Buridanov's donkey

Buridanov's donkey
From Latin: Asinus Buhdani inter duo prata (Azinus Buridani inter duo prata). Translation: Buridanov settled between two lawns.
Attributed to the French scholastic philosopher Jean Buridan (1300-1358). Allegedly, the latter, wanting to prove the lack of free will in man, likened him to a donkey, which stands in a meadow exactly in the middle between two equal haystacks. And the philosopher allegedly argued that the donkey in this case would not be able to choose any of them, even if he were dying of hunger. Hence, accordingly, the expression “Buridan’s donkey” arose.
But nowhere in the writings of J. Buridan is there an example of this kind, and there is no evidence that he ever expressed such a thought in oral conversation. Why in in this case Buridan's name is mentioned, unknown.
But other authors have the idea that a person cannot make a choice between two absolutely equal options. Aristotle (384-322 BC) in his essay “On Heaven” speaks of a man who is tormented by hunger and thirst, but since food and drink are at an equal distance from him, he remains motionless. Also Dante in his “ Divine Comedy"(Paradise, canto 4) describes a similar situation: if someone is between two identical dishes, then he would rather die than make any choice.
Ironically: about an indecisive, weak-willed person who hesitates between options for solving a problem and cannot choose any of them.

encyclopedic Dictionary winged words and expressions. - M.: “Locked-Press”. Vadim Serov. 2003.

See what "Buridan's donkey" is in other dictionaries:

- “BURIDAN’S DONKEY”, the paradox of absolute determinism in the doctrine of will: a donkey placed at an equal distance from two identical bundles of hay must die of hunger, because it will not be able to choose one or another bundle. In the works of J. Buridan this image is not... ... encyclopedic Dictionary

Buridanov Donkey- Buridan's Donkey ♦ Âne de Buridan The name of the 14th century French philosopher Jean Buridan is known today exclusively thanks to this very donkey, the parable of which is attributed to him, although in none of his surviving works is there any donkey... ... Sponville's Philosophical Dictionary

Noun, number of synonyms: 1 Buridan donkey (1) ASIS Dictionary of Synonyms. V.N. Trishin. 2013… Synonym dictionary

The paradox of absolute determinism in the doctrine of will: a donkey placed at an equal distance from two identical bundles of hay must die of hunger, because it will not be able to choose one or another bundle. This image was not found in the works of J. Buridan. IN… … Big Encyclopedic Dictionary

A comparison used to explain free will and which, in fact, already existed in Aristotle and Dante: a donkey standing between two completely identical armfuls of hay located at an equal distance from it had to starve, because - with... ... Philosophical Encyclopedia

Buridanov's donkey philosophical paradox, named after Jean Buridan, despite the fact that it was known from the works of Aristotle, where the question was posed: how can a donkey, which is given two equally tempting treats, ... ... Wikipedia

Buridan's donkey- burida/new donkey only singular, stable combination of books. A person hesitating between two equal possibilities. There were as many arguments for as against; at least these arguments were equal in strength, and Nekhlyudov, laughing... ... Popular dictionary of the Russian language

"BURIDAN'S DONKEY"- a famous fable attributed to the scholastic philosopher Buridan, depicting a donkey dying of hunger between an armful of oats and a bucket of water due to the inability to choose between two equal goods. Contrary to popular belief here... ... Philosophical Dictionary

Buridanov's donkey- about an extremely indecisive person, hesitating in the choice between two equivalent desires, two equivalent decisions. The expression is attributed to the French scholastic philosopher of the 4th century. J. Buridan, who argued that the actions of living beings... ... Phraseology Guide

Buridans- Buridan. By the name of fr. 14th century scholastic philosopher Jean Buridan, who, supposedly to prove that there is no free will, gave the following example: a donkey; being at the same distance from two identical armfuls of hay, must die, because... Historical Dictionary Gallicisms of the Russian language

Books

• The paradox of choice, Schwartz B.. The problem of choice has always existed. Buridan's donkey once chose between two haystacks; modern man, possessing big amount alternatives, can easily fall into...

Karl Erp, manager district library in Berlin - the capital of the GDR, forty years old family man with a developing belly, he wakes up in his room with a smile on his face. While reading a book at breakfast, he thinks about Fraulein Broder. After graduating from library school, she, along with another student, undergoes a six-month internship in his library.

The day before, at a team meeting, the question of which of the two trainees would be left in the library after passing the final exams was decided. The director of the school recommended Broder, she is a Berliner, one of those who would wither away without Berlin. The issue was resolved in favor of the girl, everyone recognized that her knowledge was enormous and moral character impeccable. But after the meeting, colleague Hasler unofficially expressed the opinion of many employees that the fraulein may not have enough cordiality, she is too straightforward, he himself is afraid that in her presence he will “get a chill in his soul.”

