Photon

The photon is, in mainstream physics, the quantum of the electromagnetic field: a massless, spin-1 boson carrying energy E = hf and momentum h/λ, introduced by Einstein in 1905 to account for the photoelectric effect and treated since as the mediator of the electromagnetic interaction. On the standard account light is neither simply a wave nor simply a corpuscle but exhibits wave-particle duality, and the quantised field is held to be confirmed by the photoelectric effect, by Compton scattering, by single-photon interference and by the correlations measured in parametric down-conversion and Bell-test experiments.

The literature collected on this wiki treats almost none of that as settled. It divides, however, in an unusually sharp way. One body of work argues that there is no photon at all — that light is a continuous wave phenomenon and that the quantum of light is an artefact of how detectors are modelled and how their statistics are read. Another body of work accepts a real, localised light particle and objects instead that the standard photon is too poor a model of it: a structureless point with no size, no internal parts and no rest mass, where what is needed is an extended object with geometry, a spin axis, a cross-section and in many treatments a small but non-zero mass. Both groups reject Einstein's photon; they reject it for opposite reasons. This article sets out the mainstream position briefly, then the lines of criticism found in the papers archived here, then the alternative models advanced in their place, and finally the points on which the researchers here disagree with one another.

The mainstream account, and what is disputed in it

The standard photon rests on a small number of load-bearing claims: that the electromagnetic field is quantised, so that energy is exchanged only in units of hf; that the quantum is indivisible, so that a single photon striking a beam splitter goes one way or the other but never both; that the photon has zero rest mass and therefore travels at exactly c in vacuum for every observer; and that it carries one unit of spin angular momentum. A review of Einstein's argument and its consequences for the subsequent development of theoretical physics is given on this wiki, from a broadly sympathetic standpoint, in Robert Schor's Einstein and the Photoelectric Effect (2005), and the tacit assumptions built into the concepts of "electron" and "light" are examined by A. O. Barut in Electromagnetic Interactions and Particle Physics (1994), which opens with the observation that the foundations of physics must be continuously re-examined because "there are tacit assumptions, imprecise wordings, preconceived ideas or pictures that have been taken for granted."

Each of the four load-bearing claims is contested somewhere in this archive. The papers below are organised by which of them they attack.

The photon rejected

The photoelectric effect proves less than is claimed

The photoelectric effect is the historical foundation of the photon, and it is the first thing this literature goes after. The argument is not that the effect is misreported but that the inference from it is invalid.

Johann Marinsek states the case most directly in Physics EA: Photoelectric Effect No Empirical Confirmation for the Existence of a Photon That Carries Energy Packet E = hf (2008). The release of metallic electrons, he argues, is not a photon-electron collision but a frequency-dependent resonance effect explicable only in wave terms; and since the measured stopping potential represents a potential energy, no inference runs from it to a photon kinetic energy, so that "there is no measurement of a photon energy E = hf possible."

Thomas Smid turns the usual argument around in Wave and Particle Theory of Light applied to the Photoelectric Effect (2001). The standard objection to a wave account is that it cannot deliver energy to a bound electron quickly enough. Smid argues that a correct dynamic model of the electron-wave interaction does account for the short photoionization times — and that it is the particle model which fails, because momentum and energy conservation in a photon-electron collision do not permit the required energy transfer.

Bing-Xin Gong reanalyses the effect in classical electrodynamics in A Classical Approach to the Photoelectric Effect & Photoelectron Emission (2007), identifying what he takes to be the limitations of Einstein's photon hypothesis and reinterpreting the relation between photoelectron kinetic energy and the circular frequency of the incident light, with emission depending on both frequency and light intensity. Philipp M Kanarev argues in The New Interpretation of Photoeffect (2004) that Einstein's photoeffect equation is not evidence for a light quantum at all but a mathematical model of the law of formation of atomic and ionic spectra. Ionel Dinu reaches the effect at the end of a critique of Maxwell's wave theory itself in Radio Waves - Part III: The Photoelectric Effect (2013).

Quantum optics without quanta

The second front is quantum optics, where the strongest modern evidence for the photon is supposed to lie. Trevor W Marshall and Emilio C. Santos give the programme its name in The Myth of the Photon (1997). Their claim is technical and sweeping at once: all "single-photon" and "photon-pair" states produced in atomic transitions and in parametric down-conversion can be represented by positive Wigner densities of the relevant mode amplitudes, so that the light field of every such state is a real probability ensemble — not a pseudo-ensemble — of solutions of the unquantized Maxwell equation. What then does the work usually assigned to the quantum is the theory of detection, which on their account must go beyond the fashionable single-mode photon theory.

Marshall extends the argument to down-conversion specifically in The Myth of the Down Converted Photon (2008). Parametric down-conversion is routinely described in photon language even by its supporters as "mind-boggling" and "absurd"; a classical description of the light field which takes proper account of its vacuum fluctuations, he argues, renders all of it consistent and rational, with the conclusion that "'nonlocality' in quantum optics is simply an artifact of the Photon Concept." The paper also makes a prediction — a second, satellite down-conversion rainbow — which is what distinguishes it from a purely interpretive exercise.

Thomas Smid reaches a parallel conclusion for Bell-type experiments in Classical Interpretation of EPR- Bell Test Photon Correlation Experiments (2006), showing that the correlations can be recovered semi-classically once detection is modelled as a statistical stepwise photoionization process rather than as the arrival of an indivisible quantum. M Ardehali's Atomic Cascade Experiments With Two-Channel Polarizers and Quantum Mechanical Nonlocality (1994) works over the same experimental ground from the EPR premises, and Carroll Alley, T. E. Kiess, A. V. Sergienko and Yanhua Shih, in Experiments with Entangled Two-Photon States From Type-H Parametric Down Conversion: Evidence for Wave-Particle Duality (1994), press the point that although the abstract rules of quantum mechanics describe the outcomes, what is actually "going on" physically remains unaccounted for — a "conceptual incompleteness". Yutaka Mizobuchi and Yoshiyuki Othake report a direct test of Bohr's extension of complementarity to the wave and particle pictures of light in A Test of the Complementarity Principle in Single-Photon States of Light (1994).

