Schrödinger's cat and his difficult fate. Schrödinger's cat in simple words

Yuri Gordeev
Programmer, game developer, designer, artist

"Schrödinger's cat" is a thought experiment proposed by one of the pioneers of quantum physics to show how strange quantum effects look when applied to macroscopic systems.

I will try to explain in really simple words: gentlemen of physics, do not exact. The phrase "roughly speaking" is implied further before each sentence.

On a very, very small scale, the world is made up of things that behave in very unusual ways. One of the strangest characteristics of such objects is the ability to be in two mutually exclusive states at the same time.

What is even more unusual from an intuitive point of view (someone will even say, creepy) is that the act of purposeful observation eliminates this uncertainty, and an object that has just been in two contradictory states at the same time appears before the observer in only one of them, as if in nothing never happened, looks off to the side and whistles innocently.

At the subatomic level, everyone has long been accustomed to these antics. There is a mathematical apparatus that describes these processes, and knowledge about them has found a variety of applications: for example, in computers and cryptography.

At the macroscopic level, however, these effects are not observed: objects familiar to us are always in a single specific state.

And now a thought experiment. We take a cat and put it in a box. We also place a flask with poisonous gas, a radioactive atom and a Geiger counter there. A radioactive atom may or may not decay at any time. If it decays, the counter will detect radiation, a simple mechanism will break the flask with gas, and our cat will die. If not, the cat will live.

We close the box. From this point on, from the point of view of quantum mechanics, our atom is in a state of uncertainty - it decayed with a probability of 50% and did not decay with a probability of 50%. Before we open the box and look into it (make an observation), it will be in both states at once. And since the fate of a cat directly depends on the state of this atom, it turns out that the cat is also literally alive and dead at the same time (“... smearing a living and dead cat (sorry for the expression) in equal proportions ...” - writes the author of the experiment). This is how quantum theory would describe this situation.

Schrödinger hardly guessed what a stir his idea would make. Of course, the experiment itself, even in the original, is described extremely rudely and without pretense of scientific accuracy: the author wanted to convey to his colleagues the idea that the theory needs to be supplemented with clearer definitions of such processes as “observation” in order to exclude scenarios with cats in boxes from its jurisdiction.

The idea of ​​a cat was even used to “prove” the existence of God as a supermind, which by its continuous observation makes our very existence possible. In reality, "observation" does not require a conscious observer, which deprives quantum effects of some mysticism. But even so, quantum physics remains today the front of science with many unexplained phenomena and their interpretations.

Ivan Boldin
Candidate of Physical and Mathematical Sciences, Researcher, MIPT graduate

The behavior of objects in the microworld (elementary particles, atoms, molecules) differs significantly from the behavior of objects with which we usually have to deal. For example, an electron can fly simultaneously through two spatially distant places or is simultaneously in several orbits in an atom. To describe these phenomena, a theory was created - quantum physics. According to this theory, for example, particles can be smeared in space, but if you want to determine where the particle is after all, then you will always find the whole particle in some place, that is, it will sort of collapse from its smeared state to some specific place. That is, it is believed that until you measure the position of a particle, it has no position at all, and physics can only predict with what probability in what place you can find a particle.

Erwin Schrödinger, one of the creators of quantum physics, asked himself the question: what if, depending on the result of measuring the state of a microparticle, some event occurs or does not occur. For example, this could be implemented as follows: a radioactive atom is taken with a half-life of, say, an hour. An atom can be placed in an opaque box, a device can be placed there that, when the products of the radioactive decay of the atom hit it, breaks an ampoule with poisonous gas, and a cat can be put in this box. Then you will not see from the outside whether the atom has decayed or not, that is, according to quantum theory, it simultaneously decayed and did not decay, and the cat, therefore, is both alive and dead. Such a cat became known as Schrödinger's cat.

It may seem surprising that a cat can be alive and dead at the same time, although formally there is no contradiction here and this is not a refutation of quantum theory. However, questions may arise, for example: who can carry out the collapse of an atom from a smeared state to a certain state, and who, in such an attempt, himself passes into a smeared state? How does this collapse process proceed? Or how is it that the one who performs the collapse does not himself obey the laws of quantum physics? Whether these questions make sense, and if so, what are the answers to them, is still unclear.