Reflecting on the appearance of his subordinate, Earp remembers her posture, pleasant restraint, and finds something “alienating” in her facial features. Then he sees the girl’s smiling lips, hears her soft intonations, which sometimes confuse the interlocutor. She becomes irresistible when “naturalness breaks through artificial coldness.”

While Earp is thinking about the intern, eating a delicious and healthy breakfast prepared by his wife, Elizabeth is busy with the children. Elizabeth asks her husband if he will return home on time, and is satisfied with a negative answer. She studied her husband well and has no doubt that she will later find out about everything in detail. She is not afraid of stories with women; he always talks about everything himself. Elizabeth is sure that her husband did not deceive her or commit adultery. She tries to suppress the anxiety or jealousy that sometimes arises.

The family lives in a comfortable house with a garden, which Elisabeth received from her parents, who moved to West Berlin. Earp loved this house and is proud of the lawn, which he does himself.

The working day drags on unbearably long for Earp. He has to inform trainee Krach about the decision in favor of Fraulein Broder. Earp tries to console the dissatisfied Krach, revealing to him the prospects for library activities in the village and scolding Berlin. The conversation ends with an angry remark from the bypassed trainee - for some reason Earp himself does not go to work in the village. Earp is embarrassed, it is painful for him to have enemies, he is used to being popular with both women and men.

In the evening, Earp goes to visit his sick trainee and, under a plausible pretext, tells her good news: Fraulein Broder lives in an old, neglected house with many noisy and crowded residents. Here she was born and lived with her parents, now deceased.

Earp climbs the dirty stairs and stands for a long time in front of the Fraulein's door to calm down his excitement. Since the morning he had been looking forward to this moment, and now he was afraid that one look from her would “kill all hope.” This does not happen, and since both were tireless talkers, their meeting lasted six hours.

Earp returns home at half past two in the morning. Elizabeth silently accepts his apology and then listens to the details. Karl has no secrets from his wife; he feels the need for “honesty.” The husband describes Broder's house and tiny room: the kitchen is on the landing, the restroom is on another floor, one for all residents. He already has difficulty remembering what they talked about: about the problems of librarianship, literature, the psychology of readers, sleep patterns, mint tea, the Bundeswehr... Earp describes in detail the girl’s peculiar habit: she constantly strokes her eyebrows when she listens. The following is a conclusion about the dangers of sleepless nights and the benefits of cozy evenings at home with your wife and children. Elizabeth must understand that this Broder is the most intelligent and the most tiresome of all the girls.

Elizabeth is an unusually silent woman, her life and interests belong entirely to her family. Karl always felt that he could not unravel the soul of his wife, and he did not strive for this, he only allowed himself to bliss under the “warm rays of her love.” That night, Elizabeth realizes that her husband has fallen in love, which she tells him to his face. She immediately notices some changes in him, noticeable only to her, and vaguely feels a readiness to violate marital fidelity.

Karl disappoints Fraulein Broder as a man and a boss, not meeting her ideas about him. She always expects more from people than they can give. Brodeur has read all of Earp's library articles published in the press and has long respected him as a professional. And he comes to her with a bottle, the same as all men, arrogant and, apparently, with one desire - to sleep with her.

In the morning, Earp writes the girl letter No. 1 - an angry, “propaganda” letter from a party member (Erp is a member of the SED) to a non-party woman, who should know that socialist morality does not require a vow of chastity. Broder finds an unstamped letter in his mailbox and realizes what is happening to him.

One evening, when Earp is sitting at Brodeur’s, his colleague Hasler comes to his house and stays, talking with Elizabeth, almost until his return in the morning. The colleague is concerned about the issue of moral standards, since Krach has already started gossiping about the library. Hasler learns many things from Elizabeth and feels that her accommodation and submission are the foundation on which many families rest.

This time, a decisive conversation takes place between the spouses. Karl is trying to shift his guilt onto his wife’s shoulders: he married her without loving her, because that’s what she wanted. After such a false statement, Elizabeth decides to divorce, although Karl does not insist on it at all. His wife's behavior is again a mystery to him. Library employees discuss among themselves the director's affair with his subordinate. Krach intends to complain “through the authorities.” One employee, a great polymath, calls Earp “Buridan’s donkey,” described in the Middle Ages. That donkey died after long deliberation about which of two identical fragrant haystacks he should prefer.

Karl spends Christmas night with the fraulein, this is the first real night of their love. The next day he moves in with her with two suitcases.

The first day together is filled with discoveries for both. Broder discovers that "gigantic love" turns into a "dwarf" fear for his reputation. Karl learns that the neighbors call his beloved “little sparrow,” and also that she is used to deciding everything on her own.

Hasler is waiting for a decisive statement from Earp about the creation new family. But he remains silent, and then Hasler himself formulates the conditions - an immediate divorce with the transfer of one of the two to another library.

