Is there life in a parallel universe? Parallel universes. The universe is too big to exclude the possibility of the existence of parallel realities

Multiverse – scientific concept suggesting the existence of many parallel universes. There are a number of hypotheses describing the diversity of these worlds, their properties and interactions.

The success of quantum theory is undeniable. After all, it, along with it, represents all the fundamental laws of physics known modern world. Despite this, quantum theory still poses a number of questions to which there are still no definite answers. One of them is the well-known “Schrödinger’s cat problem,” which clearly demonstrates the shaky foundation of quantum theory, which is formed on predictions and the probability of a particular event. The point is that a feature of a particle, according to quantum theory, is its existence in a state equal to the sum of all its possible states. In this case, if we apply this law to the quantum world, it turns out that the cat is the sum of the states of a living and a dead cat!

And although the laws of quantum theory are successfully used in the application of technologies such as radar, radio, Cell phones and the Internet, we have to put up with the above paradox.

In an attempt to solve the quantum problem, the so-called “Copenhagen theory” was formed, according to which the state of the cat becomes definite when we open the box and observe its state, which was previously indefinite. However, applying the Copenhagen theory to, say, means that Pluto has existed only since it was discovered by the American astronomer Clyde Tombaugh on February 18, 1930. Only on this day was the wave function (state) of Pluto recorded, and the rest all collapsed. But Pluto's age is known to be well over 3.5 billion years, which points to problems with the Copenhagen interpretation.

Plurality of Worlds

Another solution quantum problem proposed by American physicist Hugh Everett in 1957. He formulated the so-called “many-worlds interpretation of quantum worlds.” According to it, every time an object moves from an uncertain state to a certain one, this object is split into a number of probable states. Taking the example of Schrödinger's cat, when we open the box, a universe appears with a scenario where the cat is dead and a universe appears where he remains alive. Thus, he is in two states, but in parallel worlds, that is, all the wave functions of the cat remain valid and none of them collapses.

It was this hypothesis that many science fiction writers used in their science fiction works. The plurality of parallel worlds suggests the presence of a number of alternative events, due to which history took a different course. For example, in some world the invincible Spanish Armada was not defeated or the Third Reich won the Second World War.

A more modern interpretation of this model explains the impossibility of interaction with other worlds by the lack of coherence of wave functions. Roughly speaking, at some point our wave function stopped oscillating in time with the functions of parallel worlds. Then it is quite possible that we can coexist in an apartment with “roommates” from other universes, without interacting with them in any way, and, like them, be convinced that our Universe is the real one.

In fact, the term “many-worlds” is not entirely appropriate for this theory, since it assumes one world with many variants of events occurring simultaneously.

Most theoretical physicists agree that this hypothesis is incredibly fantastic, but it explains the problems of quantum theory. However, a number of scientists do not consider the many-worlds interpretation to be scientific, since it cannot be confirmed or refuted using the scientific method.

In quantum cosmology

Today, the hypothesis of the plurality of worlds is returning to the scientific scene, as scientists intend to use quantum theory not for any objects, but to apply it to the entire Universe. We are talking about the so-called “ quantum cosmology”, which, as it may seem at first glance, is absurd even in its formulation. Questions in this scientific field are related to the Universe. The miniscule size of the Universe at the first stages of its formation is quite consistent with the scale of quantum theory.

In this case, if the dimensions of the Universe were of the order of , then by applying quantum theory to it, we can also obtain an indefinite state of the Universe. The latter implies the existence of other universes in different states with different probabilities. Then the states of all parallel worlds in total give one single “wave function of the Universe.” Unlike the many-worlds interpretation, quantum universes exist separately.

As you know, there is a problem of fine-tuning the Universe, which draws attention to the fact that the physical fundamental constants that define the basic laws of nature in the world are chosen ideally for the existence of life. If the mass of the proton were slightly smaller, the formation of elements heavier than hydrogen would be impossible. This problem can be solved using the multiverse model, in which many parallel universes with different fundamental values ​​are realized. Then the probability of the existence of some of these worlds is small and they “die” soon after their birth, for example, they shrink or fly apart. Others, whose constants form non-contradictory laws of physics, most likely remain stable. According to this hypothesis, the multiverse includes a large number of parallel worlds, most of which are “dead”, and only a small number of parallel universes allow them to exist for a long time, and even give the right to the presence of intelligent life.

In string theory

One of the most promising areas of theoretical physics is. She is engaged in the description of quantum strings - extended one-dimensional objects, the vibrations of which appear to us in the form of particles. The original purpose of this theory is to unify two fundamental theories: general relativity and quantum theory. As it turned out later, this can be done in several ways, as a result of which several string theories were formed. In the mid-1990s, a number of theoretical physicists discovered that these theories were different instances of a single construct, later called "M-theory".

Its peculiarity lies in the existence of a certain 11-dimensional membrane, the strings of which permeate our Universe. However, we live in a world with four dimensions (three spatial coordinates and one time), where do the other dimensions go? Scientists suggest that they close on themselves on a very small scale, which cannot yet be observed due to insufficient development of technology. Another purely mathematical problem follows from this statement - a large number of “false vacua” arise.

The simplest explanation for this convolution of spaces unobservable by us, as well as the presence of false vacua, is the multiverse. String physicists rely on the idea that there are a huge number of other universes in which not only the physical laws are different, but also the number of dimensions is different. Thus, the membrane of our Universe in a simplified form can be represented as a sphere, a bubble on the surface of which we live, and whose 7 dimensions are in a “collapsed” state. Then our world, together with other membrane universes, is something like a lot of soap bubbles that float in 11-dimensional hyperspace. We, existing in 3-dimensional space, cannot get out of it, and therefore do not have the opportunity to interact with other universes.

