Electron-Spin-Reversal Noise in the Gigahertz and Terahertz Ranges as a Basis for Tired-Light Cosmology
| Scientific Paper | |
|---|---|
| Title | Electron-Spin-Reversal Noise in the Gigahertz and Terahertz Ranges as a Basis for Tired-Light Cosmology |
| Read in full | Link to paper |
| Author(s) | Donald G Carpenter |
| Keywords | Tired Light, Cosmology, Electron Spin Reversal |
| Published | 1990 |
| Journal | Apeiron |
| Volume | 1 |
| Number | 6 |
| No. of pages | 12 |
| Pages | 7-11 |
Read the full paper here
Abstract
A well-known quantum mechanical hypothesis is found to anticipate ubiquitous electromagnetic noise in the gigahertz and terahertz ranges. It also appears to anticipate the so-called cosmic "thermal background" radiation and the astronomical redshift. It might form the long-sought underlying physical basis for the tired-light model of the universe.
Overview
Donald Gilbert Carpenter, then in the Department of Electrical Engineering at Colorado Tech, published this short paper in the sixth issue of Apeiron in 1990. Its strategy is unusual and worth stating plainly: rather than proposing a new physical postulate, Carpenter takes an orthodox textbook hypothesis — the one that explains the reduced speed of light in a medium as the accumulated delay of successive absorptions and re-emissions by the atoms of that medium — and argues that it carries an unnoticed consequence. If the hypothesis is right, he says, then in a particular class of two-electron systems the absorption-and-re-emission cycle can go wrong in a way that splits one photon into three, two of which are low-energy spin-reversal photons. Carpenter had raised this consequence in a 1987 paper in Speculations in Science and Technology; the present paper works out the frequencies and asks what a universe full of such systems would look like.
The answer he arrives at is a pervasive electromagnetic background in the 74–220 GHz band, which he notes "bears a striking resemblance" to the microwave background attributed to the Big Bang by Penzias and Wilson and by Dicke and co-workers, together with a steady degradation of optical photon energies with path length — that is, an astronomical Redshift of non-Doppler, non-expansion origin. Carpenter's target is explicitly the Tired Light model, which he takes to have been abandoned for reasons rather than refuted. He quotes Geller and Peebles' 1972 list of four objections to tired light and claims to answer the first two: the absence of an identified physical basis, and the absence of any natural provision for the microwave background. He does not claim to answer the other two, and says so.
The argument
The mechanism: one photon in, three photons out
Consider a system with two electrons in identical quantum states except for Spin — parahelium, or the negative hydrogen ion, or (Carpenter adds) suitable molecules and crystals. A photon arrives whose energy is insufficient to raise the system to its next stable level. Ordinarily the higher-energy electron of the pair (call it #2) is excited and falls straight back, re-emitting an identical photon after a small delay; this is the standard picture.
Carpenter's case is the other branch. Suppose instead the lower-energy electron (#1) is raised into the unstable state. Electron #2 now "sees" a vacancy below it, another electron of the same spin slightly above it, and an abrupt increase in the ambient magnetic field B. It therefore has non-zero probability of reversing its spin and dropping into the vacancy, emitting a spin-reversal photon. Electron #1 then reverses spin into the ortho state, emitting a photon carrying the original energy minus two spin-reversal quanta, and finally reverses again into the para state, emitting the second spin-reversal photon. Net result: one photon absorbed, three emitted, in the same direction, separated slightly in time, with the same total energy. The process requires the incident photon to carry at least about three times the spin-reversal energy.
