Is Quantum Physics paradoxical?
Classical physics is more of a paradox. Quantum physics, or more precisely quantum field theory is the solution.
The article is a continuation of the article “Slavoj Žižek: Quantum physics is ontologically incomplete?”. I further elaborate on ideas about quantum physics and the relevance of quantum field theory when interpreting properties of quantum physics. The ideas are comments to ideas by philosopher Slavoj Žižek. Although, the ideas on their own are answers to certain difficult problems in quantum physics. I try to categorize paradoxes that appear in quantum physics. And, I demonstrate why in order by rank, infinite mass and energy, is a worse paradox then possible ontological incompleteness of reality. Every statement presented here is an established theory, and supported by both quantum theory and experiments. More quotes by Slavoj Žižek:
Quote: “[The] moment one wants to provide an ontological account of quantum physics (what notion of reality fits its results), paradoxes emerge which undermine standard common-sense scientistic objectivism”.
True Slavoj, but for me quantum physics is not paradoxical, quantum theory is an inevitable necessity. What is also important is that there are worse paradoxes then whether quantum physics is ontologically complete or objective. How about infinite mass or energy of every particle or many other paradoxes from classical physics, that are obviously in conflict with reality and every experiment. The same and many more infinities and singularities appear in quantum physics, without quantum field theory or renormalization theory: which deals with removal of infinities. It took decades and 90 Nobel laureates to fully develop the theory of quantum and particle physics — I will try to summarize some of the important results. Further, if the quantum field theory works so well, and corresponds to reality of every experiment, there has to be a rational explanation why it does — maybe a proper interpretation of quantum theory is yet to be proposed.
‘Standard scientific objectivism’ represents nothing to a quantum physicist, there was nothing standard about when Heisenberg and others started quantum revolution in physics, or when Dirac posited existence of antiparticles based on his equation, even before there were no real particle accelerators that could produce them. Physicists change standards, mathematicians attempt to show the same with theorems and logic, an then philosophers try to categorize it. Also philosophers use inadequate terminology, which is sometimes archaic, and try to understand an unparalleled paradigm shift in science. Although, a paradigm shift did occur in physics, more then once. Famously Aristotle believed that force is dependent on velocity and that without applying force on a object, things would stop moving. Because he did not perform an experiment. All the religious scholars for centuries believed him. Ignorance that withstood change, until the renaissance — until Galileo and Newton.
There is a difference between quantum physics and quantum field theory. When Heisenberg, Dirac, Bohr, Pauli and others completed the first initial stage of quantum revolution known as ‘first quantization’, which successfully described the atom, it was immediately obvious that somehow particles have to be created and annihilated. First, elementary particle properties had to be quantized, then the classical fields had to be quantized as well (such as electromagnetic field, gravitational field, and so on). Without development of quantum field theory (QFT) the quantum revolution had not been complete. According to QFT, at each point in space and time it is possible to create and annihilate particles (electrons, photons and so on) — which is a loose definition of a quantum field. Every field has a certain value in spacetime — the simplest example of a classical field is temperature. Without quantum fields it is impossible to describe fundamental forces and interaction between elementary particles. Obviously the photon can decay into a particle and antiparticle and the other way around, for example an electron and positron can annihilate and produce photons. The original first quantum physics theory could not describe creation and annihilation of particles.
Development of quantum field theory (mainly due to efforts of Paul Dirac) stalled in 1930s because every calculation resulted in infinite results: infinities appeared in every calculation of energy or mass of the elementary particle. Wavefunction was also infinite.
The most important infinity, that appears also in classical physics, is the infinity of the electron that has infinite energy and mass.
If one tries to confine the electron to an infinitely small point, the electric field around the electron has infinite strength. Electromagnetic force is also infinite because electric charge causes infinite repulsion. Then electromagnetic energy is also infinite, and since according to Einstein energy equals mass, the mass has an infinite value. Further, since electron has spin, an infinitely small electron has infinite velocity of rotation, and then also infinite rotational energy. That is an another infinity. Infinite mass, infinite energy, infinite rotation and infinite charge — these are the real paradoxes that are in conflict with reality. Heisenberg, Bohr and Dirac were puzzled by these infinities for decades without progress.
