What does Schrödinger's cat mean? Schrödinger's cat and his difficult fate

29.09.2019

Can a cat be both alive and dead at the same time? How many exist parallel universes? And do they even exist? These are not science fiction questions at all, but very real scientific problems solved by quantum physics.

So let's start with Schrödinger's cat. This is a thought experiment proposed by Erwin Schrödinger to point out a paradox that exists in quantum physics. The essence of the experiment is as follows.

An imaginary cat is simultaneously placed in a closed box, as well as the same imaginary mechanism with a radioactive core and a container of poisonous gas. According to the experiment, if the nucleus disintegrates, it will activate the mechanism: the gas container will open and the cat will die. The probability of nuclear decay is 1 in 2.

The paradox is that, according to quantum mechanics, if the nucleus is not observed, then the cat is in a so-called superposition, in other words, the cat is simultaneously in mutually exclusive states (it is both alive and dead). However, if the observer opens the box, he can verify that the cat is in one specific state: it is either alive or dead. According to Schrödinger, the incompleteness of quantum theory lies in the fact that it does not specify under what conditions a cat ceases to be in superposition and turns out to be either alive or dead.

This paradox is compounded by Wigner's experiment, which adds the category of friends to an already existing thought experiment. According to Wigner, when the experimenter opens the box, he will know whether the cat is alive or dead. For the experimenter, the cat ceases to be in superposition, but for the friend who is behind the door, and who does not yet know about the results of the experiment, the cat is still somewhere “between life and death.” This can be continued with an infinite number of doors and friends, and according to similar logic, the cat will be in superposition until all people in the Universe know what the experimenter saw when he opened the box.

How does quantum physics explain such a paradox? Quantum physics offers a thought experiment quantum suicide and two possible options developments of events based on different interpretations of quantum mechanics.

In a thought experiment, a gun is pointed at the participant and either it will fire as a result of the decay of a radioactive atom or it will not. Again, 50 to 50. Thus, the participant in the experiment will either die or not, but for now he is, like Schrödinger’s cat, in superposition.

This situation can be interpreted in different ways from the point of view of quantum mechanics. According to the Copenhagen interpretation, the gun will eventually go off and the participant will die. According to Everett's interpretation, superposition provides for the presence of two parallel universes in which the participant simultaneously exists: in one of them he is alive (the gun did not fire), in the second he is dead (the weapon fired). However, if the many-worlds interpretation is correct, then in one of the universes the participant always remains alive, which leads to the idea of the existence of "quantum immortality".

As for Schrödinger’s cat and the observer of the experiment, then, according to Everett’s interpretation, he also finds himself and the cat in two Universes at once, that is, in “quantum language”, “entangled” with him.

This sounds like a story from a science fiction novel, but it is one of many... scientific theories, which takes place in modern physics.

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

« Schrödinger'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 laureate. 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. Here's the quote:

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

If we leave this entire 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 disintegrate. The very first disintegration of the atom would poison the cat. The psi-function of the system as a whole will express this by mixing or smearing a living and a dead cat (pardon the expression) in equal parts. Typical in similar cases is that the uncertainty, initially limited atomic world, is converted into macroscopic uncertainty, which can be eliminated by direct observation. This prevents us from naively accepting the “blur model” as reflecting reality. This in itself does not mean anything unclear or contradictory. There's a difference between a blurry or out-of-focus photo and a photo of clouds or fog.

In other words:

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 were selected so that the probability of nuclear decay in 1 hour is 50%. If the nucleus disintegrates, a container of gas opens and the cat dies. If the nucleus does not decay, the cat remains alive and well.
We close the cat in a box, wait an hour and ask the question: is the cat alive or dead?
Quantum mechanics seems to tell us that the atomic nucleus (and therefore the cat) is in all possible states simultaneously (see quantum superposition). Before we open the box, the cat-nucleus system is in the state “the nucleus 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.
According to the modern Copenhagen interpretation, the cat is 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 associated with the human observer of the box, but is associated 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 decayed, the cat is dead” or “the nucleus has not decayed, the cat is alive.”

The essence in human language

Schrödinger's experiment showed that, from the point of view of quantum mechanics, the cat is both alive and dead, which cannot be. Therefore, quantum mechanics has significant flaws.