The frequency formula
The heart of the paper is the appendix, which estimates the spin-reversal frequency semiclassically rather than by differencing two computed level energies — Carpenter's point being that for levels differing only in spin, the splitting is smaller than the error on either level. Following a treatment in Beiser's Concepts of Modern Physics, he balances the centrifugal force mu2/r against the net electric force, taking the nuclear attraction Ze2/(4πε0r2) less the mutual repulsion of two electrons at opposite ends of a diameter, e2/(16πε0r2). Closing the system with the de Broglie condition nλ = 2πr gives the orbital radius and speed, hence the revolution rate W = me4(4Z−1)2/(26ε02h3n3). Treating the two circulating charges as current loops, iZ = WZe and ie = We, the field seen by each electron is
- B = πμ0m2e7(4Z−1)3(2Z−1)/(210ε03h5n5)
and the spin-flip photon energy E = 2B(eh/4πm)(g/2) then yields, on inserting constants,
- ν = 1.368 (4Z − 1)3 (2Z − 1) g n−5 GHz
with Z the atomic number, g the Landé factor and n the orbital quantum number. Carpenter is careful that this is an estimate: it assumes both electrons share one circular orbit at opposite ends of a diameter, an arrangement the absorbed photon itself disturbs, so B comes out too small for one of the electrons by an amount depending on the incident photon's energy. He accordingly refuses more than two-figure accuracy.
The derivation is internally consistent and the numerical constant is correct: substituting the values Carpenter lists reproduces 1.368 GHz. The three applications also reproduce. Ground-state helium (Z = 2, g = 2, n = 1) gives 2.8 THz, in the long-wavelength infrared. Positive lithium ion (Z = 3) gives about 18 THz. Negative hydrogen ion (Z = 1) gives about 74 GHz.
From line to background
Carpenter then asks which of these lines survives in space. He takes the local interstellar medium to be at roughly 50 K, sparse, mostly hydrogen as negative ions, atoms and positive ions, with a sizeable helium minority and an electron gas, and notes that low-frequency photons scatter most readily. The 2.8 THz helium line sits slightly above the ambient temperature, so it is degraded toward the background and, being weak and thermally blurred to begin with, becomes very hard to detect.
The 74 GHz H− line is the one he cares about. It sits well below ambient, so scattering pushes photons upward in energy until one exceeds three times the spin-reversal quantum, whereupon it has a high probability of splitting into three again. The result, he argues, is a quasi-thermal, essentially isotropic spectrum rising from below 74 GHz to a maximum "in the vicinity of 220 GHz" and falling off sharply above — and, he emphasises, easily observable from the ground, since 74 GHz lies 14 GHz clear of the 60 GHz atmospheric oxygen noise. He notes that H− is the main source of solar atmospheric opacity, so the Sun and every star should be a strong 74 GHz source, and urges a laboratory search for the line.
Left alone the flux would grow without limit, so Carpenter invokes losses: the same spin-reversal process in molecules and crystals removes energy and re-radiates it lower down, solid matter absorbs and re-emits as heat, and other sinks (he mentions black holes) are presumed to exist.
Consequences for cosmology
Two conclusions follow. First, the 74–220 GHz noise resembles the microwave background. Second, infrared, visible and ultraviolet photons crossing intergalactic, interstellar and interplanetary space encounter H− ions and ground-state helium, spawn spin-reversal photons, and are themselves shifted downward in energy — "the further these latter photons travel the less energy each of them will have". This is offered as an alternative to the Expanding Universe account of the astronomical redshift, and as the missing physical basis for tired light.
Assessment
The paper's real merit is methodological. Carpenter does not ask the reader to accept a new force, a new medium or a modified electrodynamics; he asks only that the standard absorption/re-emission account of refractive delay be taken seriously and pushed. That is a legitimate and rather elegant move, and the resulting derivation is honest work — the appendix is complete enough to check line by line, and it checks: the constant 1.368 GHz follows correctly from the stated formula and constants, and 2.8 THz, 18 THz and 74 GHz all follow correctly from the formula. He is also unusually forthright about the limits of his own estimate, and about which of the four Geller–Peebles objections he has and has not addressed.