As mentioned earlier, most parallel worlds and universes are dead. That is, due to unstable or unsuitable physical laws for life, their substance can be represented, for example, only in the form of a structureless accumulation of electrons and. The reason for this is the variety of possible quantum states of particles, different values ​​of fundamental constants and a different number of dimensions. It is noteworthy that such an assumption does not contradict the Copernican principle, which states that our world is not unique. Since, although in small quantities, there may be worlds whose physical laws, despite their differences from ours, still allow the formation of complex structures and the emergence of intelligent life.

The validity of the theory

Although the multiverse hypothesis sounds like something out of a science fiction book, it has one drawback: it is impossible for scientists to prove or disprove it using the scientific method. But there is complex mathematics behind it and a number of significant and promising physical theories. Arguments in favor of the multiverse are presented in the following list:

• It is the foundation for the existence of a many-worlds interpretation of quantum mechanics. One of the two leading theories (along with Copenhagen interpretation), solving the problem uncertainty in quantum mechanics.
• Explains the reasons for the existence of fine tuning of the Universe. In the case of the multiverse, the parameters of our world are only one of many possible options.
• It is the so-called “string theory landscape”, as it solves the problem of false vacua and allows us to describe the reason why a certain number of dimensions of our Universe fold up.

• supported, which the best way explains its expansion. In the early stages of the formation of the Universe, most likely it could have been divided into two or more universes, each of which evolved independently of the other. The modern standard cosmological model of the Universe, Lambda-CDM, is based on the theory of inflation.

Swedish cosmologist Max Tegmark proposed a classification of various alternative worlds:

1. Universes beyond our visible Universe.
2. Universes with other fundamental constants and numbers of dimensions, which, for example, can be located on other membranes, according to M-theory.
3. Parallel universes, arising according to the many-worlds interpretation of quantum mechanics.
4. The final ensemble is all possible universes.

ABOUT future fate there is nothing to say about the theory of the multiverse yet, but today it occupies an honorable place in cosmology and theoretical physics, and is supported by a number of outstanding physicists of our time: Stephen Hawking, Brian Greene, Max Tegmark, Michio Kaku, Alan Guth, Neil Tyson and others.

Disputes and hypotheses about the existence of unknown twin planets, parallel universes and even galaxies have spanned many decades. All of them are based on the theory of probability without involving the concepts of modern physics. IN last years to them was added the idea of ​​​​the existence of a superuniverse, based on proven theories - quantum mechanics and the theory of relativity.

“Polit.ru” publishes an article by Max Tegmark “Parallel Universes”, which puts forward a hypothesis about the structure of the alleged superuniverse, which theoretically includes four levels. However, in the next decade, scientists may have real opportunity get new property data outer space and, accordingly, confirm or refute this hypothesis. The article was published in the journal “In the World of Science” (2003. No. 8).

Evolution has given us intuitions about everyday physics that were vital to our early ancestors; therefore, as soon as we go beyond the everyday, we can well expect strange things.

The simplest and most popular cosmological model predicts that we have a twin in a galaxy about 10 to the power of 1028 meters away. The distance is so great that it is beyond the reach of astronomical observations, but this does not make our twin any less real. The assumption is based on probability theory without involving the concepts of modern physics. The only assumption accepted is that space is infinite and filled with matter. There may be many inhabited planets, including those where people live with the same appearance, the same names and memories, who have gone through the same vicissitudes of life as us.

But we will never be given the opportunity to see our other lives. The farthest distance we can see is the distance that light can travel in the 14 billion years since the Big Bang. The distance between the farthest visible objects from us is about 431026 m; it determines the observable region of the Universe, called the Hubble volume, or volume cosmic horizon, or simply the Universe. The universes of our twins are spheres of the same size with centers on their planets. This is the simplest example of parallel universes, each of which is only a small part of the superuniverse.

The very definition of “universe” suggests that it will forever remain in the field of metaphysics. However, the boundary between physics and metaphysics is determined by the possibility of experimental testing of theories, and not by the existence of unobservable objects. The boundaries of physics are constantly expanding, including more and more abstract (and previously metaphysical) ideas, for example, about a spherical Earth, invisible electromagnetic fields, time dilation at high speeds, superposition of quantum states, space curvature and black holes. In recent years, the idea of ​​a superuniverse has been added to this list. It is based on proven theories—quantum mechanics and relativity—and meets both basic criteria of empirical science: predictive and falsifiable. Scientists consider four types of parallel universes. Main question not whether a superuniverse exists, but how many levels it can have.

Level I

Beyond our cosmic horizon

The parallel universes of our counterparts constitute the first level of the superuniverse. This is the least controversial type. We all recognize the existence of things that we cannot see, but could be seen by moving to another place or simply by waiting, as we wait for a ship to appear over the horizon. Objects located beyond our cosmic horizon have a similar status. The size of the observable region of the Universe increases by one light year every year, as light emanating from ever more distant regions reaches us, beyond which lies an infinity that has yet to be seen. We'll probably be dead long before our counterparts come within observational range, but if the expansion of the universe helps, our descendants might be able to see them with powerful enough telescopes.

Level I of the superuniverse seems banally obvious. How can space not be infinite? Is there a sign somewhere that says “Beware! The end of space"? If there is an end to space, what is beyond it? However, Einstein's theory of gravity called this intuition into question. A space can be finite if it has positive curvature or an unusual topology. A spherical, toroidal, or "pretzel" universe can have a finite volume without boundaries. Cosmic microwave background radiation makes it possible to test the existence of such structures. However, the facts still speak against them. The data corresponds to the model of an infinite universe, and all other options are subject to strict restrictions.

Another option is this: space is infinite, but matter is concentrated in limited area around us. In one of the options there is no time popular model The “island Universe” assumes that on large scales matter is rarefied and has a fractal structure. In both cases, almost all universes in a Level I superuniverse should be empty and lifeless. Recent studies of the three-dimensional distribution of galaxies and background radiation have shown that the distribution of matter tends to be uniform on large scales and does not form structures larger than 1024 m. If this trend continues, then the space beyond the observable Universe should be replete with galaxies, stars and planets.

