What shape does the universe have? exotic universes.

Many vaguely heard that the universe has the shape of a donut. Most do not attach any importance to this, because it is too strange: why a bagel? Where exactly is the hole? And other inevitable questions in the same vein. Otherwise, there is a saying that the world is in the shape of a suitcase ... Well, about a suitcase - just an idiotic saying, but about a bagel, to some extent, it's true.

Others have read that the universe is a crystal. This image is popular in non-science fiction, it allows you to speculate about the "edge transitions" when traveling to parallel worlds. An attempt to combine both of these images - a crystal and a donut - sometimes leads to the appearance in the fan's head of chimerical pictures such as "a faceted pencil closed in a ring" and other similar horrors that have nothing to do with reality. Meanwhile, the image of the Great Crystal is also to some extent true.

Pictures and captions to them are not related to the main topic of the post and rather distract from the essence, although they are not intended to do so. So I recommend, in order not to get confused, first read one and then the other. Pictured here, the galaxy NGC 2683 is very similar to our own galaxy. Milky Way. It is located at an average distance of 20 million light-years from us in the direction of the northern constellation Cats (Lynx). Even more distant galaxies are scattered in the background, and bright stars- much closer to us, these are the stars of our arm of the Milky Way. The core of NGC 2683 is made up of a huge number of old yellow stars. Dark clouds are cosmic dust in spiral arms through which the blue dots of clusters of young stars peep through.

Let's start with the bagel. There is no bagel. The legs of this image grow from the fact that our Universe has a very large, but still finite volume, but it has no boundaries. Representing this is quite simple in a two-dimensional example: in some simple computer games an object that goes beyond the right border of the playing field appears on the left, and an object that goes down appears on top. Even more good example- three-dimensional - you can see if at any of the levels of the game "Quake" (in any case, the first or second game of the series; maybe other similar 3D shooters, I just haven't tried) use cheats at the same time that allow you to pass through walls and fly , and move straight in any direction: the camera will quickly leave the location, your virtual hero will fly in a black void for some time, and then a cluster of corridors and rooms that seems to be left behind will appear in front of him, and the hero will return to the same point, where did you start, but opposite side as if walking around the globe– although he was flying in a straight line. You can move in any direction for an infinitely long time - there are no boundaries, but you cannot go beyond the level, and you will not fly into any "other space" - the volume is finite and closed. This is the same as the real Universe, only more spacious.

Globular star clusters - satellites of galaxies - travel through the halo of the Milky Way. These ancient spherical formations of several hundred thousand stars are connected by mutual attraction. All of them are much older than the stars of the disk of the galaxy. In fact, measurements of the age of globular clusters put limits on the age of the universe itself (it must be older than the stars in it!). Precise measurements of distances to globular clusters have helped create one of the astronomical distance scales in the universe. The globular star cluster NGC 6934 lies about 50,000 light-years away towards the constellation Dolphin. The stars of the cluster are crowded into a region with a diameter of 150 light years, and near the core of the cluster in a cube with a side of 3 light years, up to a hundred stars can fit. For comparison, the nearest star to the Sun is 4 light years away from us.

But this is good for me now - there are computer games, so you can quickly explain "finiteness and infinity in one bottle" in a simple way. finished example, and earlier one would have to use the good old way - to interpret the features of the structure of three-dimensional space using the example of a two-dimensional one, for example, a sheet of paper. And the space of a sheet of paper with a finite area can be made unlimited in our three-dimensional world without violating the Euclidean geometry (the columns of parallel lines drawn on it remained parallel), in only one way: first, roll the sheet into a tube, connecting the opposite edges along the X axis, and then glue the ends of the tube, doing the same along the Y axis. Here's a donut for you!

The large, beautiful spiral galaxy M66 is only 35 million light-years away and spans 100,000 light-years across. Along the spiral arms of the galaxy are dark dust streaks and bright blue clusters of young stars, and the red dots on the arms are light from regions of intense star formation. All of the bright individual stars you see in this cosmic landscape are, of course, part of our galaxy. However, numerous other distant galaxies can be seen against the dark background of the sky.

With a three-dimensional limited space, the same can be done if, in the fourth dimension, the opposite sides of the cube are glued together in pairs. Do not break your brain, trying to visualize this - our brains are designed to process information about three-dimensional space and are not imprisoned for such tricks in principle, it’s not even worth trying. But in any case, it will not be a bagel, but some kind of hyperfigure twisted in four spatial dimensions.

