Alexey Paevsky
First, let's debunk one myth. Einstein never said the words "God does not play dice." In fact, he wrote to Max Born about Heisenberg's uncertainty principle: “Quantum mechanics is really impressive. But an inner voice tells me that this is not yet ideal. This theory says a lot, but still does not bring us closer to unraveling the mystery of the Almighty. At least I'm sure He doesn't roll the dice."
However, he also wrote to Bohr: “You believe in God playing dice, and I believe in complete regularity in the world of objectively existing.” That is, in this sense, Einstein spoke about determinism, that at any moment you can calculate the position of any particle in the Universe. As Heisenberg showed us, this is not so.
However, this element is very important. Indeed, paradoxically, greatest physicist Albert Einstein of the 20th century, who broke the physics of the past with his articles at the beginning of the century, then turned out to be a zealous rival of even newer, quantum mechanics. All his scientific intuition protested against describing the phenomena of the microworld in terms of the theory of probability and wave functions. But it is difficult to go against the facts - and it turned out that any measurement of a system of quantum objects changes it.
Einstein tried to "get out" and suggested that there are some hidden parameters in quantum mechanics. For example, there are some sub-tools that can measure the state of a quantum object and not change it. As a result of such reflections, in 1935, together with Boris Podolsky and Nathan Rosen, Einstein formulated the principle of locality.
Albert Einstein
This principle states that the results of any experiment can be affected only by objects close to the place of its conduct. At the same time, the motion of all particles can be described without involving the methods of probability theory and wave functions, introducing into the theory those very “hidden parameters” that cannot be measured using conventional tools.
Bell's theory
John Bell
Almost 30 years have passed, and John Bell theoretically showed that it is actually possible to conduct an experiment, the results of which will determine whether quantum mechanical objects are indeed described by wave functions probability distributions, as they are, or there is a hidden parameter that allows you to accurately describe their position and momentum, like a billiard ball in Newton's theory.
Then technical means there was no such experiment: to begin with, it was necessary to learn how to obtain quantum entangled pairs of particles. These are particles that are in a single quantum state, and if they are separated by any distance, they still instantly feel what is happening to each other. We wrote a little about the practical use of the entanglement effect in about quantum teleportation.
In addition, it is necessary to quickly and accurately measure the states of these particles. Here, too, everything is fine, we can do it.
However, there is a third condition in order to test Bell's theory: you need to collect large statistics on random changes in the settings of the experimental setup. That is, it was necessary to conduct a large number of experiments, the parameters of which would be set completely randomly.
And here there is a problem: all our random number generators use quantum methods - and here we can introduce the very hidden parameters into the experiment ourselves.
How gamers choose numbers
And here the researchers were saved by the principle described in the joke:
“One programmer approaches another and says:
– Vasya, I need a random number generator.
“One hundred and sixty-four!”
The generation of random numbers was entrusted to gamers. True, a person does not actually randomly choose numbers, but this is precisely what the researchers played on.
They created a browser game in which the player's task was to get as long as possible a sequence of zeros and ones - at the same time, with their actions, the player trained a neural network that tried to guess which number the person would choose.
This greatly increased the “purity” of randomness, and given the breadth of coverage of the game in the press and reposts in social networks, up to a hundred thousand people played the game at the same time, the flow of numbers reached a thousand bits per second, and more than a hundred million random choices have already been created.
These truly random data, which were used on 13 experimental setups in which different quantum objects were entangled (qubits on one, atoms on two, photons on ten), were enough to show: Einstein was still wrong .
There are no hidden parameters in quantum mechanics. The statistics showed it. This means that the quantum world remains truly quantum.
"God does not play dice with the universe."
With these words, Albert Einstein challenged his colleagues who were developing a new theory - quantum mechanics. In his opinion, the Heisenberg uncertainty principle and the Schrödinger equation introduced an unhealthy uncertainty into the microcosm. He was sure that the Creator could not allow the world of electrons to be so strikingly different from the familiar world of Newtonian billiard balls. In fact, throughout for long years Einstein played the role of the devil's advocate in relation to quantum mechanics, inventing ingenious paradoxes designed to lead the creators of a new theory into a dead end. In doing so, however, he did a good deed, seriously perplexing the theoreticians of the opposite camp with his paradoxes and forcing them to think deeply about how to solve them, which is always useful when working out new area knowledge.
There is a strange irony of fate in the fact that Einstein went down in history as a principled opponent of quantum mechanics, although initially he himself stood at its origins. In particular, Nobel Prize in physics in 1921, he received not at all for the theory of relativity, but for explaining the photoelectric effect on the basis of new quantum concepts that literally swept the scientific world at the beginning of the 20th century.
Most of all, Einstein protested against the need to describe the phenomena of the microworld in terms of probabilities and wave functions ( cm. Quantum mechanics), and not from the usual position of coordinates and particle velocities. That's what he meant by "dice". He recognized that the description of the motion of electrons in terms of their speeds and coordinates contradicts the uncertainty principle. But, Einstein argued, there must be some other variables or parameters, taking into account which the quantum-mechanical picture of the microworld will return to the path of integrity and determinism. That is, he insisted, it only seems to us that God is playing dice with us, because we do not understand everything. Thus, he was the first to formulate hypotheses for a latent variable in the equations of quantum mechanics. It consists in the fact that, in fact, electrons have fixed coordinates and speed, like Newton's billiard balls, and the uncertainty principle and the probabilistic approach to their determination in the framework of quantum mechanics are the result of the incompleteness of the theory itself, which is why it does not allow them determine for sure.