The same problem appears in quantum physics, the electron emits photons which interact with everything that has electric charge (protons, electrons, positrons). It is how electromagnetic force works. It is also the basis of almost every modern technology we have. The information on how do electrons know each other positions is transferred through virtual photons that electrons exchange with each other through the quantum field. That is also how planet Earth know where the Sun is, by exchange of gravitational waves, or gravitons, which are gravitational equivalent to the photon. Gravitons are also massless, and also travel with speed of light c, confirmed experimentally from detection of gravitational waves. That was unexplainable with classical physics, classical theory fails in many different ways.
There is a problem: as soon as the electron emits a photon, the electron can immediately absorb its own photon — before it can interact with other particles. In quantum physics, as a general rule, anything that can happen, will happen, with a certain probability. Probability as the structure constant of the electromagnetic force is related to the value of the charge of electron — experimental value of probability in the current universe is actually equal to 0.7297% or 1/137. What is fundamental is the structure constant and not the classical charge of the electron. In fact the electron is constantly emitting photons and absorbing them. Further, to make things worse, the photon can have any wavelength and energy possible. Even a photon with infinite energy can be emitted and absorbed by the electron. By emitting and absorbing photons electron produces its own self-energy. Because of all of it, the electron self-energy is infinite. It is the same problem as with the classical electron. In quantum physics developed by Dirac, Heisenberg and Bohr the electron has infinite charge, infinite field value, infinite energy and mass. But obviously from every experiment, value of the charge or mass of the electron is not infinite.
Quantum field theory provides an explanation why electron does not have infinite energy or mass, which results from infinite charge as a point particle. As I have explained in previous article “Slavoj Žižek: Quantum physics is ontologically incomplete?”, the vacuum is not empty but has structure quantified by a small Planck constant. Because of the Heisenberg uncertainty principle it is possible to borrow a small amount of energy from nothing and create virtual particles. The easiest to create are the least massive particles that do not require a lot of energy: electrons and positrons (which have the same mass but opposite charge). The virtual electrons and positrons are constantly being created (they last approximately for 10^-21 seconds according to Heisenberg uncertainty principle) in the vacuum and in the field around the electron. Then positive charge positrons cancel and screen out infinite negative electron charge — the effect has been confirmed by many experiments.
The photon emitted by the electron, before being absorbed by the same electron, can decay into a positron/electron pair which have total charge and spin zero, and then annihilate. The energy of the electron by that process is reduced to the measured value, as the positive virtual positron reduces the electric field generated by the real negative charge electron. Infinite electron charge is screened out by virtual positrons that are being spontaneously created in the vacuum.
All the processes have to calculated and considered before the results of an experiment can be understood.
Even more complicated processes can happen but with decreasing probability. The virtual positron can emit another virtual photon which decays into a another positron/electron pair which annihilate back and produce a photon which is absorbed. And so on. Processes with increasing complexity have to be added up and calculated until some level of precision. The more precision you require the more complicated ‘virtual’ processes have to be considered and included in the calculation.
The structure constant of the electromagnetic force is one of the most precise physical constants measured in human history with accuracy to 11 decimal places, its value is: 1/ 137.035 999 206(11).
Theoretical mathematical value corresponds to experimental value at better than one part per billion. Although it is not actually constant and changes with energy scale.
If the energy of the field is larger then mass of the positron and electron, electron/positron pairs will be spontaneously created in the field around the electron. If the energy is larger then masses of more massive particles (such as other leptons or quarks), they can also be spontaneously created in the vacuum. The vacuum can have an extremely complicated structure. The number of possible combinations and elementary processes is actually infinite. But infinite complexity can be reduced, as more complicated processes contribute with smaller probability, and can be excluded from the calculation until certain precision.