In the wretched surroundings of the house, Broder Earp truly suffers. You can hear the noises of your neighbors all night, mice and rats are busy in the attic, since four o’clock in the morning the walls have been shaking from the roar of the printing house, it’s unusual to sleep on an inflatable mattress. Insomnia torments him, he is exhausted from self-pity. “Sparrow” occupies the washstand in the ice-cold kitchen for a long time, then makes unstrained coffee and eats foul-smelling sausage for breakfast instead of marmalade. When she leaves for work, she leaves the bed unmade until the evening - for “airing” - how can he return to such a room?

Karl constantly attacks his beloved, while she only defends herself, defends herself from the remnants (as it seems to her) of male lust for power. But she is not irritated, because she suffers only from him, and he suffers from both her and the environment. She invites him to go together to work in the village, but he knows how attached “she” is to Berlin.

Gradually, Broder fears that Karl's love is beyond his strength.

Earp visits his terminally ill father in the village, former teacher in those parts. He shares with him the change in his personal life and sees that his father is on Elizabeth's side. The old man notices to his son that he does not like the word “duty” and persistently talks about happiness, and only those who are able to refuse it have happiness.

Time passed, and Earp never filed for divorce. Meanwhile, things are going well with his career. At the next meeting in the library, he admits that he “lives with a colleague Broder” and intends to divorce his wife. The director thinks it would be unfair if Broder had to leave the library because she was promised a position. He takes the blame and says he will leave on his own. His decision is made - this is a shock for Earp, who secretly hoped that his sacrifice would not be accepted. He comes to the “sparrow” with a tragic face and the expectation of gratitude for the sacrifice made.

At this time, Earp's friend from the ministry reports that he is officially offered a post in the same ministry in Berlin. Thus, all conflicts are finally resolved by the socialist state. But Earp does not feel any particular joy, since now all his decisions are devoid of a heroic aura. He reluctantly accepts the offer.

Broder doesn't know anything, she's giving in final exams at the school, after which she asks to be sent to work in the village. When she returns home and tells Earp about her decision, he is not horrified, does not ask her to take the decision back and does not assure her that he is ready to go with her anywhere, especially to his favorite province. He immediately accuses the “little sparrow” of arbitrariness and takes on the appearance of an insulted lover whom the woman wants to leave. Earp does not inform Brodeur of his new assignment in Berlin and allows her to go into self-imposed exile. He is left with a “bleeding heart” - from which the stone of responsibility has fallen.

Earp returns to his family. As before, he tells Elizabeth about everything himself, “honestly”, “without subterfuge” and “mercy” towards himself, the “Golden Chain of Love” turned into “shackles” and “traps”, he had to forcefully break.

Elizabeth takes him back to the family where fourteen years have passed life together. Elizabeth tells herself that she is doing this for the children. During these months without her husband, she is already winning her place in public life having mastered a new profession.

Elizabeth goes to bed with the door locked. What is this woman, who has changed so much, thinking about? No one can know this.

What is the meaning of the phraseological unit "Buridan's donkey"? Perhaps not so often in modern communication you can hear such a phrase, but it is quite well-known, and even in 1968 German writer Gunter de Bruin wrote the novel Buridan's Donkey. First we will look at the history of this expression, and then we will look at what "Buridan's donkey" means today.

So, first of all, let’s define the phraseological unit “Buridan’s donkey” - this is a paradox in philosophy, which received its name from the name of such a French philosopher and logician as Jean Buridan. Although it must be said that Aristotle also raised this topic. Then the question was formulated something like this: if a donkey is given two treats, each of which is tempting for the donkey, will he be able to make a rational choice?

Speaking about the meaning of "Buridan's Donkey", it is important to note that Jean Buridan himself did not cover the issue in his writings, introducing the donkey, but he touched upon similar topic. Buridan's position can be described as moral determinism, that is: when a person has to choose, he should do it, leaning towards greater good. True, the philosopher suggested that sometimes the choice is slowed down because a person must first evaluate the results.

If you are also trying to understand the meaning of the phraseological unit "Buridan's donkey", then pay attention to its translation from Latin language- "Buridan's donkey between two lawns." After some time, other literary figures somewhat modified this concept, citing the example of a donkey and two good haystacks, which are equally accessible from the donkey. They argued that the donkey was doomed to starve in this situation because it would not be able to make a decision. This view was very firmly held by Leibniz, a Saxon philosopher and mathematician. He also made efforts to disseminate this version of the phraseology "Buridan's donkey."

Task logic

Speaking in more detail about the logic of the problem, it is worth drawing the following conclusion: a donkey that thinks rationally will not die at all starvation, however, it is impossible to say with certainty which haystack he will choose. After all, if the donkey refuses to eat, that will also be a choice. It turns out that he has three options: a haystack on the left, a haystack on the right, and death by starvation. Since the worst of these options is the third, the donkey's choice will never fall on it.