The theory of the latent variable can be visualized something like this: the physical justification of the uncertainty principle is that the characteristics of a quantum object, such as an electron, can be measured only through its interaction with another quantum object; the state of the measured object will change. But perhaps there is some other way to measure using tools that are not yet known to us. These instruments (let's call them "subelectrons") will probably interact with quantum objects without changing their properties, and the uncertainty principle will not apply to such measurements. Although there was no evidence to support hypotheses of this kind, they loomed ghostly on the sidelines of the main path of development of quantum mechanics - mainly, I believe, due to the psychological discomfort experienced by many scientists due to the need to abandon the established Newtonian ideas about the structure of the universe.
And so, in 1964, John Bell obtained a new and unexpected theoretical result for many. He proved that it is possible to conduct a certain experiment (details a little later), the results of which will determine whether quantum mechanical objects are really described by the wave functions of the probability distribution, as they are, or whether there is a hidden parameter that allows you to accurately describe their position and momentum, as at the Newtonian ball. Bell's theorem, as it is now called, shows that, as if there is a hidden parameter in quantum mechanical theory that affects any physical characteristic quantum particle, and in the absence of such a serial experiment, the statistical results of which will confirm or disprove the presence of hidden parameters in the quantum mechanical theory. Relatively speaking, in one case the statistical ratio will be no more than 2:3, and in the other - no less than 3:4.
(Here I want to parenthetically point out that I was an undergraduate student at Stanford the year Bell proved his theory to him. Red-bearded and with a thick Irish accent, Bell was hard to miss. I remember standing in the science building corridor of the Stanford Linear accelerator, and then he came out of his office in a state of extreme excitement and publicly announced that he had just discovered a really important and interesting thing.And although I have no proof of this, I would very much like to hope that I that day I became an unwitting witness to its discovery.)
However, the experience proposed by Bell turned out to be simple only on paper and at first seemed almost impossible. The experiment was supposed to look like this: under external influence, the atom had to synchronously emit two particles, for example, two photons, and in opposite directions. After that, it was necessary to capture these particles and instrumentally determine the direction of the spin of each and do this a thousand times in order to accumulate sufficient statistics to confirm or refute the existence of a hidden parameter according to Bell's theorem (in the language of mathematical statistics, it was necessary to calculate correlation coefficients).
The most unpleasant surprise for everyone after the publication of Bell's theorem was precisely the need to conduct a colossal series of experiments, which at that time seemed practically impossible, in order to obtain a statistically reliable picture. However, less than a decade later, experimental scientists not only developed and built the necessary equipment, but also accumulated a sufficient amount of data for statistical processing. Without going into technical details, I will only say that then, in the mid-sixties, the complexity of this task seemed so monstrous that the probability of its implementation seemed to be equal to that of someone planning to put a million trained monkeys from the proverb at typewriters in the hope of finding among the fruits of their collective labor, a creation equal to Shakespeare.
When the results of the experiments were summarized in the early 1970s, everything became crystal clear. The probability distribution wave function accurately describes the movement of particles from the source to the sensor. Therefore, the equations of wave quantum mechanics do not contain hidden variables. This is the only known case in the history of science when a brilliant theorist proved opportunity experimental verification hypotheses and gave justification method such a test, brilliant experimenters with titanic efforts carried out a complex, expensive and protracted experiment, which in the end only confirmed the already dominant theory and did not even introduce anything new into it, as a result of which everyone felt cruelly deceived in their expectations!
However, not all work was in vain. More recently, scientists and engineers, much to their own surprise, have found Bell's theorem to be of very worthy practical application. The two particles emitted by the Bell source are coherent(have the same wave phase), since they are emitted synchronously. And this property of theirs is now going to be used in cryptography to encrypt highly secret messages sent through two separate channels. When intercepting and attempting to decrypt a message via one of the channels, coherence is instantly broken (again, due to the uncertainty principle), and the message inevitably and instantly self-destructs at the moment when the connection between the particles is broken.
And Einstein, it seems, was wrong: God still plays dice with the universe. Perhaps Einstein still should have heeded the advice of his old friend and colleague Niels Bohr, who, once again hearing the old refrain about "dice game", exclaimed: "Albert, finally stop telling God what to do !"
Is it possible to experimentally determine whether there are unaccounted for hidden parameters in quantum mechanics?
“God does not play dice with the universe” - with these words, Albert Einstein challenged his colleagues who developed a new theory - quantum mechanics. In his opinion, the Heisenberg uncertainty principle and the Schrödinger equation introduced an unhealthy uncertainty into the microcosm. He was sure that the Creator could not allow the world of electrons to be so strikingly different from the familiar world of Newtonian billiard balls. In fact, for many years, Einstein played the role of the devil's advocate in relation to quantum mechanics, inventing ingenious paradoxes designed to lead the creators of the new theory into a dead end. In doing so, however, he did a good deed, seriously perplexing the theoreticians of the opposite camp with his paradoxes and forcing them to think deeply about how to solve them, which is always useful when a new field of knowledge is being developed.
There is a strange irony of fate in the fact that Einstein went down in history as a principled opponent of quantum mechanics, although initially he himself stood at its origins. In particular, he received the Nobel Prize in Physics in 1921 not at all for the theory of relativity, but for explaining the photoelectric effect based on new quantum concepts that literally swept the scientific world at the beginning of the 20th century.
