From the molecule to the universe, a game. The size of our earth to the scale of the universe. The distance between our Earth and the Moon

The sizes of objects in the Universe in comparison (photo)

1. This is the Earth! We live here. At first glance, it looks very large. But, in fact, compared to some objects in the Universe, our planet is negligible. The following photos will help you at least roughly imagine something that simply does not fit in your head.

2. The location of the planet Earth in the solar system.

3. The scaled distance between the Earth and the Moon. Doesn't look too far, does it?

4. Within this distance, you can place all the planets of our solar system, beautifully and neatly.

5. This small green spot is the continent of North America, on the planet Jupiter. One can imagine how much larger Jupiter is than Earth.

6. And this photo gives an idea of ​​the size of the planet Earth (that is, six of our planets) in comparison with Saturn.

7. This is how the rings of Saturn would look if they were around the Earth. The beauty!

8. Hundreds of comets fly between the planets of the solar system. This is how comet Churyumov-Gerasimenko looks like, on which the Philae probe landed in the fall of 2014, in comparison with Los Angeles.

9. But all objects in the solar system are insignificant small compared to our sun.

10. This is how our planet looks from the surface of the Moon.

11. This is how our planet looks from the surface of Mars.

12. And this is us from Saturn.

13. If you fly to the border of the solar system, you will see our planet like this.

14. Let's go back a little. This is the size of the Earth compared to the size of our Sun. Impressive, isn't it?

15. And this is our Sun from the surface of Mars.

16. But our Sun is only one of the stars in the Universe. Their number is more than grains of sand on any beach on Earth.

17. This means that there are stars much larger than our Sun. Just look at how tiny the Sun is compared to the largest star known to date, VY, in the constellation Canis Major.

18. But no star can match the size of our Milky Way Galaxy. If we reduce our Sun to the size of a white blood cell and reduce the entire Galaxy by the same factor, then the Milky Way will be the size of Russia.

19. Our Milky Way Galaxy is huge. We live somewhere here.

20. Unfortunately, all objects that we can see with the naked eye in the sky at night are placed in this yellow circle.

21. But the Milky Way is far from the largest galaxy in the Universe. This is the Milky Way compared to Galaxy IC 1011, which is 350 million light-years from Earth.

22. But that's not all. This Hubble telescope image captures thousands and thousands of galaxies, each containing millions of stars with their own planets.

23. For example, one of the galaxies in the photo, UDF 423. This galaxy is ten billion light-years from Earth. When you look at this photo, you are looking billions of years into the past.

24. This dark piece of the night sky looks completely empty. But when zoomed in, it turns out to contain thousands of galaxies with billions of stars.

25. And this is the size of the black hole compared to the size of the Earth's orbit and the orbit of the planet Neptune.

One such black abyss can easily suck in the entire solar system.

Today we will talk about the fact that the Earth is small and about the size of other huge celestial bodies in the Universe. What are the dimensions of the Earth in comparison with other planets and stars of the Universe.

In fact, our planet is very, very small ... compared to many other celestial bodies, and even compared to the same Sun, the Earth is a pea (a hundred times smaller in radius and 333 thousand times in mass), and there are stars in times, hundreds, thousands (!!) times larger than the Sun ... In general, we humans, and each of us especially, are microscopic traces of existence in this Universe, atoms invisible to the eyes of creatures that could live on huge stars (theoretically, but perhaps practically).

Thoughts from the film on the topic: it seems to us that the Earth is big, it is so - for us, since we ourselves are small and the mass of our body is negligible in comparison with the scale of the Universe, some have never even been abroad and do not leave for most of their lives the limits of a house, a room, and they know almost nothing about the Universe. And the ants think that their anthill is huge, but we will step on the ant and will not even notice it. If we had the power to reduce the Sun to the size of a leukocyte and proportionally reduce the Milky Way, then it would be equal to the scale of Russia. And there are thousands or even millions and billions of galaxies besides the Milky Way ... This cannot fit into the consciousness of people.