This not-so-spectacular photo captures the grandest cataclysm - in fact, the NGC 7252 galaxy is two galaxies in the process of colliding. The process takes hundreds of millions of years, so in the picture it seems to be frozen in time. The resulting stellar pandemonium was named the Peaceful Atom galaxy. NGC 7252 is about 600,000 light-years across and lies almost 220 million light-years away towards the constellation of Aquarius. Perhaps the same awaits our Milky Way - if in a few billion years our Galaxy will collide with the Andromeda Nebula. Since we still don't know how fast the Andromeda Nebula (M31) is moving sideways (scientists can only measure that component of the speed that is directed along the line of sight), no one knows for sure if this will happen.

So in reality there is no “donut”, and in general it is not needed, and for an example with a two-dimensional space - it would be more correct to imagine an infinite plane, completely covered with identical sheets - exactly repeating one another, because in fact it is one and the same sheet… this is also too abstract, by the way (and some who still haven’t got the hang of it may be drawn to talk about the “reflections” of our world), let’s better go back to the example with “Quake” and dwell on it - this is the most illustrative a model from those described here, the rest only knock down with a pantalyk. Moreover, the geometry of such a model remains Euclidean: parallel lines do not intersect, the sum of the angles of a triangle is 180o, etc., and according to the most authoritative modern cosmological model of the Universe, our world does not have global spatial curvatures.

The very first of the discovered compact groups of galaxies is Stefan's Quintet. This group lies at a distance of about 300 million light years from us. But only four out of five galaxies are actually together in space. The extra galaxy is not hard to see: the four interacting galaxies (NGC 7319, 7318A, 7318B and 7317) look more yellow and have more distorted structures: loops and tails that appeared as a result of mutual destructive gravitational tides. A bluer and larger galaxy, NGC 7320, is much closer to us. It is separated from the Earth by about 40 million light years, so it is not part of the group. In this image, you can even see individual stars in NGC 7320, as if confirming that it is indeed much closer than other galaxies.

Now for the crystal. Each level of the same 3D game is written by programmers in the form of a parallelepiped - that is, it still has certain boundaries that do not exist "inside" the level from the point of view of the hero. So we can say that the universe of the game, which has no boundaries, nevertheless has the shape of a parallelepiped. At the same time, its boundaries can be arbitrarily drawn through any point of the playing space - they will not be felt by the "inhabitants" of the virtual world in any way. However, if the height of the parallelepiped is less than its length, then by "flying" constantly upwards, the cheater will reach the starting point faster than "flying" forward. Even if all the faces are the same - a cube - then in this case the diagonal path will be longer than the path along one of the sides. So it turns out that the virtual microuniverse, having no boundaries, nevertheless has a certain shape - in the case of the game, a parallelepiped.

Edge-on spiral galaxy NGC 4216 is 40 million light-years distant and nearly 100,000 light-years across, about the size of our own Milky Way. NGC 4216 is surrounded by other members of the cluster, NGC 4206 (right) and NGC 4222. Like other large spiral galaxies, including our own Milky Way, NGC 4216 grows by consuming small satellite galaxies. In the photo, these satellite galaxies are visible, and faint stellar streams depart from them, stretching for thousands of light years to the halo of NGC 4216.

What is the shape of our universe? The most primitive way to determine is to fly it all from end to end in different directions and measure the time required to return from different directions to the starting point. Personally, I would not undertake this experiment - to fly for a long time, and the starting point during this time would change beyond recognition, and the Universe itself would expand - all down the drain. It would be nice if there was something that has already done this way. And there is such a thing - this is the so-called relict radiation, penetrating the entire cosmos and being, roughly speaking, not going anywhere from the Universe (because there is nowhere) the electromagnetic "echo" of the Big Bang.

So, when interpreting the distribution parameters of this radiation in 2003, conclusions were drawn (still, however, not finally confirmed and questioned) that the "shape" of our Universe can be a dodecahedron - a regular polyhedron with 12 pentagonal faces - infinitely (see above) reflected itself in itself. Well, or, again, using the previous analogies, the Universe is an infinite space filled with "virtual" dodecahedrons, which are the same dodecahedron. If you also come across the concept of "mirror Universe", "the Universe as a system of zarkals" - then it is precisely this self-closure that is perceived by an internal observer as reflections (more precisely, would be perceived if the diameter of the Universe were much smaller and the light would return to starting point not after tens of billions of years).

