What is Schrödinger's cat, Schrödinger's cat, everything about Schrödinger's cat, Schrödinger's cat paradox, Schrödinger's experience with a cat, cat in a box, neither alive nor dead cat, is Schrödinger's cat alive, experiment with a cat

This is a cat that is both alive and dead at the same time. He owes such an unfavorable state to the Nobel laureate in physics, the Austrian scientist Erwin Rudolf Joseph Alexander Schrödinger.

Sections:

The essence of the experiment / paradox

The cat is in a closed box, where there is a mechanism containing a radioactive core and a container with poisonous gas. The characteristics of the experiment are chosen so that the probability that the nucleus will disintegrate in 1 hour is 50%. If the core disintegrates, it sets the mechanism in motion, the gas container opens, and the cat dies. 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.

It is worth opening the box - and the experimenter should see only one state - "the nucleus has decayed, the cat is dead" or "the nucleus has not decayed, the cat is alive." But while there is no observer in the process, the ill-fated little animal remains "dead".

Marginals

• Misfortune never comes alone
  Not only the health of the tailed inhabitant of the box is in doubt, but also its gender: in the original experiment, Schrödinger's cat was still a cat (die Katze).
• There are no "dead" cats
  It is important to remember that Schrödinger's experiment is not intended to prove the existence of "dead" cats (and, contrary to what was said in the second part of the Portal game, was not invented as an excuse for killing cats). Obviously, the cat must necessarily be either alive or dead, since there is no intermediate state.
  Experience shows that quantum mechanics is not able to describe the behavior of macrosystems (which the cat belongs to): it is incomplete without some rules that indicate when the system chooses one particular state, under what conditions the wave function collapses and the cat either remains alive or becomes dead. , but ceases to be a mixture of both.

Interpretations Copenhagen interpretation denies that before opening the box, the cat is in a state of mixing of the living and the dead. Some believe that as long as the box is closed, the system is in a superposition of the states “decayed nucleus, dead cat” and “undecayed nucleus, living cat”, and when the box is opened, only then does the wave function collapse to one of the options. Others - that "observation" occurs when a particle from the nucleus enters the detector; however, alas, in the Copenhagen interpretation there is no clear rule that says when this happens, and therefore this interpretation is incomplete until such a rule is introduced into it or it is not said how it can be introduced in principle. Everett's Many Worlds Interpretation, unlike Copenhagen, does not consider the process of observation to be something special. Here both states of the cat exist, but decohere - that is, as the author understood, the unity of these states is broken as a result of interaction with the environment. When the observer opens the box, he becomes entangled (mixed) with the cat, which results in two states of the observer, one corresponding to a live and one to a dead cat. These states do not interact with each other. The cat as a competent observer
The author believes that the decisive word should have been left to the cat, who, although not understanding a single belmes in quantum mechanics, is certainly the best aware of his condition. However, his competence as an observer, obviously, raises doubts among scientists. The exceptions are Hans Moravec, Bruno Marshal and Max Tegmark, who proposed a modification of the Schrödinger experiment known as "quantum suicide", which is an experiment with a cat from the point of view of a cat. Scientists pursued the goal of showing the difference between the Copenhagen and many-worlds interpretations of quantum mechanics. If the multi-world interpretation is correct, the cat, to the delight of the sympathizers, becomes Tsoi and always remains alive, since the participant is able to observe the result of the experiment only in the world in which he survives.

• Nadav Katz of the University of California and his colleagues published the results of a laboratory experiment in which they managed to "return" the quantum state of a particle back, and after measuring this state. Thus, it is possible to save the life of a cat, regardless of the conditions for the collapse of the wave function. It doesn't matter if he is alive or dead: you can always win back [link] .
• 06/03/2011 RIA Novosti reported that Chinese physicists were able to create eight-photon "Schrodinger's cat"[link] which should contribute to the development of future quantum computers