For observers in parallel universes of the first level, the same laws of physics apply as for us, but under different starting conditions. According to modern theories, the processes that took place on initial stages The Big Bang scattered matter randomly, so there was a possibility of any structures emerging.

Cosmologists accept that our Universe, with an almost uniform distribution of matter and initial density fluctuations of the order of 1/105, is very typical (at least among those in which there are observers). Estimates based on this assumption indicate that the nearest exact replica of you is at a distance of 10 to the power of 1028 m. At a distance of 10 to the power of 1092 m there should be a sphere with a radius of 100 light years, identical to the one at the center of which we are located; so that everything that we see in the next century will also be seen by our counterparts there. At a distance of about 10 to the power of 10118 m from us, there should be a Hubble volume identical to ours. These estimates are derived by calculating the possible number of quantum states that the Hubble volume can have if its temperature does not exceed 108 K. The number of states can be estimated by asking the question: how many protons can the Hubble volume accommodate at this temperature? The answer is 10118. However, each proton can either be present or absent, giving 2 to the power of 10118 possible configurations. A “box” containing so many Hubble volumes covers all possibilities. Its size is 10 to the power of 10118 m. Beyond it, universes, including ours, must repeat themselves. Approximately the same figures can be obtained based on thermodynamic or quantum-gravitational estimates of the total information content of the Universe.

However, our closest twin is most likely closer to us than these estimates suggest, since the process of planet formation and the evolution of life favors this. Astronomers believe our Hubble volume contains at least 1,020 habitable planets, some of which may be similar to Earth.

In modern cosmology, the concept of a Level I superuniverse is widely used to test theories. Let's look at how cosmologists use cosmic microwave background radiation to reject the model of finite spherical geometry. Hot and cold “spots” on CMB maps have a characteristic size that depends on the curvature of space. So, the size of the observed spots is too small to be consistent with spherical geometry. Their the average size varies randomly from one Hubble volume to another, so it is possible that our Universe is spherical, but has anomalously small spots. When cosmologists say they rule out the spherical model at the 99.9% confidence level, they mean that if the model is correct, then less than one Hubble volume in a thousand would have spots as small as those observed. It follows that the superuniverse theory is testable and can be rejected, although we are not able to see other universes. The key is to predict what the ensemble of parallel universes is and find the probability distribution, or what mathematicians call the measure of the ensemble. Our Universe must be one of the most likely. If not, if within the framework of the superuniverse theory our Universe turns out to be improbable, then this theory will encounter difficulties. As we will see later, the problem of measure can become quite acute.

Level II

Other post-inflationary domains

If it was difficult for you to imagine a Level I superuniverse, then try to imagine an infinite number of such superuniverses, some of which have a different dimension of space-time and are characterized by different physical constants. Together they constitute the Level II superuniverse predicted by the theory of chaotic eternal inflation.

Inflation theory is a generalization of the Big Bang theory that eliminates shortcomings of the latter, such as its inability to explain why the Universe is so large, homogeneous and flat. The rapid expansion of space in ancient times makes it possible to explain these and many other properties of the Universe. Such stretching is predicted by a wide class of theories elementary particles, and all available evidence supports it. The expression "chaotic perpetual" in relation to inflation indicates what is happening on the largest scale. In general, space is constantly stretching, but in some areas the expansion stops and separate domains arise, like raisins in rising dough. An infinite number of such domains appear, and each of them serves as the embryo of a Level I superuniverse, filled with matter born from the energy of the field causing inflation.

The neighboring domains are more than infinity away from us, in the sense that they cannot be reached even if we move forever at the speed of light, since the space between our domain and the neighboring ones is stretching faster than we can move in it. Our descendants will never see their Level II counterparts. And if the expansion of the Universe is accelerating, as observations indicate, then they will never see their counterparts even at level I.

The level II superuniverse is much more diverse than the level I superuniverse. The domains differ not only in their initial conditions, but also in their fundamental properties. The prevailing view among physicists is that the dimensions of spacetime, the properties of elementary particles, and many so-called physical constants are not built into physical laws, but are the result of processes known as symmetry breaking. It is believed that space in our Universe once had nine equal dimensions. At the beginning of cosmic history, three of them took part in the expansion and became the three dimensions that characterize the Universe today. The remaining six are now undetectable, either because they remain microscopic, maintaining a toroidal topology, or because all matter is concentrated in a three-dimensional surface (membrane, or simply brane) in nine-dimensional space. Thus, the original symmetry of the measurements was broken. Quantum fluctuations causing chaotic inflation could cause different symmetry violations in different caverns. Some could become four-dimensional; others contain only two rather than three generations of quarks; and still others - to have a stronger cosmological constant than our Universe.

Another way of the emergence of a level II superuniverse can be represented as a cycle of births and destructions of universes. In the 1930s physicist Richard C. Tolman proposed this idea, and recently Paul J. Steinhardt of Princeton University and Neil Turok of Cambridge University expanded on it. Steinhardt and Turok's model envisions a second three-dimensional brane, completely parallel to ours and only displaced relative to it in a higher-order dimension. This parallel universe cannot be considered separate, since it interacts with ours. However, the ensemble of universes - past, present and future - that these branes form represents a superuniverse with diversity apparently approaching that resulting from chaotic inflation. Another hypothesis of a superuniverse was proposed by physicist Lee Smolin from the Perimeter Institute in Waterloo (Ontario, Canada). Its superuniverse is close to Level II in diversity, but it mutates and generates new universes through black holes rather than branes.

Although we cannot interact with Level II parallel universes, cosmologists judge their existence by indirect evidence, since they may cause strange coincidences in our Universe. For example, a hotel gives you room number 1967, and you note that you were born in 1967. “What a coincidence,” you say. However, upon reflection, you come to the conclusion that this is not so surprising. There are hundreds of rooms in a hotel, and you wouldn't think twice about it if you were offered a room that meant nothing to you. If you knew nothing about hotels, to explain this coincidence you might assume that there were other rooms in the hotel.

