The Essence of Electromagnetic Wave is not Energy
| Scientific Paper | |
|---|---|
| Title | The Essence of Electromagnetic Wave is not Energy |
| Read in full | Link to paper |
| Author(s) | Qing Zeng |
| Keywords | energy, vector field, T.Yang experiment, physical essence, physical action |
| Published | 2010 |
| No. of pages | 13 |
Read the full paper here
Abstract
The customary opinion is: electric wave or light wave is energy, T. Yang's experiment is the interference of energy, its shading fringes are the energy magnitude. But, this article summarizes the physical experiments to point out: the essence of electric wave is not energy, and its shading fringes are not the energy magnitude, but the amplitude magnitude of the vector field. Then, this article summarizes all the experiments of electromagnetic wave, and derives the conclusion that the essence of the electric wave is not energy. Now that the essence of electric wave is not energy, as extension, this means that Maxwell's vector E x H (energy flux density) does not have the real physical implication, thus we can consider that electric field and magnetic field radiate independently.
Overview
Zeng Qingping, a professor at the Air Force Radar Academy in Wuhan, here presses a thesis that runs through his whole body of work: that Maxwell's electromagnetic theory has been misread as describing a flow of substance. The specific target is the Poynting vector E × H. The mainstream reading treats it as an energy flux density — a real physical quantity carrying real energy across space, so that a radio wave or a light beam is propagating energy. Zeng denies this. On his account what radiates is a vector field, and only a vector field; E × H "does not have the real physical implication."
The claim is deliberately ontological rather than merely computational, and it is a claim about reification: energy, for Zeng, is not the thing that travels but a bookkeeping quantity that appears only at the moment a field acts on matter. His recurring analogy is force. A force acting on a body produces kinetic energy, "but the essence of force (constant force or time variable force) is not energy" — force is the agent, energy the consequence, and the two must not be identified. Electric and magnetic fields, he argues, stand in exactly the same relation to energy.
A second consequence follows immediately, and it is the one Zeng cares most about across his publications. If E × H is not a real flux, then the picture of electric and magnetic fields as "mutual generation" — each curling into existence from the other's rate of change — loses its physical motivation, and one may instead treat "electric field and magnetic field [as radiating] independently." The paper is thus an attack on the coupled structure of Maxwell's equations mounted from the energy side.
The argument
Mechanical waves versus radiated fields
Zeng begins by insisting that Maxwell's wave picture is an analogy imported from mechanics, and that the analogy fails at its foundation. A mechanical wave is transmitted "through the oscillation of the medium, so it obeys Newton's mechanic law", and the energy it carries, W = ½ρV ω2A2, is conserved because there is a mass density ρ to carry it. For an electric or magnetic field wave, by contrast, "the mass in the unit volume is zero, there is no medium of oscillation-transmission, there is no force of oscillation-transmission either, so it is a kind of radiation." What is conserved, he says, is the radiated field quantity through successive spherical surfaces S1 and S2, not a transported energy.
Young's double slit computed two ways
The centrepiece is a comparison of two calculations of the fringe pattern in Thomas Young's double-slit experiment. Zeng's methodological rule is stated plainly: if both the field picture and the energy picture reproduce the observed fringes, then light has both characters; if only one does, the other is wrong.
Taking the energy route, he writes two arriving energy densities w1 = εE02cos2(ωt − 2πr1/λ) and w2 = εE02cos2(ωt − 2πr2/λ), adds them, and finds that for r2 − r1 = kλ the sum has module value 2w0, and for r2 − r1 = (2k−1)λ/2 the module value is still 2w0. "The energy density under these two situations are the same, there is no interference fringes." He then repeats the exercise with w = εE2 in place of E × H and obtains the same null result.
Taking the field route, he superposes the vectors instead: E = E1 + E2 = 2E0 cos(πδ/λ) cos[ωt − π(r1+r2)/λ] with δ = r2 − r1. Bright fringes appear at δ = kλ, dark fringes at δ = (2k−1)λ/2, and with δ ≈ xd/D the fringe spacing is λD/d — the textbook result. Zeng concludes that "T. Yang experiment is just the interference of vector field, not the interference of energy", that "shading fringes are the amplitude magnitude of vector field", and that the same holds for every interference arrangement he lists: equal-inclination, film, Michelson, Newton's rings, biprism, Lloyd's mirror and Laue spots.
The two-transmitter antenna argument
The second experimental prop is a radio-communication geometry. Two identical transmitters of equal frequency, amplitude and phase are placed symmetrically about a receiving wire ab parallel to both. If radiation carried energy W, Zeng reasons, then since "energy W is scalar", the wire receives W from the left and W from the right, total 2W, and the induced signal current should be twice that from one transmitter. In fact, he asserts, the current on ab is zero, "because vector has direction, the vector fields on the wire ab are just counteracted to be zero."