Image in culture

Perhaps no one has done more to popularize quantum mechanics than the poor cat. Even the people who are farthest from this complex field of knowledge, excited by the fate of the probably suffering little animal, are trying to figure out the intricacies of the experiment, hoping that not everything is so bad. The cat inspires artists and popular culture.
Let us mention his main merits:

Literature: The situation with Schrödinger's cat is discussed by the protagonists of Douglas Adams' book Dirk Gently's Detective Agency. In Dan Simmons' book Endymion, the protagonist Raul Endymion writes his narration while orbiting Armagast in Schrödinger's "cat box". In the last third of Robert Heinlein's book "The Cat Passing Through Walls", the ginger cat Pixel appears, which has the property of the Schrödinger cat to be in two states at the same time. In Terry Pratchett's book "Cat Without Fools", a breed of so-called "Schrödinger cats" is described in a humorous form, descended from the same Schrödinger's cat. Also, this thought experiment is mentioned more than once in other works of Pratchett, for example, in the novel Ladies and Gentlemen. In F. Gwinplein McIntyre's story "Nursing Schrödinger's Cat", one of the characters is Schrödinger's own pet, Tibbles the cat. Around this cat, in fact, the action of a humorous story unfolds, generously seasoned with details from different areas of physics. The plot of Frederick Pohl's science fiction novel The Coming of the Quantum Cats (1986) is based on the idea of ​​the interaction of "neighboring" Universes. In Nikolai Baitov's philosophical and satirical miniature "Schrödinger's Cat", Schrödinger's paradox is turned inside out: an organization called the "League of Reversible Time" has been monitoring a live cat in a box for 50 years without interruption, believing that while the observation is being carried out - the state , in which the cat resides, should not change. In Lukyanenko's book "The Last Watch", the main character is thrown around the neck with a noose called "Schrödinger's cat", the peculiarity of which is that magicians do not understand whether this creature is alive or not. Mentioned in Greg Egan's novel "Quarantine", in Christopher Stashef's fantasy "Mage Healer", in Greg Beer (Gregory Dale Bear) in the story "Schrödinger's Plague"; Polish writer Sapkowski mentions Kodringer's cat. Mercy Shelley's cyberpunk novel 2048 states that "a guy with a last name that looks like a file was putting some unfortunate biorg in an iron box containing nothing but a vial of poison." Svetlana Shirankova's poem "Schrödinger's Cat" has a very inspiring beginning: "Doctor Schrödinger, your cat is still alive." Screen: In the Coen brothers' film A Serious Man, a student says to a professor, "I understand the dead cat experiment," which, of course, suggests otherwise. In the film "Repo Man" ("Collectors", in the Russian box office "Rippers"), the main character at the beginning of the film talks about an unknown scientist who has a cat. And this cat is in the state of "... both alive and dead at the same time ...". In one of the episodes of the science fiction series Stargate SG-1, a cat named Schrödinger appears. The protagonist of the sci-fi series Sliders also has the same name cat. In Stargate SG-1, a ginger cat named Schrödinger was given to an alien. Dead cat Schrödinger appears in CSI: Las Vegas (Season 8, Episode 15: The Theory of Everything). Schrödinger's cat is also mentioned in the TV series The Big Bang Theory, where, as an answer to a girl's question whether she should go on a date, the hero draws an analogy with Schrödinger's cat, meaning that until you try, you won't know: "Penny, for in order to find out whether the cat is alive or dead, you need to open the box. In the series "Bugs", the role of Schrödinger's cat was played by the Red Mercury clue in a booby-trapped safe. In the Japanese anime "Hellsing (OVA)" (as well as in the manga of the same name), there is a cat-man character named Schrödinger, who is neither alive nor dead, has the ability to