Every year astronomers discover thousands (and more) new stars, planets, celestial bodies. Space is an unexplored area, and how many more galaxies, stellar, planetary systems will be discovered, and it is quite possible that there are many similar solar systems with theoretically existing life. We can judge the size of all celestial bodies only approximately, and the number of galaxies, systems, celestial bodies in the Universe is unknown. However, based on the known data, the Earth is not the smallest object, but far from the largest, there are stars and planets hundreds, thousands of times larger !!

The largest object, that is, a celestial body, in the Universe is not defined, since human capabilities are limited, with the help of satellites, telescopes, we can see only a small part of the Universe, and what is there, in the unknown distance and beyond the horizons, we do not know ... perhaps even larger celestial bodies than those discovered by humans.

So, within the solar system, the largest object is the sun! Its radius is 1,392,000 km, followed by Jupiter - 139,822 km, Saturn - 116,464 km, Uranus - 50,724 km, Neptune - 49,244 km, Earth - 12,742.0 km, Venus - 12,103.6 km, Mars - 6780.0 km, etc.

Several dozen large objects - planets, satellites, stars and several hundred small ones, these are only from the open, and there are not open ones.

The Sun is larger than the Earth in radius - more than 100 times, in mass - 333 thousand times. These are the scales.

Earth is the 6th largest object in the solar system, very close to the scale of the Earth Venus, and Mars is half the size.

The Earth is generally a pea in comparison with the Sun. And all other planets, smaller ones, are practically dust for the Sun ...

However, the Sun warms us regardless of its size and our planet. Did you know, imagined, walking with your feet on the mortal soil, that our planet is almost a point in comparison with the Sun? And accordingly - we are on it - microscopic microorganisms ...

However, people have a lot of pressing problems, and, at times, there is no time to look beyond the ground under their feet.

Jupiter is more than 10 times the size of Earth, it is the fifth planet in the distance from the Sun (classified as a gas giant along with Saturn, Uranus, Neptune).

Earth after the gas giants is the first largest object after the Sun in the solar system, then there are the rest of the terrestrial planets, Mercury after the moon of Saturn and Jupiter.

Terrestrial planets - Mercury, Earth, Venus, Mars - planets located in the inner region of the solar system.

Pluto is about one and a half times smaller than the Moon, today it is ranked among dwarf planets, it is the tenth celestial body in the solar system after 8 planets and Eris (a dwarf planet roughly similar in size to Pluto), consists of ice and stones, as in area as South America , a small planet, however, and it is larger in scale in comparison with the Earth with the Sun, the Earth is still two times smaller in proportions.

For example, Ganymede - the satellite of Jupiter, Titan - the satellite of Saturn - is only 1.5 thousand km less than Mars and more than Pluto and large dwarf planets. There are many dwarf planets and satellites discovered recently, and even stars - even more, more than several million, or even billions.

There are several dozen objects in the solar system that are slightly smaller than the Earth and half as small as the Earth, and there are several hundred of those that are slightly smaller. Can you imagine how many flies around our planet? However, to say "flies around our planet" is incorrect, because as a rule, each planet has some relatively fixed place in the solar system.

And if some asteroid flies towards the Earth, then it is even possible to calculate its approximate trajectory, flight speed, time of approach to Earth, and with the help of certain technologies, devices (such as the defeat of an asteroid with the help of super-powerful atomic weapons in order to destroy part of the meteorite and how consequent change in speed and flight trajectory) change the direction of flight if the planet is in danger.

However, this is a theory, in practice such measures have not yet been applied, but cases of an unexpected fall of celestial bodies to Earth have been recorded - for example, in the case of the same Chelyabinsk meteorite.

In our consciousness, the Sun is a bright ball in the sky, in abstraction it is some kind of substance, which we know about from satellite images, observations and experiments of scientists. However, all that we see with our own eyes is a bright ball in the sky that disappears at night. If we compare the sizes of the sun and the earth, then it is like a toy car and a huge jeep, the jeep will crush the car without even noticing. Likewise, the Sun, if it had at least a little more aggressive characteristics and an unrealistic ability to move, would have swallowed everything in its path, including the Earth. By the way, one of the theories of the death of the planet in the future says that the Sun will swallow the Earth.