The most direct experimental challenge in the archive is Eric S. Reiter's A Challenge To Quantized Absorption by Experiment and Theory (2012). Reiter repeated the famous beam-split coincidence test — the experiment usually taken to show that a single quantum cannot be halved — but with gamma-rays rather than visible light, and performed a similar split on alpha-rays. In both cases coincidence rates greatly exceeded chance, an outcome he calls the unquantum effect and reads as a strong experimental contradiction of quantum theory and of photons, and as evidence for the long-abandoned accumulation (loading) hypothesis. He restates the case in his later conference paper "Experiment and Theory Removing all that Quantum Photon Wave-particle-Duality Entanglement Nonsense" (2017), which is held in the archive but does not yet have a page here.

There is no photon

A number of papers dispense with the concept outright. Robert L. Henderson's Lightwaves, Not Photons (2011) retells the 1905 turn as a wrong one and argues for a return to a wave-in-a-medium account. Milos Abadzic asks the question in its blunt form in Photon: Reality or Fiction (2009), and adds a warning about the cost of the answer: because so much of modern physics is built on the photon concept, changing it means reviewing and correcting a great many accepted laws — which is, he suspects, why the change is resisted. Alvaro Quinteros Valenzuela revives the old classical theory of extended elementary particles in The Revenge of Old Classical Physics: No Space for Photons or Relativity (2009), rejecting in turn each of the standard arguments that classical physics fails in the microscopic domain.

Xavier Borg's Abolishing the Wave-Particle Duality Nonsense (2010) argues that waves account for their own apparently particulate behaviour without any particles at all, once quantisation is understood in terms of electromagnetic radiation patterns and antenna theory; the photon he calls "the ghost particle". Bill Gaede rejects both halves of the duality in Light: Neither Particle nor Transverse Wave (2005) and develops his rope model in An Alternative to Waves and Wave-Packets (2011), arguing that waves, wave-packets and particles are all merely pictorial devices attached to mathematics and that none of them is offered as a literal architecture of light.

Volodymyr V Krasnoholovets denies wave-particle duality for material particles and field particles alike in Sub Microscopic Description of the Diffraction Phenomenon (2010). On his sub-microscopic account, real space is a tessel-lattice; the ψ-function of a particle is its field of inertia, carried by quasi-particles he calls inertons; and the diffraction of photons is the deflection of photons by transverse inerton flows in the diffracting substance rather than the self-interference of a wavefunction.

Classical wave, wave-packet and soliton models

Between outright rejection and a structured particle lies a large body of work which keeps a localised entity but builds it entirely from classical fields — usually from Maxwell's equations, applied more carefully than usual.

Robert L Carroll's 1996 paper "The Photon" models it as a wave motion limited to one wavelength longitudinally and one wavelength in transverse circumference, giving a cylinder which shows no spreading with distance of travel. This, he argues, supplies the characteristics of both wave and particle and so dissolves the "either-or" controversy; notably, he finds no indication that a medium is required for propagation.

Geoffrey Hunter and Robert L. P. Wadlinger model photons and neutrinos as electromagnetic solitons in Photons and Neutrinos as Electromagnetic Solitons (1989): oscillatory states of the electromagnetic field confined to a local domain whose size and shape are limited by the requirement that intervals between events inside it be timelike. The resulting localised soliton waves — they call them "wavicles" — occupy a circular ellipsoid whose length is the wavelength, and are eigenstates of intrinsic angular momentum.

John E Carroll pursues the same aim in A Relativistic Wave-Particle Based on Maxwell's Equations: A Model for a Classical Photon (2006), arguing that conventional localised wave-packets cannot explain either quantisation or non-local behaviour, and that the harmonic-oscillator quantisation of Maxwellian modes leaves the Schrödinger frequencies without clear physical significance. With Joseph Beals IV and Ruth Thompson he constructs Photon-Like Solutions of Maxwell's Equations (2009), free-space solutions carrying local helical rotations across the whole cross-section — "distributed spin rotations" — at a frequency independent of the propagation frequency.

Richard Oldani has returned to the problem over three decades. The Photon with a Classical Field (1980) proposes a model intended to account for the differences between the semiclassical and quantum theories of radiation and argues that the evidence then held to rule it out is inconclusive. A Field Based Model of the Photon; Lorentz Covariant Quantization (2005) argues that the macroscopic Maxwell equations which quantum mechanics uses to define radiation fields violate the special principle of relativity, and resolves this by applying Maxwell's equations microscopically to each of the constituent wave trains of a macroscopic wave, from which spontaneous emission and a widespread frequency-doubling phenomenon follow. Secondary Field Theory and Photons (2008) argues that the standard field diagram for an electromagnetic wave has the electric and magnetic vectors violating Gauss's laws, and corrects this with a dipole-field geometry for the photon.

Jan Olof Jonson builds the photon up from classical electron dynamics: Towards a Classical Explanation to the Stable Electron Paths around Nuclei and to Radiation in Connection with the De-Excitation of Excited Electrons (2004) argues that a classically orbiting electron need not radiate away its energy, Photon as a Classical Wave Packet from Classically Stabilized Electron Orbits (2007) derives the emitted photon as a classical wave packet from those stabilised orbits, and Coulomb's Law is the Basis for Radiation Energy (2011) recovers the radiated energy from Coulomb's law alone, without the Poynting vector.

Peter Marquardt takes a different line again in Light Waves as a Many-Particle Phenomenon (2006), where waves and quantisation are consequences of many particles coherently forming rigid crystalline arrays. He argues that the mathematics of Newton's particle-flux theory and of the wave-in-a-medium theory are isomorphous, that both hold only for interacting ensembles, and that the loss of interference below a critical intensity threshold shows that what is emitted are photon bunches: "single photons are never involved nor observed in any experiment, the photoelectrical effect included. Single particles do not make waves."

Tuomo Suntola approaches quantisation from radio engineering in Photon - The Minimum Dose of Electromagnetic Radiation (2005). Solving Maxwell's equations for a one-wavelength dipole radiating a single oscillation cycle of a unit charge gives an emitted energy of the form E = (2/3)hf, with Planck's constant itself expressible in terms of the unit charge, the vacuum permeability and c — so that the quantum of radiation appears as the minimum dose emitted by a point dipole rather than as a particle.