teleport ("be everywhere and nowhere"), and is absolutely unkillable. In the anime "To Aru Majutsu no Index", the protagonist objects to the girl's proposal to name the kitten Schrödinger that cats cannot be called this name. The anime Shigofumi also features a cat named Schrödinger. In the Japanese anime and game Umineko no naku koro ni, experience is used in Battler's attempt to prove the impossibility of magic (also used are Devil's Proof, Hempel's Crows, Laplace's Demon). In one of the Futurama episodes Law and Oracle, Schrödinger hid drugs in a box with a cat. Comics/manga: A small comic book about Schrödinger's cat and Maxwell's demon. He's Dead: Schrödinger of the Cat: And More Comics at joyreactor.ru. Games: There is a quest game "The Return of the Quantum Cat". In the Nethack game, there is a Quantum Mechanic monster, who sometimes has a box with a cat with him. The state of the cat is not determined until the moment the box is opened. In the game "Half-Life 2" there was a cat in the laboratory with teleporters, nightmares about which "still" visit Barney. The portrait of Schrödinger's cat is also found in the 1998 remake based on Half-Life. - "Black Mesa" ("Black Mesa", formerly known as "Black Mesa: Source"). Link to notarized screenshot. In every level of Bioshock, there is a dead cat in a nook, labeled Shrodinger. In the second part, it can also be found - the cat rests in one of the ice floes in a frozen room with four surveillance cameras in the corners. The NPC cat of the same name is featured in the Japanese RPG Shin Megami Tensei: Digital Devil Saga. The main slogan of the game Portal, "The cake is a lie", is an errative of one of the outcomes of the Schrödinger experiment, namely "The cat is alive". In the second part of the game, the cat is also not forgotten. A mention of the experiment can be found in the rule book of the Russian board game Age of Aquarius. The cat even has its own characteristic plate there - it is completely empty, so it seems that it is not there. Music: The so-called festival of non-standard music "Schrödinger's Cat", which took place under the slogan "Real life - real death - real music!" and “Is Schrödinger's Cat alive or dead? And you?" Google also reports that the name "Schrödinger's Cat" is a near-musical project of a very small team from Korolev near Moscow. The album of the British band Tears for Fears "Saturnine Martial and Lunatic" contains a song of the same name. The Russian band "Allein Fur" Immer also performs a song with the same name. Humor: Any joke about Schrödinger's cat is funny and unfunny at the same time. Schrödinger and Heisenberg drive down the highway to the conference, Schrödinger driving. Suddenly there is a blow and he stops the car. Heisenberg looks down the road:
- My God, it looks like I hit a cat!
- He died?
- I can not say exactly. Schrödinger walked around the room in search of a kitten that had shit, and he was sitting in a box, neither alive nor dead. Miscellaneous: Artists pay attention to Schrödinger's cat, trying to convey the ambiguity of his position by means of painting and graphics. Also, images of this little animal can be seen on T-shirts and mugs. Terrorists of whom it is not known exactly whether they are alive or dead are sometimes referred to as "Schrödinger terrorists". Of the well-known personalities, for example, Yasser Arafat was in this state when he was in a coma before his death, as well as Osama bin Laden. According to Absurdopedia, the cat in the poke is a simplified version of the Schrödinger's cat experiment [link] . Stephen Hawking paraphrased Hans Jost's catchphrase "When I hear about culture, I grab a gun" as follows: "When I hear about Schrödinger's cat, my hand reaches for a gun!" This is explained by the fact that, like many other physicists, Hawking is of the opinion that the "Copenhagen School" of the interpretation of quantum mechanics emphasizes the role of the observer unreasonably. In connection with the opening of the MEPhI Department of Theology, the following picture has become widespread on the network:

"Schrödinger's cat" is the name of an entertaining thought experiment set up by, you guessed it, Schrödinger, or rather, the Nobel laureate in physics, the Austrian scientist Erwin Rudolf Josef Alexander Schrödinger. "Wikipedia" defines the experiment as follows: cat. There is a mechanism in the box containing a radioactive core and a container with poisonous gas. The parameters of the experiment are chosen so that the probability that the nucleus will decay in 1 hour is 50%. If the nucleus decays, it sets the mechanism in motion - the container with gas opens and the cat dies.

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 must see only one specific state: "the nucleus has decayed, the cat is dead", or "the nucleus has not decayed, the cat is alive."

It turns out that at the output we have a live or dead cat, but in potential, the cat is both alive and dead at the same time. Thus, Schrodinger tried to prove the limitations of quantum mechanics, without applying certain rules to it.

The Copenhagen interpretation of quantum physics - and in particular this experiment - indicates that the cat acquires the properties of one of the potential phases (alive or dead) only after the observer interferes with the process.

That is, when a particular Schrödinger opens the box, he will have to cut sausages with one hundred percent certainty or call the veterinarian. The cat will definitely be alive or suddenly dead. But as long as there is no observer in the process - a specific person who has undoubted advantages in the form of vision, and, at least, a clear consciousness - the cat will be in a suspended state "between heaven and earth."

The ancient parable about a cat that walks by itself takes on new shades in this context. Undoubtedly, Schrödinger's cat is not the most prosperous creature in the universe. Let's wish the cat a successful outcome for him and turn to another entertaining problem from the mysterious and sometimes merciless world of quantum mechanics.

It sounds like this: "What sound does a tree falling in the forest make if there is no person nearby who can perceive this sound?" Here, in contrast to the black and white fate of the unfortunate / happy cat, we are faced with a multi-colored palette of speculations: there is no sound / there is a sound, what is it, if it is, and if it is not, then why? It is impossible to answer this question for a very simple reason - the impossibility of carrying out the experiment. After all, any experiment implies the presence of an observer who is able to perceive and draw conclusions.

The famous Argentinean writer Julio Kartasar, a prominent representative of "magical realism", has a short story about how office furniture, left without an observer, moves around the office, as if using free time to stretch "stiffened" limbs.

That is, it is impossible to assume what happens to the objects of the reality around us in our absence. And if it cannot be perceived, then it does not exist. As soon as we leave the room, all its contents, together with the room itself, cease to exist or, more precisely, continue to exist only in potential.

At the same time, there is a fire or flood, equipment theft or intruders. Moreover, we also exist in it, in different potential states. One I walks around the room and whistles a stupid melody, the other I looks sadly at the window, the third one talks to his wife on the phone. Even our sudden death or joyful news in the form of an unexpected phone call lives in it.

Imagine for a moment all the possibilities hidden behind the door. Now imagine that our entire world is just a collection of such unrealized potentials. Funny, right?

However, a natural question arises here: so what? Yes - funny, yes - interesting, but what, in fact, does it change? Science is modestly silent about this. For quantum physics, such knowledge opens up new ways in understanding the Universe and its mechanisms, but for us, people far from great scientific discoveries, such information seems to be useless.

How is that for nothing!? After all, if I, a mortal, exist in this world, then I, an immortal, exist in another world! If my life consists of a streak of failures and sorrows, then somewhere I exist - lucky and happy? In fact, there is nothing outside our sensations, just as there is no room until we enter it. Our organs of perception only deceive us, drawing in the brain a picture of the world "surrounding" us. What is actually outside of us remains a mystery behind seven seals.

There is a tiny amount of radioactive material, so small that within an hour maybe only one atom will decay, but with the same probability it may not decay; if this happens, the reading tube is discharged and the 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 soon as the decay of the atom will not occur. 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, which can be eliminated through 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.

original text(German)

Man kann auch ganz burleske Fälle konstruieren. Eine Katze wird in eine Stahlkammer gesperrt, zusammen mit folgender Höllenmaschine (die man gegen den direkten Zugriff der Katze sichern muß): in einem Geigerschen Zählrohr befindet sich eine winzige Menge radioaktiver Substanz, so wenig, daß im Laufe einer Stunde vielleicht eines von den Atomen zerfällt, ebenso wahrscheinlich aber auch keines; geschieht es, so spricht das Zählrohr an und betätigt über ein Relais ein Hämmerchen, das ein Kölbchen mit Blausäure zertrümmert. Hat man dieses ganze System eine Stunde lang sich selbst überlassen, so wird man sich sagen, daß die Katze noch lebt, Wenn inzwischen kein Atom zerfallen ist. Der erste Atomzerfall würde sie vergiftet haben. Die ψ -Funktion des ganzen Systems würde das so zum Ausdruck bringen, daß in ihr die lebende und die tote Katze (s.v.v.) zu gleichen Teilen gemischt oder verschmiert sind.
Das Typische an solchen Fällen ist, daß eine ursprünglich auf den Atombereich beschränkte Unbestimmtheit sich in grobsinnliche Unbestimmtheit umsetzt, die sich dann durch direkte Beobachtung entscheiden läst. Das hindert uns, in so naiver Weise ein "verwaschenes Modell" als Abbild der Wirklichkeit gelten zu lassen. An sich enthielte es nichts Unklares oder Widerspruchsvolles. Es ist ein Unterschied zwischen einer verwackelten oder unscharf eingestellten Photographie und einer Aufnahme von Wolken und Nebelschwaden.

