Second quantization (Quantum Field Theory of Dirac, Feynman et al.) is physically correct and debunks the non-relativistic, physically wrong first quantization approximation to Quantum Mechanics (Schroedinger and Heisenberg)

Just as Bohr’s atom is taught in school physics, most mainstream general physicists with training in quantum mechanics are still trapped in the use of the “anything goes” false (non-relativistic) 1927-originating “first quantization” for quantum mechanics (where anything is possible because motion is described by an uncertainty principle instead of a quantized field mechanism for chaos on small scales). The physically correct replacement is called “second quantization” or “quantum field theory”, which was developed from 1929-48 by Dirac, Feynman and others.

The discoverer of the path integrals approach to quantum field theory, Nobel laureate Richard P. Feynman, has debunked the mainstream first-quantization uncertainty principle of quantum mechanics. Instead of anything being possible, the indeterminate electron motion in the atom is caused by second-quantization: the field quanta randomly interacting and deflecting the electron.

“… Bohr … said: ‘… one could not talk about the trajectory of an electron in the atom, because it was something not observable.’ … Bohr thought that I didn’t know the uncertainty principle … it didn’t make me angry, it just made me realize that … [ they ] … didn’t know what I was talking about, and it was hopeless to try to explain it further. I gave up, I simply gave up …”

– Richard P. Feynman, quoted in Jagdish Mehra’s biography of Feynman, The Beat of a Different Drum, Oxford University Press, 1994, pp. 245-248. (Fortunately, Dyson didn’t give up!)

‘I would like to put the uncertainty principle in its historical place: When the revolutionary ideas of quantum physics were first coming out, people still tried to understand them in terms of old-fashioned ideas … But at a certain point the old-fashioned ideas would begin to fail, so a warning was developed that said, in effect, “Your old-fashioned ideas are no damn good when …” If you get rid of all the old-fashioned ideas and instead use the ideas that I’m explaining in these lectures – adding arrows [path amplitudes] for all the ways an event can happen – there is no need for an uncertainty principle!’

– Richard P. Feynman, QED, Penguin Books, London, 1990, pp. 55-56.

‘When we look at photons on a large scale – much larger than the distance required for one stopwatch turn [i.e., wavelength] – the phenomena that we see are very well approximated by rules such as “light travels in straight lines [without overlapping two nearby slits in a screen]“, because there are enough paths around the path of minimum time to reinforce each other, and enough other paths to cancel each other out. But when the space through which a photon moves becomes too small (such as the tiny holes in the [double slit] screen), these rules fail – we discover that light doesn’t have to go in straight [narrow] lines, there are interferences created by the two holes, and so on. The same situation exists with electrons: when seen on a large scale, they travel like particles, on definite paths. But on a small scale, such as inside an atom, the space is so small that [individual random field quanta exchanges become important because there isn’t enough space involved for them to average out completely, so] there is no main path, no “orbit”; there are all sorts of ways the electron could go, each with an amplitude. The phenomenon of interference becomes very important, and we have to sum the arrows [in the path integral for individual field quanta interactions, instead of using the average which is the classical Coulomb field] to predict where an electron is likely to be.’

– Richard P. Feynman, QED, Penguin Books, London, 1990, Chapter 3, pp. 84-5.

His path integrals rebuild and reformulate quantum mechanics itself, getting rid of the Bohring ‘uncertainty principle’ and all the pseudoscientific baggage like ‘entanglement hype’ it brings with it:

‘This paper will describe what is essentially a third formulation of nonrelativistic quantum theory [Schroedinger’s wave equation and Heisenberg’s matrix mechanics being the first two attempts, which both generate nonsense ‘interpretations’]. This formulation was suggested by some of Dirac’s remarks concerning the relation of classical action to quantum mechanics. A probability amplitude is associated with an entire motion of a particle as a function of time, rather than simply with a position of the particle at a particular time.

‘The formulation is mathematically equivalent to the more usual formulations. … there are problems for which the new point of view offers a distinct advantage. …’

– Richard P. Feynman, ‘Space-Time Approach to Non-Relativistic Quantum Mechanics’, Reviews of Modern Physics, vol. 20 (1948), p. 367.

‘… I believe that path integrals would be a very worthwhile contribution to our understanding of quantum mechanics. Firstly, they provide a physically extremely appealing and intuitive way of viewing quantum mechanics: anyone who can understand Young’s double slit experiment in optics should be able to understand the underlying ideas behind path integrals. Secondly, the classical limit of quantum mechanics can be understood in a particularly clean way via path integrals. … for fixed h-bar, paths near the classical path will on average interfere constructively (small phase difference) whereas for random paths the interference will be on average destructive. … we conclude that if the problem is classical (action >> h-bar), the most important contribution to the path integral comes from the region around the path which extremizes the path integral. In other words, the article’s motion is governed by the principle that the action is stationary. This, of course, is none other than the Principle of Least Action from which the Euler-Lagrange equations of classical mechanics are derived.’

– Richard MacKenzie, Path Integral Methods and Applications, pp. 2-13.

