Predictions of Quantum Field Theory (draft introductory passages)


Introduction Modern physics is based on the implications of quantum field theory, the quantum theory of fields. The mathematical and practical utility of the theory is proved by the fact that it predicts thousands of particle reaction rates to within a precision of 0.2 percent, and the non-nuclear quantum field theory of electrons (quantum electrodynamics) predicts the Lamb shift and the magnetic moment of the electron more accurately than any other theory in the history of science.Paul Dirac founded quantum field theory by guessing a relativistic time-dependent particle-applicable version of the Schroedinger wave equation (that modelled the electron in the atom). Schroedinger’s equation could not be used for free particle because it was non-relativistic, so its solutions were not bounded by the constraint of ‘relativity’ (or spacetime) whereby changing electromagnetic fields are restricted to propagate only the distance ct in the time interval t.

Spectacular physical meaning was immediately derived from Dirac’s equation because it implied the existence of a bound state electron-positron sea in the vacuum throughout spacetime, and predicted that a gamma ray of sufficient energy travelling in a strong electromagnetic field – near a high atomic (proton) number nucleus – can release an electron-positron pair. This creation of positrons (antimatter electrons, positively charged) was observed in 1932, confirming Dirac.

Pair production only occurs where gamma rays enter a very strong electric field (caused by the close confinement of many protons in a nucleus), because in a strong electric field the Dirac sea is polarized strongly enough along the electric field lines, weakening the electron-positron binding energy. Polarization consists of separation of charges along electric field lines. As the average distance of vacuum electrons from positrons is slightly increased, the Coulomb binding energy falls, hence gamma rays with energy above the energy of a freed electron-positron pair (1.022 MeV) have a significant chance of freeing such a pair. This pair production mechanism in practical use enables lead nuclei to stop shield gamma rays with energies above 1.022 MeV. (Of course, electrons in atoms can also shield gamma rays by the Compton and photoelectric effects.)

Gravity (readers should pay special attention to the following!)

Electrons and positrons in bound states in the vacuum take up space, and are fermions; each space taken up by a fermion cannot be shared with another fermion as demonstrated by the experimental verification of the Pauli exclusion principle. Therefore, when a real fermion moves, it cannot move into a virtual fermion’s space. The vacuum charges are therefore displaced around the moving real charge according to the restraint of Pauli’s exclusion principle. We can make definite predictions from this because the net flow of the Dirac sea around a moving real fermion is (by Pauli’s exclusion principle) constrained have exactly equal charge and mass but oppositely directed motion (velocity, acceleration) to the real moving fermion. This prediction means that in the cosmological setting where real charges (matter) is observed to be receding at a rate proportional to radial spacetime, there is an outward force of matter given by Newton’s second law F = mdv/dt = mdc/dt = mcH where H is Hubble’s constant.

By Newton’s 3rd law, we then find that there is an equal inward reaction force carried by some aspect of the Dirac sea. This predicts the strength of gravity. The duality of this Dirac sea pressure gravity prediction is that the inward reaction force is carried via the Dirac sea specifically by the light speed gauge boson radiation of a Yang-Mills quantum field theory, which allows us to deduce the nature of matter from the quantitative shielding area associated with a quark or with a lepton such as an electron. This gives us the size of a fundamental particle as the black-hole radius, not the Planck length, so we obtain useful information from factual input without any speculations whatsoever.

The Standard Model

The greatest difficulty for a quantum field theory is the prediction of all observed properties of matter and energy, which are summarised by the Standard Model SU(3)xSU(2)xU(1) which is a set of symmetry groups constraining quantum field theory to make contact with particle physics correctly. The problem here is that the symmetry description varies as a function of collision energy or distance of closest approach.

Unfortunately, the Standard Model as it stands does not consistently model all of particle physics because different forces unify at different energies or distances from a particle, which implies that the symmetries are broken at low energy but become unified at high energy. The symmetries, while excellent for most properties, omit masses entirely.

The Standard Model does not supply rigorous or usefully predictive (checkable) mechanisms for electroweak symmetry breaking which is the process by which the SU(2)xU(1) electroweak symmetry breaks to yield U(1) at low energy. It is obvious that the 3 weak gauge bosons of the SU(2) symmetry are attenuated in the polarized vacuum somehow, such as by a hypothetical ‘Higgs field’ of inertia-giving (and hence mass-giving) ‘Higgs bosons’, but there are no properties scientifically predicted for such a field. The SU(3) symmetry unitary group describes the strong nuclear (gluon) field by means of a new symmetry parameter called colour charge.Instead of coming up with a useful, checkable, electroweak symmetry breaking theory, the mainstream effort has been devoted since 1985 to a speculative, non-checkable hypothesis that the Standard Model particles and gravity can be explained by string theory. One major problem with string theory is that it’s claim to predict unification at extremely high energy is uncheckable; the energy is beyond experimental physics and would require going back in time to the moment of the big bang or using a particle accelerator as big as the solar system.