According to quantum mechanics, if the nucleus is not observed, 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 goes like this: when the system ceases 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.

In large complex systems consisting of many billions of atoms, decoherence occurs almost instantly, and for this reason a cat cannot be both dead and alive for any measurable length of time. The decoherence process is an essential component of the experiment.

The original article appeared in 1935. The purpose of the paper was to discuss the Einstein-Podolsky-Rosen (EPR) paradox published by Einstein, Podolsky and Rosen earlier that year. Articles by EPR and Schrödinger outlined the strange nature of " quantum entanglement" (German Verschränkung, English quantum entanglement, a term introduced by Schrödinger), characteristic of quantum states, which are a superposition of the states of two systems (for example, two subatomic particles).

Copenhagen interpretation

In fact, Hawking and many other physicists are of the opinion that the "Copenhagen School" of the interpretation of quantum mechanics emphasizes the role of the observer unreasonably. Final unity among physicists on this issue has not yet been achieved.

The parallelization of the worlds at each moment of time corresponds to a genuine non-deterministic automaton, in contrast to the probabilistic one, when one of the possible paths is selected at each step depending on their probability.

Wigner's paradox

This is a complicated version of the Schrödinger experiment. Eugene Wigner introduced the "friends" category. After completing the experiment, the experimenter opens the box and sees a live cat. The state vector of the cat at the moment of opening the box goes into the state “the core has not disintegrated, the cat is alive”. Thus, in the laboratory, the cat was recognized as alive. Outside the laboratory is friend. Friend does not yet know whether the cat is alive or dead. Friend recognizes the cat as alive only when the experimenter informs him of the outcome of the experiment. But everyone else friends the cat has not yet been recognized as alive, and they will recognize it only when they are informed of the result of the experiment. Thus, a cat can be considered completely alive (or completely dead) only when all people in the universe know the result of the experiment. Up to this point, on the scale of the Big Universe, the cat, according to Wigner, remains alive and dead at the same time.

If you are interested in an article on the topic of quantum physics, then there is a high probability that you love the Big Bang Theory series. So, Sheldon Cooper came up with a fresh interpretation Schrödinger's thought experiment(You can find a video with this fragment at the end of the article). But in order to understand Sheldon's dialogue with his neighbor Penny, let's first turn to the classical interpretation. So, Schrödinger's Cat in simple words.

In this article, we will look at:

• Brief historical background
• Description of the experiment with Schrödinger's Cat
• Solving the paradox of Schrödinger's Cat

Good news right away. During the experiment Schrödinger's cat was not harmed. Because the physicist Erwin Schrödinger, one of the creators of quantum mechanics, only conducted a thought experiment.

Before diving into the description of the experiment, let's make a mini digression into history.

At the beginning of the last century, scientists managed to look into the microcosm. Despite the outward similarity of the “atom-electron” model with the “Sun-Earth” model, it turned out that the Newtonian laws of classical physics familiar to us do not work in the microcosm. Therefore, a new science appeared - quantum physics and its component - quantum mechanics. All microscopic objects of the microworld were called quanta.

Attention! One of the postulates of quantum mechanics is "superposition". It will be useful to us for understanding the essence of the Schrödinger experiment.

