The role of the observer in quantum physics. Report: The role of the observer in quantum mechanics Who is the observer in quantum physics

Report: The role of the observer in quantum mechanics

Alexey Mazur

The main problem of quantum mechanics is the question of what happens when the wave function is reduced. Why is a plane wave of an electron “realized” at one point on the photographic plate? Is our inability to “calculate” which of the available possibilities is “realized” a fundamental law of nature, or a consequence of the imperfection of the methods and instruments we use. The process of reduction itself is as imperceptible as the horizon line or the base of the rainbow. At what point does it happen? At the moment of interaction of the wave function with the photographic plate, which is a “classical” object, or at the moment of the experimenter’s “observation” of the photographic plate? And why is the “observer” so distinguished that he is given the right to choose according to which of the possible ways will the world move on?

Let's try to figure out where the line between a “classical” and a quantum object lies. When I was a student (and perhaps only students nowadays ask such questions), my father V.A. Mazur and his friend A.V. Gainer reasoned approximately as follows. The process of “observation” is the process of interaction of a wave function with a device that has such a complex wave function that there is no way to calculate it. Therefore it is a classical object. The result of the interaction of the electron wave function with such an object is unpredictable and probabilistic in nature, but not because this is a fundamental law of nature, but because our research methods are imperfect. Wanting to simplify the “observation” model, they hypothetically set up such an experiment. We take a plane wave of an electron incident on an ideally flat photographic plate consisting of hydrogen atoms arranged in a checkerboard pattern. All atoms are in the ground state. Calculating the result of interaction is not difficult. The wave function of the plate after interaction is the sum of N (where N is the number of atoms in the plate) terms, each of which has a “weight” of 1/N. The first term is that atom number 1 is excited, the rest are in the ground state, the second term is that atom number 2 is excited, the rest are in the ground state, etc. The conclusion that my father and A.V. Gainer made from this is that such a plate is not a classical object, but remains a quantum one, while real plates are structured quite complex to be classical.

I propose to bring their hypothetical experiment to the end, and consider what will happen after the interaction of this plate with the observer. Of course, we are unable to simulate the wave function of the observer. But some analogies seem quite obvious. So, our “quantum” observer looked at this photographic plate. What will happen to its wave function? As you can easily understand, it will break down into N terms. Conventionally, they can be called as follows: the first term - the observer sees excited atom number 1, the second term - the observer sees excited atom number 2, etc. Again, it would seem, the moment of reduction has eluded us. But let's look at the subjective sensations of the observer. Suppose he performed this experiment three times. As is easy to see, its wave function already has N cubed terms. And this is where the reduction occurred. Suppose he met a "classical" rather than a "quantum" observer who asked him the results of these experiments. And of the N cubed terms of our “quantum” observer, only one will remain. But note that he will be firmly convinced that in the first case he saw an excited atom, say number 27, in the second - 3, and in the third - 137. No memories of the other terms of his wave function will remain in him. He will tell the “classical” observer about these “subjective” sensations.

From this we see that the process of reduction may not be at all connected with the process of “observation”. At the moment of “observation”, it is not the observer who “chooses” one of the possible states of the world, but he himself “breaks down” into components. Each of these terms corresponds to the terms of the “measured” object. Let us assume that reduction occurs very rarely in general. Once a year, for example. All observers, including you and me, after reduction, will have no idea that our wave functions had other, “unrealized” terms.

Obviously, there is no special need for “implementation” as such. It stemmed from the subjective feeling of those observers who “saw” how, out of equally probable possibilities, only one was randomly “realized.” After all, none of the terms of the observer’s wave function contains information about the other terms.

Here we come up against the question of what the “I” of the observer is. It is easy to understand that the “subject” is not the entire ensemble of “components”, but only one of them. Moreover, any. That is, a person is not a “world line”, but a “tree”, and the branching points are moments of “observation”, but simply moments of interaction with the outside world. And this, as you understand, concerns not only people.

The picture of the world that appears after realizing the above looks absolutely fantastic. Everything that could happen happened. All lost opportunities have been realized, they exist in the same world and space with us, but do not have any impact on us. And, it must be admitted that this picture of the world is a direct consequence of the laws of quantum mechanics, and not the idle speculation of pseudoscientific fiction writers.

Skeptics, of course, can say - what are the consequences of these arguments? They do not carry any practical meaning. This is not entirely true.