Another major problem with string theory is that its alleged unification of gravity and the standard model rests upon unifying speculative (unchecked) ideas about what quantum gravity is (gravitons mediated between mass-giving Higgs bosons), with speculative ideas concerning 10/11 dimensional time (M-theory). Speculation is only useful in physics where there is some hope of experimental checks. If a speculation is made that God exists, that speculation is not scientific because it is impossible in principle to refute it. Similarly, extra dimensions cannot even in principle be refuted.

Finally, string theory invents many properties of the universe in such a vague and ambiguous way that virtually any experimental results could be read as a validation of some variant of a stringy speculation. Such experimental results could also be consistent with many other theories, so such indirect ‘validation’ will turn physics into either a farce and battleground or into an orthodox religion whose power comes not from unique evidence by from suppressing counter evidence as a religious-type heresy. Critics of general relativity in 1919 wrongly claimed that there are potentially other theories that predicted the correct deflection of sunlight by gravity, or they disputed the accuracy of the evidence (Sir Edmund Whittaker being an example). However, the starlight deflection in general relativity can be justified on energy conservation grounds, from the way that gravitational potential energy – gained by a photon approaching the sun – must be used entirely for directional deflection and not partly used for speeding up an object as would occur to an object initially moving slower than the speed of light (light cannot be speeded up, so all gained gravitational energy is used for deflecting it). So such local predictions of general relativity are constrained to empirical facts. However, Einstein also ‘predicted’ in 1917 from general relativity that the entire universe is static and not expanding, which is a completely false prediction and was based on Einstein’s ad hoc cosmological constant value.

If Einstein’s steady state theory of cosmology had been defended based on the correct (local) predictions of the theory, then the failure of general relativity as a steady state cosmology may never have been exposed either by experiment (peer-review would suppress big bang crackpotism and force authors to invent ‘epicycles’ to fit experiments to the existing paradigm) or theory (Einstein’s steady state solution was unstable theoretically!).

The problem is that string theory, quite unlike general relativity, cannot even be objectively criticised because it contains no objective physics, it is just a ‘hunch’ to use ‘t Hooft’s description. String theory, explains Woit, is not even wrong. It has no evidence and can never have direct evidence because we can only experiment and observe in a limited number of dimensions which is smaller than the number of dimensions postulated by string theory, and even if it did have some alleged indirect evidence, that would destroy rigor in science by turning it into a religion of those who believe the holy alleged evidence, and those who have alternatives.

This is because almost any evidence can be ‘explained away’ by some of the numerous versions of string theory. Supersymmetry is a 10 dimensional string theory in which there is a bosonic superpartner for every fermion of the Standard Model. This is supposed to unify forces, but that cannot be checked as we can’t measure how forces unify since the energy is way too high. In addition, of the 10 dimensions, 6 are rolled up into a Calabi-Yau manifold that has many variable parameters, and hence a vast number of possible states! Nobody knows exactly how many different ground states of the universe are even possible – if the Calabi-Yau manifold is real, but it is probably between 10^100 and 10^1000 solutions. These numbers are far greater than the total number of fermions in the universe (about 10^80). There is no way to predict objectively which vacuum state describes the universe. The best that can be done is to plot a ‘landscape’ of solutions as a three dimensional plot and then to claim that the nearest one to experimental data is the prediction, by the ‘anthropic principle’ (which says we would not exist if it was another state, because the laws of nature are sensitive to the value of the vacuum energy).

By the same scientifically fraudulent argument, a child asked ‘what is 2 + 2?’ would reply: ‘it is either 1, 2, 3, 4, 5, 6, 7 … or 10^1000, the correct answer being decided by whichever solution of mine happens to correspond to the experimentally determined fact, shown by the counting beads!’

Sir Fred Hoyle used the anthropic argument (sometimes falsely called a principle) to ‘predict’ life exists due to nuclear carbon energy level which allows three alpha particles (helium-4 nuclei) to stick together forming carbon-12. He did this simply because his theory would fail otherwise. However, it was a subjective ‘I exist, therefore helium fuses’ prediction and was not objectively based on an understanding of nuclear science. Therefore, Hoyle did not win a Nobel Prize, and his so-called ‘explanation’ of the carbon-12 energy level – despite correctly predicting the value later observed in experiment – does not deliver you hard physics.

To be added:


NATURE OF GAUGE BOSONS (new section on physical propagation of polarized radiations)