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One,
Brief introduction of current measurement problems: Since the development of quantum mechanics at the beginning of last century, there have been many famous conceptual disputes. Among them, the so-called quantum mechanical measurement problem has become the most basic problem in this long-lasting dispute over the world view of quantum mechanics.
According to the standard of quantum mechanics, the wave function of quantum collapses and its motion law consists of two parts. One is linear dynamics: if a physical system is not measured, it will evolve in a definite linear way according to Schrodinger equation; The second is nonlinear collapse dynamics: if the system is measured, it will immediately jump from the initial superposition state to an observable eigenstate nonlinearly and randomly. At this time, the experimenter will perceive an observed value, that is, the eigenvalue corresponding to the eigenvalue. This is the eigenvalue-eigenvalue correlation first proposed by P Dirac-john von neumann in the early 1930s in order to unify the theoretical work of W Heisenberg and W Schrodinger with the probability explanation of M Born.
In this way, a logical contradiction called measurement problem arises between the universal validity of Schrodinger equation, the reliability of experimenter's perception and the eigenvalue-eigenvalue correlation. On the one hand, the general validity of Schrodinger equation requires Schrodinger equation to dominate the dynamic evolution of every physical system in the universe, so in quantum measurement, the macroscopic instrument used to measure any microscopic object will almost certainly evolve into a quantum entangled state with the measured object, rather than the observable eigenstate of the instrument pointer; On the other hand, according to the eigenvalue-eigenvalue correlation, if the experimenter is awake, their measurement conclusion will be that the measurement result they get is a certain direction indicated by the instrument pointer, that is, an observation value, rather than the quantum superposition state of the pointer.
How to solve this logical contradiction? Although orthodox quantum theorists often resort to the "collapse hypothesis" or quantum classical "segmentation" to solve this problem, in their view, the universal validity of Schrodinger equation is the only dangerous hypothesis. However, none of the above three hypotheses is redundant in the origin of this contradiction, and denying any of them is enough to escape this dilemma. In order to avoid contradictions, at least one of the three hypotheses must be rejected. According to the inherent requirements of the formal system of quantum mechanics, it is assumed that the general validity of Schrodinger equation in the quantum world is acceptable. However, if we keep the reliability of the experimenter's perception, then the eigenvalue-eigenvalue correlation becomes a hypothesis that can be considered for removal.
It can be said that von Neumann's theory of quantum measurement first broke N Bohr's hypothesis of quantum-classical "segmentation", that is, the classical instruments of quantum measurement are indispensable, and pioneered the theoretical exploration of the dynamic mechanism of quantum measurement with consistent quantum mechanics. However, this theoretical attempt does not take into account the macroscopic or classical characteristics of the instrument, that is, the statistical thermodynamic properties of the instrument, but ideally assumes that the instrument is a quantum pointer with only one degree of freedom, which leads to the infinite regression of the instrument. In order to cut off the instrument chain of infinite regression, eliminate interference terms and realize "wave packet collapse", von Neumann finally turned to human consciousness, which led to the philosophical dilemma of parallel body and mind. So far, there is no reasonable explanation for this dilemma that we can understand.
Second,
After thinking, the author found the crux of the measurement problem. Let's try to solve this problem in a way that all ordinary IQ people can understand, and try to put forward a series of new assumptions. Let's look at how to remove consciousness and subjective factors from quantum mechanics. You are welcome to question the article.
First of all, let's talk about a very familiar concept: "time". On the stage of quantum mechanics, time is a neglected small role. Although we are familiar with time, no one has answered clearly what is the essential definition of time. And what is the essence of time in the sense of quantum mechanics theory?
Try to analyze it. Let's divide the timeline into two sections and take the current time t? It is divided into two parts: historical time and future time (mathematical diagram: straight line with directional arrow on the right, with a point in the middle representing current time, right point representing future time and left point representing historical time).