Most of all, Einstein protested against the need to describe the phenomena of the microcosm in terms of probabilities and wave functions (see Quantum Mechanics), and not from the usual position of particle coordinates and velocities. That's what he meant by "dice". He recognized that the description of the motion of electrons in terms of their speeds and coordinates contradicts the uncertainty principle. But, Einstein argued, there must be some other variables or parameters, taking into account which the quantum-mechanical picture of the microworld will return to the path of integrity and determinism. That is, he insisted, it only seems to us that God is playing dice with us, because we do not understand everything. Thus, he was the first to formulate the hidden variable hypothesis in the equations of quantum mechanics. It consists in the fact that, in fact, electrons have fixed coordinates and speed, like Newton's billiard balls, and the uncertainty principle and the probabilistic approach to their determination in the framework of quantum mechanics are the result of the incompleteness of the theory itself, which is why it does not allow them to be known for certain. define.
The theory of the latent variable can be visualized something like this: the physical justification of the uncertainty principle is that the characteristics of a quantum object, such as an electron, can be measured only through its interaction with another quantum object; the state of the measured object will change. But perhaps there is some other way to measure using tools that are not yet known to us. These instruments (let's call them "subelectrons") will probably interact with quantum objects without changing their properties, and the uncertainty principle will not apply to such measurements. Although there was no evidence to support hypotheses of this kind, they loomed ghostly on the sidelines of the main path of development of quantum mechanics - mainly, I believe, due to the psychological discomfort experienced by many scientists due to the need to abandon the established Newtonian ideas about the structure of the universe.
And in 1964, John Bell received a new and unexpected theoretical result for many. He proved that it is possible to conduct a certain experiment (details a little later), the results of which will determine whether quantum mechanical objects are really described by the wave functions of the probability distribution, as they are, or whether there is a hidden parameter that allows you to accurately describe their position and momentum, as at the Newtonian ball. Bell's theorem, as it is now called, shows that both in the presence of a hidden parameter in a quantum mechanical theory that affects any physical characteristic of a quantum particle, and in the absence of such, it is possible to conduct a serial experiment, the statistical results of which will confirm or disprove the presence of hidden parameters in quantum mechanical theory. Relatively speaking, in one case the statistical ratio will be no more than 2:3, and in the other - no less than 3:4.
(Here I want to parenthetically point out that I was an undergraduate student at Stanford the year Bell proved his theorem. Red-bearded and with a thick Irish accent, Bell was hard to miss. I remember standing in the science building corridor of the Stanford Linear Accelerator , and then he came out of his office in a state of extreme excitement and publicly announced that he had just discovered a really important and interesting thing.And although I have no evidence of this, I would very much like to hope that I that day was an involuntary witness to its discovery.)
However, the experience proposed by Bell turned out to be simple only on paper and at first seemed almost impossible. The experiment was supposed to look like this: under external influence, the atom had to synchronously emit two particles, for example, two photons, and in opposite directions. After that, it was necessary to catch these particles and instrumentally determine the direction of the spin of each and do this a thousand times in order to accumulate sufficient statistics to confirm or refute the existence of a hidden parameter according to Bell's theorem (in the language of mathematical statistics, it was necessary to calculate the correlation coefficients).
The most unpleasant surprise for everyone after the publication of Bell's theorem was precisely the need to conduct a colossal series of experiments, which at that time seemed practically impossible, in order to obtain a statistically reliable picture. However, less than a decade later, experimental scientists not only developed and built the necessary equipment, but also accumulated a sufficient amount of data for statistical processing. Without going into technical details, I will only say that then, in the mid-sixties, the complexity of this task seemed so monstrous that the probability of its implementation seemed to be equal to that of someone planning to put a million trained monkeys from the proverb at typewriters in the hope of finding among the fruits of their collective labor, a creation equal to Shakespeare.
When the results of the experiments were summarized in the early 1970s, everything became crystal clear. The probability distribution wave function accurately describes the movement of particles from the source to the sensor. Therefore, the equations of wave quantum mechanics do not contain hidden variables. This is the only known case in the history of science, when a brilliant theoretician proved the possibility of experimental testing of a hypothesis and gave a justification for the method of such testing, brilliant experimenters with titanic efforts carried out a complex, expensive and protracted experiment, which in the end only confirmed the already dominant theory and did not even introduce into it is nothing new, as a result of which everyone felt cruelly deceived in their expectations!
However, not all work was in vain. More recently, scientists and engineers, much to their own surprise, have found a very worthy practical application for Bell's theorem. The two particles emitted by the Bell source are coherent (have the same wave phase) because they are emitted synchronously. And this property of theirs is now going to be used in cryptography to encrypt highly secret messages sent over two separate channels. When intercepting and attempting to decrypt a message via one of the channels, coherence is instantly broken (again, due to the uncertainty principle), and the message inevitably and instantly self-destructs at the moment when the connection between the particles is broken.
And Einstein, it seems, was wrong: God still plays dice with the universe. Perhaps Einstein still should have heeded the advice of his old friend and colleague Niels Bohr, who, once again hearing the old refrain about "dice game", exclaimed: "Albert, finally stop telling God what to do !"
Encyclopedia of James Trefil “The nature of science. 200 laws of the universe.
James Trefil is a professor of physics at George Mason University (USA), one of the most famous Western authors of popular science books.
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Physics professor Jim Al-Khalili explores the most accurate and one of the most confusing scientific theories- quantum physics. In the early 20th century, scientists penetrated the hidden depths of matter, the subatomic building blocks of the world around us. They discovered phenomena that are different from anything seen before. A world where everything can be in many places at the same time, where reality really exists only when we observe it. Albert Einstein opposed the mere idea that the essence of nature is based on chance. Quantum physics implies that subatomic particles can interact faster than the speed of light, and this contradicts his theory of relativity.