We are accustomed, living in a limited world, to believe only what we see and take for granted only what is under our feet and perceive the Sun exactly as a ball in the sky that lives for us in order to illuminate the path for mere mortals, warm us, give energy for us, in general, we use the sun to the fullest, and the thought that this bright star carries potential danger seems ridiculous. And only a few people will seriously think that there are other galaxies in which there are celestial objects more than those in the solar system hundreds, and sometimes thousands of times.

People simply do not understand in their minds what the speed of light is, how celestial bodies move in the Universe, these are not the formats of human consciousness ...

We talked about the size of celestial bodies within the solar system, about the size of large planets, said that the earth is the 6th largest object in the solar system and that the earth is a hundred times smaller than the sun (in diameter), and 333 thousand times in mass , however, there are celestial bodies in the Universe MUCH larger than the Sun. And if the comparison of the Sun and the Earth did not fit into the consciousness of ordinary mortals, then the fact that there are stars in comparison with which the Sun is a ball - even more so does not fit into us.

However, as evidenced by the research of scientists, it is. And this is a fact, based on the data obtained by astronomers. There are other stellar systems where the life of the planets exists like ours, the Solar. By "life of the planets" is meant not earthly life with people or other creatures, but the existence of planets in this system. So, to the question of life in Space - every year, every day, scientists come to the conclusion that life on other planets is more and more possible, but this remains only speculation. In the solar system, Mars is the only planet close to terrestrial conditions in terms of conditions, but the planets of other star systems have not been fully explored.

For example:

“It is believed that earth-like planets are the most favorable for the emergence of life, so their search attracts close public attention. So in December 2005, scientists from the Institute of Space Sciences (Pasadena, California) reported the discovery of a sun-like star around which rocky planets are supposedly forming.

Later, planets were discovered that are only several times more massive than the Earth and, probably, should have a solid surface.

Super-Earths are an example of terrestrial exoplanets. As of June 2012, more than 50 super-lands have been found. "

These super-earths are the potential carriers of life in the Universe. Although this is a question, since the main criterion for the class of such planets is more than 1 times the mass of the Earth, however, all discovered planets revolve around stars with less thermal radiation in comparison with the Sun, usually white, red and orange dwarfs.

The first super-earth discovered in the habitable zone in 2007 is the planet Gliese 581 c near the star Gliese 581, the planet had a mass of about 5 Earth masses, “removed from its star by 0.073 AU. That is, it is located in the region of the "life zone" of the star Gliese 581 ". Later, a number of planets were discovered near this star and today they are referred to as a planetary system, the star itself has a low luminosity, several tens of times smaller than the Sun. It was one of the most sensational discoveries in astronomy.

However, back to the topic of big stars.

Below are photos of the largest objects in the solar system and stars in comparison with the sun, and then with the last star in the previous photo.

Mercury< Марс < Венера < Земля;

Earth< Нептун < Уран < Сатурн < Юпитер;

Jupiter< < Солнце < Сириус;

Sirius< Поллукс < Арктур < Альдебаран;

Aldebaran< Ригель < Антарес < Бетельгейзе;

Betelgeuse< Мю Цефея < < VY Большого Пса

And in this list there are still the smallest stars and planets (the really large in this list, perhaps, only the star VY Canis Major) .. The largest can not even be compared in a row with the Sun, since the Sun will simply not be visible.

The equatorial radius of the Sun, 695,700 km, is used as a unit for measuring the radius of a star.

For example, the star VV Cephei is 10 times larger than the Sun, and Wolf 359 (a single star in the constellation Leo, a faint red dwarf) is considered the largest star between the Sun and Jupiter.

VV Cepheus (not to be confused with the star of the same name with the "prefix" A) - “An eclipsing binary Algol-type star in the constellation Cepheus, about 5,000 light-years from Earth. Component A is the seventh radial star known to science in 2015 and the second largest star in the Milky Way Galaxy (after VY Canis Major). "

Capella (α Aur / α Auriga / Alpha Auriga) is the brightest star in the constellation Auriga, the sixth brightest star in the sky and the third brightest in the sky of the Northern Hemisphere.