George Panin
graduated from RKhTU them. DI. Mendeleeva, Chief Specialist of the Research Department (Marketing Research)

As Heisenberg explained to us, due to the uncertainty principle, the description of the objects of the quantum microworld is of a different nature than the usual description of the objects of the Newtonian macrocosm. Instead of spatial coordinates and speed, which we used to describe the mechanical movement of, for example, a ball on a billiard table, in quantum mechanics, objects are described by the so-called wave function. The crest of the "wave" corresponds to the maximum probability of finding a particle in space at the moment of measurement. The motion of such a wave is described by the Schrödinger equation, which tells us how the state of a quantum system changes with time.

Now about the cat. Everyone knows that cats love to hide in boxes (thequestion.ru). Erwin Schrödinger was also aware. Moreover, with purely Nordic savagery, he used this feature in a famous thought experiment. Its essence was that a cat was locked in a box with an infernal machine. The machine is connected through a relay to a quantum system, for example, to a radioactively decaying substance. The decay probability is known and is 50%. The infernal machine works when the quantum state of the system changes (disintegration occurs) and the cat dies completely. If you leave the “Cat-box-infernal machine-quanta” system to itself for one hour and remember that the state of the quantum system is described in terms of probability, then it becomes clear that it’s probably impossible to find out whether the cat is alive or not, at a given moment in time, just as it will not work out exactly to predict the fall of a coin on heads or tails in advance. The paradox is very simple: the wave function describing a quantum system mixes two states of a cat - it is alive and dead at the same time, just as a bound electron with equal probability can be located anywhere in space equidistant from the atomic nucleus. If we don't open the box, we don't know exactly how the cat is. Without making observations (read measurements) on the atomic nucleus, we can describe its state only by a superposition (mixing) of two states: a decayed and non-decayed nucleus. A nuclear-addicted cat is both alive and dead at the same time. The question is this: when does a system cease to exist as a mixture of two states and chooses one concrete one?

The Copenhagen interpretation of the experiment tells us that the system ceases to be a mixture of states and chooses one of them at the moment when an observation takes place, which is also a measurement (the box opens). That is, the very fact of measurement changes the physical reality, leading to the collapse of the wave function (the cat either becomes dead or remains alive, but ceases to be a mixture of both)! Think about it, the experiment and the measurements that accompany it change the reality around us. Personally, this fact makes my brain much stronger than alcohol. The notorious Steve Hawking also takes this paradox hard, repeating that when he hears about Schrödinger's cat, his hand reaches for the Browning. The sharpness of the reaction of the outstanding theoretical physicist is due to the fact that, in his opinion, the role of the observer in the collapse of the wave function (falling it to one of two probabilistic) states is greatly exaggerated.

Of course, when Professor Erwin conceived his cat-fraud back in 1935, it was a clever way to show the imperfection of quantum mechanics. Indeed, a cat cannot be alive and dead at the same time. As a result, one of the interpretations of the experiment was the obvious contradiction between the laws of the macro-world (for example, the second law of thermodynamics - a cat is either alive or dead) and the micro-world (a cat is alive and dead at the same time).

The above is applied in practice: in quantum computing and in quantum cryptography. A fiber-optic cable sends a light signal that is in a superposition of two states. If attackers connect to the cable somewhere in the middle and make a signal tap there in order to eavesdrop on the transmitted information, then this will collapse the wave function (from the point of view of the Copenhagen interpretation, an observation will be made) and the light will go into one of the states. Having carried out statistical tests of light at the receiving end of the cable, it will be possible to find out whether the light is in a superposition of states or whether it has already been observed and transmitted to another point. This makes it possible to create means of communication that exclude imperceptible signal interception and eavesdropping.

Another most recent interpretation of Schrödinger's thought experiment is the story of Big Bang Theory's Sheldon Cooper, who spoke to Penny's less educated neighbor. The point of Sheldon's story is that the concept of Schrödinger's cat can be applied to relationships between people. In order to understand what is happening between a man and a woman, what kind of relationship between them: good or bad, you just need to open the box. Until then, relationships are both good and bad. youtube.com

Recently published on the well-known scientific portal "PostNauka" Emil Akhmedov's author's article about the causes of the famous paradox, as well as what it is not.

Physicist Emil Akhmedov on probabilistic interpretation, closed quantum systems and paradox formulation.

In my opinion, the most difficult part of quantum mechanics, both psychologically and philosophically, and in many other respects, is its probabilistic interpretation. Many people have argued with the probabilistic interpretation. For example, Einstein, along with Podolsky and Rosen, came up with a paradox that refutes the probabilistic interpretation.

