Slavoj Žižek is a brilliant philosopher. However, as far as Slavoj Žižek can understand quantum physics, which is more then most philosophers, I will state a couple of examples how he is wrong, and when he is right. Some of his ideas are true, some of them are vague and border on quasi-science and serve the purpose of philosophical ideas, and some of the are just wrong. With development of technology and quantum theory, physics had overtaken philosophy as the main and most advanced attempt to understand existence and our universe. The prime problem in metaphysics is the problem of existence, and how is it possible to create something out of nothing — a problem that can be phrased in different ways. What was in metaphysics a subject of futile debate over millennia: physics had answered through work of Heisenberg, Dirac and many others. Not only in theory, properties of nothing and how things emerge from nothing had been measured to such accuracy that quantum theory is the most successful theory in human history. Žižek has problems understanding completely quantum physics, specifically the problem of how universe emerges nothing. Unfortunately there is no way of understanding quantum theory without studying physics for a long period of time on a college level. So I can try to clarify some of the concepts in physics for Slavoj.
The quotes by Slavoj Žižek and my comments are:
a) Quote: “Quantum physics or reality is not mechanical.”
Not true. Reality IS quantum mechanical. Originally, the development of quantum theory by Heisenberg, Dirac, Bohr and others were mostly directed towards change of classical mechanics to quantum mechanics. Many mathematical concepts that worked for classical mechanics (or classical physics) were adapted to quantum physics, such as work of 19th century mathematicians Lagrange, Hamilton, Euler, Poisson, Fourier and others. Every quantum theory (the same as classical theory) is studied with either a function called Lagrangian or Hamiltonian. The universe is quantum mechanical and objects with large number of particles (such as planets or asteroids) can be described with classical mechanics. So there is no conflict between the classical and quantum universe and its mechanical properties. Early names for quantum theory were Wave mechanics and Quantum mechanics as well. In most textbooks the title Quantum mechanics persists.
b) Quote: “Universe was not programmed completely because of the uncertainty. Reality is incomplete, because at the level of elementary particles the reality is not completely programmed.”
Quantum mechanics is inevitable. Without it, all sorts of paradoxes would ensue. It would be a paradox to precisely determine position of a particle to infinite precision, as would then density, energy and mass of a particle also be infinite. Particles that have spin would have infinite rotational velocity and infinite rotational energy. Which would produce infinite gravitational force, as energy equals mass. In fact in classical physics all particles would have infinite mass — classical physics fails in many different ways. It makes sense that at microscopic level classical physics breaks down and has to be replaced by quantum physics, as it would be impossible to measure position or any other observable quantity with infinite precision. Quantum mechanics is not just required, but necessary to make any sense of the universe. Is it really necessary to know with infinite precision position an velocity of every particle, even if it would somehow technologically possible — which it is not. Every measurement consists of using a photon to observe the particle — and by doing so obtain the position. If no uncertainty is required, then the photon would have to have an infinitely small wavelength — and then infinite energy. A paradox. The most precise measurement of position ever is performed by gravitational wave detectors, a measurement of position so precise it is almost a trillion times smaller then size of the proton. Almost all the uncertainty is transferred to momentum/velocity.
It depends on definition of reality but what limits completeness is not quantum physics (which can be used to understand any experiment or develop any conceivable technology), but gravity which causes the information paradox. Since we do not have theory of quantum gravity, that is where knowledge of our universe is (ontologically) incomplete. The entanglement problem (as posited by Einstein) and measurement problem could be a property of the universe which is inherently probabilistic and a consequence of creation from nothing, in accordance with laws of conservation of energy, momentum, spin and charge.
The universe could not have been better programmed then it is. Heisenberg uncertainty principle is a mandatory and essential part of the programming of the universe. Without it, the universe would have many singularities and infinities of all sorts. Through quantum field theory all these infinities were successfully removed mathematically (except for gravity), in accordance with all quantum experiments ever performed.
Without uncertainty there would be no fluctuations in the initial universe as seeds of structure formation and there would be no gravitational collapse of matter into galaxies. The universe would be featureless and mostly Hydrogen gas evenly spread out through space — without planets or galaxies.
Without quantum uncertainty it would be impossible to create particles or anything from nothingness of space. The reason why the universe works so well is quantum uncertainty, without it, existence would be impossible.