What does the expression "Buridan's donkey" mean today?

Having considered the history of this phraseological unit, it becomes clear that the expression “Buridan’s donkey” is usually applied to a very indecisive person who does not know what choice to make and hesitates. Especially if we're talking about about making two equivalent decisions.

Let's summarize: when we call a person this way, we refer to the philosopher Buridan, who proved that living beings make decisions not of their own free will, but due to external reasons.

The philosophical question known as “Buridan’s donkey” will always excite the minds of mankind. Here we will analyze the meaning of the phraseological unit, its origin, and how not to become this very donkey.

The ancient Greek philosopher Aristotle, who lived in the fourth century BC, told his students and listeners a parable. In his Buridan story, the donkey is an indecisive man who dies of thirst and hunger. This person is within walking distance of food and food and does not know what to choose for his salvation.
What Aristotle really meant was that if a person is faced with such a choice, he should choose what he thinks will turn out to be the greatest good for him. Much later, in the Middle Ages, the scholastic philosopher Jean Buridan retold this parable in different words.

BURIDAN'S DONKEY PROBLEM

Actually there is no problem. There is a donkey dying of hunger, and there are two piles of seemingly identical hay. What to choose? According to the parable, the donkey can endlessly decide and in the end simply die of hunger. Also, a lop-eared animal can simply choose one of two haystacks and start eating. Jean Buridan was able to formulate the question of choice in exactly this way. Is it possible to make a rational choice if it is not entirely possible to calculate what this or that decision will lead to? True, according to rumors that have survived to this day, Buridan, when telling this story to his listeners, always asked if he had seen donkeys die in such cases. Otherwise, all of Asia would simply be littered with the corpses of eared animals. In fact, animals are not tormented by the problem of choice; this property is inherent only in humans.

IT'S OR IT'S GONE OR IT'S GONE

In fact, Buridan's ass is each of us at least several times a week. How often do you catch yourself thinking about what is best for you to do in a particular situation and which of two evils to choose? This question is illustrated very well by the famous joke about a monkey who could not decide who to join - the smart ones or the beautiful ones.
There is not and cannot be a single correct answer in such situations, because a person has his own own worldview and worldview.

HEADS OR TAILS?

Let's start from the very beginning simple option– when you need to choose one of two alternatives (things, objects, possibilities). In such a situation, the “heads or tails” principle is often used, which, of course, greatly simplifies the selection procedure itself, but automatically presupposes that the chooser has a certain “submission to fate.” As they say, “it’s hit or miss.” Although I recently came across a note on the Internet that claims that a tossed coin is governed by some complex physical laws.

DON'T LIT!

However, even without the intervention of complex scientific theories they managed to make the choice from two equivalent alternatives extremely difficult even in ancient times, having come up with the well-known parable about Buridan’s donkey, who died of hunger, unable to choose which of two identical haystacks he should start his meal with. The parable demonstrates what very often happens in many scientific discussions about choice, where one problem is imperceptibly replaced by another. A real donkey would probably have been smarter than the philosophers who invented it and would hardly have bothered with the problem of the absolute identity of two haystacks, but would have obeyed the instinct of self-preservation, which prescribes to satisfy hunger at all costs, and not to solve complex logical problems. He would just start eating one of the haystacks! And I would have a second bite for future use. It would be nice for a mere mortal to use this very “donkey strategy”, that is, to ask not the question of implementing a complex pattern, but to remember the purpose of his choice. the main task donkey - to eat, and not to choose the best of the haystacks. You immediately understand that only people are capable of so sophisticatedly fooling themselves with speculative reasoning to the detriment of their own stomach.

STEP INTO THE FUTURE

The problem is that any choice is always a certain choice of the future. And we evaluate it, already looking back from the “resulting” future, and decide whether it was successful or not very successful. Therefore, the task itself - to make a good choice - has no solution in the present tense. You can only take certain actions that in the future will or will not bring positive result. As a result, the problem of choice often comes down not to choice as such, but to the problem of a person’s lack of an image of the desired future. To the inability to formalize own wish- what do we need? That is, behind the problem of choice we often hide the problem of introspection. We can't decide what we need.