In addition to them, Schrödinger also argued with the probabilistic interpretation of quantum mechanics. As a logical contradiction in the probabilistic interpretation of quantum mechanics, Schrödinger came up with the so-called Schrödinger's cat paradox. It can be formulated in different ways, for example: let's say you have a box in which a cat sits, and a cylinder of lethal gas is connected to this box. To the switch of this cylinder, which admits or does not let in lethal gas, some device is connected, which works as follows: there is a polarizing glass, and if a passing photon of the required polarization, then the cylinder turns on, the gas flows to the cat; if the photon is not of the correct polarization, then the balloon does not turn on, the key does not turn on, the balloon does not let gas into the cat.

Suppose a photon is circularly polarized, and the device responds to linear polarization. It may not be clear, but it is not very important. With some probability, the photon will be polarized in one way, with some probability - in another. Schrodinger said: it turns out such a situation that at some point, until we open the lid and see if the cat is dead or alive (and the system is closed), the cat will be alive with some probability and will be dead with some probability. Maybe I am casually formulating a paradox, but the result is a strange situation that the cat is neither alive nor dead. This is how the paradox is formulated.

In my opinion, this paradox has a perfectly clear and precise explanation. Perhaps this is my personal point of view, but I will try to explain. The main property of quantum mechanics is the following: if you describe a closed system, then quantum mechanics is nothing but wave mechanics, the mechanics of waves. This means that it is described by differential equations whose solutions are waves. Where there are waves and differential equations, there are matrices and so on. These are two equivalent descriptions: matrix description and wave description. The matrix description belongs to Heisenberg, the wave description belongs to Schrödinger, but they describe the same situation.

The important thing is that while the system is closed, it is described by a wave equation, and what happens to this wave is described by some wave equation. The whole probabilistic interpretation of quantum mechanics arises after the system is opened - it is affected from the outside by some large classical, that is, non-quantum, object. At the moment of impact, it ceases to be described by this wave equation. There is a so-called reduction of the wave function and a probabilistic interpretation. Until the moment of opening, the system evolves in accordance with the wave equation.

Now we need to make a few remarks about how a large classical system differs from a small quantum one. Generally speaking, even a large classical system can be described using the wave equation, although this description is usually difficult to provide, and in reality it is completely unnecessary. These systems differ mathematically in action. The so-called object exists in quantum mechanics, in field theory. For a classical large system, the action is huge, but for a quantum small system, the action is small. Moreover, the gradient of this action - the rate of change of this action in time and space - is huge for a large classical system, and small for a small quantum one. This is the main difference between the two systems. Due to the fact that the action is very large for a classical system, it is more convenient to describe it not by some wave equations, but simply by classical laws like Newton's law and so on. For example, for this reason, the Moon does not rotate around the Earth like an electron around the nucleus of an atom, but along a certain, clearly defined orbit, along a classical orbit, trajectory. While the electron, being a small quantum system, inside the atom around the nucleus moves like a standing wave, its movement is described by a standing wave, and this is the difference between the two situations.

Measurement in quantum mechanics is when you influence a small quantum system with a large classical system. After that, the reduction of the wave function occurs. In my opinion, the presence of a balloon or a cat in the Schrödinger paradox is the same as the presence of a large classical system that measures the polarization of a photon. Accordingly, the measurement takes place not at the moment when we open the lid of the box and see if the cat is alive or dead, but at the moment when the photon interacts with the polarizing glass. Thus, at this moment, the photon wave function is reduced, the balloon is in a completely definite state: either it opens or it does not open, and the cat dies or does not die. Everything. There are no "probabilistic cats" that he is alive with some probability, dead with some probability. When I said that there are many different formulations of the Schrodinger's cat paradox, I was only saying that there are many different ways to come up with the device that kills or keeps the cat alive. In fact, the formulation of the paradox does not change.

I have heard of other attempts to explain this paradox in terms of multiple worlds and so on. In my opinion, all these explanations do not stand up to scrutiny. What I explained during this video in words can be put into mathematical form and the correctness of this statement can be verified. I emphasize once again that, in my opinion, the measurement and reduction of the wave function of a small quantum system occurs at the moment of interaction with a large classical system. Such a big classical system is a cat with a device that kills him, and not a person who opens a box with a cat and sees if the cat is alive or not. That is, the measurement occurs at the moment of interaction of this system with a quantum particle, and not at the moment of checking the cat. Such paradoxes, in my opinion, find explanations from the application of theories and common sense.