As a closer example, consider the mass of the Sun. As is known, the luminosity of a star is determined by its mass. Using the laws of physics, we can calculate that life on Earth can exist only if the mass of the Sun lies in the range: from 1.6x1030 to 2.4x1030 kg. Otherwise, the Earth's climate would be colder than Mars or hotter than Venus. Measurements of the mass of the Sun gave a value of 2.0x1030 kg. At first glance, the solar mass falling within the range of values ​​that supports life on Earth is accidental.

The masses of stars occupy the range from 1029 to 1032 kg; If the Sun acquired its mass by chance, then the chance of falling exactly into the optimal interval for our biosphere would be extremely small.

The apparent coincidence can be explained by assuming the existence of an ensemble (in this case, many planetary systems) and a selection factor (our planet must be suitable for life). Such observer-related selection criteria are called anthropic; and although the mention of them usually causes controversy, most physicists agree that these criteria cannot be neglected when selecting fundamental theories.

What do all these examples have to do with parallel universes? It turns out that a small change in the physical constants determined by symmetry breaking leads to a qualitatively different universe - one in which we could not exist. If the mass of a proton were just 0.2% greater, protons would decay to form neutrons, making atoms unstable. If the electromagnetic interaction forces were 4% weaker, hydrogen and ordinary stars would not exist. Be weak interaction weaker still, there would be no hydrogen; and if it were stronger, supernovae could not fill interstellar space with heavy elements. If the cosmological constant were noticeably larger, the Universe would become incredibly inflated before galaxies could even form.

The given examples allow us to expect the existence of parallel universes with different values ​​of physical constants. The second-level superuniverse theory predicts that physicists will never be able to derive the values ​​of these constants from fundamental principles, but will only be able to calculate the probability distribution of various sets of constants in the totality of all universes. Moreover, the result must be consistent with our existence in one of them.

Level III

Quantum many universes

Superuniverses of levels I and II contain parallel universes, extremely distant from us beyond the limits of astronomy. However, the next level of the superuniverse lies right around us. It arises from the famous and highly controversial interpretation of quantum mechanics - the idea that random quantum processes cause the universe to “multiply”, forming many copies of itself - one for each possible outcome of the process.

At the beginning of the twentieth century. quantum mechanics explained the nature atomic world, which did not obey the laws of classical Newtonian mechanics. Despite the obvious successes, there were heated debates among physicists about what the true meaning was. new theory. It defines the state of the Universe not in terms of classical mechanics, such as the positions and velocities of all particles, but through a mathematical object called the wave function. According to Schrödinger's equation, this state changes over time in a way that mathematicians call "unitary." It means that the wave function rotates in an abstract infinite-dimensional space called Hilbert space. Although quantum mechanics is often defined as fundamentally random and uncertain, the wave function evolves in a quite deterministic manner. There is nothing random or uncertain about it.

The hardest part is relating the wave function to what we observe. Many valid wave functions correspond to unnatural situations such as when a cat is both dead and alive at the same time, in what is called a superposition. In the 20s XX century physicists got around this oddity by postulating that the wave function collapses to some specific classical outcome when one makes an observation. This addition made it possible to explain the observations, but it turned an elegant unitary theory into a sloppy and non-unitary one. The fundamental randomness usually attributed to quantum mechanics is a consequence of precisely this postulate.

Over time, physicists abandoned this view in favor of another, proposed in 1957 by Princeton University graduate Hugh Everett III. He showed that it is possible to do without the postulate of collapse. Pure quantum theory does not impose any restrictions. Although it predicts that one classical reality will gradually split into a superposition of several such realities, the observer subjectively perceives this splitting as simply a small randomness with a probability distribution exactly matching that given by the old collapse postulate. This superposition of classical universes is the Level III superuniverse.

For more than forty years, this interpretation confused scientists. However, physical theory is easier to understand by comparing two points of view: external, from the position of a physicist studying mathematical equations (like a bird surveying the landscape from its height); and internal, from the position of an observer (let's call him a frog) living on the landscape observed by the bird.

From the bird's point of view, the Level III superuniverse is simple. There is only one wave function that smoothly evolves in time without splitting or parallelism. The abstract quantum world described by the evolving wave function contains a huge number of continuously splitting and merging lines of parallel classical histories, as well as a number of quantum phenomena that cannot be described within the framework of classical concepts. But from the frog's point of view, only a small part of this reality can be seen. She can see the Level I universe, but the process of breaking coherence, similar to collapse wave function, but maintaining unitarity, does not allow her to see parallel copies of herself at level III.

When an observer is asked a question to which he must quickly answer, the quantum effect in his brain leads to a superposition of decisions like this: “keep reading the article” and “stop reading the article.” From the bird's point of view, the act of making a decision causes the person to multiply into copies, some of which continue to read, while others stop reading. However, from an internal point of view, neither of the doubles is aware of the existence of the others and perceives the splitting simply as a slight uncertainty, some possibility of continuing or stopping reading.

No matter how strange it may seem, exactly the same situation arises even in the Level I superuniverse. Obviously, you decided to continue reading, but one of your counterparts in a distant galaxy put the magazine down after the first paragraph. Levels I and III differ only in where your counterparts are located. At level I they live somewhere far away, in good old three-dimensional space, and at level III they live on another quantum branch of infinite-dimensional Hilbert space.

The existence of level III is possible only under the condition that the evolution of the wave function in time is unitary. So far, experiments have not revealed its deviations from unitarity. In recent decades it has been confirmed for everyone more than large systems, including fullerene C60 and kilometer-long optical fibers. Theoretically, the assumption of unitarity was supported by the discovery of violation of coherence. Some theorists working in the field quantum gravity, question it. In particular, it is assumed that evaporating black holes can destroy information, which is not a unitary process. However, recent advances in string theory suggest that even quantum gravity is unitary.