French physicist Pierre Simon Laplace important question, about whether everything in the world is predetermined by the previous state of the world, or whether a cause can cause several consequences. As expected by the philosophical tradition, Laplace himself in his book “Statement of the System of the World” did not ask any questions, but said a ready-made answer that yes, everything in the world is predetermined, however, as often happens in philosophy, the picture of the world proposed by Laplace did not convince everyone and thus his answer gave rise to a discussion around that question which continues to this day. Despite the opinion of some philosophers that quantum mechanics allowed this question in favor of a probabilistic approach, however, Laplace's theory of complete predestination, or as it is otherwise called, the theory of Laplace's determinism is being discussed today.
If the initial conditions of the system are known, it is possible, using the laws of nature, to predict its final state.
In everyday life, we are surrounded by material objects, the dimensions of which are comparable to us: cars, houses, grains of sand, etc. Our intuitive ideas about the structure of the world are formed as a result of everyday observation of the behavior of such objects. Since we all have a life behind us, the experience accumulated over the years tells us that since everything we observe over and over again behaves in a certain way, it means that in the entire Universe, on all scales, material objects should behave in a similar way. And when it turns out that somewhere something does not obey the usual rules and contradicts our intuitive concepts of the world, this not only surprises us, but shocks us.
Hidden parameters and limits of applicability of quantum mechanics.
N.T. Saynyuk
The paper shows that a nonzero size can be used as a hidden parameter in quantum mechanics elementary particles. This made it possible to explain the fundamental physical concepts used in the theory of the de Broglie wave, wave-particle duality, and spin. The possibility of using the mathematical apparatus of the theory to describe the motion of macrobodies in a gravitational field was also shown. The existence of discrete vibrational spectra of elementary particles is predicted. The question of the equivalence of the inertial and gravitational masses is considered.
Despite the existence of quantum mechanics for almost a century, disputes about the completeness of this theory have not subsided to this day. The success of quantum mechanics in reflecting the existing regularities in the field of the subatomic world is beyond doubt. However, some physical concepts, with which quantum mechanics operates, such as wave-particle duality, the Heisenberg uncertainty relation, spin, etc., remain misunderstood and do not find proper justification within this theory. It is widely believed among scientists that the problem of substantiating quantum mechanics is closely related to hidden parameters, that is, physical quantities, which really exist, determine the results of the experiment, but for some reason cannot be detected. In this paper, based on an analogy with classical physics, it is shown that a non-zero size of elementary particles can claim the role of a hidden parameter.
Trajectory in classical and quantum physics.
Let's imagine a material body with a rest mass, for example, a nucleus flying in space with a speed at a sufficiently large distance from other bodies so that their influence can be excluded. In classical physics, such a state of the body is described by a trajectory that establishes the location of its central point in space at each moment of time and is determined by the function:
How accurate is this description? As you know, any material body with a rest mass has a gravitational field that extends to infinity and which cannot be separated from the body in any way, therefore it should be considered an integral part of a material object. In classical physics, when determining the trajectory, as a rule, the potential field is neglected because of its small value. And this is the first approximation that classical physics allows. If we tried to take into account the potential field, then such a concept as a trajectory would disappear. You can't assign a trajectory infinitely big body and formula (1) would lose all meaning. In addition, any material body has some dimensions and it also cannot be localized at one point. You can only talk about some volume that the body occupies in space or about its linear dimensions. And this is the second approximation that classical physics allows, endowing physical bodies with trajectories. The existence of dimensions for material bodies entails another uncertainty, the impossibility to accurately determine the time of the location of the material body in space. This is due to the fact that the speed of signal propagation in nature is limited by the speed of light in vacuum, and so far there are no reliably experimentally established facts that this speed can be significantly exceeded. This can only be done with a certain accuracy required by the light signal to cover a distance equal to the linear size of the body:
Uncertainty in space and time in classical physics is of fundamental nature, it cannot be bypassed by any tricks. This uncertainty can only be neglected, which is done everywhere and for most practical engineering calculations, accuracy and without taking into account uncertainties is quite sufficient.
From the above, two conclusions can be drawn:
1. The trajectory in classical physics is not strictly justified. These concepts can be applied only when it is possible to neglect the potential field of a material object and its dimensions.
2. In classical physics, there is a fundamental uncertainty in determining the position of a body in space and time due to the presence of dimensions in material bodies and the finite speed of propagation of signals in nature.
It turns out that the Heisenberg uncertainty relation in quantum mechanics is also due to these two factors.
There is no concept of a trajectory in quantum mechanics. It would seem that in this way quantum mechanics eliminates the above listed shortcomings of classical physics and describes reality more adequately. This is only partly true and there are very significant nuances. Let's consider this question on the example of the electron at rest in what coordinate system. From classical physics, in particular from Coulomb's law, it is known that an electron, having an electric field, is an infinite object. And at every point in space this field is present. In quantum mechanics, such an electron is described by a wave function , which also has a non-zero value at every point in space. And in this plan, it correctly reflects the fact that the electron occupies all space. But it is explained in a different way. According to the Copenhagen interpretation, the square of the modulus of the wave function, at some point in space, is the probability density of finding an electron at that point in the process of observation. Is this interpretation correct? The answer is unequivocal - no. An electron as an infinite object cannot be instantly localized at one point. This directly contradicts the special theory of relativity. The collapse of an electron into a point is possible only if the speed of propagation of signals in nature was infinite. So far, no such facts have been found experimentally. In our case, the real field, quantum mechanics compares the probability of finding an electron at some point. Obviously, such an interpretation of quantum mechanics does not correspond to reality, but is only some approximation to it. And it is not surprising that when describing electric field electron, quantum mechanics faces great mathematical difficulties. The example below shows why this happens. Coulomb's law is a deterministic law, while quantum mechanics uses a probabilistic approach. In this case, classical physics is more adequate. It allows you to determine the strength of the electric field in any region of space. All that is needed for this is to indicate in the Coulomb's law the coordinates of the point at which this field is to be found. And here we are directly confronted with the question of the limits of applicability of quantum mechanics. The successes of quantum theory in various directions are so huge and the predictions are so accurate that many have wondered if there are limits to its applicability. Unfortunately there are. If there is a need to move from a probabilistic description of the world to its deterministic interpretation as it really is, then we must remember that it is at this transition that the powers of quantum mechanics end. She did an excellent job. Its possibilities are far from being exhausted, and it can still explain a lot. But it is only a certain approximation to reality, and judging by the results, it is a very successful approximation. Below we will show why this is possible.