The chapel is 12, 2 times the radius of the Sun.

The North Star is 30 times the radius of the Sun. A star in the constellation of Medviditsa Minor, located near the North Pole of the world, a supergiant of spectral type F7I.

The Star Y of the Hounds of the Dogs is (!!!) 300 times larger than the Sun! (that is, it is about 3000 times larger than the Earth), a red giant in the constellation of the Hounds of the Dogs, one of the coolest and reddest stars. And this is far from the largest star.

For example, the star VV Cephei A is larger than the Sun in radius by as much as 1050-1900 times! And the star is very interesting for its inconstancy and "leakage": “Luminosity is 275,000-575,000 times more. The star fills the Roche lobe, and its matter flows to its neighboring companion. The gas outflow velocity reaches 200 km / s. It has been established that VV of Cepheus A is a physical variable pulsating with a period of 150 days. "

Of course, most of us will not understand information with scientific terms, if, in short, the star is incandescent, losing matter. Its size, strength, brightness of luminosity is simply impossible to imagine.

So, the 5 largest stars in the Universe (recognized as those of the currently known and discovered ones), in comparison with which our Sun is a pea and a speck of dust:

- VX Sagittarius - 1520 times the diameter of the Sun. Supergiant, hypergiant, a variable star in the constellation Sagittarius, is losing its mass due to the stellar wind.

- Westerland 1-26 - about 1530-2544 times the radius of the Sun. The red supergiant, or hypergiant, "is located in the star cluster Westerland 1 in the constellation of the Altar."

- Star WOH G64 from the constellation Doradus, a red supergiant of spectral type M7.5, is located in the neighboring Large Magellanic Cloud galaxy. The distance to the solar system is approximately 163 thousand sv. years. More than the radius of the Sun 1540 times.

- NML Swan (V1489 Swan) is 1183 - 2775 times larger than the Sun in radius, - "a star, a red hypergiant, is in the constellation Cygnus."

- UY of the Shield is 1516 - 1900 times larger than the Sun's radius. It is currently the largest star in the Milky Way and in the universe.

“UY Shield is a star (hypergiant) in the constellation Shield. Located at a distance of 9500 sv. years (2900 pc) from the Sun.

It is one of the largest and brightest stars known. According to scientists, the radius of the UY Shield is equal to 1708 solar radii, the diameter is 2.4 billion km (15.9 AU). At the peak of the pulsations, the radius can reach 2000 solar radii. The volume of a star is about 5 billion times the volume of the Sun. "

From this list, we see that there are about a hundred (90) stars much larger than the Sun (!!!). And there are stars, on the scale of which the Sun is a grain, and the Earth is not even dust, but an atom.

The fact is that the places in this list are distributed according to the principle of the accuracy of determining the parameters, mass, there are approximately more huge stars than UY Shield, but their sizes and other parameters have not been established for certain, however, the parameters of this star may one day be called into question. It is clear that stars 1000-2000 times larger than the Sun exist.

And, perhaps, some of them are or are forming planetary systems, and who can guarantee that there can be no life ... or not now? Wasn't there or never will be? Nobody ... We know too little about the Universe and Space.

Yes, and even of the stars shown in the pictures - the most recent star - VY Canis Major - has a radius equal to 1420 solar radii, but the UY Shield star at its peak pulsation is about 2000 solar radii, and there are stars supposedly more than 2.5 thousand solar radii. Such a scale is impossible to imagine, these are truly extraterrestrial formats.

Of course, the question is interesting - look at the very first picture in the article and at the last photos, where there are many, many stars - how do such a number of celestial bodies coexist in the Universe quite calmly? There are no explosions, collisions of these very supergiants, because the sky, from what is visible to us, is teeming with stars ... In fact - this is just the conclusion of mere mortals who do not understand the scale of the Universe - we see a distorted picture, but in fact there is enough space for everyone , and, perhaps, there are explosions and collisions, it just does not lead to the death of the Universe and even a part of galaxies, because the distance from star to star is enormous.