The NGC 7771 group of galaxies lies nearly 200 million light-years from Earth beyond the constellation Pegasus. Actually NGC 7771 - the largest, turned somewhat edge - 75,000 light-years across. The beautiful round galaxy to the left is NGC 7769.

You can also set it with soap foam - a lot of spheres, closely adjacent to each other, form planes at the junctions. Only in the case of the Universe, the foam comes from the same bubble. And - once again - unlike soap foam, there are no faces, these boundaries as such: more precisely, they can be drawn anywhere, and the reference point, the center of the "bubble"-polyhedron is the point where the observer is located.

That's how it is somehow. Understandably?

The stars in the universe are grouped into galaxies (the average number of stars in a galaxy is 10,000,000,000).
Galaxies are collected in clusters of galaxies (average 100-1000 galaxies).
Clusters - to superclusters (average 100 clusters)

Such statements are akin to those great ideas that radically change the view of our place in this world. One such upheaval in consciousness occurred in 1543, when Nicolaus Copernicus showed that the Earth is not the center of the universe. In the 1920s, Edwin Hubble, noticing that the galaxies in the universe were moving away from each other, gave life to the idea that our universe did not exist forever, but was formed as a result of a certain event - the Big Bang. Now we are on the threshold of a new discovery. If the limits of the Universe are found, we will face a new, even more difficult question: what is there - on the other side of the boundaries?

Navigating by the stars

The infinity of the Universe implies that it must be infinite not only in space, but also in time, which means that it must have an infinite number of stars. In this case, our sky would be completely dotted with luminaries and dazzlingly bright around the clock. However, the darkness of the sky is evidence that the cosmos has not existed forever. According to a popular theory, it all started with the Big Bang, which made it possible for the very existence and expansion of matter. This concept itself refutes the idea of ​​the eternity of the Universe, and therefore undermines the belief in its infinity. At the same time, the Big Bang theory creates certain difficulties for astronomers who are looking for the boundaries of our outer space.

“The fact is that traveling over vast distances takes light years, and, therefore, scientists always receive outdated data. The space traveled by light in the early universe grew due to its subsequent expansion. The stars closest to us are relatively young, with distant objects counting for thousands of years, and if you look at other galaxies, then for billions. However, we do not see all the galaxies. 13.7 billion years is the maximum available to us, ”explains Neil Cornish, an astrophysicist from Montana State University. A kind of barrier to our vision is the relic radiation, formed approximately 380 thousand years after the Big Bang, when the Universe expanded and cooled down so much that atoms appeared. This radiation is something like a child's photograph of space, in which it is captured even before the stars appeared. Behind it, both boundaries and an infinitely continuing Universe can exist. But, despite the power of telescopes, this area remains invisible.

space music

Relic radiation prevents scientists from peering into the farthest reaches of space, but at the same time it carries very valuable information, which consists in the microwave background. Scientists suggest: if the universe were unlimited in size, it would be possible to find waves of all possible lengths in it. However, in fact, the wave spectrum of space is very narrow: the NASA WMAP apparatus, designed to study the relic radiation, has never detected truly large waves. "The universe has properties musical instrument, inside which the wavelength cannot exceed its length. We realized that the universe does not vibrate at long wavelengths, which was a confirmation of its finiteness, ”says Jean Pierre Luminet from the Paris Observatory in France.

The point is small - to determine its boundaries and shape. Glen Starkmann, a Canadian physicist at Case Western University in Cleveland, thinks he's found a way to determine the boundaries of the universe, even if they're beyond our line of sight. This can be done again with the help of waves. " sound waves, spread throughout the universe during its youth, can tell a lot. The shape of the universe, such as the shape of a drum, determines what type of vibration it will have,” says Glenn. His team plans to apply spectral analysis to our Universe in order to determine its shape based on the sounds it makes. True, these studies are long-term, and it may take years to find an answer.

We live in a donut...

However, there is another way to find out if the Universe has boundaries. Jeanne Levin, a theorist from the University of Cambridge, is currently working on it. She explains the principle of building the Universe using the good old computer game "Asteroids" as an example. If player controlled spaceship goes up, off the screen, it will immediately appear below. Such a strange maneuver becomes clear if you mentally roll the screen into a tube, like a magazine: it turns out that the device simply moves in a circle.
“In the same way, we, living inside the Universe, cannot get out. We do not have access to a dimension from which we could look at our three-dimensional Universe from the outside. Take, for example, a bagel - this, by the way, is quite suitable for this case a form for the universe - although its surface is clearly defined, no one living inside will stumble upon its limits: it seems to them that there are no boundaries, ”says Zhanna.