Wave properties of particles, wave-particle duality
in quantum mechanics.
This is probably the most confusing question in quantum theory. There are countless works written on this topic and opinions expressed. The experiment unambiguously states that the phenomenon exists, but it is so incomprehensible, mythical and inexplicable that it even served as a reason for jokes that a particle, on its own whim, behaves like a corpuscle on some days of the week, and like a wave on others. Let us show that the existence of a hidden parameter of a nonzero particle size makes it possible to explain this phenomenon. Let's start with the Heisenberg uncertainty relation. It has also been repeatedly confirmed by experiment, but it does not find the proper justification within the quantum theory. Let us use the conclusions from classical physics that two factors are necessary for the emergence of uncertainty and see how these factors are implemented in quantum theory. Regarding the speed of light, we can say that it is organically built into the structures of the theory, and this is understandable, since almost all the processes that quantum mechanics deals with are relativistic. And without the special theory of relativity here simply can not do. The other factor is different. All calculations in quantum mechanics are made on the assumption that the particles it deals with are point particles, in other words, there is no second condition for the occurrence of the uncertainty relation. Let us introduce a non-zero size of elementary particles into quantum mechanics as a hidden parameter. But how to choose it? Physicists involved in the development of string theory are of the opinion that elementary particles are not point particles, but this manifests itself only at significant energies. Is it possible to use these dimensions as a hidden parameter. Most likely not, for two reasons. Firstly, these assumptions are not entirely substantiated, and on the other hand, the energies with which the developers of string theory work are so large that these ideas are difficult to verify experimentally. Therefore, it is better to look for a candidate for the role of a hidden parameter at a low-energy level accessible for experimental verification. The most suitable candidate for this is the Compton wavelength of the particle:
It is constantly in sight, is given in all reference books, although it does not find a proper explanation. Let us find an application for it and postulate that it is the Compton wavelength of a particle that determines, in some approximation, the size of this particle. Let's see if the Compton wavelength satisfies the Heisenberg uncertainty relation. It takes time to travel a distance equal to the speed of light:
Substituting (4) into (3) and taking into account that we get:
As can be seen in this case, the Heisenberg uncertainty relation is fulfilled exactly. The above reasoning cannot be considered as a justification or conclusion of the uncertainty relation. It only states the fact that the conditions for the emergence of uncertainty, both in classical physics and in quantum theory, are absolutely the same.
Let us consider the passage of a particle with a velocity , which has dimensions of the Compton wavelength, through a narrow slit. The time of passage of the particle through the slot is determined by the expression:
Due to its potential field, the particle will interact with the walls of the slot and experience some acceleration. Let this acceleration be small and the speed of the particle after passing through the gap, as before, can be considered equal to . The acceleration of the particle will cause a wave of perturbation of its own field, which will propagate at the speed of light. During the time the particle passes through the slit, this wave propagates over a distance:
Substituting into expression (7) expressions (3) and (6) we get:
Thus, the introduction of a non-zero particle size as a hidden parameter into quantum mechanics makes it possible to automatically obtain expressions for the de Broglie wavelength. Get what quantum mechanics was forced to take from experiment, but could not substantiate it in any way. It becomes obvious that the wave properties of particles are due only to their potential field, namely, the appearance of a wave of perturbation of the own field or, as it is commonly called, a retarded potential during their accelerated motion. Based on the foregoing, it can also be argued that the expression for the de Broglie wave (8) is by no means a statistical function, but a real wave of all characteristics, which, if necessary, can be calculated based on the concepts of classical physics. Which in turn is another proof that the probabilistic interpretation of the physical processes occurring in the subatomic world by quantum mechanics is incorrect. Now there is already an opportunity to reveal the physical essence of wave-particle duality. If the potential field of the particle is weak and can be neglected, then the particle behaves like a corpuscle and can safely be assigned a trajectory. If the potential field of particles is strong and can no longer be neglected, namely, such electromagnetic fields act in atomic physics, then in this case you need to be prepared for the fact that the particle will show its wave properties to the fullest. Those. one of the main paradoxes of quantum mechanics about corpuscular-wave dualism turned out to be easily resolved due to the existence of a hidden parameter of a non-zero size of elementary particles.
Discreteness in quantum and classical physics.