"FREEDOM OF CHOICE

Often behind the problem of choice there are “hidden” problems generated, so to speak, by a certain organization of our consciousness and education based on currently “current” values. After all, in order for a person to lose sleep when deciding which brand of clothing to prefer, this very choice of “brand” must be significant for him. If you take a closer look, “freedom of choice” is allowed in modern society almost exclusively in the sphere of consumption. At one time, even the very concept of “freedom” somehow imperceptibly “stuck together” with the ability to choose goods and services. The abundance of goods has become a symbol of the free world. But what is freedom? Is it that they strictly dictate to you how you should look at work, introducing the concept of a “dress code”? Or is it that to a certain degree of wealth, society dictates everything to you - the brand of car, place of residence, method and place of recreation? And only the richest are again allowed to “wonder” and decide at their own discretion. There is an old joke about how a young employee came to a cool company, where there was very strict control over compliance with all modern standards, from clothing to a strict smoking ban, and suddenly sees a man in faded jeans and a faded T-shirt smoking by the window. He is surprised and quite loudly begins to wonder who it is. To which he receives an answer in a frightened whisper: “Hush, hush, don’t disturb him! The last time he thought like this, our company earned tens of millions of dollars!”

FEAR AS A STIMULUS

Quite often, choices, especially in personal relationships, are made out of fear or under duress of circumstances. Not everyone has the courage to risk waiting for “their” person. More than once I have heard from those who come for consultations about problems that have not worked out family relations I will tell you that the motivation for marrying this particular man was: “there was no other”, “he was the best there was”, “it was time to have a child.” Another conversation is that life is such a complex and unpredictable thing, but human relations such a mysterious substance that happy marriages sometimes happen even with such flimsy foundations. Even “on the fly.”

THE MEANING OF PATIENCE

Self-control in the face of choice is also an art. If you can’t choose for a long time, most likely you are not very happy with both options - and circumstances do not allow you to wait for the third. If you nevertheless made your choice from two alternatives that are not entirely satisfactory, then be prepared to accept responsibility for the obvious - most likely, after some time you will not be satisfied with your choice and will have to choose again. So don’t invent people a place in your life, wait a little, and they themselves will take their rightful place.

RULES

So, before choosing, it’s worth considering a simple list of four questions: “Why do we choose? On what basis do we choose (what are we guided by?) In what situation do we choose?” And only then - “What do we choose?”

1. First, decide on the purpose of your choice - ask yourself a question about the reasons. Don’t forget that a clear understanding of “why” makes any “what” elementary.

2. Remember that often people in a situation of time pressure or the special significance of a win begin to introduce “secondary” reasons - from insignificant to fictitious. For example, when playing roulette or lottery, they begin to base their choices on “significant” dates, birthdays, etc., attributing to them the properties of “lucky” numbers. So if a choice has to be made in extreme conditions, trust your intuition. Especially when it comes to your professional competence.

3. There are some things you should come to terms with in advance and “don’t bother.” So, for example, in situations where we make choices under conditions beyond our control, we can only try to reduce risks. That is, either try to “calculate the risks” (which is modern conditions almost impossible), or “minimize” possible losses, risking in advance only that amount (those resources) that we can lose relatively painlessly.

4. One more opportunity should not be overlooked. After all, we don’t always really need to make a choice between something. Often the choice is to give it up. The simplest strategy is to reduce the value of what we are offered to choose or would like to receive, but there is no such opportunity. Let us at least recall the famous Krylov fable about the fox and the grapes: “It looks good, but it’s green - there are no ripe berries: you’ll immediately set your teeth on edge!”

In order to achieve ideal purity of the experiment, it is better to conduct it purely theoretically.
Yuri Tatarkin

The concept of a thought experiment was introduced at the beginning of the twentieth century by the Austrian physicist Ernst Mach. He meant, first of all, preliminary playback in the imagination real experiment. Mach believed that with the help of fantasy it is possible to introduce any experimental conditions, even completely absurd ones, and this makes it possible to consider all possible results.

The history of science is full of exotic thought experiments, which not only changed the generally accepted view of the world, but also gave rise to debates that lasted for decades. We will tell you about the ten most famous ones. Be careful - some of them can drive you crazy!

Ancient philosophers loved to come up with paradoxical propositions, but few could compare in this with the Greek Zeno of Elea, who lived in the 5th century BC. e. His aporias (that is, “difficulties”) were not preserved in original form and are known in the retellings of Plato and Aristotle. Zeno formulated at least forty aporia, but only nine reached interpreters.

Zeno's most famous aporia is the paradox of Achilles and the tortoise. It owes its origin to a fable by the ancient Greek poet Aesop. It tells how the tortoise bet with the hare that he could outrun him in a fair race, and was able to do so. She took advantage of the carelessness of her opponent, who decided to take a break, confident that he would have time to come running first. Zeno replaced the hare with the fleet-footed hero Achilles, glorified in the Iliad.

Imagine that the tortoise and Achilles decided to compete in a race. Achilles is ten times faster than the tortoise and gives it a head start of a thousand steps. During the time it takes Achilles to run this distance, the tortoise will crawl a hundred steps in the same direction. When Achilles runs a hundred steps, the tortoise crawls another ten, and so on. The chase will be endless, Achilles will never catch up with the turtle. Therefore, any movement is an illusion.