Rati Ram Sharma replaces duality with unity in Unified Theory's Wave-Quantum Unity of Light (2011): light propagates as a wave-quantum unity along a transverse electromagnetic wave in a "sharmon medium" whose elements do not themselves move, and appears as a duality only because both characters are never observed at once. Gin Conesa, in On Light (2005) and with Manuel Conesa in A New Hypothesis on Light (2006), argues that three centuries of confusion between corpuscle, wave and photon arose from neglect of the magnetosphere, and proposes that light is simply a perturbation of the electromagnetic values of empty space.

Structured and extended photon models

A second family accepts a light particle but insists it has parts, dimensions and internal motion. These researchers are the mirror image of the first: where Marshall and Borg hold that the photon is one entity too many, these hold that the standard photon is far too little.

The dipole models are the oldest strand. Daniel H Deutsch proposes a rotating dipole of massless point charges in Electromechanical Physical Model of the Photon (1988), tying the construction to the fine structure constant and to electromagnetic mass. D E McLennan's The Photon (1989) makes the photon a dipole of two fundamental charges separated by αλ/π, rotating in a plane transverse to its direction of travel, with the consequence that the Maxwell waves conventionally used to describe radiation must be in equilibrium with the dipole and therefore circularly polarized. In Maxwell Equations: A New Approach (1989) he derives Maxwell's equations for the free field from the postulated existence of a subatomic particle he calls the emon, which has only an electric property at rest and acquires its magnetic property from motion.

The helical models form a second strand. Wladimir Guglinski's A Model of the Photon (2002) starts from the problem Einstein himself never solved — that a quantum of light is not compatible with Maxwell's equations — and argues that the corpuscular photon can be reconciled with them by adopting a helical trajectory for elementary particles, offering this as an alternative to duality. Erich Wanek develops the same intuition in The Particlewave: A New Model for Light and the Matter Waves (2008), in which photons and elementary particles alike consist of arrays of subparticles oscillating perpendicular to the direction of motion; circular polarization makes the path a helix, and two subparticles make it a double helix. He follows this in The "Mass" of a Photon only an Expression of its Helical Configuration? (2009) by asking whether photon mass is nothing but that geometry.

Other constructions are more elaborate still. William M Honig's A Minimum Photon Rest Mass Using Planck's Constant and Discontinuous Electromagnetic Waves (1974) offers a vortex-ring photon sustained by a two-fluid zero-point-energy model, expanding at the speed of light, with implications he draws out for non-local connectivity. János Rohan's The Structure of a Photon (2005) builds the photon from four fundamental particles — two kinds of gravity particle and two of electric charge — and takes it to be neither elementary particle nor wave. Werner A Hofer argues in Internal Structures of Electrons and Photons and some Consequences in Relativistic Physics (1997) that both quantum mechanics and de Broglie-Bohm mechanics are formal rather than realistic approaches, and that on a realistic approach the internal structure of particles satisfies a wave equation, with the uncertainty relations expressing the resulting arbitrariness in the internal energy components — electrons and photons then being describable by an identical formalism.

Liudmila B. Boldyreva and Nina B. Sotina make the photon's internal structure do work against special relativity in The Possibility of Developing a Theory of Light Without Special Relativity (2002): treating the photon as a complex object with intrinsic motions whose energy must be included in the conservation laws applied at detection, they recover both longitudinal and transverse Doppler formulae in three-dimensional Euclidean space with time independent of the spatial coordinates.

Philipp M Kanarev built a photon model as part of a wholesale reconstruction of physical chemistry. Modelling the Photon and Analyzing Its Electromagnetic and Physical Nature (2002) and Photon Model (2003) derive an electromagnetic model of the photon — including the mass of the moving photon and the location of its centre of mass — from what he calls the axiom of space-matter-time unity. The surrounding papers argue that the results conventionally taken to require quantum physics do not: The Law of the Radiation of the Perfect Blackbody is the Law of Classical Physics (2002) claims Planck's radiation law for classical physics; The Doppler Effect at Photon Emission (2003) argues the Doppler calculation at emission is possible only with classical models; Electrons in Atoms (2002) replaces orbital motion with electron precession; and The Spectrum of the Universe (2009) attributes the cosmic microwave maximum to hydrogen fusion and the infrared maxima to hydrogen molecule fusion near stars.

Mitch Emery derives photon emission from a dual electron spin, one component perpendicular to the other, in Electron Spin and the Emission of Photons (2007), and in What Experiments on Diffraction of Photons Say (2012) uses Panarella's diffraction experiments against the wave-packet foundation of quantum theory. The idea that the photon has internal structure and can therefore age is tested by Ramalho Croca in Laboratory-Scale Test of de Broglie's Tired-Photon Model (1997), which proposes a bench-scale experiment on de Broglie's model of the photon as a real physical entity with inner complex structure that loses energy to the medium as it travels — and so offers a non-ad hoc account of cosmological redshift without a Doppler interpretation. Franco Selleri argues in On the Possibility of a Rationalistic Approach to Microphysics (1989) that the Einstein-de Broglie picture of duality can give quantum phenomena an understandable foundation, and reviews proposals for directly detecting the empty waves of photons and neutrons.

The singleness of the photon

A distinct minority position holds that the trouble is not the photon's existence, nor its lack of structure, but its singleness: that light is never one particle, and that the properties attributed to a lone photon belong to a group.

Besides Peter Marquardt's photon bunches, the 2012 note The "multiple photon", an alternative to the single particle photon. proposes replacing the single-particle photon with a set of homokinetic particles, on the ground that — unlike a single particle — such a set can be divided, which is what entanglement experiments appear to require.

The most direct statement of the case is David de Hilster's, in The Impossible Photon: Why One Particle Can Never Be Light (2026). His argument is not experimental but logical, and it fastens on frequency.

Frequency is a measure of how often something happens; it is defined over a series of events in time. A single object that passes once therefore cannot have one. De Hilster puts it through an analogy:

One bus has no frequency. One particle has no frequency.