Did you know that the universe we observe has fairly definite boundaries? We are used to associating the Universe with something infinite and incomprehensible. However, modern science to the question of the "infinity" of the Universe offers a completely different answer to such an "obvious" question.

According to modern concepts, the size of the observable universe is approximately 45.7 billion light years (or 14.6 gigaparsecs). But what do these numbers mean?

The first question that occurs to an ordinary person is how the Universe cannot be infinite at all? It would seem indisputable that the container of everything that exists around us should have no boundaries. If these boundaries exist, what are they?

Let's say an astronaut has flown to the borders of the universe. What will he see in front of him? A solid wall? Fire barrier? And what is behind it - emptiness? Another Universe? But can emptiness or another Universe mean that we are on the border of the universe? After all, this does not mean that there is "nothing". The emptiness and the other Universe are also “something”. But the Universe is something that contains absolutely everything “something”.

We come to an absolute contradiction. It turns out that the border of the Universe should hide from us something that should not be. Or the border of the Universe should fence off “everything” from “something”, but this “something” should also be a part of “everything”. In general, a complete absurdity. Then how can scientists claim the limiting size, mass, and even age of our universe? These values, although unimaginably large, are still finite. Is science arguing with the obvious? To deal with this, let's first trace how humans came to a modern understanding of the universe.

Expanding the boundaries

From time immemorial, man has been interested in what the world around them is. One need not give examples of the three whales and other attempts of the ancients to explain the universe. As a rule, in the end it all came down to the fact that the foundation of all that exists is the earthly firmament. Even in antiquity and the Middle Ages, when astronomers had extensive knowledge of the laws governing the motion of planets along the "stationary" celestial sphere, the Earth remained the center of the Universe.

Naturally, even in Ancient Greece there were those who believed that the Earth revolved around the Sun. There were those who spoke about the many worlds and the infinity of the universe. But constructive justification for these theories emerged only at the turn of the scientific revolution.

In the 16th century, the Polish astronomer Nicolaus Copernicus made the first major breakthrough in the knowledge of the Universe. He firmly proved that the Earth is only one of the planets orbiting the Sun. Such a system greatly simplified the explanation of such a complex and intricate movement of the planets in the celestial sphere. In the case of a stationary Earth, astronomers had to invent all sorts of ingenious theories to explain this behavior of the planets. On the other hand, if the Earth is taken to be mobile, then the explanation for such intricate movements comes naturally. This is how a new paradigm called "heliocentrism" became entrenched in astronomy.

Many Suns

However, even after that, astronomers continued to confine the universe to the "sphere of fixed stars." Until the 19th century, they could not estimate the distance to the stars. For several centuries, astronomers have tried in vain to detect deviations in the position of stars relative to the Earth's orbital motion (annual parallaxes). The instruments of those times did not allow such accurate measurements.

Finally, in 1837, the Russian-German astronomer Vasily Struve measured the parallax. This marked a new step in understanding the scale of space. Now scientists could safely say that the stars are distant similarities to the Sun. And from now on our luminary is not the center of everything, but an equal "inhabitant" of the endless star cluster.

Astronomers have come even closer to understanding the scale of the Universe, because the distances to the stars turned out to be truly monstrous. Even the size of the orbits of the planets seemed insignificant in comparison with this. Next, it was necessary to understand how the stars are concentrated in.

Many Milky Way

The famous philosopher Immanuel Kant anticipated the foundations of the modern understanding of the large-scale structure of the Universe back in 1755. He hypothesized that the Milky Way is a huge rotating cluster of stars. In turn, many of the observed nebulae are also more distant "milky ways" - galaxies. Despite this, until the 20th century, astronomers adhered to the fact that all nebulae are sources of star formation and are part of the Milky Way.

The situation changed when astronomers learned to measure distances between galaxies using. The absolute luminosity of stars of this type is strictly dependent on the period of their variability. Comparing their absolute luminosity with the visible one, it is possible to determine the distance to them with high accuracy. This method was developed in the early 20th century by Einar Herzsrung and Harlow Shelpy. Thanks to him, the Soviet astronomer Ernst Epik in 1922 determined the distance to Andromeda, which turned out to be an order of magnitude larger than the size of the Milky Way.