Classical physics does not really describe how and why the universe works, or how gravity works, it only allows you to calculate gravitational force according to Newton’s law without explanation where it comes from, or how gravity works. Isaac Newton had stated that he does not understand how gravity works, in classical physics it is only possible to calculate the force. Classical physics is a mathematical mechanical model and nothing more. Classical physics does not have a measurement problem, because is does not explain origin of forces, particles or fields. Quantum theory, even though probabilistic and ambiguous with a measurement problem, is still a better option by far, and describes how fundamental forces work.
c) Quote: “It is not possible to determine the velocity and position of a particle. Position and velocity of a elementary particle can not be measured simultaneously. Einstein claims that quantum physics does not represent full description of reality.”
It is more complicated then that, uncertainty of velocity of a measured particle depends on how precisely the position had been measured. The uncertainty in the measurement is defined by the Planck constant, which is, fortunately for our reality and existence, very small, and has a very small effect on macroscopic objects. The fact there is uncertainty in simultaneously measuring position and velocity of a particle is a consequence of that: measuring first position and then velocity, is not the same thing as first measuring velocity and then position. By measuring the position you use a photon with a certain wavelength, and then the precision of the position is determined by the same wavelength. Then, there is uncertainty in position of the particle because of the finite wavelength, that ultimately changes the velocity of particle because every photon has energy and transfers it to the particle. The immediate subsequent measurement of the velocity will not be the same as if the position had not been measured to begin with.
Uncertainty is also a consequence from the fact that, as known from Newton and Leibniz and development of calculus, velocity is a derivative and the rate of change with position and time. That is why velocity and position have a special connection, and are connected by uncertainty, because change in position requires change of velocity, and change of velocity changes position. In fact every observable that is a derivative of another observable is connected by quantum uncertainty to that other observable. It is impossible to remove that property of the universe from ‘programming’. At least in a sense, that the universe could work without it.
Further, experimental verification of Bell’s inequality theorems are in conflict with Einstein, and imply that quantum theory is the true theory of the universe. One of the reasons that it is impossible to completely understand or measure a quantum system in its entirety without uncertainty, is because we are made of the same quantum particles we are trying to measure. Another is that universe is fundamentally probabilistic. A consequence of it, the still unresolved measurement problem remains.
d) Quote: “Materialism is a wrong idea: which is the idea that in empty space there are bits of matter which constitute reality. Reality (according to quantum physics) can be abstract, and constituted of waves.”
True Slavoj, but not completely or precisely. Quantum theory also changes the idea of empty space. Quantum physics allows empty space to have structure. The amount of structure in the vacuum is quantified by a small Planck constant, according to quantum theory and the Heisenberg uncertainty principle. There is not just quantum uncertainty in position and velocity of any particle, but uncertainty in many other physical properties, that can either be observed or not. There is uncertainty in energy and time (as by calculus kinetic energy is dependent on derivative with respect to time), which allows extraction of a small amount of energy from empty space for a small period of time. That energy can be used to create temporary ‘virtual’ particles.
As measuring position and then velocity is not the same as measuring first velocity and then the position of a particle, the same way, creating a particle and destroying it, is not the same as first destroying a particle and creating the same type of particle at the same position in spacetime. Which is more obvious in a example when attempting to first destroy a ‘real’ particle in empty space — which is impossible as there are no ‘real’ particles to destroy. The opposite example is an attempt to first create a particle in empty space (and then destroying it), which is definitely possible. Creation and destruction of particles and matter at the same place and time is governed by the same uncertainty principle — which is more precisely defined through a mathematical concept taken from classical mechanics: the Commutator.
Since creation and annihilation of particles is also uncertain, the uncertainty allows creation of ‘virtual’ particles in empty space, from nothing. The ‘virtual’ particles have the form of wave-like fluctuations, as all quantum particles do. The ‘virtual’ particles can become ‘real’ particles for a specific physical system. As an example: fluctuations in the cosmic background radiation of the universe (as measured by the Planck satellite) were formed by virtual particles that existed in the moment of creation of our universe, and that were magnified to the size of clusters of galaxies by accelerated expansion of space, described by inflation theory, and became ‘real’. Uncertainty can be exactly mathematically calculated and compared with experiments.
Further, these ‘virtual’ particles create effects and change energy of ‘real’ particles, like electrons in regular matter (Lamb effect). They represent constant vacuum energy, and can cause accelerated expansion of the universe (cosmological constant) or even produce forces on objects (Casimir effect). The same effects can be precisely measured, and effects are very much mechanical and real. What is reality then? Well, it depends on the definition.
In fact, we know mechanical properties of elementary particles with such precision, that quantum theory is the most precise and successful theory in human history. Further, mathematically, based on that uncertainty, it is even possible (although improbable) to create an entire universe out of nothing.