‘… light doesn’t really travel only in a straight line; it “smells” the neighboring paths around it, and uses a small core of nearby space. (In the same way, a mirror has to have enough size to reflect normally: if the mirror is too small for the core of neighboring paths, the light scatters in many directions, no matter where you put the mirror.)’

– Richard P. Feynman, QED, Penguin Books, London, 1990, Chapter 2, p. 54.

There are other serious and well-known failures of first quantization aside from the nonrelativistic Hamiltonian time dependence:

“The quantum collapse [in the mainstream interpretation of first quantization quantum mechanics, where a wavefunction collapse occurs whenever a measurement of a particle is made] occurs when we model the wave moving according to Schroedinger (time-dependent) and then, suddenly at the time of interaction we require it to be in an eigenstate and hence to also be a solution of Schroedinger (time-independent). The collapse of the wave function is due to a discontinuity in the equations used to model the physics, it is not inherent in the physics.” – Thomas Love, California State University.

“In some key Bell experiments, including two of the well-known ones by Alain Aspect, 1981-2, it is only after the subtraction of ‘accidentals’ from the coincidence counts that we get violations of Bell tests. The data adjustment, producing increases of up to 60% in the test statistics, has never been adequately justified. Few published experiments give sufficient information for the reader to make a fair assessment.” – http://arxiv.org/PS_cache/quant-ph/pdf/9903/9903066v2.pdf

First quantization for QM (e.g. Schroedinger) quantizes the product of position and momentum of an electron, rather than the Coulomb field which is treated classically. This leads to a mathematically useful approximation for bound states like atoms, which is physically false and inaccurate in detail (a bit like Ptolemy’s epicycles, where all planets were assumed to orbit Earth in circles within circles). Feynman explains this in his 1985 book QED (he dismisses the uncertainty principle as complete model, in favour of path integrals) because indeterminancy is physically caused by virtual particle interactions from the quantized Coulomb field becoming important on small, subatomic scales! Second quantization (QFT) introduced by Dirac in 1929 and developed with Feynman’s path integrals in 1948, instead quantizes the field. Second quantization is physically the correct theory because all indeterminancy results from the random fluctuations in the interactions of discrete field quanta, and first quantization by Heisenberg and Schroedinger’s approaches is just a semi-classical, non-relativistic mathematical approximation useful for obtaining simple mathematical solutions for bound states like atoms:

‘You might wonder how such simple actions could produce such a complex world. It’s because phenomena we see in the world are the result of an enormous intertwining of tremendous numbers of photon exchanges and interferences.’

– Richard P. Feynman, QED, Penguin Books, London, 1990, p. 114.

‘Underneath so many of the phenomena we see every day are only three basic actions: one is described by the simple coupling number, j; the other two by functions P(A to B) and E(A to B) – both of which are closely related. That’s all there is to it, and from it all the rest of the laws of physics come.’

– Richard P. Feynman, QED, Penguin Books, London, 1990, p. 120.

‘It always bothers me that, according to the laws as we understand them today, it takes a computing machine an infinite number of logical operations to figure out what goes on in no matter how tiny a region of space, and no matter how tiny a region of time. How can all that be going on in that tiny space? Why should it take an infinite amount of logic to figure out what one tiny piece of spacetime is going to do? So I have often made the hypothesis that ultimately physics will not require a mathematical statement, that in the end the machinery will be revealed, and the laws will turn out to be simple, like the chequer board with all its apparent complexities.’

– R. P. Feynman, The Character of Physical Law, November 1964 Cornell Lectures, broadcast and published in 1965 by BBC, pp. 57-8.

Sound waves are composed of the group oscillations of large numbers of randomly colliding air molecules; despite the randomness of individual air molecule collisions, the average pressure variations from many molecules obey a simple wave equation and carry the wave energy. Likewise, although the actual motion of an atomic electron is random due to individual interactions with field quanta, the average location of the electron resulting from many random field quanta interactions is non-random and can be described by a simple wave equation such as Schroedinger’s.

This is fact, it isn’t my opinion or speculation: professor David Bohm in 1952 proved that “brownian motion” of an atomic electron will result in average positions described by a Schroedinger wave equation. Unfortunately, Bohm also introduced unnecessary “hidden variables” with an infinite field potential into his messy treatment, making it a needlessly complex, uncheckable representation, instead of simply accepting that the quantum field interations produce the “Brownian motion” of the electron as described by Feynman’s path integrals for simple random field quanta interactions with the electron.