In the case of quantum wave function collapse, we assume that time marks its collapse process: as time goes on, the wave function on the future time axis does not collapse, but when we observe (current time), the wave function collapses and the time axis enters historical time at the same time. We find that observation or measurement is always the same as time t? Overlap together. Ladies and gentlemen, what matters is that time is closely connected with our three-dimensional space, or the consciousness of the observer? Are intelligent creatures watching at the current moment t? With the passing away, the wave functions of all quanta in the whole universe have been collapsing, and the quantum that has not been disturbed and measured will still be moving in the next future, and will still exist in the superposition state of quantum wave functions in the future; The measured quantum particles naturally change their state of motion. This process can be understood by our daily experience, and the Copenhagen school expressed it as the approximate result of such a part as' measurement leads to the collapse of quantum wave function'.
Now we can assume a different conclusion: the quantum wave function has collapsed at the historical time (symbol t-), and at the current time T? The wave function is collapsing, and t* will keep the wave function state in the future. Take a single quantum as an example. A photon in the depths of the universe flies from a star 65.438+000 billion light years away and reaches the edge of the solar system. According to the current theory of quantum mechanics, this photon is like a ghost before it enters our eyes, that is, before it is observed by us, that is, it is here and there (that is, quantum superposition state). Until the photon reaches the earth, when we see it, at this moment, it collapses into a real light spot on my retina! At this time, its wave function collapsed into essence (Copenhagen school view), so when the photon flew to the edge of the solar system, it was still in the wave function state because we had not observed it yet. According to my hypothesis, it should be that this photon has been collapsing since it reached the edge of the solar system 1000 billion years ago! We set the moment when photons travel to the edge of the solar system as t? Then this photon has passed through a (only one) fixed channel from 10 billion years ago and reached the edge of the solar system. But in the space from the edge of the solar system to the earth, this photon is in an uncertain state, and its path is predicted as a quantum superposition state, that is, there are many possible paths. Until we reach earth, in another test? It always collapses, enters our eyes, and is absorbed by the retina at the same time, ending the journey of 65.438+0 billion years, while other homologous photons flying over our ears three centimeters away from our eyes continue to move until they interact with other particles.
This process matches our daily experience quite well, and it is very clear and easy to understand. Moreover, we can find that measurement is not the cause of wave function collapse, but the change of quantum motion state, because the measurement behavior is different from T? Overlap leads to misunderstanding, and unmeasurable quantum still collapses objectively according to the current moment. So my hypothesis completely covers the measured state and the unmeasured state, and does not affect the practicability of quantum mechanics theory.
Next, we use this method to explain the double-grid experiment of light. Suppose that before the experiment, we take the departure time of light source photons as t? The time when the photon passes through the double grids is the future time, and the photon randomly selects one of the double grids in the superposition state (the travel route is undetermined). Hypothesis 2, we measure after double grid in the experiment, that is, suppose t? Because the photon passes through the double grating, we will definitely find that the photon passes through one of the double gratings (of course, there is a small probability that the photon can enter the detection system without passing through the double grating, and quantum tunneling is ignored here for the time being), and its motion line is single, which accords with the quantum performance of historical time in my hypothesis. If the moment when the photon hits the screen is t? We will find that continuous single photons will form interference fringes on the fluorescent screen, which is equivalent to simultaneous irradiation of multiple photons.
Let's catch Schrodinger's cat.
Let's retell this classic thought experiment first. There is a cat and a small amount of radioactive material in the box. After that, there is a 50% probability that the radioactive material will decay and release poison gas to kill the cat, and there is a 50% probability that the radioactive material will not decay and the cat will survive. According to classical physics, one of these two results must happen in a box, and external observers can only know the result inside if they open the box. In the quantum world, when the box is closed, the whole system maintains an uncertain wave state, that is, the superposition of cat life and cat death. Whether the cat is dead or alive can only be determined when the box is opened for external observers to observe and the matter is expressed in the form of particles. The purpose of this experiment is to show the extraordinary knowledge and understanding of quantum mechanics on the world of microscopic particles, but this makes the microscopic uncertainty principle become the macroscopic uncertainty principle, the objective law is not transferred by human will, and the life and death of cats violate logical thinking.