The electron is not some kind of a point particle, it is more like a wave of probability in the quantum field, constantly interacting with other particles and fields, including the Higgs field. It is why it is not possible to measure its position with infinite precision. What is even more fascinating and also revealing, is that if you try to more precisely measure the position of the electron, the value of the electric charge changes — it increases, which can be both calculated and measured in a experiment. To measure a particle it is necessary to use a photon. The more precisely the measurement of the electron is, the smaller the wavelength of the photon has to be, and then the more energy the photon will have. In the Large Hadron Collider (LHC) in CERN, where physicists can produce more energy then in any other particle experiment, the electric charge increase had been precisely measured. At LHC the structure constant which is related to the electric charge increases by 15%. Because the more precisely the electron is being measured, virtual particles created around the electron are being excluded from the measurement — since they are being excluded, the virtual positrons can no longer screen out the electron charge and the effective electron charge increases. Lack of virtual pairs around the electron results with increase of charge and strength of the electromagnetic force.
The more precisely you measure the electron position, the larger the value of electron charge becomes — but it does not become infinite. (The most precise measurement of position can not be smaller then Planck length which is 10^-35 m). Eventually at Planck energy, the electron charge, specifically the structure constant which determines the strength of the electromagnetic force as probability of interaction becomes almost 100%. All other forces including gravity, strong and weak nuclear force at Planck energy become almost equal in strength to each other, which indicates that all forces are a part of some kind of super force. Which has lead to attempts by physicists to develop theory of everything, as of now unsuccessfully. Already from experiments at LHC it has been determined that weak nuclear force and electromagnetic force are a part of the same electro-weak force. The electro-weak force breaks into separate forces at temperature of about million times larger then produced in a nuclear explosion — the breaking is caused by interaction with the Higgs field. Weak force is massive and short range because it interacts with the Higgs field, which gives mass to all elementary particles that experimentally have mass. Electromagnetic force has infinite range because the photon does not interact with the Higgs field and remains massless.
Only because of the uncertainty principle (which Slavoj considers to be a deficiency in programming of the universe) the electron charge is not infinite. The example shows how the laws of physics and quantum uncertainty prevent formation of infinities and singularities, which indicates that the universe is probably a perfectly programmed machine. Development of quantum field theory and the standard model of particle physics culminated with discovery of the Higgs boson at LHC which is the most complicated machine ever built in human history.
Quote: “one can no longer translate [quantum physics] mathematical-theoretical edifice into the terms of our… notions of reality”
Mathematics and not English is the most efficient language of science. Notions of reality derived from natural human languages are predetermined to be wrong in describing the quantum world. Determinism, reality, ontology, epistemology, all these terms are in conflict with quantum physics. Human mind and language did not evolve for the purpose of understanding quantum physics that among other successes, resulted with invention of silicon technology on which all modern computer technology is based. We developed mathematics for the same purpose. The only way you can understand whether what you are claiming about quantum physics is true and real, is to compare mathematical theory with experiments. Reality should be defined to correspond to quantum theory, and not use archaic definitions from philosophy to understand quantum physics. So from the beginning philosophers are in disadvantage over physicists. Studying physics on the level of being able to understand quantum field theory is no easy task. However, some education is better then none at all.
There are many popular books in science that are trying to convey difficult subjects such as quantum physics to general audience. Unfortunately it is not enough, even physicists have problems explaining and interpreting quantum theory, and usually just deal with calculation and experiments — in accordance with Niels Bohr words ‘just calculate’.
I agree with words by Leonard Susskind (who probably could be the best educator in physics right now):
“We want more than anything else that people
should … understand [physics].
But we’re stuck with this obstacle of mathematics.”
Some of the other educators in physics worth mentioning: Matt O’Dowd from PBS, Don Lincoln from Fermilab, Lawrence Krauss and Sean Carroll.
All of it can be shown more effectively with mathematics, but the article would be inaccessible to laymen. I could have used obscure quantum physics terminology which would be only clear to quantum physicists. Ultimately, reality and ontology of quantum physics and the universe will never be understood completely without mathematics.