For some reason, it is generally accepted that discreteness is characteristic only of quantum physics, while in classical physics there is no such concept. In fact, everything is not so. Any musician knows that a good resonator is tuned to only one frequency and its overtones, the number of which can also be described by integer values \u003d 1, 2, 3 ... . The same thing happens in the atom. Only in this case, instead of a resonator, there is a potential well. Moving in an atom in a closed orbit at an accelerated rate, the electron continuously generates a wave of perturbation of its own field. Under certain conditions (the distance of the orbit from the nucleus, the speed of the electron), the conditions for the emergence of standing waves can be fulfilled for this wave. An indispensable condition for the appearance of standing waves is that the length of the orbit fits equal amount such waves. It is possible that Bohr was guided by such considerations when formulating his postulates regarding the structure of the hydrogen atom. This approach is based entirely on the concepts of classical physics. And he was able to explain the discrete nature of the energy levels in the hydrogen atom. There was more physical meaning in Bohr's ideas than in quantum mechanics. But both Bohr's postulates and the solution of the Schrödinger equation for the hydrogen atom gave exactly the same results regarding discrete energy levels. The discrepancies began when it was necessary to explain the fine structure of these spectra. In this case, quantum mechanics proved to be more than successful, and work on the development of Bohr's ideas was stopped. Why did quantum mechanics emerge victorious? The fact is that, being in a stationary orbit in conditions where the formation of standing waves is possible, the electron passes the same path many times. There is no experimental possibility to trace the motion of an electron in a bound state at the microscopic level. Therefore, the use of statistical methods here is fully justified, and the interpretation of the formation of antinodes in the orbit as the highest probability of finding an electron at these points has good grounds, which, in fact, is what quantum theory does with the help of the wave function and the Schrödinger equation. And this is the reason for the successful application of the probabilistic approach to describe physical phenomena taking place in atomic physics. Here we consider only one, the most simple example. But the conditions for the emergence of standing waves can also arise in more complex systems. And quantum mechanics does a good job with these questions as well. One can only admire the scientists who stood at the origins of quantum physics. Working in a period of destruction of familiar concepts, in conditions of a shortage of objective information, they somehow managed to feel the essence of the processes occurring at the microscopic level in some incredible way and built such a successful and beautiful theory as quantum mechanics is. It is also obvious that there are no fundamental obstacles to obtaining the same results within the framework of classical physics, because such a concept, a standing wave, is well known to it.
Quantum of minimal action in quantum mechanics and in
classical physics.
The quantum of minimal action was first used by Planck in 1900 to explain the radiation of a black body. Since then, the constant introduced by Planck into physics, later named after the author as the Planck constant, has firmly taken its place of honor in subatomic physics and is found in almost all mathematical expressions that are used here. Perhaps this was the most significant blow to classical physics and determinists, who could not do anything to counter it. Indeed, there is no such concept as a minimum quantum of action in classical physics. Does this mean that it cannot be there in principle and that this is the domain of only the microworld? It turns out that for macrobodies with a potential field you can also use the minimum action quantum, which is defined by the expression:
(9)
where is the body weight
Diameterthis body
speed of light
Expression (9) is postulated in this paper and requires experimental verification. The use of this quantum of action in the Schrödinger equation makes it possible to show that the orbits of the planets solar system are also quantized, as are the orbits of an electron in atoms. In classical physics it is no longer necessary to take the value of the minimal action quantum from experiment. Knowing the mass and dimensions of the body, its value can be unambiguously calculated. Moreover, expression (9) is also valid for quantum mechanics. If in formula (9) instead of the diameter of the macrobody we substitute the expression that determines the size of the microparticle (3), then we get:
Thus, the value of Planck's constant, which is used in quantum mechanics, is just a special case of expression (9) used in the macrocosm. In passing, we note that in the case of quantum mechanics, expression (9) contains a hidden parameter, the particle size. Perhaps that is why Planck's constant was not understood in classical physics, and quantum mechanics could not explain what it is, but simply used its value taken from the experiment.
Quantum effects in gravity.
Introduction to quantum mechanics as a hidden parameter, a non-zero size of elementary particles, made it possible to determine that the wave properties of particles are due exclusively to the potential field of these particles. Macrobodies with rest mass also have a potential gravitational field. And if the conclusions drawn above are correct, then quantum effects should also be observed in gravity. Using the expression for the minimum quantum of action (9), we formulate the Schrödinger equation for a planet that moves in the gravitational field of the Sun. It looks like:
Wherem is the mass of the planet;
M is the mass of the Sun;
G is the gravitational constant.
The procedure for solving equation (10) is no different from the procedure for solving the Schrödinger equation for the hydrogen atom. This makes it possible to avoid cumbersome mathematical calculations and solutions (10) can be immediately written out:
Where
Since the presence of trajectories for planets moving in orbit around the Sun is beyond doubt, it is convenient to transform expression (11) and represent it in terms of the quantum radii of the planets' orbits. Let us take into account that in classical physics the energy of a planet in orbit is determined by the expression:
(12 );
Where is the average radius of the planet's orbit.
Equating (11) and (12) we get:
(13 );
Quantum mechanics does not make it possible to unequivocally answer in what excited state a bound system can be. It only allows you to find out all possible states and the probabilities of being in each of them. Formula (13) shows that for any planet there is an infinite number of discrete orbits in which it can be located. Therefore, one can try to determine the main quantum numbers of the planets by comparing the calculations made by formula (13) with the observed radii of the planets. The results of this comparison are presented in Table 1. The data on the observed values of the parameters of the orbits of the planets are taken from .