Nothing in physics and science is true, until confirmed by an experiment. As I mentioned, it is well established that observed fluctuations in the cosmic background radiation (which is the first light emitted in the universe after the big bang measured by space satellites Planck and WMAP) should have been generated by random quantum virtual particles that were formed in empty space at the moment of creation of the universe (more precisely during inflationary exponential expansion of the universe). The same fluctuations were the seeds of structure formation of galaxies in our universe, and then our reality (galaxy and planet) was initiated and formed by what can be considered virtual, and non-existent.
e) Quote: “Universe is a big void. There is nothing, basically, I mean it quite literally. But then how do things emerge? Here I feel …affinity with quantum physics… The universe is a positively charged void.”
The universe was not a void after it was created, it was dense, and then expanded. The void is not empty, as I had explained, empty space or vacuum is not empty, and inflation theory (accelerated expansion of the universe) is the best theory of the early universe we have so far on how the universe begun.
I explained already in d) how things emerge from nothing. Creation of particles in the vacuum is possible because of uncertainty in energy and time, and uncertainty in creation and annihilation of particles. The difference is that energy and time can be observed and measured, but creation and annihilation are not observable quantities, they are actions performed on a quantum state. Only consequences of annihilation can be observed. The number of particles in a system is an observable measurable quantity, and can be built from action of creation and annihilation. If there is a hundred particles in a system and one particle is destroyed there are ninety-nine. If then the same one particle is created you get again a hundred particles. That is how mathematically number of particles is measured in a experiment. Annihilation of quantum state of empty space produces no action, but as a consequence of uncertainty between annihilation and creation, the quantum state of empty space although void from real particles, has virtual particles that spontaneously form in vacuum, change properties of the ‘real’ world, and annihilate back to nothing. The empty space, the ‘nothing’ itself is uncertain.
Add gravity, then since the gravitational field potential energy is negative, the positive energy virtual particles can become real. Negative and positive energy can cancel, then total energy can be zero in accordance with the law of conservation of energy.
Also, quantum fields such as the Higgs field have their own space, where the phase is the angle degree of freedom.
Then number of particles (or density) and phase of the quantum field are also uncertain, which is how, for example, Higgs field particles can be temporarily created in vacuum — because number of particles is uncertain. Then Higgs field can interact with every other matter particle (for example electrons) which causes them to have mass. Without the Higgs field and its mechanism, matter particles, from which planets and galaxies and all other matter is made of, would be massless and life would be impossible. Uncertainty is integral to everything, including existence of life. Uncertainty is an inevitable part of the programming. Although, in principle, it is a lot more complicated then described here.
Lastly, the universe can not be a positively charged void, it has to be charge neutral. Because of law of conservation of charge the total charge of the universe has to be zero. When particles are created in the vacuum from nothing, the total charge has to be zero. Obviously because initially empty space is charge neutral. Then if you want to create a universe from nothing, the total charge of the universe has to be zero.
f) Quote: “Einstein’s idea is that matter curves space. Then matter is an effect of curving the space.”
That is just completely wrong. Matter is not created by curvature of spacetime, except in some special strong gravity systems. Gravity is very weak and it takes a lot of energy in the gravitational field (to be precise Planck energy) for it to be possible so that the gravitational field can decay into matter particles. The process would require also for gravity to be quantized. Einstein’s equations show that energy is source of gravity and curvature of spacetime, but the gravitational field also has energy.
What is true is that spacetime can be curved, and anything that is curved has energy, and then spacetime itself is a source of gravity. Which further curves spacetime, as anything that has energy gravitates. That complexity makes very difficult to develop a theory of quantum gravity, without singularities and infinities. Curved space can not cause the effect of matter. For gravitational field of planet Earth, the gravitational energy is very small, and from experience we obviously do not observe curvature of space creating matter.
g) Quote: “Higgs field energy is negative (less then nothing).”
True, Higgs field value is positive, but potential energy or the energy density as energy of the Higgs field in the vacuum is negative, which is part of the cosmological constant problem (the value of total vacuum energy), which is for some reason small and positive. Although, it should be at least million trillion trillion trillion trillion times larger then the measured value (compared to the value of the Higgs field potential energy).
The fact that Slavoj Žižek has problems with physics is not unusual. Quantum physics is very difficult and unless you have studied physics properly and solved a lot of equations mathematically, you can have a lot of fluffy ideas about what quantum physics is and how universe works, but at the end, it is unfortunately not enough. Quantum field theory is probably the most difficult theory developed in human history, and that also works and is confirmed by experiments. It is why even the most brilliant philosophers have problems understanding the still not completely resolved complexity and interpretation of quantum theory.