Aporia is puzzling, because from the standpoint formal logic it looks flawless, but in practice, as experience suggests, any runner will easily outrun a turtle. Greek philosophers seriously puzzled over this paradox. It was also reflected in literature: Lewis Carroll, Leo Tolstoy and Jorge Luis Borges wrote about the Achilles fiasco.

Of course, Zeno's statement that Achilles will never catch up with the tortoise is false. Each subsequent “breakaway” of the turtle is shorter than the previous one, and Achilles will need only one thousand one hundred and twelve steps to get ahead. The paradox arose because Zeno and his followers did not understand the physical and mathematical meaning of the problem.

Monument to swift-footed Achilles in Corfu

Buridan's donkey turned into a humorous image

Buridan's imaginary donkey, as we know, found himself between two identical armfuls of hay and died of hunger, unable to choose between them. Oddly enough, this donkey was not invented at all French philosopher XIV century Jean Buridan. The oldest mention of this problem is found in Aristotle. He jokingly described a fictitious situation in which a man dying of thirst and hunger could not choose between water and food.

The idea proved fruitful, and later philosophers used the same image to illustrate resultant forces. In 1100, the Persian scholar Abu Hamid al-Ghazali took Aristotle's dilemma seriously and stated that a person will choose between similar things in favor of the one that suits him best. this moment. Buridan added that in a situation where rational choice is impossible, a person will turn to moral principles and will follow the path of greater good.

The donkey appeared thanks to the Dutch philosopher Benedict Spinoza. He argued that if a person, who finds himself in a situation of choice between identical possibilities, like “Buridan’s donkey,” fails to make a choice, then he can hardly be considered a person.

The mathematician Gottfried Leibniz complicated the problem of choice by describing a donkey between identical bundles of hay. He believed that such an experiment could not be implemented in practice, since there is no perfect symmetry in the Universe - one mop will always be preferable to another, even if we do not notice this advantage.

Modern philosophers believe that the problem Buridan's donkey is easily solved if we accept that refusing to choose between two armfuls of hay is also a choice. The donkey chooses not between hay and hay, but between life and death, therefore the choice is predetermined at the level of instinct: the donkey will choose life.

Galileo's experiment

Italian physicist and astronomer Galileo Galilei needed a thought experiment with falling objects to show the fallacy of the misconception that the heavier the body, the faster it will fall to the ground. According to legend, in 1589 Galileo climbed the famous “leaning” tower in Pisa and dropped two balls of different masses from it, which reached the ground simultaneously, confirming the scientist’s revolutionary hypothesis. In fact, he did not climb anywhere, but relied on purely speculative considerations, which he outlined in the treatise “On Movement” (1590).

Imagine two objects, one of which is heavier than the other. Let them tie them together with a rope and throw this bunch off the tower. If heavy objects fall faster than light ones, then the light object should slow down the fall of the heavy one. But since the system in question as a whole is heavier than one heavy object, it should fall faster than it. We come to a contradiction, which means that the original assumption (heavy objects fall faster than light ones) is incorrect.

Our consciousness resists the idea that a hammer and a pen, if dropped from the same height, will fall at the same time. In the world we know, the atmosphere will slow down the pen and the hammer will fall faster. But what if you place them in an airless environment? The astronauts of the Apollo 15 mission did this in 1971: in front of millions of television viewers, Dave Scott threw a geological hammer and a falcon feather on the Moon. Everyone was able to see that Galileo was right.

Feather and hammer on the surface of the moon

The thought experiment with a space gun was invented by the great English physicist Isaac Newton.

Imagine the highest mountain, the peak of which extends beyond the atmosphere. At its very top there is a cannon that fires horizontally. The more powerful the charge used when firing, the farther the cannonball will fly from the mountain. When a certain charge power is reached, the core will develop such a speed that it will enter orbit. The force of attraction for him will be balanced by the centrifugal force.

In the same work, Newton calculated the value of the first escape velocity required to enter orbit, which for our planet is 7.91 km/s.

Newton's idea was in demand in the 19th century, when the foundations of the theory of astronautics were laid. It is the cannon that is used for space flight by the characters in Jules Verne’s novel “From the Earth to the Moon,” which influenced the pioneers of rocket science, including Tsiolkovsky. Subsequently, the idea was played upon by such writers as Georges Le Fort and Henri de Graffiny, Jerzy Zulawski and Andrei Platonov. And Gregory Keyes has an alternative history novel, Newton's Gun (1998).

Paradox of duplicates

The thought experiment, later called the "paradox of duplicates" or the "paradox of teleportation", was first "performed" in 1775, when the Scottish philosopher Thomas Reid wrote to Lord Kames:

“I would be glad to know your Excellency’s opinion regarding the following: when my brain will lose its original structure and when, hundreds of years later, from similar material will be created in an amazing way sentient being, can I consider him to be me? Or if two or three similar beings are created from my brain, can I believe that they are me and, therefore, the same intelligent being?