The essence of the experiment

Schrödinger's original paper describes the experiment as follows:

You can also construct cases in which burlesque is enough. A certain cat is locked in a steel chamber, along with the following infernal machine (which must be protected from the direct intervention of a cat): inside a Geiger counter is a tiny amount of radioactive material, so small that only one atom can decay in an hour, but with the same probability it can and not fall apart; if this happens, the reading tube is discharged and a relay is activated, lowering the hammer, which breaks the cone of hydrocyanic acid. If we leave this whole system to itself for an hour, then we can say that the cat will be alive after this time, as long as the atom does not decay. The first decay of an atom would have poisoned the cat. The psi-function of the system as a whole will express this by mixing in itself or smearing the living and dead cat (forgive the expression) in equal proportions. Typical in such cases is that the uncertainty, originally limited to the atomic world, is transformed into a macroscopic uncertainty that can be eliminated by direct observation. This prevents us from naively accepting the "blur model" as reflecting reality. By itself, this does not mean anything unclear or contradictory. There is a difference between a fuzzy or out of focus photo and a cloud or fog shot. According to quantum mechanics, if no observation is made over the nucleus, then its state is described by a superposition (mixing) of two states - a decayed nucleus and an undecayed nucleus, therefore, the cat sitting in the box is both alive and dead at the same time. If the box is opened, then the experimenter can see only one specific state - "the nucleus has disintegrated, the cat is dead" or "the nucleus has not disintegrated, the cat is alive." The question is this: when does a system cease to exist as a mixture of two states and chooses one concrete one? The purpose of the experiment is to show that quantum mechanics is incomplete without some rules that specify under what conditions the wave function collapses, and the cat either becomes dead or remains alive, but ceases to be a mixture of both.

Since it is clear that the cat must necessarily be either alive or dead (there is no state that combines life and death), this will be the same for the atomic nucleus. It must necessarily be either decayed or undecayed.

The original article appeared in 1935. The purpose of the article was to discuss the Einstein-Podolsky-Rosen (EPR) paradox published by Einstein, Podolsky and Rosen earlier that year.

Surely you have heard more than once that there is such a phenomenon as "Schrödinger's Cat". But if you are not a physicist, then, most likely, you only remotely imagine what kind of cat it is and why it is needed.

« Shroedinger `s cat”- this is the name of the famous thought experiment of the famous Austrian theoretical physicist Erwin Schrödinger, who is also a Nobel Prize winner. With the help of this fictitious experiment, the scientist wanted to show the incompleteness of quantum mechanics in the transition from subatomic systems to macroscopic systems.

In this article, an attempt is made to explain in simple terms the essence of Schrödinger's theory about the cat and quantum mechanics, so that it is accessible to a person who does not have a higher technical education. The article will also present various interpretations of the experiment, including those from the Big Bang Theory series.

Description of the experiment

The original article by Erwin Schrödinger was published in 1935. In it, the experiment was described using or even personified:

You can also construct cases in which burlesque is enough. Let some cat be locked in a steel chamber, along with the following diabolical machine (which should be independent of the intervention of the cat): inside the Geiger counter is a tiny amount of radioactive material, so small that only one atom can decay in an hour, but with the same the probability may not fall apart; if this happens, the reading tube is discharged and a relay is activated, lowering the hammer, which breaks the cone of hydrocyanic acid.

If we leave this whole system to itself for an hour, then we can say that the cat will be alive after this time, as long as the atom does not decay. The first decay of an atom would have poisoned the cat. The psi-function of the system as a whole will express this by mixing in itself or smearing the living and dead cat (forgive the expression) in equal proportions. Typical in such cases is that the uncertainty, originally limited to the atomic world, is transformed into a macroscopic uncertainty that can be eliminated by direct observation. This prevents us from naively accepting the "blur model" as reflecting reality. By itself, this does not mean anything unclear or contradictory. There is a difference between a fuzzy or out of focus photo and a cloud or fog shot.