If this is so, then black holes do not destroy information, but simply transfer it somewhere. If physics is unitary, the standard picture of the influence of quantum fluctuations in the early stages of the Big Bang must be modified. These fluctuations do not randomly determine the superposition of all possible initial conditions that coexist simultaneously. In this case, the violation of coherence causes the initial conditions to behave in a classical manner on various quantum branches. The key point is that the distribution of outcomes on different quantum branches of one Hubble volume (level III) is identical to the distribution of outcomes in different Hubble volumes of one quantum branch (level I). This property of quantum fluctuations is known in statistical mechanics as ergodicity.

The same reasoning applies to Level II. The process of breaking symmetry does not lead to a unique outcome, but to a superposition of all outcomes, which quickly diverge along their separate paths. Thus, if physical constants, the dimension of space-time, etc. may differ in parallel quantum branches at level III, then they will also differ in parallel universes at level II.

In other words, a level III superuniverse adds nothing new to what is present in levels I and II, only more copies of the same universes - the same historical lines developing again and again on different quantum branches. The heated debate surrounding Everett's theory appears to be soon subsided by the discovery of the equally grandiose but less controversial superuniverses of Levels I and II.

The applications of these ideas are profound. For example, this question: does the number of universes increase exponentially over time? The answer is unexpected: no. From the bird's point of view, there is only one quantum universe. What is the number of separate universes in this moment for a frog? This is the number of noticeably different Hubble volumes. The differences may be small: imagine planets moving in different directions, imagine yourself married to someone else, etc. At the quantum level, there are 10 to the power of 10118 universes with a temperature no higher than 108 K. The number is gigantic, but finite.

For a frog, the evolution of the wave function corresponds to an infinite movement from one of these 10 to the power of 10118 states to another. You are now in Universe A, where you are reading this sentence. And now you are already in universe B, where you read the next sentence. In other words, in B there is an observer identical to the observer in universe A, with the only difference being that he has extra memories. At every moment, all possible states exist, so that the passage of time can occur before the eyes of the observer. This idea was expressed in his science fiction novel “Permutation City” (1994) by writer Greg Egan and developed by physicist David Deutsch from Oxford University, independent physicist Julian Barbour, and others. we see that the idea of ​​a superuniverse can play key role in understanding the nature of time.

Level IV

Other mathematical structures s

The initial conditions and physical constants in the superuniverses of levels I, II and III may differ, but the fundamental laws of physics are the same. Why did we stop here? Why can't the physical laws themselves differ? How about a universe that obeys classical laws without any relativistic effects? What about time moving in discrete steps, like in a computer?

What about the universe as an empty dodecahedron? In a Level IV superuniverse, all of these alternatives do exist.

The fact that such a superuniverse is not absurd is evidenced by the correspondence of the world of abstract reasoning to ours. real world. Equations and other mathematical concepts and structures - numbers, vectors, geometric objects - describe reality with amazing verisimilitude. Conversely, we perceive mathematical structures as real. Yes, they meet the fundamental criterion of reality: they are the same for everyone who studies them. The theorem will be true no matter who proved it - a person, a computer or an intelligent dolphin. Other inquisitive civilizations will find the same mathematical structures that we know. Therefore mathematicians say that they do not create, but rather discover mathematical objects.

There are two logical, but diametrically opposed paradigms of the relationship between mathematics and physics, which arose in ancient times. According to Aristotle's paradigm, physical reality is primary, and mathematical language is only a convenient approximation. Within the framework of Plato's paradigm, it is mathematical structures that are truly real, and observers perceive them imperfectly. In other words, these paradigms differ in their understanding of what is primary - the frog point of view of the observer (Aristotle's paradigm) or the bird's view from the heights of the laws of physics (Plato's point of view).

Aristotle's paradigm is how we perceived the world from early childhood, long before we first heard about mathematics. Plato's point of view is that of acquired knowledge. Modern theoretical physicists are inclined towards it, suggesting that mathematics describes the Universe well precisely because the Universe is mathematical in nature. Then all physics comes down to solving a mathematical problem, and an infinitely smart mathematician can only, on the basis of fundamental laws, calculate the picture of the world at the level of a frog, i.e. calculate what observers exist in the Universe, what they perceive and what languages ​​they have invented to convey their perceptions.

Mathematical structure is an abstraction, an unchanging entity beyond time and space. If the story were a movie, then the mathematical structure would correspond not to one frame, but to the film as a whole. Let's take for example a world consisting of zero-size particles distributed in three-dimensional space. From the bird's point of view, in four-dimensional spacetime, particle trajectories are "spaghetti." If a frog sees particles moving at constant speeds, then a bird sees a bunch of straight, uncooked spaghetti. If a frog sees two particles revolving in orbits, then a bird sees two “spaghettins” twisted into double helix. For a frog, the world is described by Newton’s laws of motion and gravity; for a bird, the world is described by “spaghetti” geometry, i.e. mathematical structure. For her, the frog itself is a thick ball of them, the complex interweaving of which corresponds to a group of particles that store and process information. Our world is more complex than the example considered, and scientists do not know which mathematical structure it corresponds to.

Plato's paradigm contains the question: why is our world the way it is? For Aristotle, this is a meaningless question: the world exists, and that is how it is! But Plato's followers are interested: could our world be different? If the Universe is essentially mathematical, then why is it based on only one of many mathematical structures? It seems that a fundamental asymmetry lies in the very essence of nature. To solve the puzzle, I hypothesized that mathematical symmetry exists: that all mathematical structures are physically realized, and each of them corresponds to a parallel universe. The elements of this superuniverse are not in the same space, but exist outside of time and space. Most of them probably don't have observers. The hypothesis can be seen as extreme platonism, asserting that the mathematical structures of Plato's world of ideas, or the "mental landscape" of mathematician Rudy Rucker of San Jose State University, exist in a physical sense. This is akin to what cosmologist John D. Barrow of Cambridge University called the “p in the heavens,” philosopher Robert Nozick of Harvard University described as the “fertility principle,” and philosopher David K. Lewis ) from Princeton University called “modal reality.” Level IV closes the hierarchy of superuniverses, since any self-consistent physical theory can be expressed in the form of a certain mathematical structure.