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

Another most recent interpretation of Schrödinger's thought experiment is the story of Sheldon Cooper, the hero of the series "Theory big bang" ("Big Bang Theory"), which he delivered for his less educated neighbor Penny. The point of Sheldon's story is that the concept of Schrödinger's cat can be applied to human relationships. In order to understand what is happening between a man and a woman, what kind of relationship is between them: good or bad, you just need to open the box. Until then, the relationship is both good and bad.

Below is a video clip of this Big Bang Theory exchange between Sheldon and Penia.

Schrödinger's illustration is 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 simultaneously (“alive” and “dead”, if you remember the long-suffering cat). These states are called superpositions.

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 a Geiger counter, with the help of which the quantum state of microscopic systems - atoms, photons and electrons is determined. Quantum theory implies that if you connect a microscopic system (particle) to some macroscopic device that distinguishes two different states of the system, then the device (Geiger counter, for example) will go into a state of quantum entanglement and also find itself in two superpositions at the same time. 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 that nucleus. In this case, a living cat will be an indicator of “non-decay”, and a dead cat will be an indicator of decay. But according to quantum theory, the cat, like the nucleus, must exist in two superpositions of life and death.

Instead, the physicist says, the cat's quantum state should be entangled with the state of the atom, meaning they are in a "nonlocal relationship" 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, no matter how far they are from each other. At the same time, Hobson refers to experimental confirmation of this quantum theory.

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

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

Let us add that similar solutions to this paradox were proposed by three more groups of scientists over the past thirty years, but they were not taken seriously and remained unnoticed in the wider community. scientific circles. Hobson notes that solving the paradoxes of quantum mechanics, at least theoretically, is absolutely necessary for its in-depth understanding.

Schrödinger

But just recently THEORISTS EXPLAIN HOW GRAVITY KILLS SCHRODINGER'S CAT, but this is 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 had been measured. This is exactly how the superposition is destroyed, as scientists believed.

But even if somehow it became possible to isolate a macro-object 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 processes occurring on the surface of the Earth.

“Somewhere in interstellar space, perhaps a cat would have a chance to maintain quantum coherence, but on Earth or near any planet this is extremely unlikely. And the reason for this is gravity,” explains the lead author of the new study, Igor Pikovski of 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 macro-objects, and therefore we do not observe similar phenomena in the macrocosm. The basic concept of the new hypothesis, by the way, is briefly outlined in feature film"Interstellar".

Einstein's general theory relativity states that an extremely massive object will bend 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 pass somewhat slower than for one located in the orbit of our planet.

Due to the influence of gravity on space-time, a molecule affected by this influence will experience a deviation in its position. And this, in turn, should affect its internal energy - vibrations of particles in a molecule that change over time. If a molecule were 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 external influence, but in in this case the internal vibration of particles interacts with the movement of the molecule itself,” explains Pikovsky.

This effect has not yet been observed because other sources of decoherence, such as magnetic fields, thermal radiation and vibrations, are typically much stronger, causing the destruction of quantum systems long before gravity does. But experimenters strive to test the 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 vertical and horizontal interferometers: in the first, the superposition should soon disappear due to time dilation at different “heights” of the path, while in the second, the quantum superposition may remain.

What is Schrödinger's cat, Schrödinger 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 this unfortunate condition to Nobel laureate in physics, Austrian scientist Erwin Rudolf Joseph Alexander Schrödinger.

Sections:

The essence of the experiment / paradox

The cat is in a closed box with a mechanism containing a radioactive core and a container of poisonous gas. The characteristics of the experiment are selected so that the probability that the nucleus will decay in 1 hour is 50%. If the nucleus disintegrates, it activates the mechanism, the gas container opens, and the cat dies. According to quantum mechanics, if no observation is made of the nucleus, then its state is described by a superposition (mixing) of two states - a decayed nucleus and an undecayed nucleus, therefore, a cat sitting in a box is both alive and dead at once.

As soon as you open the box, 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 animal remains “dead.”