In other words:

1. There is a box and a cat. The box contains a mechanism containing a radioactive atomic nucleus and a container of poisonous gas. The experimental parameters are chosen so that the probability of nuclear decay in 1 hour is 50%. If the core disintegrates, the gas container opens and the cat dies. If the disintegration of the nucleus does not occur, the cat remains alive and well.
2. We close the cat in a box, wait an hour and ask ourselves: is the cat alive or dead?
3. Quantum mechanics, as it were, tells us that the atomic nucleus (and hence the cat) is in all possible states at the same time (see quantum superposition). Before we opened the box, the “cat-core” system is in the state “the core has decayed, the cat is dead” with a probability of 50% and in the state “the nucleus has not decayed, the cat is alive” with a probability of 50%. It turns out that the cat sitting in the box is both alive and dead at the same time.
4. According to the modern Copenhagen interpretation, the cat is still alive / dead without any intermediate states. And the choice of the decay state of the nucleus occurs not at the moment of opening the box, but even when the nucleus enters the detector. Because the reduction of the wave function of the "cat-detector-nucleus" system is not connected with the human observer of the box, but is connected with the detector-observer of the nucleus.

Explanation in simple words

According to quantum mechanics, if the nucleus of an atom is not observed, then its state is described by a mixture of two states - a decayed nucleus and an undecayed nucleus, therefore, a cat sitting in a box and personifying the nucleus of an atom is both alive and dead at the same time. If the box is opened, then the experimenter can see only one specific state - "the nucleus has disintegrated, the cat is dead" or "the nucleus has not disintegrated, the cat is alive."

Essence in human language: Schrödinger's experiment showed that, from the point of view of quantum mechanics, a cat is both alive and dead at the same time, which cannot be. Consequently, quantum mechanics has significant flaws.

The question is this: when does a system cease to exist as a mixture of two states and chooses one concrete one? The purpose of the experiment is to show that quantum mechanics is incomplete without some rules that specify under what conditions the wave function collapses, and the cat either becomes dead or remains alive, but ceases to be a mixture of both. Since it is clear that the cat must necessarily be either alive or dead (there is no intermediate state between life and death), this will be the same for the atomic nucleus. It must necessarily be either broken up or not broken up (Wikipedia).

Video from The Big Bang Theory

Another most recent interpretation of Schrödinger's thought experiment is the story of Big Bang Theory's Sheldon Cooper, who spoke to Penny's less educated neighbor. The point of Sheldon's story is that the concept of Schrödinger's cat can be applied to relationships between people. In order to understand what is happening between a man and a woman, what kind of relationship between them: good or bad, you just need to open the box. Until then, relationships are both good and bad.

Below is a video clip of this Big Bang Theory dialogue between Sheldon and Peny.

Was the cat still alive as a result of the experiment?

For those who did not read the article carefully, but still worry about the cat - good news: do not worry, according to our data, as a result of a thought experiment by a crazy Austrian physicist

NOT A SINGLE CAT WERE INJURED

To my shame, I want to admit that I heard this expression, but did not know at all what it meant and at least on what topic it was used. Let me tell you what I read on the Internet about this cat ... -

« Shroedinger `s cat”- this is the name of the famous thought experiment of the famous Austrian theoretical physicist Erwin Schrödinger, who is also a Nobel Prize winner. With the help of this fictitious experiment, the scientist wanted to show the incompleteness of quantum mechanics in the transition from subatomic systems to macroscopic systems.

The original article by Erwin Schrödinger was published in 1935. In it, the experiment was described using or even personified:

You can also construct cases in which burlesque is enough. Let some cat be locked in a steel chamber, along with the following diabolical machine (which should be independent of the intervention of the cat): inside the Geiger counter is a tiny amount of radioactive material, so small that only one atom can decay in an hour, but with the same the probability may not fall apart - if this happens, the reading tube is discharged and a relay is triggered, lowering the hammer, which breaks the cone with hydrocyanic acid.

If we leave this whole system to itself for an hour, then we can say that the cat will be alive after this time, as long as the atom does not decay. The first decay of an atom would have poisoned the cat. The psi-function of the system as a whole will express this by mixing in itself or smearing the living and dead cat (forgive the expression) in equal proportions. Typical in such cases is that the uncertainty, originally limited to the atomic world, is transformed into a macroscopic uncertainty that can be eliminated by direct observation. This prevents us from naively accepting the "blur model" as reflecting reality. By itself, this does not mean anything unclear or contradictory. There is a difference between a fuzzy or out of focus photo and a cloud or fog shot.

