = v/λ that Zeng offers as his empirical anchor is common to the classical and relativistic treatments — the two differ only at order v²/c², far below radar precision, so the reconnaissance data cited cannot discriminate between them. The paper is clear and self-consistent in its geometry, but its empirical case rests on experiments that do not test its claim, while the experiments that do test it have come out against it.