Marginalized

Trouble doesn't come 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 was not intended to prove the existence of "dead" cats (and, contrary to the statement in the second part of the game "Portal", was not invented as an excuse for killing cats). Obviously, the cat must 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 includes the cat): 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 confusion between living and 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 say that an “observation” occurs when a particle from the nucleus hits 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 the Copenhagen one, does not consider the observation process to be something special. Here both states of the cat exist, but decohere - that is, as the author understands, the unity of these states is disrupted as a result of interaction with environment. When the observer opens the box, he becomes entangled (mixed) with the cat, which creates two observer states, one corresponding to a living cat and the other to a dead one. These states do not interact with each other. The cat as a competent observer
The author believes that the final word should be left to the cat, who, even if he doesn’t know a thing about quantum mechanics, is certainly better informed than anyone else about his condition. However, his competence as an observer obviously raises doubts among scientists. An exception is Hans Moravec, Bruno Marshall and Max Tegmark, who proposed a modification of the Schrödinger experiment, known as “quantum suicide,” and which is an experiment with a cat from the cat’s point of view. Scientists pursued the goal of showing the difference between the Copenhagen and many-worlds interpretations of quantum mechanics. If the many-worlds interpretation is correct, the cat, to the joy of his 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 from the University of California and his colleagues published the results of a laboratory experiment in which they were able to “return” the quantum state of a particle back, and after measuring this state. Thus, it is possible to save the cat’s life regardless of the conditions for the collapse of the wave function. It doesn’t matter whether he’s alive or dead: you can always win it back [link] .
06/03/2011 RIA Novosti reported that Chinese physicists were able to create eight-photon "Schrodinger's cat"[link] , which should facilitate the development of future quantum computers

Image in culture

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

Literature: The situation with Schrödinger's cat is discussed by the main characters of Douglas Adams's book "Dirk Gently's Detective Agency". In Dan Simmons' book "Endymion" main character Raoul Endymion writes his narrative while in orbit around Armagast in Schrödinger's "cat box". In the last third of Robert Heinlein's book The Cat Walks Through Walls, the ginger cat Pixel appears, who has the ability of Schrödinger's cat to be in two states at the same time. Terry Pratchett's book "The Cat No Fool" humorously describes the breed of so-called "Schrodinger cats", descended from the same Schrodinger cat. This thought experiment is also mentioned more than once in other works by Pratchett, for example, in the novel “Ladies and Gentlemen.” In the story by F. Gwynplain McIntyre “Nursing Schrödinger the Cat,” one of the characters turns out to be Schrödinger’s own pet, the cat Tibbles. The action actually unfolds around this cat. humorous story, generously seasoned with details from various areas of physics. The plot of Frederik Pohl's science fiction novel “The Coming of the Quantum Cats” (1986) is built on the idea of interaction between “neighboring” Universes. In the philosophical and satirical miniature “Schrodinger’s Cat” by Nikolai Baytov, Schrödinger’s paradox is turned inside out: an organization called the “League of Reversible Time” has been monitoring a living 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 given a noose called “Schrodinger’s cat” around his neck, the peculiarity of which is that the magicians do not understand whether this creature is alive or not. Mentioned in Greg Egan's novel "Quarantine", in Christopher Stasheff's fantasy "The Healer Magician", in Gregory Dale Bear's story "The Schrödinger Plague"; Polish writer Sapkowski mentions Codringher's cat. In Mercy Shelley's cyberpunk novel 2048, it is said that "a guy with a last name that resembled a file was putting some poor biorg in an iron box with nothing in it but a vial of poison." Svetlana Shirankova’s poem “Schrodinger’s Cat” has a very inspiring beginning: “Doctor Schrodinger, your cat is still alive.” Screen: In the Coen brothers' film A Serious Man, a student declares to a professor, “I understand the dead cat experiment,” which, of course, indicates the opposite. In the film “Repo Man” (“Collectors”, in Russian release “Rippers”) the main character at the beginning of the film talks about an unknown scientist who has a cat. And this cat is in a 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 main character of the science fiction series “Slithers” also has a cat of the same name. In the TV series Stargate SG-1, an orange cat named Schrödinger was given to an alien. Dead cat Schrödinger appears in the TV series 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 TV series Bugs, the role of Schrödinger's cat was played by evidence of Red Mercury in a booby-trapped safe. IN Japanese anime Hellsing (OVA) (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 completely indestructible. In the anime “To Aru Majutsu no Index”, when asked by a girl to name a kitten Schrödinger, the main character objects that cats cannot be called that name. The anime Shigofumi also features a cat named Schrödinger. In the Japanese anime and game Umineko no naku koro ni, the experience is used in Battler's attempt to prove the impossibility of the existence of magic (Proof of the Devil, Hempel's Crows, Laplace's Demon are also used). In one of the Futurama episodes, “Law and Oracle,” Schrödinger hid drugs in a box with a cat. Comics/manga: A small comic about Schrödinger's cat and Maxwell's demon. He's Dead: Schrödinger of the Cat: And other comics on joyreactor.ru. Games: There is a quest game “Return of the Quantum Cat”. In the game "Nethack" there is a monster "Quantum Mechanic", who sometimes has a box with a cat with him. The condition of the cat is not determined until the box is opened. In the game "Half-Life 2" there was a cat in a laboratory with teleporters, which Barney "still" has nightmares about. The portrait of Schrödinger's cat is also found in the 1998 remake based on Half-Life. - "Black Mesa" (formerly known as "Black Mesa: Source"). Link to notarized screenshot. In every level of Bioshock, there is a dead cat in a secluded corner, identified as Shrodinger. In the second part you can also find him - 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 appears 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 Schrödinger’s experiment, namely “The cat is alive.” In the second part of the game, the cat is also not forgotten. Mention of the experiment can be found in the Russian rule book board game"Age of Aquarius". The cat even has his own characteristics plate - it is completely empty, so it’s as if it doesn’t exist. Music: The so-called festival of non-standard music “Schrodinger’s Cat”, held under the slogans “ Real life- real death - real music! and “Is Schrödinger's Cat Alive or Dead? And you?" Google also reports that the name “KoT Schrödinger” is a near-musical project of a very small group from Korolev near Moscow. The British band Tears for Fears' album Saturnine Martial and Lunatic contains a song of the same name. The Russian group “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 are driving along the highway to a conference, Schrödinger is driving. Suddenly there is a bang and he stops the car. Heisenberg looks out onto the road:
- Oh my God, it looks like I hit a cat!
- Is he dead?
- I can’t say for sure. Schrödinger walked around the room looking for the shitting kitten, and it sat in the box neither alive nor dead. Miscellaneous: Artists pay attention to Schrödinger's cat, trying to convey the ambiguity of his position through painting and graphics. Also, images of this animal can be seen on T-shirts and mugs. Terrorists who are not known to be dead or alive are sometimes called "Schrodinger's terrorists." From famous 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, a pig in a poke is a simplified version of Schrödinger's cat experiment [link]. Stephen Hawking paraphrased what became catchphrase Hans Jost “When I hear about culture, I reach for a gun” like this: “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” interpretation of quantum mechanics emphasizes the role of the observer without justification. In connection with the opening of the MEPhI Department of Theology, the following picture has spread online:

In 1935, an ardent opponent of the newly emerging quantum mechanics, Eric Schrödinger, published an article that purported to expose and prove the inconsistency of the new branch of development of physics.

The essence of the article is conducting a thought experiment:

A live cat is placed in a completely sealed box.
A Geiger counter containing one radioactive atom is placed next to the cat.
A flask filled with acid is connected directly to the Geiger counter.
The possible decay of a radioactive atom will activate the Geiger counter, which, in turn, will break the flask and the acid spilled from it will kill the cat.
Will the cat stay alive or die if it stays with such inconvenient neighbors?
One hour is allocated for the experiment.

The answer to this question and was called upon to prove the inconsistency of quantum theory, which is based on superposition: the law of paradox - all microparticles of our world are always simultaneously in two states, until they begin to be observed.

That is, being in a closed space (quantum theory), our cat, like his unpredictable neighbor - the atom, are simultaneously present in two states:

A living and at the same time dead cat.
A decayed and at the same time not decayed atom.

Which, according to classical physics, is complete absurdity. The simultaneous existence of such mutually exclusive things is impossible.

And this is correct, but only from the point of view of the macrocosm. Whereas in the microworld completely different laws apply, and therefore Schrödinger was mistaken when applying the laws of the macroworld to relations within the microworld. Not understanding that purposeful observation of the ongoing uncertainties of the microworld eliminates the latter.

In other words, if we open a closed system in which a cat is placed along with a radioactive atom, we will see only one of the possible states of the subject.

This was proven by the American physicist from the University of Arkansas, Art Hobson. According to his theory, if you connect a microsystem (radioactive atom) with a macrosystem (Geiger counter), the latter will necessarily become imbued with the state of quantum entanglement of the former and go into superposition. And, since we cannot make a direct observation of this phenomenon, it will become unacceptable for us (as Schrödinger proved).

So, we found out that the atom and the radiation counter are in the same superposition. Then who or what, for this system, can we call a cat? If we think logically, the cat, in this case, becomes an indicator of the state of the radioactive nucleus (simply an indicator):

The cat is alive, the core has not decayed.
The cat is dead, the core has disintegrated.