Quantum tunnelling is possible because electromagnetic fields are not classical, but are mediated by field quanta randomly exchanged between charges. For large charges and/or long times, the number of field quanta exchanged is so large that the result is similar to a steady classical field. But for small charges and small times, such as the scattering of charges in high energy physics, there is some small probability that no or few field quanta will happen to be exchanged in the time available, so the charge will be able to penetrate through the classical “Coulomb barrier”. If you quantize the Coulomb field, the electron’s motion is indeterministic in the atom because it’s randomly exchanging Coulomb field quanta which cause chaotic motion. This is second quantization as explained by Feynman in QED. This is not what is done in quantum mechanics, which is based on first quantization, i.e. treating the Coulomb field V classically, and falsely representing the chaotic motion of the electron by a wave-type equation. This is a physically false mathematical model since it omits the physical cause of the indeterminancy (although it gives convenient predictions, somewhat like Ptolemy’s accurate epicycle based predictions of planetary positions):

Fig. 1:The Schrodinger equation, based on quantizing the momentum p in the classical Hamiltonian (the sum of kinetic and potential energy for the particle), H. This is an example of ‘first quantization’, which is inaccurate and is also used in Heisenberg’s matrix mechanics. Correct quantization will instead quantize the Coulomb field potential energy, V, because the whole indeterminancy of the electron in the atom is physically caused by the chaos of the randomly timed individual interactions of the electron with the discrete Coulomb field quanta which bind the electron to orbit the nucleus, as Feynman proved (see quotations below). The triangular symbol is the divergence operator (simply the sum of the gradients in all applicable spatial dimensions, for whatever it operates on) which when squared becomes the laplacian operator (simply the sum of second-order derivatives in all applicable spatial dimensions, for whatever it operates on). We illustrate the Schrodinger equation in just one spatial dimension, x, above, since the terms for other spatial dimensions are identical.

Dirac’s quantum field theory is needed because textbook quantum mechanics is simply wrong: the Schroedinger equation has a second-order dependence on spatial distance but only a first-order dependence on time. In the real world, time and space are found to be on an equal footing, hence spacetime. There are deeper errors in textbook quantum mechanics: it ignores the quantization of the electromagnetic field and instead treats it classically, when the field quanta are the whole distinction between classical and quantum mechanics (the random motion of the electron orbiting the nucleus in the atom is caused by discrete field quanta interactions, as proved by Feynman).

Dirac was the first to achieve a relativistic field equation to replace the non-relativistic quantum mechanics approximations (the Schroedinger wave equation and the Heisenberg momentum-distance matrix mechanics). Dirac also laid the groundwork for Feynman’s path integrals in his 1933 paper “The Lagrangian in Quantum Mechanics” published in Physikalische Zeitschrift der Sowjetunion where he states:

“Quantum mechanics was built up on a foundation of analogy with the Hamiltonian theory of classical mechanics. This is because the classical notion of canonical coordinates and momenta was found to be one with a very simple quantum analogue …

“Now there is an alternative formulation for classical dynamics, provided by the Lagrangian. … The two formulations are, of course, closely related, but there are reasons for believing that the Lagrangian one is the more fundamental. … the Lagrangian method can easily be expressed relativistically, on account of the action function being a relativistic invariant; while the Hamiltonian method is essentially nonrelativistic in form …”

Schroedinger’s time-dependent equation is: Hy= iħ.dy /dt, which has the exponential solution:

y_t = y_o exp[-iH(t – t_o)/ħ].

This equation is accurate, because the error in Schroedinger’s equation comes only from the expression used for the Hamiltonian, H. This exponential law represents the time-dependent value of the wavefunction for any Hamiltonian and time. Squaring this wavefunction gives the amplitude or relative probability for a given Hamiltonian and time. Dirac took this amplitude e^-iHT/ħ and derived the more fundamental lagrangian amplitude for action S, i.e. e^iS/ħ. Feynman showed that summing this amplitude factor over all possible paths or interaction histories gave a result proportional to the total probability for a given interaction. This is the path integral.

Schroedinger’s incorrect, non-relativistic hamiltonian before quantization (ignoring the inclusion of the Coulomb field potential energy, V, which is an added term) is: H = ½ p²/m. Quantization is done using the substitution for momentum, p -> -iħ{divergence operator} as in Fig. 1 above. The Coulomb field potential energy, V, remains classical in Schroedinger’s equation, instead of being quantized as it should.

The bogus ‘special relativity’ prediction to correct the expectation H = ½ p²/m is simply: H = [(mc²)² + p²c²]², but that was falsified by the fact that, although the total mass-energy is then conserved, the resulting Schroedinger equation permits an initially localised electron to travel faster than light! This defect was averted by the Klein-Gordon equation, which states:

ħ²d²y/dt² = [(mc²)² + p²c²]y.

While this is physically correct, it is non-linear in only dealing with second-order variations of the wavefunction. Dirac’s equation simply makes the time-dependent Schroedinger equation (Hy = iħ.dy/dt) relativistic, by inserting for the hamiltonian (H) a totally new relativistic expression which differs from special relativity:

H = apc + b mc²,

where p is the momentum operator. The values of constants a and b can take are represented by a 4 x 4 = 16 component matrix, which is called the Dirac ‘spinor’.  This is not to be confused for the Weyl spinors used in the gauge theories of the Standard Model; whereas the Dirac spinor represents massive spin-1/2 particles, the Dirac equation yields two Weyl equations for massless particles, each with a 2-component Weyl spinor (representing left- and right-handed spin or helicity eigenstates).  The justification for Dirac’s equation is both theoretical and experimental. Firstly, it yields the Klein-Gordon equation for second-order variations of the wavefunction. Secondly, it predicts four solutions for the total energy of a particle having momentum p:

E = ±[(mc²)² + p²c²]^1/2.