However, there is still a chance to recognize these limits, albeit a meager one - you need to monitor how light behaves. Imagine that the Universe is a room, and you, armed with a flashlight, are standing in its center. The light from the lantern will reach the wall behind you and then bounce off the wall opposite. and you will see a reflection of your own back in it. The same rules can work in limited space. "Light portraits" can be reflected from the alleged space walls and thus duplicated many times, but with some changes. And be the universe a little more earth, the light would instantly circle around it, and the distorted images of the planet would appear throughout the sky. But the cosmos is so vast that it would take billions of years for light to travel around and reflect.

But back to our "donuts". Jeanne Levin, with her donut theory of the universe, found support in Frank Steiner from the University of Ulm in Germany. After analyzing the data obtained using WMAP, this scientist concluded that the doughnut universe gives the greatest coincidence with the observed cosmic microwave background radiation. His team also tried to guess the likely size of the universe - according to research, it could reach 56 billion light-years across.

...or in a soccer ball?

Jean Pierre Lumine, with all due respect to Ms. Levin's donut, is still sure that the Universe is a spherical dodecahedron, or, more simply, a soccer ball: twelve pentagonal rounded surfaces arranged symmetrically. In fact, the theory of the French scientist does not particularly contradict the scientific research of Jeanne Levin with her game of Asteroids. The same scheme works here - leaving one of the sides, you find yourself on the opposite one. For example, having flown in a straight line on some "super-fast" rocket, you can eventually return to the starting point. Does not deny Jean-Pierre and the principle specular reflections. He is sure that if there were a super-powerful telescope, one could see in different sides space are the same objects, only at different stages of life. But when the edges of the dodecahedron are billions of light-years away, faint reflections on them cannot be seen even by the most observant astronomers.

Note that Lumine, with his concept of a soccer ball, found an ally - mathematician Jeffrey Wicks. This scientist claims that the waves in the cosmic microwave background look exactly the same as they should appear inside the right geometric figure with twelve pentagonal faces.

Universal Inflation

The first moment of the life of the Universe played a huge role in its further evolution. Scientists are still building complicated hypotheses about inflation - a very short period of time, much less than a second, during which the size of the universe increased by a hundred trillion times. Most scientists are inclined to believe that the expansion of the universe continues to this day. And, it would seem, the theory of the infinity of the cosmos is a logical continuation of the idea of ​​inflation.

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Computer model of the universe

However, Andy Albracht, a theoretical physicist at the University of California at Davis, has a different opinion on this matter: although the expansion of the Universe continues to this day, this process still has limits. To explain his theory, Andy picked up a metaphor for the universe soap bubble. The conventional theory of inflation allows for this bubble to expand indefinitely, but even kindergarteners know that sooner or later the bubble must burst. Andy believes that, having reached its maximum, inflation should stop. And this maximum is not so great as we think. According to Albracht, the universe is only 20% larger than the space we see. “Of course, it is incredibly difficult to come from infinity to such a tiny size - only some 20% more! I even got claustrophobia,” the scientist jokes. Of course, Albracht's conclusions are very controversial and require factual confirmation, but for now, most astronomers believe that inflation will not die out for a very long time.

Dark stream and other universes

The expansion of the Universe, by the way, is the best explanation for the movement of galaxies in the territory we see. True, some features of this galactic movement are puzzling. A NASA team led by astrophysicist Alexander Kashlinsky, studying microwave and X-ray radiation, found that about eight hundred distant galactic clusters are moving together in one direction at a speed of a thousand kilometers per second, as if they were attracted by some kind of magnet. This universal movement has been called the "dark current". According to the latest data, it already covers 1400 galaxies. They are aimed at an area located more than three billion light years from Earth. Scientists suggest that just somewhere out there, beyond the limits inaccessible to observations, there is a huge mass that attracts matter. However, according to existing theory, the substance after the Big Bang, which gave rise to our Universe, was distributed more or less evenly, which means that there can be no concentrations of masses that have such fantastic power. Then what is there?