Reed's question leads to a serious problem of personal identity that has been addressed by philosophers many times. For example, Stanislaw Lem in Dialogues (1957) comprehensively examines the “paradox of duplicates” and concludes that it cannot be resolved until we know what the soul is and what physical processes it is reduced to.

In 1984, the English philosopher Derek Parfit modified the “paradox of duplicates” by describing a teleporter that breaks a person into atoms and transmits information about these atoms to Mars, where it recreates a copy from local resources. Parfit wondered: could such a teleport be considered a means of transportation and would a person on Mars be the same person who split into atoms on Earth?

The task can be complicated. Let's say the teleport was improved and it stopped destroying the original, but learned to create an infinite number of copies of a person. Can they be considered full-fledged people? Parfit came to the conclusion that philosophy does not offer a single satisfactory criterion for distinguishing a copy from an original, which means that duplicates should be considered equally valid. It follows from this that the law must take into account the rights of “future personalities” of citizens.

In science fiction, the “duplicate paradox” is especially popular. Recent examples include the films The Sixth Day (2000), The Island (2005) and The Prestige (2006)

Twin paradox

Twin astronauts Scott and Mark Kelly

Imagine two twins, one of whom went on an interstellar journey on a ship flying at near-light speed. The other remained on Earth and grew old faster than his brother. This thought experiment wonderfully illustrates the effects described in Einstein's theory of special relativity. But it follows from the twin paradox, which formulated French physicist Paul Langevin in 1911.

According to the special theory of relativity, the processes of moving objects slow down, that is, the twin, returning from a trip, will be younger than his brother. For example, a flight to Alpha Centauri and back with an acceleration of 1 g in the earth’s reference frame will take 12 years, and according to the ship’s clock it will take 7.3 years. On the other hand, the theory declares the equality of inertial reference systems. That is, the Earth relative to the spaceship is also moving with increasing speed. Consequently, time should slow down there too. This is where a contradiction arises that needs to be explained.

Gennady Golobokov’s painting “Time Paradox” illustrates the “twin effect”

Eventually explanations were found. True, to briefly outline them, a separate article is needed. But it is much more important that the effect of time dilation for a fast-moving object has been experimentally recorded in particles in accelerators and in atomic clocks on GPS satellites, the readings of which must be corrected. If the effect of time dilation were not taken into account when using these satellites, then the coordinates calculated from GPS would be incorrect after just two minutes, and the error would accumulate at a rate of 10 km per day! The effect and its consequences have often been described in science fiction - from Ivan Efremov's Andromeda Nebula (1957) to the recent Interstellar (2014).

Murder of Grandfather

This thought experiment of traveling back in time was originally called the "Professor's Paradox." It was first formulated by the British science fiction writer Fowler Wright in his novel The World Below (1929) through the mouth of his character, a professor:

Any changes in the past are obviously impossible; everything happens irrevocably. Otherwise there would be no finality and there would be unbearable confusion... For example, knowing that a murder has occurred, I can go there and intervene to save the victim. In this case, the murder seemed to have occurred, but was also prevented, which is absurd.

Two years later, the story "Time Flight" by the American Robert H. Wilson appeared, in which a murder in the past is not abstract, but is connected with the time traveler's grandparents. In 1933, the stereotype was reinforced by Nat Schachner in the story “Voices of the Ancestors.”

The “murdered grandfather paradox” in modern philosophy has an analogue called “auto-infanticide”: flying into the past with the goal of killing oneself. It is often used as evidence that time travel is impossible because it violates cause and effect. For example, the American philosopher Bradley Dowden in his book Logical Reasoning (1993) stated:

No one will ever create a machine that can send a person back in time. No one should seriously try to build it, because there is a reliable argument why the machine cannot be built.<…>Suppose you have a time machine, you enter it and are transported back in time. Your actions may prevent your grandparents from meeting. This would lead to the fact that you would not have been born and would not be able to go back in time in a time machine. Thus, the claim that a time machine can be built is internally contradictory.

But perhaps the events of the past already include an invasion by an alien from the future. Circumstances simply prevented him from killing or quarreling his ancestors. This point of view is shared by cosmologist Igor Novikov, who introduced the “principle of self-consistency” in 1983. According to it, when moving into the past, the probability of an action changing an event that has already happened tends to zero. The principle is well demonstrated in the film 12 Monkeys (1995), in the stories of Ted Chan, and even in one of the Harry Potter films.