Table 1.
|
Planet |
Actual orbit radius R million km |
Result computing million km |
n |
Error
million km |
Relative error % |
|
|
Mercury |
57.91 |
58.6 |
0.69 |
|||
|
Venus |
108.21 |
122.5 |
14.3 |
13.2 |
||
|
Earth |
149.6 |
136.2 |
13.4 |
|||
|
Mars |
227.95 |
228.2 |
0.35 |
0.15 |
||
|
Jupiter |
778.34 |
334.3 |
||||
|
Saturn |
1427.0 |
|||||
|
Uranus |
2870.97 |
2816 |
54.9 |
|||
|
Neptune |
4498.58 |
4888.4 |
||||
|
Pluto |
5912.2 |
5931 |
18.8 |
|||
As can be seen from Table 1, each planet can be assigned a certain main quantum number. And these numbers are quite small compared to those that could be obtained if in the Schrödinger equation, instead of the minimum action quantum determined by formula (9), Planck's constant, usually used in quantum mechanics, would be used. Although the discrepancy between the calculated values and the observed radii of the orbits of the planets is quite large. Perhaps this is due to the fact that the derivation of formula (11) did not take into account the mutual influence of the planets, leading to a change in their orbits. But it is shown that the main orbits of the planets of the solar system are quantized, just as it takes place in atomic physics. The given data unambiguously testify that quantum effects also take place in gravitation.
There are also experimental confirmations of this. V. Nesvizhevsky with colleagues from France managed to show that neutrons moving in a gravitational field are detected only at discrete heights. This is a precision experiment. The difficulty of conducting such experiments is that the wave properties of the neutron are due to its gravitational field, which is very weak.
Thus, it can be argued that the creation of a theory of quantum gravity is possible, but it should be taken into account that elementary particles have a non-zero size, and the minimum quantum of action in gravity is determined by expression (9).
Particle spin in quantum mechanics and classical physics.
In classical physics, every rotating body has an internal angular momentum, which can take on any value.
In subatomic physics, experimental studies also confirm the fact that particles have an internal angular momentum called spin. It is believed, however, that in quantum mechanics the spin cannot be expressed in terms of coordinates and momentum, since for any allowable particle radius, the speed on its surface will exceed the speed of light and, therefore, such a representation is unacceptable. Introduction to quantum physics of non-zero particle size allows us to somewhat clarify this issue. For this, we use the concepts of string theory and imagine a particle whose diameter is equal to the Compton wavelength as a string closed in three-dimensional space, along which a stream of some field circulates at the speed of light. Since any field has energy and momentum, it is possible with good reason to attribute to this field an impulse associated with the mass of this particle:
Considering that the radius of the field circulation around the center is , we obtain the expression for the spin:
Expression (15) is valid only for fermions and cannot be considered a justification for the existence of spin in elementary particles. But it allows us to understand why particles with different rest masses can have the same spin. This is due to the fact that when the particle mass changes, the Compton wavelength changes accordingly, and expression (15) remains unchanged. This did not find an explanation in quantum mechanics and the values for the particle spin were taken from the experiment.
Vibrational spectra of elementary particles.
In the previous chapter, when considering the issue of spin, a particle with a size equal to the Compton wavelength was represented as a string closed in three-dimensional space. This representation makes it possible to show that discrete vibrational spectra can be excited in elementary particles.
Let us consider the interaction of two identical closed strings with rest masses moving towards each other with a speed . From the beginning of the collision to the complete stop of the strings, some time will pass, due to the fact that the speed of momentum transfer inside the strings cannot exceed the speed of light. During this time kinetic energy strings will be converted into potential energy, due to their deformation. At the moment the string stops, its total energy will consist of the sum of the rest energy and the potential energy stored during the collision. Later, when the strings begin to move in the opposite direction, part of the potential energy will be spent on excitation of the natural vibrations of the strings. The simplest form of vibration at low energies that can be excited in strings can be represented as harmonic vibrations. The potential energy of the string when deviating from the equilibrium state by a value has the form.
k - coefficient of elasticity of the string
We write the Schrödinger equation for stationary states of a harmonic oscillator in the form:
The exact solution of equation (17) leads to the following expression for discrete values :
Where 0, 1, 2, … (18)
In formula (18) unknown coefficient of elasticity of elementary particles k . It can be approximately calculated based on the following considerations. When particles collide at the moment they stop, all kinetic energy is converted into potential energy. Therefore, we can write the equality:
If the momentum inside the particle is transmitted with the maximum possible speed equal to the speed of light, then from the moment the collision begins to the moment the particles diverge time will pass necessary for the impulse to propagate along the diameter of the entire particle, equal to the Compton wavelength:
During this time, the deviation of the string from the equilibrium state due to deformation can be:
Taking into account (21), expression (19) can be written as:
Substituting (23) into (18) we obtain an expression for possible values suitable for practical calculations:
Where , 1, 2, … (24)
Tables (2, 3) present the values for the electron and proton calculated by formula (24). The tables also indicate the energies released during the decay of excited states during transitions and the total energies of particles in an excited state. All experimental values of particle rest masses are taken from .
Table 2. Vibrational spectrum of electron e (0.5110034 MeV.)
|
Quantum number n |
|||
Table 3. Vibrational spectrum of proton P (938.2796 MeV)
|
Quantum number n |
An experimental study of quantum systems made it possible to discover that they have statistical properties: repeating the experiment with a quantum system in fixed 50 experimental conditions can lead to non-repeatable results. An example is the sequential passage of photons with the same polarization through the analyzer: some photons pass through it, while others are reflected. Quantum mechanics correctly describes the statistics of such experiments, but does not explain the nature of this statistics; the latter is postulated by quantum theory.