The answer to this question was given by theoretical physicist Laura Mersini-Hoftan, team leader from the University of North Carolina. She seriously considers the existence of another universe, located next to ours. Her conclusions, which seem incredible at first glance, are quite compatible with the theory of inflation and the “soap bubble” voiced by Andy Albracht, as well as with the “dark stream” of Alexander Kashlinsky. Now the research of these scientists is formed into a single picture like puzzles. The dark stream observed in our outer space can be provoked by one of the neighboring "bubbles" - another Universe.

Hoftan explains the multiplicity of universes with the theory of probability. She considers the birth of our world a miracle, it could easily not appear: the chances of its occurrence are negligible and amount to 1 in 10133.

“It is possible to ask the question about the origin of the Universe when we have a multiple structure in which it was formed - places where the conditions are favorable for its origin. In other words, we can assume many Big Bangs and many universes,” notes Hoftan. For clarity, she compares these auspicious places with rooms in a hotel. The universe can only be born in a free "room" and exist there alone. However, this does not mean that another such cosmic world cannot move into the “number” through the wall. But if our universe is a hotel room, should we be able to hear our neighbors? In 2007, the WMAP apparatus recorded an unusual region of a significantly reduced background of the background radiation, which indicates the absence of matter in it. According to the scientist lady, the only explanation for such a cold and absolute emptiness is that some other forces are at work there, perhaps the presence of another universe, the huge mass of which attracts neighboring matter. And although these "foreign" objects are not subject to our vision, our neighbor still makes itself felt with messages in the form of a cold spot and a stream of galactic clusters.

Of course, in scientific community reactions to the conclusions about multiple universes are mixed. However, scientists who are trying to characterize outer space are ready to make new revolutions in science. Our Universe, previously considered infinite, may cease to be such and take its rightful place in space, among such a number of universes that it is impossible even to imagine.

In ancient times, people believed that the Earth was flat, but time has shown that they were wrong. Now we can also be deceived about the shape of the universe. General relativity deals with four-dimensional space, where time is represented as the fourth coordinate, and, according to this theory, any massive body curves this space, and the entire mass of the Universe turns its plane into a sphere. But this is a plane in four-dimensional space, and what form this space itself will take was still unknown. Most were inclined to believe that it has the shape of a torus.

Grigor Aslanyan, a cosmologist at the University of California, thinks it's not exactly a torus. The shape of the universe, he says, depends on the extent of its coordinates. It may be finite in all three spatial dimensions; can have two finite dimensions and one infinite; it can also have two infinite dimensions and one finite - Aslanyan did not want to perceive three infinite dimensions. And in each of these three options, space will have its own special four-dimensional shape. And, most importantly, Aslanyan knows how to check which option is accepted in our Universe. He tried to find out by comparing his calculations with data obtained by the WMAP space probe, which studies the distribution of cosmic microwave background radiation in the sky.

True, a problem arose here - Aslanyan quickly realized that calculations of such complexity regular computer not under force. Then he turned to the help of GRID - a distributed computing system that covers many computers through the likeness of the Internet. The calculations themselves were easy to parallelize, and the 500,000 hours required to get the result turned out to be quite an acceptable time.

The result confirmed expectations - he rejected the option of three infinite dimensions. It turned out interesting - the space has the shape of an elongated torus, roughly speaking, a bagel, elongated in the very direction in which the "axis of evil" recently discovered by astrophysicists is directed - the direction in the sky, where the values ​​of the cosmic microwave background radiation differ from the values ​​in other directions. Aslanyan hopes to learn more precisely the shape of the universe by receiving data this year from another satellite called Planck.

Comments (10):

"General relativity deals with four-dimensional space, where time is represented as the fourth coordinate"

We are talking about the 4th spatial coordinates.

Time is not a spatial coordinate, but an evolutionary one.

This is where the main incorrectness in the conclusions of the theory of relativity lies.

They (these conclusions) imply the treatment of the direction of time, as with an ordinary vector.

But time is not a spatial vector... Time is a measure of the evolution of processes, a scalar.

And that is why it is irreversible!