In other words:

1. There is a box and a cat. The box contains a mechanism containing a radioactive atomic nucleus and a container of poisonous gas. The experimental parameters are chosen so that the probability of nuclear decay in 1 hour is 50%. If the core disintegrates, the gas container opens and the cat dies. If the disintegration of the nucleus does not occur, the cat remains alive and well.
2. We close the cat in a box, wait an hour and ask ourselves: is the cat alive or dead?
3. Quantum mechanics, as it were, tells us that the atomic nucleus (and hence the cat) is in all possible states at the same time (see quantum superposition). Before we opened the box, the “cat-core” system is in the state “the core has decayed, the cat is dead” with a probability of 50% and in the state “the nucleus has not decayed, the cat is alive” with a probability of 50%. It turns out that the cat sitting in the box is both alive and dead at the same time.
4. According to the modern Copenhagen interpretation, the cat is still alive / dead without any intermediate states. And the choice of the decay state of the nucleus occurs not at the moment of opening the box, but even when the nucleus enters the detector. Because the reduction of the wave function of the "cat-detector-nucleus" system is not connected with the human observer of the box, but is connected with the detector-observer of the nucleus.

According to quantum mechanics, if the nucleus of an atom is not observed, then its state is described by a mixture of two states - a decayed nucleus and an undecayed nucleus, therefore, a cat sitting in a box and personifying the nucleus of an atom is both alive and dead at the same time. If the box is opened, then the experimenter can see only one specific state - "the nucleus has disintegrated, the cat is dead" or "the nucleus has not disintegrated, the cat is alive."

Essence in human language: Schrödinger's experiment showed that, from the point of view of quantum mechanics, a cat is both alive and dead at the same time, which cannot be. Consequently, quantum mechanics has significant flaws.

The question is this: when does a system cease to exist as a mixture of two states and chooses one concrete one? The purpose of the experiment is to show that quantum mechanics is incomplete without some rules that specify under what conditions the wave function collapses, and the cat either becomes dead or remains alive, but ceases to be a mixture of both. Since it is clear that the cat must necessarily be either alive or dead (there is no intermediate state between life and death), this will be the same for the atomic nucleus. It must necessarily be either decayed or undecayed ().

Another most recent interpretation of Schrödinger's thought experiment is the story of Big Bang Theory's Sheldon Cooper, who spoke to Penny's less educated neighbor. The point of Sheldon's story is that the concept of Schrödinger's cat can be applied to relationships between people. In order to understand what is happening between a man and a woman, what kind of relationship between them: good or bad, you just need to open the box. Until then, relationships are both good and bad.

Below is a video clip of this Big Bang Theory dialogue between Sheldon and Peny.

Schrödinger's illustration is the best example to describe the main paradox of quantum physics: according to its laws, particles such as electrons, photons and even atoms exist in two states at the same time ("-live" - ​​and "-dead" - if you remember the long-suffering cat). These states are called.

American physicist Art Hobson () from the University of Arkansas (Arkansas State University) proposed his solution to this paradox.

“-Measurements in quantum physics are based on the operation of certain macroscopic devices, such as the Geiger counter, which determine the quantum state of microscopic systems - atoms, photons and electrons. Quantum theory implies that if you connect a microscopic system (particle) to some macroscopic device that distinguishes between two different states of the system, then the device (Geiger counter, for example) will go into a state of quantum entanglement and will also be simultaneously in two superpositions. However, it is impossible to observe this phenomenon directly, which makes it unacceptable,” says the physicist.

Hobson says that in Schrödinger's paradox, the cat plays the role of a macroscopic device, a Geiger counter, connected to a radioactive nucleus, to determine the state of decay or "-non-decay" - of this nucleus. In this case, a live cat will be an indicator of "-non-decay"-, and a dead cat - an indicator of decay. But according to quantum theory, the cat, like the nucleus, must be in two superpositions of life and death.

Instead, according to the physicist, the quantum state of the cat must be entangled with the state of the atom, which means that they are in a “non-local connection” with each other. That is, if the state of one of the entangled objects suddenly changes to the opposite, then the state of its pair will also change in the same way, no matter how far apart they are. In doing so, Hobson refers to this quantum theory.

“The most interesting thing in the theory of quantum entanglement is that the change in the state of both particles occurs instantly: no light or electromagnetic signal would have time to transfer information from one system to another. So you can say that it's one object, divided into two parts by space, no matter how great the distance between them," explains Hobson.