The existing hypotheses about the nature of the statistical nature of quantum systems are clearly divided into two classes. The first group includes hypotheses that connect the statistical properties of quantum systems with the corpuscular-wave dualism of the properties of microparticles, with the influence of physical fields on vacuum particles, etc. Common to them is the recognition of the objective existence of random phenomena in the microworld. Dialectical materialism considers the statistical connection between the initial state of the system and the result of the experiment as a new character of causal relationships, not reducible to classical causality. V. I. Lenin wrote about a simplified, approximate reflection of the objective connection of phenomena by classical causality [2, vol. 18, p. 139] long before the creation of quantum mechanics.
(The logical conclusion of the first hypothesis within the framework of the concept of integrity is the conclusion that the natural basis for the statistical nature of quantum objects is the objective property of the finite non-detailedness of their states in terms of elements and sets):
The second class includes hypotheses that suggest the presence in the complex of a quantum system - a measuring device of the so-called hidden parameters, which have not yet been observed. It is assumed that each value of the hidden parameter uniquely determines the result of an individual experiment, and the statisticalness observed and described by quantum mechanics is the result of averaging over all values of the hidden parameters. Thus, these hypotheses assume a one-to-one relationship between the value of the hidden parameter and the result of a separate experiment, i.e., the existence in quantum physics classical causation.
Finding out which of these two possibilities is realized in nature is of fundamental importance for physics and philosophy, since it is connected with the question of the existence or non-existence of non-classical causal relationships.
Criticism of the conclusions of the experiment was given by Bohr, who showed that the resulting paradox is the result of the assumption about the locality of quantum systems [28, p. 187-188, 425-428]. The rejection of this assumption, i.e., the recognition of the existence of a correlation between the separated parts of a quantum system (characterized by the term "integrity"), eliminates the EPR paradox.
It was the analysis of the EPR paradox that led Bohr to formulate the complementarity principle for quantum systems, which expresses one of the main differences between the latter and classical systems. The principle of complementarity requires that the quantum system and the measuring device be considered as one, complete system. The measurement results of a quantum system depend on its state, as well as on the design and state of the measuring device. Fock called this property of quantum systems relativity to means of measurement.
In three experiments, the correlation of polarizations of photons emitted during positronium annihilation was studied. In the works of Kasdei, Ulman and By [208; 209] obtained results consistent with QM. Gutkowski, Notarrigo, and Pennisi concluded that the results are consistent with TSP. However, since the initial state of positronium is not known, and the results of the work correspond to the upper bound of Bell's inequality and lie between quantum mechanical results corresponding to various assumptions about the initial state of positronium, a reliable conclusion cannot be drawn from this work. The work of Lamehi-Rahti and Mittig studied the correlation between the polarizations of two protons in proton-proton scattering; experimental results are consistent with QM.
In the next group of experiments, the correlation between the polarizations of two photons emitted by an atom during a cascade radiative transition is studied. Friedman and Clauser's work uses calcium atoms; the results are consistent with KM.
Holt and Pipkin's research used mercury atoms; the results agree with the TFT, but they are not obtained cleanly enough and are therefore unreliable. This is evident from the work of Clauser, who repeated the experiment on the basis of a different method of excitation of atoms [189; 227; 228]. The results obtained by him are quite reliable and agree with KM. Frey and Thomson use radiation from a different isotope of mercury and a different radiation cascade; the results obtained are consistent with KM.
Of particular note is the experiment of Asspec, Gringier and Roger, who investigate the radiation of calcium. The authors significantly increased the number of measurements compared to previous works and obtained greater statistical accuracy. The results agree well with KM and violate Bell's inequality by nine standard deviations, making the conclusions very robust. Increasing the distance from source to each analyzer to 6.5 m did not change the results of the experiment, which indicates the independence of long-range correlations from distance.
The accumulated theoretical and experimental material does not yet allow making a final choice between RFT and QM. The formulation of the postulate of locality and the structure of the TSP can be improved. There is already a work generalizing Bell's theorem. New experiments can be performed with other objects; there is a proposal to use 55 experiment, particles decaying as a result of weak interaction, etc. [198; 243].
Nevertheless, based on the available theoretical and experimental works, the following conclusions can be drawn.
The experimental data seem to contradict the local TSP and Bell's theorem based on it. The two experiments consistent with Bell's theorem are among the earliest, are not sufficiently clean, and are not supported by later work.
Thus, the existing TSPs contradict the observed properties of quantum systems. So far, it has not been possible to “substitute” TSP for QM and restore classical causality in quantum physics. The nonrelativistic QM in its field still remains the only theory that correctly describes the experimental facts.
The existence of long-range correlations in quantum systems has been established experimentally: directly - by confirming QM - and indirectly - by falsifying Bell's theorem and the postulate of locality on which it is based.
The presence of long-range correlations is not specific to EPR-type experiments, they are well known in other quantum phenomena: light interference in the Michelson experiment, the existence of a superfluid component in liquid helium and Cooper electron pairs in superconductors.
The alternative - locality or integrity - is decided in favor of the integrity of quantum systems, which is embedded in QM in the form of the principle of indistinguishability of identical particles and the principle of complementarity.
The property of quantum systems observed experimentally and described by the QM apparatus - the preservation of correlations between parts of the system as the interaction between them tends to zero - is not trivial. Its interpretation requires a dialectical approach.
Particularly acute is the problem of integrity, the question of the relationship between the part and the whole, raised by elementary particle physics. The achieved unification of the electromagnetic and weak interactions and the task of the “great unification” of all interactions facing modern physics, in fact, represent various stages in the reflection in physics of the integrity of the surrounding world, the universal connection and interdependence of phenomena of which is one of the laws of materialistic dialectics. 56