Two solutions to this equation arise from the fact that momentum is directional and so can be can be positive or negative. The spin of an electron is ± ½ ħ = ± h/(4p). This explains two of the four solutions! The electron is spin-1/2 so it has a spin of only half the amount of a spin-1 particle, which means that the electron must rotate 720 degrees (not 360 degrees!) to undergo one revolution, like a Mobius strip (a strip of paper with a twist before the ends are glued together, so that there is only one surface and you can draw a continuous line around that surface which is twice the length of the strip, i.e. you need 720 degrees turning to return it to the beginning!). Since the spin rate of the electron generates its intrinsic magnetic moment, it affects the magnetic moment of the electron. Zee gives a concise derivation of the fact that the Dirac equation implies that ‘a unit of spin angular momentum interacts with a magnetic field twice as much as a unit of orbital angular momentum’, a fact discovered by Dirac the day after he found his equation (see: A. Zee, Quantum Field Theory in a Nutshell, Princeton University press, 2003, pp. 177-8.) The other two solutions are evident obvious when considering the case of p = 0, for then E = ± mc².  This equation proves the fundamental distinction between Dirac’s theory and Einstein’s special relativity. Einstein’s equation from special relativity is E = mc². The fact that in fact E = ± mc², proves the physical shallowness of special relativity which results from the lack of physical mechanism in special relativity.  E = ± mc² allowed Dirac to predict antimatter, such as the anti-electron called the positron, which was later discovered by Anderson in 1932 (anti-matter is naturally produced all the time when suitably high-energy gamma radiation hits heavy nuclei, causing pair production, i.e., the creation of a particle and an anti-particle such as an electron and a positron). 

Much of the material above is from the previous post (I’m putting it here on a separate post because that previous post began with sorting out errors in mainstream cosmology, which may have put off some bigoted and dogmatic people who are only interested in non-cosmology aspects of quantum field theory; it also helps me towards assembling background/draft material for a forthcoming book/paper).

To understand how the path integrals approach explains the double slit experiment, see this post. To see how scientific criticisms of mainstream first quantization lies have been censored out of mainstream journals by dogmatic mathematical simpletons who lack a grasp of the nature of science itself (‘Science is the organized skepticism in the reliability of expert opinion.’ – Richard Feynman in Lee Smolin, The Trouble with Physics, Houghton-Mifflin, 2006, p. 307), see this post. There’s a completely causal explanation: the photon is not a point but has transverse spatial extent; when it encounters two nearby slits (closer than a wavelength) part diffracts through each slit and the recombination on the other side gives rise to the photon whose probability of landing at any point depends on both slits, not just one of them.

String theorists who believe dogmatically that mathematical elegance, mystery and beauty in physics rather than hard evidence of agreement with experiment, are the central requirements, should listen to Einstein and Boltzmann:

“I adhered scrupulously to the precept of that brilliant theoretical physicist L. Boltzmann, according to whom matters of elegance ought to be left to the tailor and to the cobbler.”

– A. Einstein, December 1916 Preface to his book Relativity: The Special and General Theory, Methuen & Co., London, 1920.

Mathematical relationship between the Hamiltonian formalism of first quantization quantum mechanics (bound states of particles) and the Lagrangian path integral formalism necessary to adequately describe quantum fields

Heisenberg’s uncertainty principle (for minimum uncertainty, i.e. intrinsic uncertainty):

px = ħ

is quantized in first quantization (Heisenberg and Schroedinger methods) by turning uncertainties in momentum p and position x into non-commuting operators (which I’ll signify by simply placing square brackets around them), and replacing ħ with -iħ. This gives [p,x] = ħ. The two solutions to that are firstly

[x] = iħd/dp with [p]=p,

and secondly

[p] = -iħd/dx with [x] = x.

Either of these solutions is a first quantization of classical physics. Then you do the same thing replacing momentum p = E/c and x = ct for light, giving px = (E/c)(ct) = Et, which allows you to replace the product of uncertainties px in Heisenberg’s uncertainty principle with the product of uncertainties in energy and time, Et. Repeating the previous recipe for quantization on this energy-time Heisenberg uncertainty principle then gives us [E,t] = ħ. This has the two solutions:

[E] = -iħd/dt with [t] = t,

and

[t] = iħd/dE with [E] = E.

Taking [E] = -iħd/dt, this gives Schroedinger’s time-dependent equation when it acts on wavefunction y, with energy operator [E] = H, the Hamiltonian:

Hy = -ħdy/dt

Rearranging

(1/y)dy = -H.dt/(iħ)

integrating this gives:

ln y = -Ht/(iħ)

(ln y_t) – (ln y₀) = -Ht/(iħ)

Taking both sides to natural exponents to get rid of the natural logarithms on the left hand side:

(y_t)/(y₀) = exp(-Ht/(iħ))

hence

y_t = y₀exp(-Ht/(iħ))

Thus the time-dependent wavefunction equals simply the time-independent wavefunction multiplied by the exponential amplitude factor, exp(-Ht/(iħ)), in which the fraction can be rewritten by multiplying both its numerator and denominator by i, giving:

exp(-Ht/(iħ)) = exp(-iHt/(iiħ)) = exp(iHt/ħ).