— David de Hilster, The Impossible Photon

A lone bus, like a lone particle, has "no 'how often'". Yet the standard photon is defined as a single indivisible quantum and assigned a frequency f, from which its energy E = hf and its colour follow. De Hilster's contention is that these two commitments cannot both be held: the quantity being attributed requires repetition, and a single indivisible particle supplies none. Physics has lived with the contradiction for a century, on his account, because the mathematics works — but a formalism that predicts correctly is not thereby a coherent physical claim.

He notes that the obvious corpuscular alternative fails for a related reason. Newton attributed colour to the size of the light corpuscle; but size is a property an individual object can have, and frequency is not the same kind of property, so substituting one for the other does not answer the question of what is oscillating.

The resolution he proposes is the one his father Robert de Hilster had reached from the opposite direction in 2015. Light consists of many similar particles travelling together — same direction, same speed, in formation. Frequency is then the spacing between successive groups, a real repetition in time, and colour is "the literal rhythm of a procession of particles streaming past". Wavelength becomes the distance between groups and intensity the number of particles in each, so that both properties come from one picture without duality.

The property that could not belong to a singleton is thus relocated to the ensemble, where a frequency can exist without contradiction. This is the account of light developed as luminic motion within the Particle Model of Robert and David de Hilster, set out in The Four Universal Motions in Physics and Principia Mathematica 2; see Light for its fuller treatment and for David de Hilster's parallel argument that the textbook picture of perpendicular electric and magnetic sine waves is a graph mistaken for an object.

It is worth marking how this position sits relative to the two camps above. It is not the claim that there is no light particle — de Hilster's light is emphatically corpuscular. Nor is it the claim that the photon needs internal structure. It is the claim that the unit has been drawn in the wrong place: that what physics calls one photon is a description of a group, and that the puzzles of duality follow from having assigned a collective property to an individual.

Aether and medium-based photon models

For a large group of researchers here the photon question is inseparable from the question of a medium; see Aether for the wider literature.

Joseph F Cuny's The Photon and Its Aether (2002) uses Faraday's force lines to construct both the aether and the photon's structure and means of propagation, with the conclusion that the photon travels as a wave and is detected as a particle, and that its speed depends on the state of local matter rather than being the absolute limit Einstein postulated. Adolphe Martin's The Ether Revisied (1994) assumes a gas permeating all space and matter and argues that the long-known mechanical properties of gases suffice to explain electromagnetism, light propagation, gravitation, quantum mechanics and the structure of elementary particles including the photon. Antonis Agathangelidis and Anastasios Th. Triantafillides define a "polarized Maxwellian photon" in Light as Dynamic Maxwellian Photons: Interference in Terms of Trajectories (2010): a linearly polarized, transversely vibrating sinusoidal micro-disturbance of exactly one period's duration, of total length cT = λ, propagating in Maxwell's vibrating medium — the photon constituting the field rather than being governed by it.

Alan McCone's Sub-Quantum Physics series is the most sustained medium-based treatment in the archive. Sub-Quantum Physics 7: The Spin-Zero Photon Hypothesis (2004) argues, by way of a technique he calls Maxwellian decomposition, that it is incorrect to ascribe spin angular momentum to the photon at all: the excited-state motions of the hydrogen electron consist of radial motions along nearly degenerate ellipse orbits with essentially no angular momentum, so that what is called orbital angular momentum should be called orbital directionality, and no angular momentum need change in an atomic transition. Freed of spin, the photon becomes a propagating disturbance in a medium, and Sub-Quantum Physics 8: Photons Have Inertial Properties of Weak Shock N-Waves (2005) models it as a weak shock N-wave — the physics of the sonic boom — in a compressible space medium whose density McCone takes from Weinberg's estimate of 10⁹⁰ times that of water, with the speed of sound in that medium being what we call the speed of light. Sub-Quantum Physics 9: The N-Wave Photon is Compatible with Special Relativity (2007) argues that although such a medium constitutes an absolute rest frame, a Lorentz transformation between any two frames can always be performed in two steps through it. Sub-Quantum Physics 10: The N-Wave Photon Explains Planck's Constant (2008) adds granularity to the medium and derives Planck's constant from transport properties, the shock length being fixed by viscosity and thermal conductivity and the shock-front thickness by the mean free path. Sub-Quantum Physics 11: The N-Wave Photon, Particles, Transversality, & Polarization (2009) accounts for transversality from the inertial response of an electron in the medium, and for polarization by giving the N-wave a blade-shaped rather than circular cross-section.

Nainan K Varghese's Hypothesis on MATTER derives everything from a single postulated quantum of matter and an all-encompassing universal medium built from it. In Linear speed of light (According to 'Hypothesis on MATTER') (2011) light is a flow of basic three-dimensional matter corpuscles accompanied by an energy radiation: the photon is the matter-core — a disc-shaped body spinning about one of its diameters — together with the electromagnetic distortions it produces in the medium, the two supporting each other for the photon's stability. The framework is set out in Hypothesis on MATTER (2010) and applied in Inertia (According to 'Hypothesis on MATTER') (2010), where inertia belongs to the latticework of the medium rather than to matter, in Matter and Mass (according to Hypothesis on MATTER) (2011), and in Black hole (According to 'Hypothesis on MATTER') (2012).

Francis Viren Fernandes has written more on the photon than anyone else in this archive, developing a system in which the photon is a torus and matter is made of photons. The Quantum of Light (2009) describes the photon in terms of mass, charge, radius, time-period, cross-sectional area and contained ether, resolving the particle and wave natures by having photon particles ripple the waves of a quantised "186-ether". The Fractal Structure of Light & Emanation of Matter (2010) makes the photon a torus composed of aitherons, from which tubular chains of photons coil into elements measured as atomic mass. Faraday's Equation (2009) reads electrochemistry the same way, a cluster of photons about a 186-ether seed constituting atomic mass and the seed itself being what is measured as electric charge; Emanation of Matter - Creation of Water (2009) applies this to pair production and to water; Defining Inertial & Gravitational Mass (2009) has toroidal photon rings aligning into fibres filled with ether; Gaussian Surface of a Photon (2009) relates elementary charge to the photon's surface charge density. In cosmology, The CMBR Wave-Maker Rydberg Photon (2011) and CMBR - A RYDBERG PHOTON PRECESSION IN STARS (2013) attribute the microwave background to Rydberg photons in stellar hydrogen rather than to a Big Bang relic. Notably, Radiation of Light by 186-Ether: Unity of Light and Gravity (2010) draws a conclusion that sets him against most of the model-builders above: "the transmission of light is not locomotion of photons" but the rippling of the ether by a source wave-maker.