Schrödinger's cat is no longer alive and dead at the same time. He is dead if decay happens, and alive if decay never happens.

We add that similar solutions to this paradox have been proposed by three more groups of scientists over the past thirty years, but they were not taken seriously and remained unnoticed in the broad scientific community. Hobson that the solution of the paradoxes of quantum mechanics, at least theoretical, is absolutely necessary for its deep understanding.

Schrödinger

And just recently, THEORETICS EXPLAINED HOW GRAVITY KILLS SCHROEDINGER'S CAT, but this is already more complicated ...-

As a rule, physicists explain the phenomenon that superposition is possible in the world of particles, but impossible with cats or other macro objects, interference from the environment. When a quantum object passes through a field or interacts with random particles, it immediately assumes just one state - as if it were measured. This is how the superposition collapses, as scientists believed.

But even if in some way it became possible to isolate the macroobject, which is in a state of superposition, from interactions with other particles and fields, it would still sooner or later take on a single state. At least, this is true for the processes occurring on the surface of the Earth.

“Somewhere in interstellar space, maybe a cat would have a chance, but on Earth or near any planet this is extremely unlikely. And the reason for this is gravity, ”explains lead author of the new study Igor Pikovsky () from the Harvard-Smithsonian Center for Astrophysics.

Pikovsky and his colleagues from the University of Vienna argue that gravity has a destructive effect on quantum superpositions of macroobjects, and therefore we do not observe such phenomena in the macrocosm. The basic concept of the new hypothesis, by the way, in the feature film "-Interstellar"-.

Einstein's general theory of relativity states that an extremely massive object will warp space-time near it. Considering the situation at a smaller level, we can say that for a molecule placed near the surface of the Earth, time will go somewhat slower than for one that is in the orbit of our planet.

Due to the influence of gravity on space-time, a molecule that falls under this influence will experience a deviation in its position. And this, in turn, should also affect its internal energy - vibrations of particles in a molecule, which change over time. If a molecule is introduced into a state of quantum superposition of two locations, then the relationship between position and internal energy would soon force the molecule to “-choose” only one of the two positions in space.

“In most cases, the phenomenon of decoherence is associated with an external influence, but in this case, the internal vibration of particles interacts with the movement of the molecule itself,” Pikovsky explains.

This effect has not yet been observed, since other sources of decoherence, such as magnetic fields, thermal radiation and vibrations, are usually much stronger, and cause the destruction of quantum systems long before gravity does. But experimenters tend to test the stated hypothesis.

A similar setup could also be used to test the ability of gravity to destroy quantum systems. To do this, it will be necessary to compare the vertical and horizontal interferometers: in the first, the superposition will soon disappear due to the dilation of time at different "-heights" - paths, while in the second, the quantum superposition may persist.

sources

http://4brain.ru/blog/%D0%BA%D0%BE%D1%82-%D1%88%D1%80%D0%B5%D0%B4%D0%B8%D0%BD%D0% B3%D0%B5%D1%80%D0%B0-%D1%81%D1%83%D1%82%D1%8C-%D0%BF%D1%80%D0%BE%D1%81%D1% 82%D1%8B%D0%BC%D0%B8-%D1%81%D0%BB%D0%BE%D0%B2%D0%B0%D0%BC%D0%B8/

http://www.vesti.ru/doc.html?id=2632838

Here's a little more near-scientific: for example, and here. If you don't already know, read about and what it is. And we find out what

The article describes what the Schrödinger theory is. The contribution of this great scientist to modern science is shown, as well as the thought experiment he invented about a cat is described. The area of ​​application of this kind of knowledge is briefly outlined.

Erwin Schrödinger

The notorious cat, which is neither alive nor dead, is now being used everywhere. Films are made about him, communities about physics and animals are named after him, there is even such a clothing brand. But most often people mean the paradox with the unfortunate cat. But about its creator, Erwin Schrödinger, as a rule, they forget. He was born in Vienna, which was then part of Austria-Hungary. He was the son of a highly educated and wealthy family. His father, Rudolf, produced linoleum and invested in science, among other things. His mother was the daughter of a chemist, and Erwin often went to listen to his grandfather's lectures at the academy.