The product of the Hamiltonian operator for energy with time is analogous to the integral of the Lagrangian for energy over time, so let Ht = {integral symbol}L dt = S, action. Thus the relative amplitude of a wavefunction (representing the contribution from one Feynman diagram or one “path” in the path integral) is given by:

exp(iHt/ħ). = exp(iS/ħ).

So the path integral amplitude factor is mathematically equivalent to both the Heisenberg matrix mechanics and the Schroedinger wave equation. However, there are physical differences. First quantization is physically wrong. Second quantization is physically correct in the way Feynman presents it.

For a detailed derivation of the time-dependent Schroedinger equation using the path integrals formulation, see David Derbes, “Feynman’s derivation of the Schroedinger equation”, Am. J. Phys. v64, issue 7, July 1996, pp. 881-4. For discussions of random or stochastic quantization, see Poul Henrik Damgaard and Helmuth Hüffel, Stochastic quantization (1988) and Mikio Namiki, Stochastic quantization (1992).

The mathematician in modern physics resolutely refuses to see the difference physically between the Hamiltonian and the Lagrangian approaches, 1st and 2nd quantization, instead seeing them as mathematically equivalent descriptions of the same thing This is totally bogus, because in 1st quantization you keep the field classical (falsely) and then falsely make particle motions intrinsically indeterminate (falsely) with no mechanism for this (hence leading to wave function collapses upon measurement and multiple universe entanglement speculations which are provably false in consequence of the falsehood of the 1st quantization model), and in doing this your model is non-relativistic, i.e. contravenes physically confirmed equations of relativity. But 2nd quantization correctly attributes the indeterminancy of real, relativistically on-shell particles to simple random interactions with the Coulomb field quanta, instead of having the Coulomb field classical. This is just like air pressure being approximately classical and contionuous on large scales (where individual random air molecule bombardments are large enough in number to average out statistically), but produces chaotic, random motion on small scales, called Brownian motion, due to the fact that on small scales there is not enough space for good averaging and cancellation of randomness by large numbers of interactions, so that individual impacts become relatively more important and so randomness predominates in the Coulomb field quanta exchanged by atomic electrons and nuclei. There is no magic of the sort that the string theorists and science fiction buffs would like to believe in, such as wave functions collapsing and being entangled, leading to quantum information theory, etc. That is a myth. Caroline H. Thompson has shown how Alain Aspect’s entanglement experiments are not good experimental data, but are adjusted to make them agree with prejudiced beliefs like a religion: http://arxiv.org/abs/quant-ph/9903066, Subtraction of “accidentals” and the validity of Bell tests:

“In some key Bell experiments, including two of the well-known ones by Alain Aspect, 1981-2, it is only after the subtraction of ‘accidentals’ from the coincidence counts that we get violations of Bell tests. The data adjustment, producing increases of up to 60% in the test statistics, has never been adequately justified. Few published experiments give sufficient information for the reader to make a fair assessment. There is a straightforward and well known realist model that fits the unadjusted data very well. In this paper, the logic of this realist model and the reasoning used by experimenters in justification of the data adjustment are discussed. It is concluded that the evidence from all Bell experiments is in urgent need of re-assessment, in the light of all the known ‘loopholes’. Invalid Bell tests have frequently been used, neglecting improved ones derived by Clauser and Horne in 1974. ‘Local causal” explanations for the observations have been wrongfully neglected.”

Update:

Relevant copy of a comment to Professor Johnson’s Asymptotia:

“Gell-Mann is best known as the person who came up with the idea of quarks, the particles that make up (for example) protons and neutrons, the building blocks of atomic nuclei.”

It took genius to publish such a speculative idea. According to William H. Cropper’s book Great physicists (Oxford U.P., p. 418), George Zweig’s paper on that theory was “emphatically rejected” by Physical Review but Murray Gell-Mann was “older and wiser” so he “anticipated a negative reception at the Physical Review to such bizarre entities as unobservable, fractionally charged elementary particles, and he published his first quark paper in Physics Letters. Zweig’s theory went unpublished except in a CERN report, but it and its author acquired a certain reputation. When Zweig sought an appointment at a major university, the head of the department pronounced him a ‘charlatan’.”

It’s good that Gell-Mann managed to anticipate and avoid that censorship so cleverly, or we wouldn’t have quark theory, with the SU(3) strong interaction part of the Standard Model. Another example: Pauli’s attempt to censor Yang-Mills theory in February 1954 because the particles are massless (Pauli had already discarded the idea for this “failure”) is another example (Yang simply sat down when Pauli persisted in objecting).