Bruce Nappi's Space Lattice Theory (2015) takes space to be a densely packed crystal-like lattice in which matter consists of movable dislocations, and offers this as a route to photon "dualism" among much else.

The rest mass of the photon

Zero rest mass is the claim on which special relativity's use of the photon depends, and a distinct group of papers here denies it.

James Carter puts the objection at its sharpest in Photons and the Change in Mass of Moving Bodies (1999): the premise that the photon has no mass is, he writes, "a purely metaphysical assumption that is not confirmed by any experiment", and the apparent conflict between the mass and energy relations satisfied by measured photons is resolved in practice simply by ignoring one of them and declaring the photon massless. Harold A Papazian introduces the notions of phase mass and group mass in On the Mass of the Photon (1993) to complete the symmetry of de Broglie's relations. Mohamed Elmansour Hassani argues for a photon "relative rest mass" in On the Relative Rest Mass of the Photon (2010), and William M Honig derived a minimum photon rest mass from Planck's constant and discontinuous electromagnetic waves as early as 1974.

The most consequential use of a photon mass in this archive is experimental. Jean Pierre Vigier argues in Relativistic Interpretation (with Non-Zero Photon Mass) of the Small Ether Drift Velocity Detected by Michelson, Morley and Miller (1997) that the small non-null drifts reported from 1887 to 1926 are not compatible with Newtonian mechanics but are recovered if the small photon mass considered by Einstein, Schrödinger and de Broglie is admitted, since it implies a small frequency-dependent anisotropy in the velocity of light. Hector A. Munera extends the proposal to absolute space in his 1997 companion paper, arguing that the Michelson-Morley residuals are compatible either with an extended Newtonian mechanics or with Vigier's reading, provided a small photon rest mass of order 10⁻³⁵ g for yellow light is introduced. Patrick J Fleming applies a non-zero photon rest mass, together with the de Broglie-Bohm interpretation, to the Sagnac effect in a 1997 paper held in the archive but not yet given a page here; see Sagnac Effect.

Against all of this stands Ari Brynjolfsson's Weightlessness of photons: A quantum effect (2004), which argues that quantum mechanical effects reverse the photons' gravitational redshift as they travel from the Sun to the Earth, and that the solar Fraunhofer lines are plasma redshifted rather than gravitationally redshifted — the classical experiments thought to have demonstrated gravitational redshift of photons being, on his analysis, incapable of detecting the reversal.

Photons in gravitation, redshift and cosmology

Because cosmological redshift is measured on light, what one takes the photon to be propagates directly into cosmology, and several of the tired-light and static-universe proposals on this wiki are at bottom claims about photons.

Ari Brynjolfsson's plasma redshift, set out here in Redshift of Photons Penetrating a Hot Plasma (2005), is an energy loss suffered by photons traversing hot, sparse electron plasma, additional to ionization, excitation, Compton and Raman losses. Lyndon E Ashmore proposes a different mechanism in Recoil Interaction Between Photons and The Electrons In The Plasma Of Intergalactic Space Leading To The Hubble Constant And CMB (2006): absorption and re-emission by intergalactic electrons which recoil on both occasions, a double Mössbauer effect yielding a redshift, and a Hubble constant expressible as h r_e/m_e per cubic metre of space. Charles E Weber argues in The Cosmological Red Shift as a Gravitational Interaction of Photons with Masses in Space (2006) that a photon passing a mass climbs out of a slightly deeper well than it fell into, because its trajectory bends toward the mass, leaving a slight residual redshift which he proposes as the main cause of the cosmological redshift. Peter F Browne interprets the Hubble redshift as a gradual decrease of photon frequency arising from graviton scattering toward blackbody equilibrium in Large Anamalous Redshifts and Zero-Point Radiation (1994), and Matthew R Edwards proposes a continuous interconversion of graviton and photon energy at rates set by the Hubble constant in Photon-Graviton Recycling as Cause of Gravitation (2007). Raymond H. Gallucci examines whether such photon-particle interactions can instead be handled by varying the speed of light in Can Photon-Particle Interactions be Explained with Varying Light Speed? (2015).

On gravitational redshift specifically, Jorge A Guala-Valverde argues in Gravitational Redshift Revisited (1992) that the shift occurs not during the journey from source to destination but at emission, at an energy level already affected by the gravitational field. Vyacheslav N Streltsov makes the gravitational shift of photon frequency the foundation for quantum gravity in The Principal Solution of the Greatest Problem in Physics (Quantum Gravity) (2002), deriving a four-vector gravitational field whose time component is the Newtonian potential and so avoiding the quantisation of the metric. Chung Y Lo argues in The Gravity of Photons and the Necessary Rectification of Einstein Equation (2006) that the gravity of an electromagnetic wave must be an accompanying gravitational wave travelling at the same speed, so that the Einstein equation requires an additional photonic energy-stress tensor with antigravity coupling. Curtis E. Renshaw accounts for both Mercury's perihelion advance and photon deflection with a velocity-dependent Newtonian potential in The Gravitational Potential for a Moving Observer, Mercury's Perihelion, Photon Deflection and Time Delay of a Solar Grazing Photon (2012), and Philipp M Kanarev argues in The Gravitational Radius of a Black Hole (2002) that the Schwarzschild radius is incomplete because it takes no account of the photon's wavelength.