The Level IV superuniverse hypothesis makes several testable predictions. As at level II, it includes the ensemble (in this case, the totality of all mathematical structures) and selection effects. In classifying mathematical structures, scientists must note that the structure that describes our world is the most general of those consistent with observations. Therefore, the results of our future observations should be the most general of those that are consistent with the data of previous research, and the data of previous research should be the most general of those that are generally compatible with our existence.

Assessing the degree of generality is not an easy task. One of the striking and reassuring features of mathematical structures is that the properties of symmetry and invariance that keep our universe simple and orderly are generally shared. Mathematical structures usually have these properties by default, and getting rid of them requires introducing complex axioms.

What did Occam say?

Thus, theories of parallel universes have a four-level hierarchy, where at each subsequent level the universes are less and less like ours. They may be characterized by different initial conditions (level I), physical constants and particles (level II) or physical laws (level IV). It's funny that level III has been the most criticized in recent decades as the only one that does not introduce qualitatively new types of universes. In the coming decade, detailed measurements of the cosmic microwave background radiation and the large-scale distribution of matter in the Universe will allow us to more accurately determine the curvature and topology of space and confirm or disprove the existence of Level I. The same data will allow us to obtain information about Level II by testing the theory of chaotic eternal inflation. Advances in astrophysics and high-energy particle physics will help refine the degree of fine-tuning of physical constants, strengthening or weakening Level II positions. If the efforts to create quantum computer will be successful, there will be an additional argument in favor of the existence of level III, since parallel computing will use the parallelism of this level. Experimenters are also looking for evidence of violation of unitarity, which will allow them to reject the hypothesis of the existence of level III. Finally, the success or failure of the attempt to solve the most important problem of modern physics - to combine the general theory of relativity with quantum theory fields - will answer the question about level IV. Either a mathematical structure will be found that accurately describes our Universe, or we will hit the limit of the incredible efficiency of mathematics and be forced to abandon the Level IV hypothesis.

So, is it possible to believe in parallel universes? The main arguments against their existence are that they are too wasteful and incomprehensible. The first argument is that superuniverse theories are vulnerable to Occam's razor because they postulate the existence of other universes that we will never see. Why should nature be so wasteful and “have fun” by creating an infinite number of different worlds? However, this argument can be turned in favor of the existence of a superuniverse. In what ways is nature wasteful? Of course, not in space, mass or number of atoms: an infinite number of them are already contained in level I, the existence of which is beyond doubt, so there is no point in worrying that nature will spend any more of them. The real issue is the apparent decrease in simplicity. Skeptics are concerned about the additional information needed to describe invisible worlds.

However, the entire ensemble is often simpler than each of its members. The information volume of a number algorithm is, roughly speaking, the length of the shortest computer program that generates this number, expressed in bits. Let's take for example the set of all integers. What is simpler - the whole set or a single number? At first glance - the second. However, the former can be constructed using a very simple program, and a single number can be extremely long. Therefore, the entire set turns out to be simpler.

Similarly, the set of all solutions to the Einstein equations for a field is simpler than each specific solution - the first consists of only a few equations, and the second requires specifying a huge amount of initial data on a certain hypersurface. So, complexity increases when we focus on a single element of the ensemble, losing the symmetry and simplicity inherent in the totality of all elements.

In this sense, the superuniverses of higher levels are simpler. The transition from our Universe to a Level I superuniverse eliminates the need to specify initial conditions. Further movement to level II eliminates the need to specify physical constants, and at level IV there is no need to specify anything at all. Excessive complexity is just a subjective perception, a frog's point of view. And from the perspective of a bird, this superuniverse could hardly be any simpler. Complaints about incomprehensibility are aesthetic, not scientific, and are justified only in an Aristotelian worldview. When we ask a question about the nature of reality, shouldn't we expect an answer that may seem strange?

A common feature of all four levels of the superuniverse is that the simplest and apparently most elegant theory involves parallel universes by default. To reject their existence, it is necessary to complicate the theory by adding processes that are not confirmed by experiment and postulates invented for this purpose - about the finiteness of space, the collapse of the wave function and ontological asymmetry. Our choice comes down to what is considered more wasteful and inelegant - many words or many universes. Perhaps over time we will become accustomed to the quirks of our cosmos and find its strangeness charming.

The science

The universe we live in is not unique. In fact, she is just one unit of an infinite number of universes, the totality of which is called Multiverse.

The claim that we exist in the Multiverse may seem like a fantasy, but there are reasons behind it. real scientific explanations. A huge number of physical theories independently indicate that the Multiverse really exists.

We invite you to familiarize yourself with the most famous scientific theories that confirm the fact that our Universe is just a particle of the Multiverse.

1) Infinity of universes

Scientists are not yet sure exactly what shape space-time has, but most likely this physical model has flat shape (as opposed to spherical or donut shape) and extends indefinitely. If spacetime is infinite, it must repeat itself at some point. This is due to the fact that particles can be arranged in space and time in certain ways, and the number of these ways is limited.

So if you look far enough, you may stumble upon another version of yourself, or rather, for an infinite number of options. Some of these twins will do what you do, while others will wear different clothes, have different jobs, and make different choices in life.

The size of our universe is difficult to imagine. Particles of light travel the distance from its center to the edge in 13.7 billion years. This is exactly how many years ago the Big Bang took place. Spacetime beyond this distance can be considered a separate universe. Thus, multiple universes exist next to each other, representing an infinitely gigantic patchwork quilt.

2) Bubble Giant Universe

IN scientific world There are other theories of the development of universes, including a theory called Chaotic theory of inflation . According to this theory, the universe began to expand rapidly after the Big Bang. This process was reminiscent bloat balloon which is filled with gas.