The difficulties, however, are severe, and several of them are visible inside the paper. The most damaging is the redshift mechanism itself. Each event removes a fixed amount of energy — two spin-reversal quanta, set by ν = 1.368(4Z−1)3(2Z−1)g'n−5 GHz and independent of the incident photon. A photon therefore loses an absolute energy proportional to path length, not a fixed fraction of its energy. That gives a redshift that depends strongly on wavelength: for a given distance, an ultraviolet line would shift by a much smaller fractional amount than an infrared line from the same source. Observed spectra do the opposite — the Lyman, Balmer, optical, infrared and 21 cm features of a single galaxy or quasar share one common z to high precision. Any loss-per-interaction tired-light scheme has to reproduce ΔE ∝ E, and this one does not. Carpenter does not raise the point.
Second, the mechanism is a scattering mechanism, and he says so: the emitted photons are "randomized in direction". Scattering that is efficient enough to redden light across cosmological distances is efficient enough to blur it. Distant galaxies are observed sharp, and the angular resolution achieved on high-redshift objects is inconsistent with the scattering depth the model needs. This objection applies to tired-light proposals generally and is not answered here.
Third, the thermal bookkeeping is internally inconsistent. Carpenter's own premise is that the interstellar medium is at about 50 K and that the 74 GHz photons, being colder, scatter upward toward equilibrium with it. Carried to completion that argument delivers a background at the ambient medium temperature — roughly 50 K — not the 2.7 K of the observed Cosmic Microwave Background. He avoids this only by invoking unspecified loss mechanisms that arrest the growth at an unspecified point, so the actual temperature is not predicted. What is offered instead is a frequency coincidence, and even that is off: he places his maximum "in the vicinity of 220 GHz", whereas the microwave background peaks near 160 GHz.
Fourth, and decisively for the CMB claim, a spectrum assembled from an emission line repeatedly pumped and split by scattering is "quasi-thermal" at best. The COBE FIRAS measurement, announced in the same year this paper appeared, showed the microwave background to be a blackbody to a few parts in 105 over the whole 60–600 GHz range, with no line structure and no excess. That level of thermalisation requires a genuine equilibrium epoch, and no line-pumping scheme reproduces it. The background is also observed to be smooth to one part in 105 yet correlated on degree scales in a pattern that matches acoustic physics in a hot early plasma — structure that a local ISM emission process has no way to generate.
Fifth, the atomic physics underlying equation (1) is Bohr-model semiclassical. It computes the internal field from the orbital currents of two circulating electrons; but the states in question — helium 1s2, H− 1s2 — have zero orbital angular momentum, so no such orbital current exists. The implied field is also large: 2.8 THz at g = 2 corresponds to a spin-flip in a field of order 100 tesla. More importantly, the para–ortho energy difference in real helium is not a magnetic dipole splitting at all but an exchange splitting arising from the Pauli Exclusion Principle, and it is of order an electron volt — roughly a hundred times the 11.6 meV that 2.8 THz represents. The quantity Carpenter computes is not the quantity that separates the singlet and triplet states.
Finally, the model makes a sharp local prediction that can be tested without cosmology at all: because H− dominates solar opacity, the Sun should be a strong 74 GHz line source, and the line should be findable in the laboratory. Carpenter deserves credit for saying so — it is the right kind of claim to make. Millimetre-wave solar spectroscopy shows continuum, not a 74 GHz emission line of the required strength. And the standing objection to tired-light cosmology as a class remains untouched here: the light curves of Type Ia supernovae are observed to be stretched by exactly the factor (1 + z), which follows immediately from expansion and has no counterpart in a mechanism that only degrades photon energies.
Read as a 1990 document, this is a serious and self-aware attempt to supply the physical basis whose absence had, by Geller and Peebles' own account, sunk tired light. Read against the measurements that arrived from COBE onward, the mechanism fails on the spectral shape of the background, on the wavelength dependence of the redshift, and on the sharpness of distant images — and the first two of those failures follow from the paper's own equations.