Two further papers connect photons to the mechanism of gravity itself: Zifeng Li's The Law of Universal Attraction with Momentum Exchange between Objects and Microparticles (2010), which surveys graviton, universal-repulsion and sub-photon-sea hypotheses and proposes momentum exchange with a sea of micro-particles, and Hossein Javadi and F. Forouzbakhsh's Zero Point Energy and the Dirac Equation (2007), which redefines the graviton from the behaviour of photons in a gravitational field. Viraj Fernando treats Doppler shifts, aberration and the Fresnel drag coefficient as photon-cosmic field interactions in Doppler Phenomena Determined by Photon-Cosmic Field Interactions (2012), and Francisco J. Müller raises the neglected question of how an absorption line — the absence of radiation — can be Doppler shifted at all in The Doppler Effect of Absorption Spectral Lines in Moving Astronomic Bodies: How Can It Happen? (2010 John Chappell Memorial Lecture).

Spin, polarization and the identity of the photon

Whether the photon carries intrinsic angular momentum is disputed here independently of whether it exists. Alan McCone argues in Sub-Quantum Physics 7: The Spin-Zero Photon Hypothesis (2004) that it does not, and rebuilds polarization from wave geometry instead. Johann Marinsek reaches the same conclusion by a different route in Physics G: Photons Would Not Spin (2008), deriving the radius a photon would have to have if it did spin and asking whether a divided photon would then have doubled spin. Against them, John E Carroll's photon-like Maxwell solutions carry distributed helical rotations over the whole cross-section, and D E McLennan's dipole photon requires the accompanying Maxwell waves to be circularly polarized.

The charge of the photon raises a related puzzle. Vyacheslav N Streltsov asks in How do Neutral Photons Carry the Sign & Value of Charge? (2002) how virtual field quanta can convey the sign and magnitude of charge between interacting particles, suggesting that the difference between the fields of positive and negative charges may lie in the helicity of the corresponding virtual photons, while acknowledging that the mechanism carrying the value of the charge remains unexplained. E Comay argues in Remarks on Photon-Hadron Interactions (2003) that vector meson dominance and related approaches to real photon-hadron interaction should not be regarded as parts of a theory but at most as phenomenological models.

Finally, several papers question whether the relations defining the photon are as universal as claimed. Ronald G. Newburgh shows in The de Broglie Relations: Lorentz Invariance and Photons (1988) that a simple covariant derivation of the de Broglie relations breaks down for propagation in an anisotropic medium, with the consequence that their covariance is restricted. J. Perdijon treats duality itself as a relativistic paradox in Wave-Particle Duality Considered as a Relativistic Paradox (1988). Allen D Allen rederives photon energy so that work done on photons during refraction is properly accounted for in Work Done on Photons During Refraction: Improved Symmetry From a More Consistent Expression for Photon Energy (1988), and Jozef S Wilczynski asks in Can Photons Travel Faster Than c? (1997) whether the speed limit itself survives a critical examination of special relativity's kinematics.

Where the researchers here disagree

This is not a literature with a single alternative to offer, and the disagreements are worth stating plainly.

• Whether the photon exists at all. Trevor W Marshall, Emilio Santos, Robert L. Henderson, Xavier Borg, Johann Marinsek, Thomas Smid, Bill Gaede and Eric Reiter argue that there is no light quantum. Philipp M Kanarev, D E McLennan, Daniel H Deutsch, Francis Viren Fernandes, Nainan K Varghese, Wladimir Guglinski, Erich Wanek and Alan McCone take the photon to be real and devote their work to giving it a structure. Both camps regard Einstein's photon as inadequate; they mean opposite things by it.
• Whether a medium is required. Robert L Carroll's cylindrical wave-photon is explicitly offered with "no indication that a medium is required for its propagation." Joseph F Cuny, Adolphe Martin, Alan McCone, Nainan K Varghese, Francis Viren Fernandes and Volodymyr V Krasnoholovets all build the photon out of a medium, and disagree among themselves about what the medium is — a gas, a compressible kinetic fluid, a latticework of quanta of matter, an ether of 186-units, a tessel-lattice.
• Whether the photon moves. Most models here have a photon that travels. Francis Viren Fernandes concludes in Radiation of Light by 186-Ether: Unity of Light and Gravity that "the transmission of light is not locomotion of photons", and Rati Ram Sharma's sharmons likewise "do not physically move". Nainan K Varghese, by contrast, makes light a literal flow of three-dimensional matter corpuscles.
• Whether the photon spins. Alan McCone and Johann Marinsek say no; John E Carroll and D E McLennan build rotation into the photon's geometry.
• Whether the photon has mass. James Carter, Jean Pierre Vigier, Harold A Papazian, William M Honig, Patrick J Fleming and Hector Munera argue for a non-zero rest mass, in Vigier's and Munera's case as the explanation of the Michelson-Morley residuals; Ari Brynjolfsson argues for weightlessness as a quantum effect.
• One paper here is an explicit rebuttal of another author on this wiki. Robert A. Kerr's Light Is Transmitted By Photons (2010) opens by naming Glenn Borchardt and disputing his statement that light is not transmitted by photons; Kerr's photons are "the smallest detectable mass particle", detected and quantified by their pressure, which is temperature, and transferring energy to larger particles by impact.
• Single or many. Peter Marquardt holds that single photons are never observed and that what exists are coherent bunches; the "multiple photon" note replaces the single particle with a divisible set of homokinetic particles; Robert and David de Hilster argue that a single particle cannot carry a frequency at all, so that light must be a procession of particles whose spacing is the frequency; most of the model-builders assume a single localised object.