Edwin Hubble continued Epic's endeavor. By measuring the brightness of Cepheids in other galaxies, he measured the distance to them and compared it with the redshift in their spectra. So in 1929 he developed his famous law. His work has definitively refuted the entrenched notion that the Milky Way is the edge of the universe. It was now one of many galaxies that had once been considered an integral part of it. Kant's hypothesis was confirmed almost two centuries after its development.

Later, the connection between the distance of the galaxy from the observer and the speed of its removal from the observer, discovered by Hubble, made it possible to compose a complete picture of the large-scale structure of the Universe. It turned out that the galaxies were only an insignificant part of it. They linked into clusters, clusters into superclusters. In turn, superclusters fold into the largest known structures in the universe - filaments and walls. These structures, adjacent to huge supervoids (), make up the large-scale structure of the currently known Universe.

Apparent infinity

From the foregoing, it follows that in just a few centuries, science has gradually leapt from geocentrism to the modern understanding of the Universe. However, this does not provide an answer as to why we are limiting the Universe these days. Indeed, until now, it was only about the scale of the cosmos, and not about its very nature.

The first who decided to substantiate the infinity of the Universe was Isaac Newton. Having discovered the law of universal gravitation, he believed that if space were finite, all her bodies would sooner or later merge into a single whole. Before him, if someone expressed the idea of ​​the infinity of the Universe, it was exclusively in a philosophical vein. Without any scientific justification. An example of this is Giordano Bruno. By the way, like Kant, he was ahead of science by many centuries. He was the first to declare that the stars are distant suns, and planets also revolve around them.

It would seem that the very fact of infinity is quite justified and obvious, but the turning points of science of the 20th century shook this "truth."

Stationary universe

The first significant step towards the development of a modern model of the Universe was made by Albert Einstein. The famous physicist introduced his model of a stationary universe in 1917. This model was based on the general theory of relativity, which he developed the same year earlier. According to his model, the universe is infinite in time and finite in space. But after all, as noted earlier, according to Newton, a universe with a finite size should collapse. To do this, Einstein introduced a cosmological constant, which compensated for the gravitational attraction of distant objects.

As paradoxical as it may sound, Einstein did not limit the very finiteness of the universe. In his opinion, the Universe is a closed shell of a hypersphere. An analogy is the surface of an ordinary three-dimensional sphere, for example, a globe or the Earth. No matter how much a traveler travels around the Earth, he will never reach its edge. However, this does not mean at all that the Earth is infinite. The traveler will simply return to the place where he started his journey.

On the surface of the hypersphere

Likewise, a space wanderer, overcoming Einstein's Universe on a starship, can return back to Earth. Only this time the wanderer will move not along the two-dimensional surface of the sphere, but along the three-dimensional surface of the hypersphere. This means that the Universe has a finite volume, and hence a finite number of stars and mass. However, the Universe has no boundaries or any center.

Einstein came to such conclusions by linking space, time and gravity in his famous theory. Before him, these concepts were considered separate, which is why the space of the Universe was purely Euclidean. Einstein proved that gravity itself is a curvature of space-time. This radically changed the early ideas about the nature of the Universe, based on classical Newtonian mechanics and Euclidean geometry.

Expanding Universe

Even the discoverer of the "new Universe" himself was no stranger to delusion. Although Einstein limited the universe in space, he continued to consider it static. According to his model, the universe was and remains eternal, and its size always remains the same. In 1922, the Soviet physicist Alexander Fridman significantly expanded this model. According to his calculations, the universe is not static at all. It can expand or contract over time. It is noteworthy that Friedman came to such a model, based on the same theory of relativity. He was able to more correctly apply this theory, bypassing the cosmological constant.