Shroedinger `s cat

The thought experiment with a cat (more precisely, a cat) was invented by the Austrian physicist Erwin Schrödinger to demonstrate the incompleteness of quantum mechanics in the transition from subatomic to macroscopic systems. He described the experiment in the article "Current Situation in Quantum Mechanics" (1935):

A certain cat is locked in a steel chamber along with an infernal machine: inside a Geiger counter there is a tiny amount of radioactive substance, so small that only one atom can decay within an hour, but with the same probability it may not; 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 disintegration of the atom does not occur. The first atomic decay 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. What is typical in such cases is that uncertainty originally limited to the atomic world is transformed into macroscopic uncertainty, which can be eliminated by direct observation.

According to quantum mechanics, if a nucleus is not observed, its state is described by a superposition (mixing) of two states - a decayed and non-decayed nucleus. This means that the cat in the box is dead and alive at the same time. If the box is opened, the experimenter will see a specific state: “the nucleus has decayed, the cat is dead” or “the nucleus has not decayed, the cat is alive.”

Erwin Schrödinger made many discoveries, but went down in history as the “cat torturer”

In 1957, American Hugh Everett put forward a theory that the moment the box was opened, the Universe would split into two: with a dead cat and a living cat. Since we ourselves are in ordinary life Every second we make a choice (down to which foot to stand on today), every moment the Universe branches into an infinite number of parallel ones. At first, the scientific community rejected Everett's theory, but later he gained followers, and "Everettism" arose - a worldview according to which the Universe is a set of realizations of all conceivable worlds. The idea turned out to be in demand among science fiction writers: an article would not be enough to list all the books and films where it is played out.

Schrödinger's cat (or cat) has long been

Monkeys and Hamlet

The infinite monkey theorem states that a billion monkeys, randomly tapping the keys of typewriters, will sooner or later type any text - even Hamlet or War and Peace.

The origin of the theorem should be sought in the works of Aristotle, who believed that the whole world is a random combination of atoms. And since their number and size are limited, the probability of repetition of combinations is high. Three centuries later, the ancient Roman orator Marcus Tullius Cicero objected to Aristotle, pointing out that if cast letters were thrown onto the ground, they were unlikely to form even one meaningful line.

The infinite monkey theorem as we know it was formulated by the French mathematician Emile Borel. Thought experiment with monkeys and typewriters he needed to illustrate the improbability of violation of the laws of mechanics from the standpoint of statistics. Borel said that, theoretically, an object thrown upward by hand may not return to Earth, but this event is so unlikely that the monkeys are more likely to type Hamlet. And the experiment with monkeys entered popular culture thanks to humorous story Russell Maloney's "Indestructible Logic" (1940), where the monkeys, contrary to the theory of probability, succeeded.

Scientists have calculated that if we discard punctuation marks and spaces, then the probability of a random set of “Hamlet” consisting of approximately 130 thousand letters is equal to 1/3.4 × 10 183946. If the entire visible part of the Universe were filled with monkeys typing throughout its existence, the probability of them typing a play would increase to 1/10 183800.

It is in principle possible to carry out the described experiment, and in 2003 it was done by students from the University of Plymouth (Britain). Six crested baboons from a local zoo worked on a computer for a month, trying to create at least some kind of literary sketch, but only broke it. The result was five pages of meaningless text with a predominance of the letter S. What the baboons wanted to say with this is a mystery. Their great work was published in a limited edition entitled “Notes to full meeting Shakespeare's works."

Brain in a vat

The thought experiment “brain in a vat” (or, alternatively, in a barrel or flask) was invented in 1973 by the American philosopher Gilbert Harman, developing the idea of ​​Rene Descartes, outlined in 1641. He believed that the best path to knowledge of the truth lies through extreme skepticism. He illustrated this idea with the hypothesis of the existence of an "evil demon" who creates an illusion for the philosopher outside world, including imitation of bodily sensations. A number of questions followed from the hypothesis. For example, how can you be sure that you are not dreaming right now?

The demon hypothesis, for which Descartes was accused of blasphemy, had become outdated by the 20th century, so Harman modernized it in the spirit of science fiction. Imagine that a mad scientist connected a person's brain to a computer that could generate electrical impulses identical to those that the brain would receive while in the body. The computer can simulate virtual reality, and the experimental subject, despite the absence of a body, will be aware of himself existing. No one can know for sure whether his brain is in a vat or in his body, which means that we cannot be sure that the world around us is real.

In 1981, philosopher Hilary Putnam expanded the idea to the whole of humanity and gave birth to a fantastic assumption that later formed the basis of the Matrix film trilogy. At the same time, Putnam showed that the basis of the thought experiment proposed by Harman is a “self-negating assumption” - a statement whose truth presupposes its falsity - and this proves the existence of reality from the standpoint of logic. You can breathe a sigh of relief: “The Matrix” is just a Hollywood fiction.

* * *

Of course, it is impossible to describe in ten examples the entire wealth of thought experiments that scientists have come up with. But this is enough to see: imagination in science is no less important than the purity of calculations and accuracy of measurements. And often the flight of this imagination exceeds the most exotic ideas of science fiction writers.