He adds a related objection about orientation: if the receiver absorbed energy density wr, it should not matter whether the receiving antenna is parallel to the transmitting one, yet in practice it matters greatly. On his own account, reception is Lorentz forcing of the metal electrons — eE(t) and ev×B(t) driving them up and down to make signal current — which is intrinsically directional (see Lorentz Force).
Time-varying fields as "virtual power"
The fourth section supplies a circuit-theoretic argument. In a sinusoidal steady-state port containing reactance, complex power splits as P = ½VmImcos(θV−θI) + j½VmImsin(θV−θI): real power, which consumes energy, and reactive ("virtual") power, which does not. Zeng solves a series RLC port and shows that the average real power delivered by the source appears entirely at the resistance, while the inductance carries positive and the capacitance negative reactive power, exchanging with each other; at resonance (ω2LC = 1) these reduce to ±j½Vm2/ω2R2C. He then performs the key extrapolation: "Expand L, C in the figure, and it radiates to the free space, which indicates that the time variable electromagnetic field in the free space is virtual power, not the energy."
Microwave heating is accordingly reinterpreted. It is "not the direct transmission from one energy to another energy", but a case where the vector field acts on the object and heat is generated — "vector field activates into heat" and "wave energy exchanges into heat" being, he insists, two different physical processes.
What the paper does not claim
Zeng is careful to say the thesis "has nothing to do with the wave particle duality and quantum hypothesis." He accepts that light of wavelength approaching atomic dimensions may be quantised for calculational convenience and that hf gives the minimum unit of transformation when a field does act on matter. His point is confined to what is happening during propagation in vacuum.
Assessment
There is a genuine and defensible philosophical position underneath this paper. The habit of speaking of energy as a substance that flows, is stored, and is handed from one body to another is a reification, and it is worth attacking; energy is a conserved bookkeeping number, and Zeng's force analogy — force produces kinetic energy but is not kinetic energy — is a sound way to make the point. His observation that Maxwell reached the electromagnetic wave equation by analogy with a material medium that electromagnetism does not possess is historically accurate and rarely acknowledged in textbooks. The paper is also unusually clear about what would refute it: he states his criterion (both pictures must give the fringes, or one is wrong) before applying it.
The execution, however, contains an error that undermines the central demonstration. Zeng computes the "energy picture" by adding the two separate energy densities w1 + w2. But no version of Maxwell's theory says energy densities superpose. Fields superpose; the energy density is then the quadratic form of the resultant field, w ∝ (E1 + E2)2 = E12 + 2E1E2 + E22. The cross term 2E1E2 is precisely the interference term, and it reproduces the fringes exactly. Zeng's own field calculation, squared and time-averaged, is the standard energy calculation. What he has shown is that energy is not additively transported as a scalar, which is true and which no one disputes; he has not shown that the fringes are anything other than the light intensity that generations of photometers have measured. The same objection dismantles the two-transmitter argument: the standard treatment also predicts zero received signal there, because it too superposes fields before computing power, and the "2W" he refutes is not a claim the energy picture makes.
Two further points conflict with established measurement. First, Zeng repeatedly asserts that the radiated field falls as 1/r2 and that the received antenna voltage does likewise. Radiation fields fall as 1/r and radiated power as 1/r2; this is the content of the Friis transmission equation, which is verified daily in exactly the radio-link engineering the paper draws its examples from, and which would fail by orders of magnitude at long range on Zeng's scaling. Second, if propagating fields carry no energy, radiation pressure should not exist, yet it was measured directly by Lebedev (1901) and by Nichols and Hull (1901–1903) and is now routinely exploited in solar-sail navigation and optical tweezers; momentum and energy flux in the beam are measured, not inferred. Zeng's paper does not mention radiation pressure at all.
The "virtual power" section rests on an extrapolation that is asserted rather than derived. Reactive power in a lumped LC port is genuinely non-dissipative, but that is a statement about a circuit small compared with a wavelength — the very condition Zeng states at the outset ("circuit size is far less than wave length"). Opening the elements out into free space is exactly the step that violates that condition and turns reactive near-field energy into radiative loss; the radiation resistance that appears is real, not imaginary. Treating the near-field result as though it survived the transition is the single unsupported move on which the section depends.
Finally, the PDF is evidently a working draft rather than a finished journal version: it carries an inline editorial note that "the wording in the article can be modified, the length of the article can be compressed", the figures are ASCII sketches, and the reference list contains numbering errors and a block of papers labelled "expecting the references that you published". Several equations survive text extraction only partially. Read charitably, it is a position paper in a long campaign against Maxwellian electrodynamics whose philosophical core is stronger than the demonstrations offered in support of it.