First, it becomes obvious that there is no boundary between a quantum and a classical object. The moment of reduction for our subjective “I” actually occurs at the moment of observation. But it is not we who do something to the world, but the world who does something to us. But for simplicity, we can leave the concept of reduction and be proud of the fact that everyone “realizes” their own world.

Secondly, the experiment, which was carried out either in the late forties or early fifties, is easily explained. Some particle disintegrated into two fragments, each of which flew in opposite directions. Since at the moment of decay the particle was at rest, all directions of flight of the 1st fragment were equally probable. But the second one, according to the law of conservation of momentum, had to fly in exactly the opposite direction. The fragment detectors were positioned so that the time difference between the “catch” of the fragments was less than it would take for light to travel from one detector to the other (to eliminate the possible influence of the results at one detector on the results at the other). The paradox was that the wave functions of the two fragments were “realized” in concert against each other, according to the laws of conservation, but perplexing physicists - how does the wave function of fragment number two “know” that the reduction of the wave function of fragment number one has occurred? Find out faster than the speed of light?

As we now understand, the reduction of fragment number two occurs not at the moment of its interaction with the detector, but at the moment of interaction of the observer with the detector, so that the cause-and-effect relationships are not broken.

Quantum superposition is destroyed not due to the disturbing interaction of a macroscopic device on a macroscopic object, but due to the interaction of a fullerene molecule with the surrounding environment
The "delayed choice" hypothesis - that if we learn about which slit an electron passes through, this can retrogradely affect the situation of the electron's "choice" of the slit - is also explained by experimental errors. In the quantum world, any observation inevitably leads to a change in the properties of the object.
The experiment with the fullerene molecule was recently repeated with chlorophyll molecules, and now they plan to carry it out with viruses.

The role of the observer depends on the purpose of the study, in accordance with which the type of observation is chosen. The degree of involvement in an object, that is, the degree of taking on certain roles, can be different: from complete detachment to active participation in the activities of the observed object.

The presence of the researcher outside the object involves observation from the outside, without interfering in the activities of the object of observation. In participant observation, the observer is somehow involved in the activities of the object he is examining. Depending on the observation procedure, the degree of inclusion can be interpreted differently. Therefore, there are various modifications of the term “participant observation” - “stimulating participant observation”, “observing participation”, “participant observation”, “provoking observation”, “provoking quasi-experiment”, etc. All of these variations reflect the specifics of use various types observation, in which the role of the observer may carry different loads.

A detailed description of the forms of participant observation depending on the degree of activity (from passive to full participation) of the researcher is presented in Table. 9.1.

Table 9.1

The degree of activity of the researcher during the observation process

Compiled by: .

Within the participant observation method, there are no ideal forms of observation. Each of them has its own disadvantages. Thus, a passive observer limits himself in terms of the ability to establish contact with members of the group being studied. The presence of predominantly visual information does not allow for a deep, and sometimes even correct, interpretation of the data obtained.

When using a form of moderate participation, the researcher appears as both a participant and an observer. As a rule, in this case, a false idea is deliberately created in the studied group about the purpose of the observer’s presence. For example, an observer in the classroom is present to observe the students' reactions to certain tasks of the teacher, and the legend is that he is a doctor and observes the students' fatigue. The legend is often used that the observer is a student, a trainee, and his goal is to learn a profession. Such observation allows you to combine both participation in the life of the group and the opportunity to objectively evaluate what you saw during the observation.

With active participation, the observer is perceived as a full participant in the events. A typical example is the study of the American sociologist W. White “Society on the Street Corner”. In the 30s XX century In America, he settled in Italian slums to study the lifestyle of Italian emigrants. His legend was that he was a history student who was going to write down the history of this place. White studied the emigrants' jargon, their habits and games, and came into contact with the gang leader. Over time, he began to be considered part of the local "setting" and was able to make his recordings in any situation.

The advantages of active participation and participant observation are obvious: they provide the most vivid and complete impressions of the environment, help the researcher to “get used to” the environment and situation being studied, and thereby better understand the behavior of those being studied. The disadvantage of this form of observation may be too strong an identification with those being studied, which does not allow the sociologist to maintain the distance and objectivity necessary for research activities.

Despite the fact that the researcher, during participant observation, strives to take on one of the roles available to him, he will nevertheless differ from an ordinary participant in the situation. The characteristics of the activities of an ordinary participant in the situation and a participant observer are presented in Table. 9.2.

Table 9.2

Characteristics of the activities of an ordinary participant in the situation and a participant observer

Compiled from: [Ilyin, 2006, p. 87].