Since one of the scientist's grandmothers was an Englishwoman, from childhood he was interested in foreign languages ​​and mastered English perfectly. Not surprisingly, at school, Schrödinger was the best in class every year, and at the university he asked difficult questions. In the science of the beginning of the twentieth century, inconsistencies between the more understandable classical physics and the behavior of particles in the micro- and nanoworld were already revealed. To resolve the emerging contradictions and threw all his strength

Contribution to science

To begin with, it is worth saying that this physicist was engaged in many areas of science. However, when we say "Schrödinger's theory", we do not mean the mathematically coherent description of color created by him, but his contribution to quantum mechanics. In those days, technology, experiment and theory went hand in hand. Photography developed, the first spectra were recorded, and the phenomenon of radioactivity was discovered. The scientists who received the results closely interacted with the theorists: they agreed, complemented each other, and argued. New schools and branches of science were created. The world began to play with completely different colors, and humanity received new mysteries. Despite the complexity of the mathematical apparatus, it is possible to describe what the Schrödinger theory is in simple language.

The quantum world is easy!

It is now well known that the scale of the studied objects directly affects the results. Objects visible to the eye obey the concepts of classical physics. Schrödinger's theory is applicable to bodies one hundred by one hundred nanometers in size and less. And most often we are talking about individual atoms and smaller particles. So, each element of microsystems simultaneously has the properties of both a particle and a wave (particle-wave dualism). From the material world, electrons, protons, neutrons, etc. are characterized by mass and the inertia, speed, and acceleration associated with it. From the theoretical wave - parameters such as frequency and resonance. In order to understand how this is possible at the same time, and why they are inseparable from each other, scientists needed to reconsider the whole idea of ​​the structure of substances in general.

Schrödinger's theory implies that mathematically these two properties are related through a construct called the wave function. Finding a mathematical description of this concept brought Schrödinger the Nobel Prize. However, the physical meaning that the author attributed to it did not coincide with the ideas of Bohr, Sommerfeld, Heisenberg and Einstein, who founded the so-called Copenhagen Interpretation. This is where the cat paradox came from.

wave function

When it comes to the microworld of elementary particles, the concepts inherent in macroscales lose their meaning: mass, volume, speed, size. And unsteady probabilities come into their own. Objects of such dimensions cannot be fixed by a person - only indirect ways of studying are available to people. For example, streaks of light on a sensitive screen or on a film, the number of clicks, the thickness of the sprayed film. Everything else is the area of ​​calculations.

Schrödinger's theory is based on the equations that this scientist deduced. And their integral component is the wave function. It unambiguously describes the type and quantum properties of the particle under study. It is believed that it shows the state, for example, of an electron. However, it itself, contrary to the ideas of its author, has no physical meaning. It's just a handy math tool. Since our paper presents the Schrödinger theory in simple terms, let's say that the square of the wave function describes the probability of finding a system in a predetermined state.

Cat as an example of a macro object

With this interpretation, which is called Copenhagen, the author himself did not agree until the end of his life. He was disgusted by the vagueness of the concept of probability, and he insisted on the visibility of the function itself, and not its square.

As an example of the inconsistency of such ideas, he argued that in this case the microworld would influence macroobjects. The theory says the following: if a living organism (for example, a cat) and a capsule with poisonous gas are placed in a sealed box, which opens if a certain radioactive element decays, and remains closed if decay does not occur, then before opening the box we get a paradox. According to quantum concepts, an atom of a radioactive element will decay with a certain probability over a certain period of time. Thus, before experimental discovery, the atom is both intact and not. And, as Schrödinger's theory says, by the same degree of probability, the cat is both dead and otherwise alive. Which, you see, is absurd, because, having opened the box, we will find only one state of the animal. And in a closed container, next to the deadly capsule, the cat is either dead or alive, since these indicators are discrete and do not imply intermediate options.

There is a concrete but not yet fully proven explanation for this phenomenon: in the absence of time-limiting conditions for determining the specific state of a hypothetical cat, this experiment is undoubtedly paradoxical. However, quantum mechanical rules cannot be used for macroobjects. It has not yet been possible to draw a precise line between the microcosm and the ordinary. Nevertheless, an animal the size of a cat is, without a doubt, a macro object.

Applications of quantum mechanics

As for any, even theoretical, phenomenon, the question arises of how Schrödinger's cat can be useful. The big bang theory, for example, is based precisely on the processes involved in this thought experiment. Everything that relates to ultra-high speeds, the ultra-small structure of matter, the study of the universe as such, is explained, among other things, by quantum mechanics.