Let's start with the bagel. There is no bagel. The legs of this image grow from the fact that our Universe has a very large, but still finite volume, but it has no boundaries. It is quite simple to imagine this in a two-dimensional example: in some simple computer games, an object that goes beyond the right border of the playing field appears on the left, and that goes down - from above. An even more illustrative example - three-dimensional - can be seen if at any of the levels of the game "Quake" (at least the first or second game of the series; maybe other similar 3D shooters, I just haven't tried) use at the same time cheats that allow you to pass through the walls and fly, and move straight in any direction: the camera will quickly leave the location, your virtual hero will fly in a black void for some time, and then a cluster of corridors and rooms that seems to be left behind will appear in front of him, and the hero will return to the same point from where he started, but from the opposite side, as if he went around the globe - although he was flying in a straight line. You can move in any direction for an infinitely long time - there are no boundaries, but you cannot go beyond the level, and you will not fly into any "other space" - the volume is finite and closed. This is the same as the real Universe, only more spacious.

In the general theory of relativity, it is assumed that the physical space is non-Euclidean, the presence of matter bends it; curvature depends on the density and motion of matter.

It turns out that the critical density value on which the future of the Universe depends (unlimited expansion or stopping and contraction) is also critical for the spatial structure of the Universe as a whole.

Our ideas about space depend on the relationship between $\rho$ and $\rho_(cr)$

The essence of the approach is as follows.
We see the redshift from distant galaxies and conclude that the light from them comes from a space of greater curvature than ours, this makes us think about the topology of the Universe, that is, we are looking for topology by observing the picture of the redshift and completely abandoning the idea of ​​expanding the space of the Universe, as deliberately redundant, violating Occam's principle
So, possible variant Spaces of the Universe - HyperThor
1. Imagine a sphere (A) inside a sphere of larger radius (B) and glue both spheres together.
Light, moving from a small sphere, reaches the surface of a large one and immediately turns out to emerge from the surface of a small one. A small sphere is inside a large one, and a large one is inside a small one.
2. It can also be represented like this (with some stretch, for a single beam of light)
Let there be two spheres of equal diameter, the light goes from one sphere to the other and immediately leaves the first, while the light went to the middle of the spheres, it turned red, and then began to turn blue, for the light it seems that this is different areas but it's the same area. Spheres seem to gravitate (this is a prop to represent a hypertorus with variable curvature)

Most models assume that (3+1) space is a given from BV. Models are built on this postulate. A sphere filled with bubbles-embryos of future universes (Alexander Kashinsky), a thin-walled bubble in the form of a dodecahedron (Jeffie Wixon), a donut-shaped torus (Frank Schneider). I think that the dimension should be considered as a variable, and each dimension has its own universe.. Evolution, in my opinion, has gone through the following stages: (0 + 1), (1 + 1), (2 + 1), (3 + 1 ) and possibly more. They are nested in each other. For example, the universe (2+1) exists and develops on the same time coordinate as (3+1). It is difficult to check such an assumption - since it is unlikely or even more categorically impossible to get from the universe of one dimension to another.

To display formulas, you can use the "$$" environment and \TeX markup.

Cosmologists have long assumed that the universe is infinite, but not limitless. This means that it has limited dimensions, but it is impossible to get to "the end of the world". Even if there were someone who tried to cross the universe, he would return to the point from which he started - similar to those who made trip around the world around the Earth.

The long-standing hypothesis of the finiteness of the universe became especially popular as a result of the study of the cosmic microwave background, or cosmic microwave background radiation left in the universe after the Big Bang. Scientists suggest that if the universe had unlimited dimensions, it would be possible to find waves of all probable lengths in it. However, we all know that the spectrum of the microwave background is very limited - and that is why it is called so.

“The universe has the properties of a musical instrument,” explains Frank Steiner from the University of Ulm in Germany. “And the wavelengths inside it cannot exceed the length of the instrument itself.

To date, cosmologists have come up with several hypotheses for the shape of the universe. The most popular were a pumpkin (or an American football ball) and a bagel, as well as three bagels, bizarrely connected to each other. Some physicists have even proposed a beautiful model, apparently borrowed from Eastern philosophy, about the Universe, which is a corridor of mirrors with images of various objects that are repeated many times in the sky. These "light portraits" can be reflected from the alleged walls of the universe and thus duplicated many times. Glen Starkman from Case Western Reserve University in Cleveland (Ohio, USA) and his colleagues began to try to somehow combine the proposed models with experimental data, but have not yet chosen which shape suits our Universe the most.

At the same time, Steiner and his colleagues began to reanalyze data obtained in 2003 using spacecraft NASA, known as the Wilkinson Microwave Anisotropic Probe, and tried to use it to substantiate their hypothesis that the Universe has the shape of a donut and three donuts. Scientists also wanted to test the widespread hypothesis of a limitless and "dimensionless" universe.