Consider Oppenheimer’s attempt to censor Feynman’s path integrals without listening at all, as described by Freeman Dyson (Stuckelberg was working on the same idea independently, but was ignored and – as with Zweig’s quarks – he received no Nobel Prize). It’s remarkable that genius in the past has consisted to such a large degree in overcoming apathy (Oppenheimer was not just a stubborn exception who objected to path integrals. E.g., Feynman is quoted by Jagdish Mehra in The Beat of a Different Drum, pp. 245-248, saying that Teller, Dirac and Bohr all also claimed to have “disproved” path integrals: Teller’s disproof consisted of saying that Feynman didn’t have to take account of the exclusion principle, Dirac disproved it for not having a unitary operator, and Bohr disproved it because he believed that Feynman didn’t know the uncertainty principle: “it was hopeless to try to explain it further.” So without Dyson’s brilliance at explaining ideas, Feynman’s path integrals would probably have been ignored.)

“… take the exclusion principle … it turns out that you don’t have to pay much attention to that in the intermediate states in the perturbation theory. I had discovered from empirical rules that if you don’t pay attention to it, you get the right answers anyway …. Teller said: “… It is fundamentally wrong that you don’t have to take the exclusion principle into account.” … Dirac asked “Is it unitary?” … Dirac had proved … that in quantum mechanics, since you progress only forward in time, you have to have a unitary operator. But there is no unitary way of dealing with a single electron. … Bohr … said: “… one could not talk about the trajectory of an electron in the atom, because it was something not observable.” … Bohr thought that I didn’t know the uncertainty principle … it didn’t make me angry, it just made me realize that … [ they ] … didn’t know what I was talking about, and it was hopeless to try to explain it further. I gave up, I simply gave up …”

– Richard P. Feynman, in Jagdish Mehra, The Beat of a Different Drum (Oxford, 1994, pp. 245-248).

Why the rank-2 stress-energy tensor of general relativity does not imply a spin-2 graviton

“If it exists, the graviton must be massless (because the gravitational force has unlimited range) and must have a spin of 2 (because the source of gravity is the stress-energy tensor, which is a second-rank tensor, compared to electromagnetism, the source of which is the four-current, which is a first-rank tensor). To prove the existence of the graviton, physicists must be able to link the particle to the curvature of the space-time continuum and calculate the gravitational force exerted.” – False claim, Wikipedia.

Previous posts explaining why general relativity requires spin-1 gravitons, and rejects spin-2 gravitons, are linked here, here, here, here, and here. But let’s take the false claim that gravitons must be spin-2 because the stress-energy tensor is rank-2. A rank 1 tensor is a first-order (once differentiated, e.g. da/db) differential summation, such as the divergence operator (sum of field gradients) or curl operator (the sum of all of the differences in gradients between field gradients for each pair of mutually orthagonal directions in space). A rank 2 tensor is some defined summation over second-order (twice differentiated, e.g. d²a/db²) differential equations. The field equation of general relativity has a different structure from Maxwell’s field equations for electromagnetism: as the Wikipedia quotation above states, Maxwell’s equations of classical electromagnetism are vector calculus (rank-1 tensors or first-order differential equations), while the tensors of general relativity are second order differential equations, rank-2 tensors.

The lie, however, is that this is physically deep. It’s not. It’s purely a choice of how to express the fields conveniently. For simple electromagnetic fields, where there is no contraction of mass-energy by the field itself, you can do it easily with first-order equations, gradients. These equations calculate fields with a first-order (rank-1) gradient, e.g. electric field strength, which is the gradient of potential/distance, measured in volts/metre. Maxwell’s equations don’t directly represent accelerations (second-order, rank-2 equations would be needed for that). For gravitational fields, you have to work with accelerations because the gravitational field contracts the source of the gravitational field itself, so gravitation is more complicated than electromagnetism.

The people who promote the lie that because rank-1 tensors apply to spin-1 field quanta in electromagnetism, rank-2 tensors must imply spin-2 gravitons, offer no evidence of this assertion. It’s arm-waving lying. It’s true that you need rank-2 tensors in general relativity, but it is not necessary in principle to use rank-1 tensors in electromagnetism: it’s merely easiest to use the simplest mathematical method available. You could in principle use rank-2 tensors to rebuild electromagnetism, by modelling the equations to observable accelerations instead of unobservable rank-1 electric fields and magnetic fields. Nobody has ever seen an electric field: only accelerations and forces caused by charges. (Likewise for magnetic fields.)

There is no physical correlation between the rank of the tensor and the spin of the gauge boson. It’s a purely historical accident that rank-1 tensors (vector calculus, first-order differential equations) are used to model fictitious electric and magnetic “fields”. We don’t directly observe electric field lines or electric charges (nobody has seen the charged core of an electron, what we see are effects of forces and accelerations which can merely be described in terms of field lines and charges). We observe accelerations and forces. The field lines and charges are not directly observed. The mathematical framework for a description of the relationship between the source of a field and the end result depends on the definition of the end result. In Maxwell’s equations, the end result of a electric charge which is not moving relative to the observer is a first-order field, defined in volts/metre. If you convert this first-order differential field into an observable effect, like force or acceleration, you get a second-order differential equation, acceleration a = d²x/dt². General relativity doesn’t describe gravity in terms of a first-order field like Maxwell’s equations do, but instead describes gravitation in terms of a second-order observable, i.e. space curvature produced acceleration, a = d²x/dt².