Papers on this wiki

Rejection of the photon and of quantised absorption:

• 1997 - The Myth of the Photon — Trevor W Marshall, Emilio C. Santos
• 2001 - Wave and Particle Theory of Light applied to the Photoelectric Effect — Thomas Smid
• 2005 - Light: Neither Particle nor Transverse Wave — Bill Gaede
• 2006 - Classical Interpretation of EPR- Bell Test Photon Correlation Experiments — Thomas Smid
• 2007 - A Classical Approach to the Photoelectric Effect & Photoelectron Emission — Bing-Xin Gong
• 2008 - The Myth of the Down Converted Photon — Trevor W Marshall
• 2008 - Physics EA: Photoelectric Effect No Empirical Confirmation for the Existence of a Photon That Carries Energy Packet E = hf — Johann Marinsek
• 2008 - Physics G: Photons Would Not Spin — Johann Marinsek
• 2009 - Photon: Reality or Fiction — Milos Abadzic
• 2009 - The Revenge of Old Classical Physics: No Space for Photons or Relativity — Alvaro Quinteros Valenzuela
• 2010 - Abolishing the Wave-Particle Duality Nonsense — Xavier Borg
• 2010 - Sub Microscopic Description of the Diffraction Phenomenon — Volodymyr V Krasnoholovets
• 2011 - Lightwaves, Not Photons — Robert L. Henderson
• 2011 - An Alternative to Waves and Wave-Packets — Bill Gaede
• 2012 - A Challenge To Quantized Absorption by Experiment and Theory — Eric S. Reiter
• 2012 - What Experiments on Diffraction of Photons Say — Mitch Emery
• 2013 - Radio Waves - Part III: The Photoelectric Effect — Ionel Dinu

Classical wave, wave-packet and soliton models:

• 1980 - The Photon with a Classical Field — Richard Oldani
• 1989 - Photons and Neutrinos as Electromagnetic Solitons — Geoffrey Hunter, Robert L. P. Wadlinger
• 1997 - A Quantum of Light Shed on Classical Potentials and Fields — Cynthia Kolb Whitney
• 2004 - Towards a Classical Explanation to the Stable Electron Paths around Nuclei and to Radiation in Connection with the De-Excitation of Excited Electrons — Jan Olof Jonson
• 2005 - A Field Based Model of the Photon; Lorentz Covariant Quantization — Richard Oldani
• 2005 - Photon - The Minimum Dose of Electromagnetic Radiation — Tuomo Suntola
• 2005 - On Light — Gin Conesa
• 2006 - A Relativistic Wave-Particle Based on Maxwell's Equations: A Model for a Classical Photon — John E Carroll
• 2006 - Light Waves as a Many-Particle Phenomenon — Peter Marquardt
• 2006 - A New Hypothesis on Light — Gin Conesa, Manuel Conesa
• 2007 - Photon as a Classical Wave Packet from Classically Stabilized Electron Orbits — Jan Olof Jonson
• 2008 - Secondary Field Theory and Photons — Richard Oldani
• 2009 - Photon-Like Solutions of Maxwell's Equations — John E Carroll, Joseph Beals IV, Ruth Thompson
• 2011 - Coulomb's Law is the Basis for Radiation Energy — Jan Olof Jonson
• 2011 - Unified Theory's Wave-Quantum Unity of Light — Rati Ram Sharma
• 2012 - Resonance Formula of the Hydrogen Spectrum against Light Quanta: Photons — Dimiter G. Stoinov, Dilian D. Stoynov

Structured and extended photon models:

• 1974 - A Minimum Photon Rest Mass Using Planck's Constant and Discontinuous Electromagnetic Waves — William M Honig
• 1988 - Electromechanical Physical Model of the Photon — Daniel H Deutsch
• 1989 - The Photon — D E McLennan
• 1989 - Maxwell Equations: A New Approach — D E McLennan
• 1989 - On the Possibility of a Rationalistic Approach to Microphysics — Franco Selleri
• 1997 - Internal Structures of Electrons and Photons and some Consequences in Relativistic Physics — Werner A Hofer
• 1997 - Laboratory-Scale Test of de Broglie's Tired-Photon Model — Ramalho Croca
• 2002 - A Model of the Photon — Wladimir Guglinski
• 2002 - Modelling the Photon and Analyzing Its Electromagnetic and Physical Nature — Philipp M Kanarev
• 2002 - The Possibility of Developing a Theory of Light Without Special Relativity — Liudmila B. Boldyreva, Nina B. Sotina
• 2003 - Photon Model — Philipp M Kanarev
• 2005 - The Structure of a Photon — János Rohan
• 2007 - Electron Spin and the Emission of Photons — Mitch Emery
• 2008 - The Particlewave: A New Model for Light and the Matter Waves — Erich Wanek
• 2009 - The "Mass" of a Photon only an Expression of its Helical Configuration? — Erich Wanek
• 2012 - The "multiple photon", an alternative to the single particle photon.
• 2015 - The Periodic Table will be Rewritten - Photons of an H-atom — Francis Viren Fernandes

Aether and medium-based models:

• 1994 - The Ether Revisied — Adolphe Martin
• 2002 - The Photon and Its Aether — Joseph F Cuny
• 2004 - Sub-Quantum Physics 7: The Spin-Zero Photon Hypothesis — Alan McCone
• 2005 - Sub-Quantum Physics 8: Photons Have Inertial Properties of Weak Shock N-Waves — Alan McCone
• 2007 - Sub-Quantum Physics 9: The N-Wave Photon is Compatible with Special Relativity — Alan McCone
• 2008 - Sub-Quantum Physics 10: The N-Wave Photon Explains Planck's Constant — Alan McCone
• 2009 - Sub-Quantum Physics 11: The N-Wave Photon, Particles, Transversality, & Polarization — Alan McCone
• 2009 - The Quantum of Light — Francis Viren Fernandes
• 2009 - Faraday's Equation — Francis Viren Fernandes
• 2009 - Emanation of Matter - Creation of Water — Francis Viren Fernandes
• 2009 - Defining Inertial & Gravitational Mass — Francis Viren Fernandes
• 2009 - Gaussian Surface of a Photon — Francis Viren Fernandes
• 2010 - Light as Dynamic Maxwellian Photons: Interference in Terms of Trajectories — Antonis Agathangelidis, Anastasios Th. Triantafillides
• 2010 - The Fractal Structure of Light & Emanation of Matter — Francis Viren Fernandes
• 2010 - Radiation of Light by 186-Ether: Unity of Light and Gravity — Francis Viren Fernandes
• 2010 - Hypothesis on MATTER — Nainan K Varghese
• 2010 - Inertia (According to 'Hypothesis on MATTER') — Nainan K Varghese
• 2011 - Linear speed of light (According to 'Hypothesis on MATTER') — Nainan K Varghese
• 2011 - Matter and Mass (according to Hypothesis on MATTER) — Nainan K Varghese
• 2011 - The Gamma Factor Resolved — Francis Viren Fernandes
• 2011 - Transient Proton Mass & Radial Length Change During Electrolysis Of Water — Francis Viren Fernandes
• 2012 - Black hole (According to 'Hypothesis on MATTER') — Nainan K Varghese
• 2015 - Space Lattice Theory — Bruce Nappi