It turned out that the data from the spacecraft best substantiate the theory of the universe in the form of a donut. Scientists also tried to guess the likely size of the universe - according to information obtained using the Probe, it can reach 56 billion light years.

Jean-Pierre Luminet of the Paris Observatory in France holds the hypothesis that the universe is shaped like an American football or a pumpkin. However, he really liked Steiner's work. In his opinion, the analysis of a colleague from Germany shows that a donut is a quite probable form of the Universe, but still does not reject the idea of ​​a pumpkin (soccer ball). “I think my soccer ball is still alive and well,” Lumine jokes.

Steiner himself believes that the study of cosmic microwave background radiation, which is now being carried out by the European Planck satellite, will more accurately determine the shape of the universe. Glen Starkman also believes that there is not enough data yet. “From a philosophical point of view, I like the idea that the universe is finite,” he says. “However, physics cannot be trusted by philosophy, and therefore I will be careful not to draw conclusions until new experimental data appear.”

> What is the shape of the universe?

What form is the universe in?: exploration of infinite space, WMAP CMB map, geometry of the Universe and supposed shapes with photo.

Is it even worth thinking about what shape the universe is? What are we dealing with? Sphere? Cone? flat? And how to define it?

The Universe is the only place in which we exist and beyond which we cannot escape (because there are none). Thanks to physical laws, natural permanent and erupting heavy metals, we managed to create life on a small rocky ball, lost in one of the many galaxies.

But don't you want to know where you live? Just to get the opportunity to look at everything from the outside, as we did with our home planet Earth. For you to see? Endless darkness? Lots of bubbles? Snowball? A rat maze in the hands of aliens or something else? What is the shape of the universe?

Well, the answer is much simpler, but also weirder. People began to think about the shape of the Universe in ancient times. And people, due to lack of information, offered quite wonderful things. In Hindu texts, it was an egg in the shape of a man. The Greeks saw an island floating in the void. Aristotle says that the universe has the shape of an infinite sphere or just a turtle.

Interestingly, Albert Einstein's contributions help test each of these models. Scientists have put forward three favorite shapes: positively curved, negatively curved and flat. We understand that the Universe exists in 4 dimensions and any of the figures borders on the insane geometry of Lovecraft. So turn on the maximum imagination and let's go!

With a positively curved version, we get a four-dimensional sphere. This variety has an end, but no clear boundary stands out. More specifically, two particles would cross it before returning to the starting point. You can even test it at home. Take balloon and draw a straight line until it returns to the starting point.

This view fits into three dimensions and appears if there are great amount energy. To completely curve or close, space would have to stop expanding. This will happen if there is a large-scale energy reserve capable of creating an edge. Modern data show that expansion is a never-ending process. So this scenario is out.

The negatively curved shape of the universe is a four-dimensional saddle. It is open, devoid of boundaries in space and time. There is little energy here, so the universe will not stop expanding. If two particles are passed along straight lines, then they will never meet, but will simply diverge until they go in different directions.

If a critical amount of energy fluctuates between extremes, then after infinity the expansion will stop. This is a flat universe. Here, two particles will travel in parallel, but will never separate or meet.

It's easy to imagine these three forms, but there are many more options. The soccer ball is reminiscent of the idea of ​​a spherical universe. The donut is technically flat, but connected at certain points. Some believe that huge warm and cool spots speak in favor of this option. You can see the alleged shape of the universe in the photo.

And so we come to the pipe. This is another kind of negative curvature. One of its ends will be narrowed, and the other - wide. In the first half, everything seemed narrow and existed in two dimensions. And in a wide one, one could travel to maximum distances, but one would have to return in the opposite direction (direction changes in a bend).

What then? What are we dealing with? Bagel? Wind instrument? Giant cheese head? Scientists still have not ruled out options with a pipe and a saddle.

Grumblers will argue that all this is meaningless and we will never know the truth. But let's not be so categorical. The latest Planck data show that our Universe is… flat! Infinitely finite, completely uncurved and with a precise critical amount of energy.

It is unthinkable that we can not only find out what the universe looks like, but there are people who are constantly trying to find even more information. If "flat" seems boring to you, then don't forget that we don't have enough information yet. Therefore, it is likely that we can all exist in a giant doughnut.