So the distinction between rank-1 and rank-2 tensors in electromagnetism and general relativity is not physically deep: it’s a matter of human decisions on how to represent electromagnetism and gravitation.

We choose in Maxwell’s equations to represent not second-order accelerations but using Michael Faraday’s imaginary concept of a pictorial field, radiating and curving “field lines” which are represented by first-order field gradients and curls. In Einstein’s general relativity, by contrast, we don’t represent gravity by such half-baked unobservable field concept, but in terms of directly-observable accelerations.

Like first-quantization (undergraduate quantum mechanics) lies, the “spin-2” graviton deception is a brilliant example of historical physically-ignorant mathematical obfuscation in action, leading to groupthink delusions in theoretical physics. (Anyone who criticises the lie is treated with a similar degree of delusional, paranoid hostility directed to dissenters of evil dictatorships. Instead of examining the evidence and seeking to correct the problem – which in the case of an evil dictatorship is obviously a big challenge – the messenger is inevitably shot or the “message” is “peacefully” deleted from the arXiv, reminiscent of the scene from Planet of the Apes where Dr Zaius – serving a dual role as Minister of Science and Chief Defender of the Faith, has to erase the words written in the sand which would undermine his religion and social tea-party of lying beliefs. In this analogy, the censors of the arXiv or journals like Classical and Quantum Gravity are not defending objsctive science, but are instead defending subjective pseudo-science – the groupthink orthodoxy which masquerades as science – from being exposed as a fraud.)

Dissimilarities in tensor ranks used to describe two different fields originate from dissimilarities in the field definitions for those two different fields, not to the spin of the field quanta. Any gauge field whose field is written in a second order differential equation, e.g., acceleration, can be classically approximated by rank-2 tensor equation. Comparing Maxwell’s equations in which fields are expressed in terms of first-order gradients like electric fields (volts/metre) with general relativity in which fields are accelerations or curvatures, is comparing chalk and cheese. They are not just different units, but have different purposes. For a summary of textbook treatments of curvature tensors, see Dr Kevin Aylward’s General Relativity for Teletubbys: “the fundamental point of the Riemann tensor [the Ricci curvature tensor in the field equation general relativity is simply a cut-down, rank-2 version Riemann tensor: the Ricci curvature tensor, R_ab = R^x_axb, where R^x_axb is the Riemann tensor], as far as general relativity is concerned, is that it describes the acceleration of geodesics with respect to one another. … I am led to believe that many people don’t have a … clue what’s going on, although they can apply the formulas in a sleepwalking sense. … The Riemann curvature tensor is what tells one what that acceleration between the [particles] will be. This is expressed by

[Beware of some errors in the physical understanding of some of these general relativity internet sites, however. E.g., some suggest – following a popular 1950s book on relativity – that the inverse-square law is discredited by general relativity, because the relativistic motion of Mercury around the sun can be approximated within Newton’s framework by increasing the inverse-square law power slightly from its value of 1/R² to 1/R^{2 + X} where X is a small fraction, so that the force appears to get stronger nearer the sun. This is fictitious and is just an approximation to roughly accommodate relativistic effects that Newton ignored, e.g. the small increase in planetary mass due to its higher velocity when the planet is nearer the sun on part of its elliptical orbit, than it has when it is moving slower far from sun. This isn’t a physically correct model; it’s just a back-of-the-envelope fudge. A physically correct version of planetary motion in the Newtonian framework would keep the geometric inverse square law and would then correctly modify the force by making the right changes for the relativistic mass variation with velocity. Ptolemy’s epicycles demonstrated the danger of constructing approximate mathematical model which have no physical validity, which then become fashion.]”

Maxwell’s theory based on Faraday’s field lines concept employs only rank-1 equations, for example the divergence of the electric field strength, E, is directly proportional to the charge density, q (charge density is here defined as the charge per unit surface area, not the charge per unit volume): div.E ~ q. The reason this is a rank-1 equation is simply because the divergence operator is the sum of gradients in all three perpendicular directions of space for the operand. All it says is that a unit charge contributes a fixed number of diverging radial lines of electric field, so the total field is directly proportional to the total charge.

But this is just Faraday’s way of visualizing the way the electric force operates! Remember that nobody has yet seen or reported detecting an “electric field line” of force! With our electric meters, iron filings, and compasses we only see the results of forces and accelerations, so the number and locations of electric or magnetic field lines depicted in textbook diagrams is due to purely arbitrary conventions. It’s merely an abstract aetherial legacy from the Faraday-Maxwell era, not a physical reality that has any experimental evidence behind it. If you are going to confuse Faraday’s and Maxwell’s imaginary concept of field “lines” with experimentally defensible reality, you might as well write down an equation in which the invisible intermediary between charge and force is an angel, a UFO, a fairy or an elephant in an imaginary extra dimension. Quantum field theory tells us that there are no physical lines. Instead of Maxwell’s “physical lines of force”, we have known since QED was verified that there are field quanta being exchanged between charges.