Albert Einstein did not immediately accept this "amendment". The Hubble discovery mentioned earlier came to the rescue of this new model. The scattering of galaxies indisputably proved the fact of the expansion of the Universe. So Einstein had to admit his mistake. Now the universe had a certain age, which strictly depends on the Hubble constant, which characterizes the rate of its expansion.

Further development of cosmology

As scientists tried to solve this issue, many other important components of the Universe were discovered and various models of it were developed. So in 1948 Georgy Gamow introduced the hypothesis "about a hot Universe", which would later turn into the theory of the big bang. The discovery in 1965 confirmed his guesses. Now astronomers could observe the light that has come down from the moment the universe became transparent.

Dark matter, predicted in 1932 by Fritz Zwicky, was confirmed in 1975. Dark matter actually explains the very existence of galaxies, galactic clusters and the Universe itself as a whole. So scientists learned that most of the mass of the Universe is completely invisible.

Finally, in 1998, during a study of the distance to, it was discovered that the universe is expanding with acceleration. This next turning point in science gave rise to the modern understanding of the nature of the universe. The cosmological coefficient, introduced by Einstein and refuted by Friedman, has again found its place in the model of the Universe. The presence of the cosmological coefficient (cosmological constant) explains its accelerated expansion. To explain the presence of the cosmological constant, the concept was introduced - a hypothetical field containing most of the mass of the Universe.

Current understanding of the size of the observable universe

The current model of the universe is also called the ΛCDM model. The letter "Λ" denotes the presence of a cosmological constant that explains the accelerated expansion of the Universe. "CDM" means that the universe is filled with cold dark matter. Recent studies indicate that the Hubble constant is about 71 (km / s) / Mpc, which corresponds to the age of the Universe 13.75 billion years. Knowing the age of the Universe, one can estimate the size of its observable area.

According to the theory of relativity, information about any object cannot reach the observer with a speed greater than the speed of light (299792458 m / s). It turns out that the observer sees not just an object, but its past. The further the object is from it, the more distant past it looks. For example, looking at the Moon, we see what it was a little over a second ago, the Sun more than eight minutes ago, the nearest stars - years, galaxies - millions of years ago, etc. In Einstein's stationary model, the Universe has no age limit, which means that its observable region is also not limited by anything. The observer, armed with more and more advanced astronomical instruments, will observe more and more distant and ancient objects.

We have a different picture with the modern model of the Universe. According to it, the Universe has an age, and therefore a limit of observation. That is, from the moment the universe was born, no photon would have had time to travel a distance greater than 13.75 billion light years. It turns out that we can state that the observable Universe is limited from the observer by a spherical region with a radius of 13.75 billion light years. However, this is not quite true. Do not forget about the expansion of the space of the Universe. Until the photon reaches the observer, the object that emitted it will be 45.7 billion sv from us. years. This size is the horizon of particles, and it is the boundary of the observable Universe.

Over the horizon

So, the size of the observable Universe is divided into two types. Visible size, also called the Hubble radius (13.75 billion light years). And the real size, called the particle horizon (45.7 billion light years). Fundamentally, both of these horizons do not at all characterize the real size of the Universe. First, they depend on the position of the observer in space. Second, they change over time. In the case of the ΛCDM model, the particle horizon expands at a speed greater than the Hubble horizon. The question of whether this trend will change in the future, modern science does not give an answer. But if we assume that the Universe will continue to expand with acceleration, then all those objects that we see now, sooner or later, will disappear from our “field of view”.

At the moment, the most distant light observed by astronomers is the microwave background radiation. Peering into it, scientists see the Universe as it was 380 thousand years after the Big Bang. At this moment, the Universe has cooled down so much that it was able to emit free photons, which are captured today with the help of radio telescopes. In those days, there were no stars or galaxies in the Universe, but only a continuous cloud of hydrogen, helium and an insignificant amount of other elements. From the inhomogeneities observed in this cloud, galactic clusters will subsequently form. It turns out that exactly those objects that are formed from the inhomogeneities of the relic radiation are located closest to the particle horizon.