The observation method in Russian sociology is described in detail by the Russian sociologist A. N. Alekseev [Alekseev, 2005; 2010]. In January 1980, Alekseev began conducting sociological research in a working environment using the “participant observation” type and went to work as a fitter at the Poligrafmash plant. In his work, the author describes in detail such a variant of participant observation as observing participation, which involves the study of social situations through the purposeful activity of the subject, making his own behavior a unique tool and a controlled factor of the study, which makes observation more complex and brings it closer to social experimentation. Any impact or intrusion into a natural process naturally raises the question: should the observer intervene in the situation being studied? “The answer to this question depends on the purpose of the study. If the main goal is to diagnose the situation... the intervention of a sociologist will distort the real picture, and as a result, unreliable data or data about a different event will be obtained. If the purpose of the research is cognitive-analytical or (or) practically applied and consists mainly of making managerial and organizational decisions, intervention is not only possible, but also useful” [Alekseev, 2010, p. 179].

There is another variation of observation - introspection. This method can provide unique data on the specifics of understanding the development of a social situation, the development of a conflict, and the reaction to the surrounding reality. Of course, introspection as a scientific technique can be used if there is constant reflection. V.I. Ilyin writes about one of the variations of introspection: “The sociologist looks at the lives of families (his own and others), the flow of people and cars on the streets, relationships between colleagues, events offered by the media, hears the words spoken by people around him - through the prism its habitus as a classification and evaluation scheme, perceiving the everyday world as an object of research... Because of this, everyday experience can be a valuable source when conducting a variety of studies” [Ilyin, 2010, p. 8].

The role of the observer in quantum mechanics

Alexey Mazur

The main problem of quantum mechanics is the question of what happens when the wave function is reduced. Why is a plane wave of an electron “realized” at one point on the photographic plate? Is our inability to “calculate” which of the available possibilities is “realized” a fundamental law of nature, or a consequence of the imperfection of the methods and instruments we use. The process of reduction itself is as imperceptible as the horizon line or the base of the rainbow. At what point does it happen? At the moment of interaction of the wave function with the photographic plate, which is a “classical” object, or at the moment of the experimenter’s “observation” of the photographic plate? And what makes the “observer” so special that he is given the right to choose which of the possible paths the world will take next?

Let's try to figure out where the line between a “classical” and a quantum object lies. When I was a student (and perhaps only students nowadays ask such questions), my father V.A. Mazur and his friend A.V. Gainer reasoned approximately as follows. The process of “observation” is the process of interaction of a wave function with a device that has such a complex wave function that there is no way to calculate it. Therefore it is a classical object. The result of the interaction of the electron wave function with such an object is unpredictable and probabilistic in nature, but not because this is a fundamental law of nature, but because our research methods are imperfect. Wanting to simplify the “observation” model, they hypothetically set up such an experiment. We take a plane wave of an electron incident on an ideally flat photographic plate consisting of hydrogen atoms arranged in a checkerboard pattern. All atoms are in the ground state. Calculating the result of interaction is not difficult. The wave function of the plate after interaction is the sum of N (where N is the number of atoms in the plate) terms, each of which has a “weight” of 1/N. The first term, atom number 1, is excited, the rest are in the ground state, the second term, atom number 2 is excited, the rest are in the ground state, etc. The conclusion that my father and A.V. Gainer made from this is that such a plate is not a classical object, but remains quantum, while real plates are structured quite complex to be classical.

I propose to bring their hypothetical experiment to the end, and consider what will happen after the interaction of this plate with the observer. Of course, we are unable to simulate the wave function of the observer. But some analogies seem quite obvious. So, our “quantum” observer looked at this photographic plate. What will happen to its wave function? As you can easily understand, it will break down into N terms. Conventionally, they can be called this: the first term the observer sees is excited atom number 1, the second term the observer sees excited atom number 2, etc. Again, it would seem, the moment of reduction has eluded us. But let's look at the subjective sensations of the observer. Suppose he performed this experiment three times. As is easy to see, its wave function already has N cubed terms. And this is where the reduction occurred. Suppose he met a "classical" rather than a "quantum" observer who asked him the results of these experiments. And of the N cubed terms of our “quantum” observer, only one will remain. But note, he will be firmly convinced that in the first case he saw an excited atom, say number 27, in the second 3, and in the third 137. No memories of the other terms of his wave function will remain in him. He will tell the “classical” observer about these “subjective” sensations.