So if we get rid of our ad hoc prejudices, getting rid of “electric field strength, E” in volts/metre and just expressing the result of the electric force in terms of what we can actually measure, namely accelerations and forces, we’d have a rank-2 tensor, basically the same field equation as is used in general relativity for gravity. The only differences will be the factor of ~10⁴⁰ difference between field strengths of electromagnetism and gravity, the differences in the signs for the curvatures (like charges repel in electromagnetism, but attract in gravity) and the absence of the contraction term that makes the gravitational field contract the source of the field, but supposedly does not exist in electromagnetism. The tensor rank will be 2 for both cases, thus disproving the arm-waving yet popular idea that the rank number may be correlated to the field quanta spin. In other words, the electric field could be modelled by a rank-2 equation if we simply make the electric field consistent with the gravitational field by expressing both field in terms of accelerations, instead of using the gradient of the Faraday-legacy volts/metre “field strength” for the electric field. This is however beyond the understanding of the mainstream, who are deluded by fashion and historical ad hoc conventions. Most of the problems in understanding quantum field theory and unifying Standard Model fields with gravitational fields result from the legacy of field definitions used in Maxwellian and Yang-Mills fields, which for purely ad hoc historical reasons are different from the field definition in general relativity. If all fields are expressed in the same way as accelerative curvatures, all field equations become rank-2 and all rank-1 divergencies automatically disappear, since are merely an historical legacy of the Faraday-Maxwell volts/metre field “line” concept, which isn’t consistent with the concept of acceleration due to curvature in general relativity!

However, we’re not advocating the use of any particular differential equations for any quantum fields, because discontinuous quantized fields can’t in principle be correctly modelled by differential equations, which is why you can’t properly represent the source of gravity in general relativity as being a set of discontinuities (particles) in space to predict curvature, but must instead use a physically false averaged distribution such as a “perfect fluid” to represent the source of the field. The rank-2 framework of general relativity has relatively few easily obtainable solutions compared to the simpler rank-1 (vector calculus) framework of electrodynamics. But both classical fields are false in ignoring the random field quanta responsible for quantum chaos (see, for instance, the discussion of first-quantization versus second-quantization in the previous post here, here and here).

Summary:

1. The electric field is defined by Michael Faraday as simply the gradient of volts/metre, which Maxwell correctly models with a first-order differential equation, which leads to a rank-1 tensor equation (vector calculus). Hence, electromagnetism with spin-1 field quanta has a rank-1 tensor purely because of the way it is formulated. Nobody has ever seen Faraday’s electric field, only accelerations/forces. There is no physical basis for electromagnetism being intrinsically rank-1; it’s just one way to mathematically model it, by describing it in terms of Faraday rank-1 fields rather than the directly observable rank-2 accelerations and forces which we see/feel.

2. The gravitational field has historically never been expressed in terms of a Faraday-type rank-1 field gradient. Due to Newton, who was less pictorial than Faraday, gravity has always been described and modelled directly in terms of the end result, i.e. accelerations/forces we see/feel.

This difference between the human formulations of the electromagnetic and gravitational “fields” is the sole reason for the fact that the former is currently expressed with a rank-1 tensor and the latter is expressed with a rank-2 tensor. If Newton had worked on electromagnetism instead of aether crackpots like Maxwell, we would undoubtedly have a rank-2 mathematical model of electromagnetism, in which electric fields are expressed not in volts/metre, but directly in terms of rank-2 acceleration (curvatures), just like general relativity.

Both electromagnetism and gravitation should define fields the same way, with rank-2 curvatures. The discrepancy that electromagnetism uses instead rank-1 tensors is due to the inconsistency that in electromagnetism fields are not defined in terms of curvatures (accelerations) but in terms of a Faraday’s imaginary abstraction of field lines. This has nothing whatsoever to do with particle spin. Rank-1 tensors are used in Maxwell’s equations because the electromagnetic fields are defined (inconsistently with gravity) in terms of rank-1 unobservable field gradients, whereas rank-2 tensors are used in general relativity purely because the definition of a field in general relativity is acceleration, which requires a rank-2 tensor to describe it. The difference is purely down to the way the field is described, not the spin of the field.

The physical basis for rank-2 tensors in general relativity

I’m going to rewrite the paper linked here when time permits.

Groupthink delusions

The real reason why gravitons supposedly “must” be spin-2 is due to the mainstream investment of energy and time in worthless string theory, which is designed to permit the existence of spin-2 gravitons. We know this because whenever the errors in spin-2 gravitons are pointed out, they are ignored. These stringy people aren’t interested in physics, just grandiose fashionable speculations, which is the story of Ptolemy’s epicycles, Maxwell’s aether, Kelvin’s vortex atom, Piltdown Man, S-matrices, UFOs, Marxism, fascism, etc. All were very fashionable with bigots in their day, but:

“… reality must take precedence over public relations, for nature cannot be fooled.” – Feynman’s Appendix F to Rogers’ Commission Report into the Challenger space shuttle explosion of 1986.