However, we must take into account the fact that the cat is also part of a single system, since it is also inside the box. Therefore, according to quantum theory, the cat is in a so-called non-local connection with the atom, i.e. in a confused state, which means in a superposition of the microworld.

It follows from this that if there is a sudden change in one of the objects of the system, the same will happen to another object, no matter how far they are from each other. An instantaneous change in the state of both objects proves that we are dealing with a single system, simply divided by space into two parts.

This means that we can say with confidence that Schrödinger’s cat is immediately either alive, if the atom has not decayed, or dead, if the atom has decayed.

And yet, it was thanks to Schrödinger’s thought experiment that a mathematical device was constructed that describes the superpositions of the microworld. This knowledge has found wide application in cryptography and computer technology.

Finally, I would like to note the inexhaustible love for the mysterious paradox of “Schrodinger’s cat” on the part of all kinds of writers and cinema. That's just some examples:

A magical device called “Schrodinger’s Cat” in Lukyanenko’s novel “The Last Watch”.
In Douglas Adams's detective novel, Dirk Gently's Detective Agency, there is a lively discussion of the problem of Schrödinger's cat.
In R. E. Heinlein's novel The Cat Walks Through Walls, the main character, a cat, is almost constantly in two states at once.
Famous Cheshire cat Lewis Carroll in the novel “Alice in Wonderland” loves to appear in several places at once.
In the novel Fahrenheit 451, Ray Bradbury raises the issue of Schrödinger's cat, in the form of a living-dead mechanical dog.
In the novel “The Healing Magician,” Christopher Stasheff describes his vision of Schrödinger’s cat in a very original way.

And many other enchanting, completely impossible ideas about such a mysterious thought experiment.

is a thought experiment by physicist Erwin Schrödinger, the essence of which is that the cat in the box is both alive and dead. Thus, the scientist proved the incompleteness of quantum mechanics during the transition from subatomic systems to macroscopic ones.

Origin

The Austrian theoretical physicist Erwin Schrödinger in 1935 proposed an experiment with a cat in a box in his article “The Current Situation in Quantum Mechanics” (Die gegenwärtige Situation in der Quantenmechanik) in the publication Naturwissenschaften.

We take the cat and put it in the box. The box contains an atomic nucleus and a container with poisonous gas. The probability of nuclear disintegration is 50%; if it occurs, the gas container will open and the cat will die. If decay does not occur, the cat is alive. According to the basics of quantum mechanics, before we open the box, the cat is in a state of quantum superposition - that is, in all states at the same time.

It turns out that in the “cat-core” system a cat can be alive or dead with the same probability of 50%. Or he is both alive and dead at the same time.

Popularity on the Internet

The issue of Schrödinger's cat was first discussed on the Internet in May 1990 on the Usenet's sci.physics forum. On August 9, 2000, a poem dedicated to Schrödinger's cat was published on the Straight Dope Q&A forum.

In August 2004, the online retailer ThinkGeek began selling T-shirts with the slogan "Schrodinger's Cat Died."

On January 4, 2006, a Schrödinger comic was released in the Xkcd comic series.

“The last panel of this comic is funny and unfunny at the same time. Until you read it, you can't tell how it will turn out in the end.

- Crap"

On June 2, 2007, the I Can Has Cheezburger website published a picture of a cat in a box with the caption: “In your quantum box...one cat...maybe.”

The crowning glory of Schrödinger's cat was the Google Doodle dedicated to him, which appeared on August 12, 2013, the day of Erwin Schrödinger's 126th birthday.

Popular culture references

Films, TV series, books and computer games, where this experiment was mentioned. Let's give just a few examples.

In episode 16 of the sixth season of Futurama, the police detain Schrödinger and his cat.

In the second episode of the first season of Rick and Morty, the main characters meet Schrödinger's cats in a parallel reality.

Sheldon Cooper in The Big Bang Theory used Schrödinger's cat theory to explain to Penny how relationships between men and women work.

Meaning

Schrödinger's cat is not only an Internet meme, but also a hero of popular culture. The cat, which is both alive and dead, symbolizes a certain ambiguity. Schrödinger is remembered when something is both funny and not, or when something is both prohibited and permitted. For example, a traffic light with red and green lights on at the same time is a Schrödinger traffic light.