"Superposition" is the ability of a quantum (it can be an electron, a photon, the nucleus of an atom) is not in one, but in several states at the same time or is located at several points in space at the same time, if no one is watching

It is difficult for us to understand this, because in our world an object can have only one state, for example, to be, or alive, or dead. And it can only be in one specific place in space. You can read about “superposition” and the stunning results of quantum physics experiments in this article.

Here is a simple illustration of the difference in the behavior of micro and macro objects. Place a ball in one of the 2 boxes. Because the ball is an object of our macro world, you will say with confidence: "The ball lies in only one of the boxes, while the second one is empty." If, instead of a ball, you take an electron, then the statement will be true that it is simultaneously in 2 boxes. This is how the laws of the microworld work. Example: the electron in reality does not rotate around the nucleus of an atom, but is located at all points of the sphere around the nucleus at the same time. In physics and chemistry, this phenomenon is called the "electron cloud".

Summary. We realized that the behavior of a very small object and a large object obey different laws. The laws of quantum physics and the laws of classical physics, respectively.

But there is no science that would describe the transition from the macrocosm to the microcosm. So, Erwin Schrödinger described his thought experiment just to demonstrate the incompleteness of the general theory of physics. He wanted Schrödinger's paradox to show that there is a science for describing large objects (classical physics) and a science for describing micro-objects (quantum physics). But there is not enough science to describe the transition from quantum systems to macrosystems.

Description of the experiment with Schrödinger's Cat

Erwin Schrödinger described the cat thought experiment in 1935. The original version of the description of the experiment is presented in Wikipedia ( Schrödinger's cat Wikipedia).

Here is a version of the description of the Schrödinger's Cat experiment in simple words:

• A cat was placed in a closed steel box.
• In the "Schrödinger box" there is a device with a radioactive core and poisonous gas placed in a container.
• The nucleus may disintegrate within 1 hour or not. The probability of decay is 50%.
• If the nucleus decays, then the Geiger counter will record it. The relay will work and the hammer will break the gas container. Schrödinger's cat is dead.
• If not, then Schrödinger's cat will be alive.

According to the law of "superposition" of quantum mechanics, at a time when we are not observing the system, the nucleus of an atom (and, consequently, the cat) is in 2 states at the same time. The nucleus is in the decayed/non-decayed state. And the cat is in a state of being alive/dead at the same time.

But we know for sure that if the "Schrödinger's box" is opened, then the cat can only be in one of the states:

• if the core has not disintegrated, our cat is alive
• if the core has disintegrated, the cat is dead

The paradox of the experiment is that according to quantum physics: before opening the box, the cat is both alive and dead at the same time, but according to the laws of physics of our world, this is impossible. Cat can be in one specific state - to be alive or to be dead. There is no mixed state "cat alive/dead" at the same time.

Before you get the clue, watch this wonderful video illustration of the paradox of the Schrödinger's cat experiment (less than 2 minutes):

Solving the paradox of Schrödinger's Cat - Copenhagen interpretation

Now the clue. Pay attention to the special mystery of quantum mechanics - observer paradox. The object of the microworld (in our case, the core) is in several states at the same time only as long as we don't monitor the system.

for example, famous experiment with 2 slits and an observer. When an electron beam was directed to an opaque plate with 2 vertical slits, then on the screen behind the plate, the electrons drew a “wave pattern” - vertical alternating dark and light stripes. But when the experimenters wanted to “see” how the electrons fly through the slits and installed an “observer” from the side of the screen, the electrons drew on the screen not a “wave pattern”, but 2 vertical stripes. Those. behaved not like waves, but like particles.

It seems that quantum particles themselves decide what state they will take at the moment when they are "measured".

Based on this, the modern Copenhagen explanation (interpretation) of the phenomenon of "Schrödinger's Cat" sounds like this:

While no one is watching the "cat-core" system, the core is in the state of decayed/non-decayed at the same time. But it is a mistake to say that the cat is alive/dead at the same time. Why? Yes, because quantum phenomena are not observed in macrosystems. It is more correct to speak not about the “cat-core” system, but about the “nucleus-detector (Geiger counter)” system.