The chaotic theory of inflation was first proposed by cosmologist Alexander Videnkin. This theory suggests that some parts of space stop while others continue to expand, thus allowing isolated "bubble universes" to form.

Our own universe is just a small bubble in the vast expanse of space, in which there are an infinite number of similar bubbles. In some of these bubble universes laws of physics and fundamental constants may differ from ours. These laws might seem more than strange to us.

3) Parallel universes

Another theory that stems from string theory is that there is the concept of parallel universes. The idea of ​​parallel worlds stems from the possibility that there are many more dimensions than we can imagine. According to our ideas, today there are 3 spatial dimensions and 1 temporal.

Physicist Brian Greene from Columbia University describes it this way: “Our universe is one “block” of a huge number of “blocks” floating in multi-dimensional space.”

Also, according to this theory, universes are not always parallel and are not always beyond our reach. Sometimes they can wedge into each other, causing repeated Big Bangs that return the universes to initial position again and again.

4) Daughter universes - another theory of the formation of universes

The theory of quantum mechanics, which is built on the concepts of the tiny world of subatomic particles, suggests another way for multiple universes to form. Quart mechanics describes the world in terms of probabilities, while avoiding making definitive conclusions.

Mathematical models, according to this theory, can assume all possible outcomes of a situation. For example, at an intersection where you can turn right or left, the present universe forms two daughter universes, in one of which you can go right, and in the other - left.

5) Mathematical universes - the hypothesis of the origin of the universe

Scientists for a long time debated whether mathematics useful tool to describe the universe or is it itself a fundamental reality and our observations are only imperfect representations of the true mathematical nature.

If the latter is true, perhaps the particular mathematical structure that shapes our universe is not the only option. Other possible mathematical structures may exist independently in separate universes.

"A mathematical structure is something that you can describe completely independent of our knowledge and concepts,- speaks Max Tegmark, a professor at the Massachusetts Institute of Technology, the author of this hypothesis. – Personally, I believe that somewhere there is a universe that can exist completely independently of me and will continue to exist even if there are no people in it."

The idea of ​​the Multiverse (that is, multiple universes existing in parallel) has occupied the minds of scientists since the mid-20th century. This theory has both opponents and ardent defenders (for example, Sheldon Cooper from the sitcom “The Big Bang Theory”). But what makes serious people even consider this possibility? Is it really possible that somewhere in a parallel universe another you is sitting and reading the same text, perhaps with minor changes? Surprisingly, there is some evidence that strongly supports this concept. Or not, it depends on how you look.

So, what does the idea of ​​parallel universes prove?

Shroedinger `s cat

Famous thought experiment Schrödinger demonstrates that in quantum mechanics there are situations when elementary particles - quanta - can exist in two positions at once. Because of this, the unfortunate cat inside the box can be both alive and dead until you open the lid - depending on how you view the particle. How this is possible in the physical world is difficult to understand. That's why the experiment is called a paradox.

The multiverse eliminates this problem by explaining exactly how this is possible. There are simply two realities: in one, everything is fine with the cat. And in the second... But let's not talk about sad things.

Infinite Universe

The infinity of the Universe is difficult to comprehend, but in general scientists seem to have come to terms with it. This property of the universe also proves the probability of the existence of parallel universes. Remember the hypothesis that if an infinite number of monkeys pound on keys for an infinite amount of time, sooner or later they will type “War and Peace”? It’s the same with matter: if you create new objects an infinite number of times, sooner or later they will begin to repeat themselves and create worlds almost the same as ours. These will be those same parallel universes.

Big Bang

Besides how the Universe can be infinite, people wonder how it came to be in the first place. What caused the Big Bang?

The multiverse may try to explain this. If we assume that parallel realities exist - yes, yes, parallel! - then they may not touch at all, being next to each other in dimensions that are inaccessible to our senses (we know only three dimensions, plus the fourth - time). The accidental contact of universes can lead to catastrophic results, causing the Big Bang. Thus, parallel universes are constantly updated, constantly restarting each other.

Time travel

Yes, time travel is impossible. But if we consider only our Universe! In this case, the time traveler paradox, described many times in science fiction literature and cinema, is inevitable. If you accidentally crush a butterfly, push a person, or do something equally insignificant in the past, it will lead to huge changes in the future.

Parallel universes solve this problem. Once in the past, you find yourself in a parallel reality in which events take place that for your reality have long passed. And changes in her change her, but not your world. Although there is still no need to crush butterflies.

Parallel universes fit into the logic of knowledge

Studying the world around us for a person throughout his history is a struggle with the human ego. At first people thought that the Earth was the center of the Universe. Then they agreed to the Sun, incidentally sending several scientists to the stake. Further - more: the Sun is already just a tiny star on the periphery of one of billions of galaxies. Following this logic, it is likely that we ourselves are not unique and are only one of an infinite number of variants of us existing in a parallel universe. We can only hope that at least somewhere we are conducting parallel healthy image life and don’t do stupid things.

Based on HowStuffWorks.com

The belief in the existence of invisible neighbors borders on fantasy. Or with a sick imagination. That's what the skeptics say. And supporters stand their ground and give as many as 10 arguments in favor of an alternative reality.

1. Many-Worlds Interpretation

The question of the uniqueness of all things worried great minds long before the authors of science fiction novels. The ancient Greek philosophers Democritus, Epicurus and Metrodorus of Chios thought about it. Alternate universes are also spoken of in Hindu sacred texts.

For official science, this idea was born only in 1957. American physicist Hugh Everett created the Many Worlds Theory to fill the gaps in quantum mechanics. In particular, find out why light quanta behave either like particles or like waves.

According to Everett, each event leads to a split and copying of the Universe. In this case, the number of “clones” is always equal to the number of possible outcomes. And the sum of the central and new universes can be depicted in the form of a branched tree.

2. Artifacts of unknown civilizations

Some finds baffle even the most experienced archaeologists.