From this we see that the process of reduction may not be at all connected with the process of “observation”. At the moment of “observation”, it is not the observer who “chooses” one of the possible states of the world, but he himself “breaks down” into components. Each of these terms corresponds to the terms of the “measured” object. Let us assume that reduction occurs very rarely in general. Once a year, for example. All observers, including you and me, after reduction, will have no idea that our wave functions had other, “unrealized” terms.

Obviously, there is no special need for “implementation” as such. It stemmed from the subjective feeling of those observers who “saw” how, out of equally probable possibilities, only one was randomly “realized.” After all, none of the terms of the observer’s wave function contains information about the other terms.

Here we come up against the question of what the “I” of the observer is. It is easy to understand that the “subject” is not the entire ensemble of “components”, but only one of them. And any. That is, a person is not a “world line”, but a “tree”, and the branching points are moments of “observation”, but simply moments of interaction with the outside world. And this, as you understand, concerns not only people.

The picture of the world that appears after realizing the above looks absolutely fantastic. Everything that could happen happened. All lost opportunities have been realized, they exist in the same world and space with us, but do not have any impact on us. And, it must be admitted that this picture of the world is a direct consequence of the laws of quantum mechanics, and not the idle speculation of pseudoscientific fiction writers.

Skeptics, of course, can say, what are the consequences of these arguments? They do not carry any practical meaning. This is not entirely true.

First, it becomes obvious that there is no boundary between a quantum and a classical object. The moment of reduction for our subjective “I” actually occurs at the moment of observation. But it is not we who do something to the world, but the world who does something to us. But for simplicity, we can leave the concept of reduction and be proud of the fact that everyone “realizes” their own world.

Secondly, the experiment, which was carried out either in the late forties or early fifties, is easily explained. Some particle disintegrated into two fragments, each of which flew in opposite directions. Since at the moment of decay the particle was at rest, all directions of flight of the 1st fragment were equally probable. But the second one, according to the law of conservation of momentum, had to fly in exactly the opposite direction. The fragment detectors were positioned so that the time difference between the “catch” of the fragments was less than it would take for light to travel from one detector to the other (to eliminate the possible influence of the results at one detector on the results at the other). The paradox was that the wave functions of the two fragments were “realized” in concert against each other, according to the laws of conservation, but perplexing physicists, how does the wave function of fragment number two “know” about the reduction of the wave function of fragment number one that has occurred? Find out faster than the speed of light?

As we now understand, the reduction of fragment number two occurs not at the moment of its interaction with the detector, but at the moment of interaction of the observer with the detector, so that the cause-and-effect relationships are not broken.

References

To prepare this work, materials from the site were used http://www.n-t.org/

Once a job analysis has been carried out and a competency model has been constructed, the next step is to select exercises that adequately measure the competencies required to perform the job effectively. At this stage it is useful to create a document that relates the exercises and the competencies associated with them. This document is often called a competency-exercise matrix.

Work Scheduling Exercise

The candidate is asked to create a schedule or plan for solving a problem or for a specific activity. The candidate is provided with related information, and is also presented with a number of conditions and restrictions, such as the amount of resources available, time frame, budget size, etc. The observer does not watch the candidate perform the exercise, but subsequently evaluates the result of the work.

Matrix of competencies (criteria) – exercises

* - Indicates that competence can be observed in this exercise

The role of the observer is extremely important. Huge number time and effort are usually invested in conducting detailed job analysis in order to compile a desired list competencies and development of suitable simulation exercises, ensuring the success of the AC. However, even if competencies and exercises meet the highest quality standards, inadequate results may be obtained due to observers not being fully trained and unable to perform their tasks. The observer's job during the CO is to accurately record what the candidate says or does during the exercise. Observers subsequently use their notes to make a judgment about the level of performance that candidates have shown in relation to the relevant competency.

At the end of the CO, I collect the records, or lists of behavioral examples received by all observers for all exercises, together and form an overall picture for each candidate. This part of the CO is called an integration session. At this session, each observer must be able to justify to his colleagues the assessments or ratings that he has given. Assessments are based on behavioral examples that correspond to each of the competencies under consideration. To provide a sufficient number of behavioral examples, it is necessary to record in as much detail as possible what the candidate says or does during the exercise. The observer works like a live video camera, his task is to record words and actions, without allowing judgments about what he saw. The observer must be very familiar with the competencies and exercises that are used in the CO and know them by heart.