In this system, based on my hypothesis, if t? When opening the box, if the cat died, it must have happened in historical time, and you can see the dead cat; If the cat is not dead, it may die at any time in the coming future timeline. This is indeed a quantum superposition state, but it is consistent with our daily experience. If you set t? For a certain moment before the experiment (Schrodinger's hypothesis seems to be this moment), the experiment has not yet started, and the cat on the future timeline in the black box may die at any time. This is very normal in the superposition of the two possibilities, and the cat's state is only described by wave function.
To sum up: whether or not you have observed the cat in the black box, use the current time t? With the arrival of, the wave function collapsed, and the cat constantly collapsed from the quantum superposition state to the fixed state in historical time; In the future time t*, the cat is still in the state of quantum superposition. It turns out that Schrodinger's cat has two cats, one is a cat in the state of historical collapse and the other is a cat in the state of future superposition.
Three. Conclusion:
1, the hypothesis that the measurement of Copenhagen school leads to the collapse of wave function is incorrect! The collapse of wave function has nothing to do with measurement, and the inherent nature of time leads to the collapse of wave function.
2. On the time axis, the current time is divided into historical time and future time. It is concluded that all quantum wave functions in the past time have collapsed, and all quantum wave functions in the future time have not collapsed. The current moment is the instantaneous collapse point of quantum wave function.
To sum up: in the early days of quantum mechanics theory, the understanding of probability collapse was still vague, although Heisenberg replaced t with measurement behavior. The practical problem was solved temporarily, but a subjective factor was introduced, which broke the scientific world outlook system established in Europe by dozens of generations of scientists such as Newton since the17th century (Renaissance made Europe get rid of the long middle ages when politics and religion were integrated, and the logical natural science made European countries become world powers. Hundreds of years later, the understanding and attitude towards science made countless classical physicists instinctively oppose the subjective part of quantum mechanics. You can imagine how strong the voice against quantum mechanics was at that time! The controversy caused by this has caused a large number of the best scientists such as Einstein to have ambiguity about the theory of quantum mechanics, and stopped or reduced their research on quantum mechanics. Although quantum mechanics finally won because its whole system is in perfect agreement with the experimental results, this great debate nearly a hundred years ago has continued to this day. Not long ago, academician of Chinese Academy of Sciences and former president of South University of Science and Technology also wrote an article to enlarge the topic between quantum mechanics and consciousness, with the intention of being a strong evidence of idealism and Buddhism, which shows that this problem has a wide and bad influence.
In addition, the concept of time is familiar in our daily experience and is a ready-made concept in classical physics, relativity and quantum mechanics. It is not abrupt to introduce the concept of time in the process of quantum wave function collapse, and it also gives more space for quantum mechanics to think and study. For example, combined with the collapse process of wave function, our understanding of the nature of time has gone further. We find that the evolution of our universe, that is, the evolution of time and space delay, is exactly the same. If this theory can be established, we can come to the conclusion that even according to Einstein's theory of relativity, we can't build a machine that can go back to the past just by visiting! Because of quantum mechanics' explanation of time, the wave function of historical time has collapsed, and it is impossible to go back to the past and create another possibility. Perhaps after that, many science fiction films will not be recognized by the scientific community.
Further assumptions are as follows: Hypothesis 1: Define the physical meaning of time in quantum mechanics theory: Time flow is the process of quantum wave function collapse. Hypothesis 2: spacetime has quantum properties (spacetime has a minimum value). Set 3: Quantum properties of spacetime endow elementary particles with quantum properties. Hypothesis 4: the historical time cannot be extended, but the future time may be extended (shortening or extending the time) as the theory of relativity says. Hypothesis 5: Quantum spacetime, classical spacetime and relativistic spacetime are equivalent.
Note: When the current time is equal to the measurement time, t? Included in the historical time.