For example, a hammer discovered in London, dated to 500 million BC, that is, a period when there was not even a hint of Homosapiens on Earth!

Or a computing mechanism that allows you to determine the trajectory of stars and planets. A bronze analogue of the computer was caught in 1901 near the Greek island of Antikythera. Research on the device began in 1959 and continues to this day. In the 2000s, it was possible to calculate the approximate age of the artifact - 1st century BC.

So far nothing indicates a fake. There are three versions left: the computer was invented by representatives of an unknown ancient civilization, lost by time travelers, or... planted by people from other worlds.

3. Teleportation Victim

The mysterious story of Spaniard Lerin Garcia began on an ordinary July morning when she woke up in an alien reality. But I didn’t immediately understand what had happened. It was still 2008, Lerin was 41 years old, she was in the same city and house where she went to bed.

Only the pajamas and bedding changed color overnight, and the closet ran into another room. The office where Lerin worked for 20 years was not there. Soon "home" materialized ex-fiance, dismissed six months ago. Even a private detective could not figure out where the current friend of his heart had gone...

Alcohol and drug tests were negative. As well as consultation with a psychiatrist. The doctor attributed the incident to stress. The diagnosis did not satisfy Lerin and prompted her to search for information about parallel worlds. She was never able to return to her native dimension.

4. Deja vu in reverse

The essence of déjà vu does not boil down to the familiar vague feeling of “repetition” and everyday foresight. This phenomenon has an antipode - jamevu. People who have experienced it suddenly stop recognizing familiar places, old friends and scenes from films they have watched. Regular jamevu indicates mental disorders. And isolated and rare memory failures also occur in healthy people.
A striking illustration is the experiment of English neuropsychologist Chris Moulin. 92 volunteers had to write the word “doors” 30 times in a minute. As a result, 68% of subjects seriously doubted the existence of the word. A glitch in thinking or instantaneous leaps from reality to reality?

5. The Roots of Dreams

Despite the abundance of research methods, the reason for the appearance of dreams still remains a mystery. According to the generally accepted view of sleep, the brain merely processes information accumulated in reality. And it translates it into pictures - the most convenient format for the sleeping mind. Solution number two - nervous system sends chaotic signals to the sleeping person. They are transformed into colorful visions.

According to Freud, in dreams we gain access to the subconscious. Freed from the censorship of consciousness, it hastens to tell us about repressed sexual desires. The fourth point of view was first expressed by Carl Jung. What you see in a dream is not a fantasy, but a specific continuation of a full life. Jung also saw a code in the dream images. But not from suppressed libido, but from the collective unconscious.
In the middle of the last century, psychologists started talking about the possibility of controlling sleep. Appropriate manuals have appeared. The most famous was the three-volume instruction manual by American psychophysiologist Stephen LaBerge.

6. Lost between two Europes

In 1952, a strange passenger appeared at Tokyo airport. Judging by the visas and customs stamps in his passport, he has flown to Japan many times over the past 5 years. But in the “Country” column there was a certain Taured. The owner of the document assured that his homeland was a European state with a thousand-year history. The “alien” presented a driver’s license and bank statements obtained in the same mysterious country.

Citizen Taured, no less surprised than the customs officers, was left overnight at a nearby hotel. The immigration officers who arrived the next morning did not find him. According to the receptionist, the guest did not even leave the room.

Tokyo police have found no trace of the missing Taured. Either he escaped through a window on the 15th floor, or he managed to transport himself back.

7. Paranormal activity

“Alive” furniture, noises of unknown origin, ghostly silhouettes hovering in the air in photographs... Meetings with the dead occur not only in the movies. For example, many mystical incidents in the London underground.

At Aldwych station, which closed in 1994, intrepid Brits hold parties, make films and periodically see a female figure walking along the tracks. The subway section near the British Museum is occupied by the mummy of an ancient Egyptian princess. Since the 1950s, a dandy has been frequenting Covent Garden, dressed in the fashion of the late 19th century and literally melting before our eyes when anyone pays attention to him...

Materialists brush aside dubious facts, believing

contacts with spirits, hallucinations, mirages and outright lies of storytellers. Then why has humanity clung to ghost stories for centuries? Perhaps the mythical kingdom of the dead is one of the alternative realities?

8. Fourth and fifth dimensions

Visible to the eye length, height and width have already been studied up and down. The same cannot be said about the other two dimensions, which are absent in Euclidean (traditional) geometry.

The scientific community has not yet delved into the intricacies of the space-time continuum discovered by Lobachevsky and Einstein. But there has already been talk about a higher – fifth – dimension, accessible only to those with psychic talents. It is also open to those who expand consciousness through spiritual practices.

If we put aside the guesses of science fiction writers, almost nothing is known about the non-obvious coordinates of the Universe. Presumably, it is from there that supernatural beings come into our three-dimensional space.

9. Rethinking the double-slit experiment

Howard Weissman is convinced that the duality of the nature of light is the result of the contact of parallel worlds. The Australian researcher's hypothesis connects Everett's many-worlds interpretation with the experience of Thomas Young.

The father of the wave theory of light published a report on the famous double-slit experiment in 1803. Jung installed a projection screen in the laboratory, and in front of it was a dense screen-screen with two parallel slits. Then light was directed onto the cracks made.

Some of the radiation behaved like electromagnetic wave– stripes of light were reflected on the rear screen, passing straight through the slits. Another half of the light flux appeared as a cluster of elementary particles and scattered across the screen.
“Each of the worlds is limited by the laws of classical physics. This means that without their intersection, quantum phenomena would simply be impossible,” explains Weissman.

10. Large Hadron Collider

The multiverse is not just a theoretical model. French astrophysicist Aurélien Barrot came to this conclusion while observing the operation of the Large Hadron Collider. More precisely, the interaction of protons and ions placed in it. The collision of heavy particles produced results incompatible with conventional physics.

Barro, like Weissman, interpreted this contradiction as a consequence of the collision of parallel worlds.