The nucleus chooses one of the states (decayed/non-decayed) at the moment of observation (or measurement). But this choice does not take place at the moment when the experimenter opens the box (the opening of the box takes place in the macrocosm, very far from the world of the nucleus). The nucleus chooses its state at the moment when it hits the detector. The point is that the system is not sufficiently described in the experiment.

Thus, the Copenhagen interpretation of the Schrödinger's Cat paradox denies that before the opening of the box, the Schrödinger's Cat was in a state of superposition - it was in the state of a live/dead cat at the same time. A cat in the macrocosm can and is only in one state.

Summary. Schrödinger did not fully describe the experiment. It is not correct (more precisely, it is impossible to connect) macroscopic and quantum systems. Quantum laws do not operate in our macrosystems. In this experiment, it is not “cat-core” that interacts, but “cat-detector-core”. The cat is from the macrocosm, and the “detector-core” system is from the microcosm. And only in its quantum world, the nucleus can be in 2 states at the same time. This occurs before the moment of measurement or interaction of the nucleus with the detector. A cat in its macrocosm can be and is only in one state. So, it only at first glance seems that the state of the cat "alive or dead" is determined at the moment of opening the box. In fact, its fate is determined at the moment of interaction between the detector and the nucleus.

Final summary. The state of the "detector-nucleus-cat" system is connected NOT with the person - the observer behind the box, but with the detector - the observer behind the nucleus.

Phew. Almost brainwashed! But how pleasant it is to understand the key to the paradox! As in an old student joke about a teacher: “While I was telling, I understood it myself!”.

Sheldon's interpretation of Schrödinger's Cat paradox

Now you can sit back and listen to Sheldon's latest interpretation of Schrödinger's thought experiment. The essence of his interpretation is that it can be applied in relations between people. To understand whether the relationship between a man and a woman is good or bad, you need to open the box (go on a date). And before that, they are both good and bad at the same time.

Well, how do you like this "cute experiment"? In our time, Schrödinger would have been punished by animal rights activists for such brutal thought experiments with a cat. Or maybe it was not a cat, but Schrödinger's Cat?! Poor girl, suffered from this Schrodinger (((

See you in the next posts!

I wish you all a good day and a pleasant evening!

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Encyclopedic YouTube

• 1 / 5

  In fact, Hawking and many other physicists are of the opinion that the "Copenhagen School" of the interpretation of quantum mechanics emphasizes the role of the observer unreasonably. Final unity among physicists on this issue has not yet been achieved.

  The parallelization of the worlds at each moment of time corresponds to a genuine non-deterministic automaton, in contrast to the probabilistic one, when one of the possible paths is selected at each step depending on their probability.

  Wigner's paradox

  This is a complicated version of the Schrödinger experiment. Eugene Wigner introduced the "friends" category. After completing the experiment, the experimenter opens the box and sees a live cat. The state vector of the cat at the moment of opening the box goes into the state “the core has not disintegrated, the cat is alive”. Thus, in the laboratory, the cat was recognized as alive. Outside the laboratory is friend. Friend does not yet know whether the cat is alive or dead. Friend recognizes the cat as alive only when the experimenter informs him of the outcome of the experiment. But everyone else friends the cat has not yet been recognized as alive, and they will recognize it only when they are informed of the result of the experiment. Thus, a cat can be considered completely alive (or completely dead) only when all people in the universe know the result of the experiment. Up to this point, on the scale of the Big Universe, the cat, according to Wigner, remains alive and dead at the same time.

  Practical use

  The above is applied in practice: in quantum computing and in quantum cryptography. A fiber-optic cable transmits 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.

  The experiment (which in principle can be performed, although working systems of quantum cryptography capable of transmitting large amounts of information have not yet been created) also shows that "observation" in the Copenhagen interpretation has nothing to do with the mind of the observer, since in this case the change in statistics to the end of the cable leads to a completely inanimate branch of the wire.