Photon rest mass:

• 1993 - On the Mass of the Photon — Harold A Papazian
• 1997 - Relativistic Interpretation (with Non-Zero Photon Mass) of the Small Ether Drift Velocity Detected by Michelson, Morley and Miller — Jean Pierre Vigier
• 1997 - Can Photons Travel Faster Than c? — Jozef S Wilczynski
• 1999 - Photons and the Change in Mass of Moving Bodies — James Carter
• 2004 - Weightlessness of photons: A quantum effect — Ari Brynjolfsson
• 2010 - On the Relative Rest Mass of the Photon — Mohamed Elmansour Hassani
• 2010 - Light Is Transmitted By Photons — Robert A. Kerr

Photons in gravitation, redshift and cosmology:

• 1992 - Gravitational Redshift Revisited — Jorge A Guala-Valverde
• 1994 - Large Anamalous Redshifts and Zero-Point Radiation — Peter F Browne
• 2002 - The Principal Solution of the Greatest Problem in Physics (Quantum Gravity) — Vyacheslav N Streltsov
• 2002 - The Gravitational Radius of a Black Hole — Philipp M Kanarev
• 2005 - Redshift of Photons Penetrating a Hot Plasma — Ari Brynjolfsson
• 2006 - Recoil Interaction Between Photons and The Electrons In The Plasma Of Intergalactic Space Leading To The Hubble Constant And CMB — Lyndon E Ashmore
• 2006 - The Cosmological Red Shift as a Gravitational Interaction of Photons with Masses in Space — Charles E Weber
• 2006 - The Gravity of Photons and the Necessary Rectification of Einstein Equation — Chung Y Lo
• 2007 - Photon-Graviton Recycling as Cause of Gravitation — Matthew R Edwards
• 2007 - Zero Point Energy and the Dirac Equation — Hossein Javadi, F. Forouzbakhsh
• 2009 - The Spectrum of the Universe — Philipp M Kanarev
• 2010 - The Law of Universal Attraction with Momentum Exchange between Objects and Microparticles — Zifeng Li
• 2010 - The Doppler Effect of Absorption Spectral Lines in Moving Astronomic Bodies: How Can It Happen? (2010 John Chappell Memorial Lecture) — Francisco J. Müller
• 2011 - The CMBR Wave-Maker Rydberg Photon — Francis Viren Fernandes
• 2012 - Doppler Phenomena Determined by Photon-Cosmic Field Interactions — Viraj Fernando
• 2012 - The Gravitational Potential for a Moving Observer, Mercury's Perihelion, Photon Deflection and Time Delay of a Solar Grazing Photon — Curtis E. Renshaw
• 2013 - CMBR - A RYDBERG PHOTON PRECESSION IN STARS — Francis Viren Fernandes
• 2015 - Can Photon-Particle Interactions be Explained with Varying Light Speed? — Raymond H. Gallucci

Duality, spin, charge and interactions:

• 1988 - Work Done on Photons During Refraction: Improved Symmetry From a More Consistent Expression for Photon Energy — Allen D Allen
• 1988 - The de Broglie Relations: Lorentz Invariance and Photons — Ronald G. Newburgh
• 1988 - Wave-Particle Duality Considered as a Relativistic Paradox — J. Perdijon
• 1994 - Electromagnetic Interactions and Particle Physics — A. O. Barut
• 1994 - A Test of the Complementarity Principle in Single-Photon States of Light — Yutaka Mizobuchi, Yoshiyuki Othake
• 1994 - Experiments with Entangled Two-Photon States From Type-H Parametric Down Conversion: Evidence for Wave-Particle Duality — Carroll O. Alley, T. E. Kiess, A. V. Sergienko, Yanhua H. Shih
• 1994 - Atomic Cascade Experiments With Two-Channel Polarizers and Quantum Mechanical Nonlocality — M Ardehali
• 2002 - How do Neutral Photons Carry the Sign & Value of Charge? — Vyacheslav N Streltsov
• 2002 - The Law of the Radiation of the Perfect Blackbody is the Law of Classical Physics — Philipp M Kanarev
• 2002 - Electrons in Atoms — Philipp M Kanarev
• 2003 - Remarks on Photon-Hadron Interactions — E Comay
• 2003 - The Doppler Effect at Photon Emission — Philipp M Kanarev
• 2004 - The New Interpretation of Photoeffect — Philipp M Kanarev
• 2005 - Einstein and the Photoelectric Effect — Robert Schor

Papers held in the archive but not yet given pages here include Patrick J Fleming's "An Explanation of the Sagnac Effect Based on the Special Theory of Relativity, the de Broglie/Bohm Interpretation of Quantum Mechanics, and a Non-Zero Rest Mass for the Photon" (1997), Hector A. Munera's "An Absolute Space Interpretation (with Non-Zero Photon Mass) of the Non-Null Results of Michelson-Morley and Similar Experiments" (1997), and Eric S. Reiter's "Experiment and Theory Removing all that Quantum Photon Wave-particle-Duality Entanglement Nonsense" (2017).

See also

• Light — the wider question of what light is and how it propagates
• Aether — the medium in which many of the photon models above are built
• Quantum mechanics — the framework whose foundations most of these papers contest
• Redshift and Tired Light — where the photon question enters cosmology
• Sagnac Effect — the experiment to which a non-zero photon mass has been applied here
• Relativity — the theory that requires the photon to be massless
• Energy — energy as a measure of matter in motion rather than a substance
• Galilean Electrodynamics — the journal in which much of this literature appeared
• Natural Philosophy Alliance — the organisation, now the John Chappell Natural Philosophy Society, whose proceedings supply most of these papers