True boundaries

Whether the universe has true, unobservable boundaries is still the subject of pseudoscientific conjectures. One way or another, everyone converges at the infinity of the Universe, but they interpret this infinity in completely different ways. Some consider the Universe to be multidimensional, where our “local” three-dimensional Universe is only one of its layers. Others say that the universe is fractal - which means that our local universe may turn out to be a particle of another. Do not forget about the various models of the Multiverse with its closed, open, parallel Universes, wormholes. And there are many, many different versions, the number of which is limited only by human imagination.

But if we turn on cold realism or simply move away from all these hypotheses, then we can assume that our Universe is an infinite homogeneous repository of all stars and galaxies. Moreover, at any very distant point, be it billions of gigaparsecs from us, all conditions will be exactly the same. At this point, there will be exactly the same horizon of particles and the Hubble sphere with the same relic radiation at their edge. There will be the same stars and galaxies around. Interestingly, this does not contradict the expansion of the universe. After all, it is not just the Universe that is expanding, but its very space. The fact that at the moment of the big bang the Universe arose from one point only says that the infinitely small (practically zero) dimensions that were then have now turned into unimaginably large ones. In the future, we will use this particular hypothesis in order to clearly understand the scale of the observable Universe.

Visual representation

Various sources provide all kinds of visual models that allow people to understand the scale of the universe. However, it is not enough for us to realize how big the cosmos is. It is important to understand how concepts such as the Hubble horizon and the particle horizon actually manifest. To do this, let's imagine our model step by step.

Let's forget that modern science does not know about the "foreign" region of the Universe. Discarding the versions about the multiverse, the fractal Universe and its other "varieties", imagine that it is simply infinite. As noted earlier, this does not contradict the expansion of her space. Of course, we will take into account the fact that its Hubble sphere and the sphere of particles are respectively equal to 13.75 and 45.7 billion light years.

The scale of the universe

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To begin with, let's try to realize how large the universal scale is. If you have traveled around our planet, then you can well imagine how big the Earth is for us. Now let's imagine our planet as a buckwheat grain that orbits around a watermelon-Sun half the size of a football field. In this case, the orbit of Neptune will correspond to the size of a small city, the region - to the Moon, the region of the boundary of the Sun's influence - to Mars. It turns out that our Solar System is as much larger than the Earth as Mars is larger than buckwheat! But this is just the beginning.

Now let's imagine that this buckwheat will be our system, the size of which is approximately equal to one parsec. Then the Milky Way will be the size of two football stadiums. However, even this will not be enough for us. We'll have to reduce the Milky Way to a centimeter size. It will somewhat resemble coffee foam wrapped in a whirlpool in the middle of the coffee-black intergalactic space. Twenty centimeters away from it there is the same spiral "crumb" - the Andromeda Nebula. Around them will be a swarm of small galaxies from our Local Cluster. The apparent size of our universe will be 9.2 kilometers. We have come to an understanding of the Universal dimensions.

Inside the universal bubble

However, it is not enough for us to understand the scale itself. It is important to understand the dynamics of the universe. Imagine ourselves as giants, for which the Milky Way has a centimeter diameter. As noted just now, we will find ourselves inside a sphere with a radius of 4.57 and a diameter of 9.24 kilometers. Let's imagine that we are able to hover inside this sphere, travel, overcoming entire megaparsecs in a second. What will we see if our Universe is infinite?

Of course, before us there will be an infinite number of all kinds of galaxies. Elliptical, spiral, irregular. Some areas will be teeming with them, others will be empty. The main feature will be that visually they will all be motionless while we are motionless. But as soon as we take a step, the galaxies themselves will begin to move. For example, if we are able to discern the microscopic Solar System in the centimeter Milky Way, we will be able to observe its development. Moving 600 meters away from our galaxy, we will see the protostar Sun and the protoplanetary disk at the time of formation. Approaching it, we will see how the Earth appears, life is born and a person appears. In the same way, we will see how galaxies change and move as we move away or approach them.

Therefore, the more distant galaxies we look, the more ancient they will be for us. So the most distant galaxies will be located further than 1300 meters from us, and at the turn of 1380 meters we will see the relic radiation. True, this distance will be imaginary for us. However, as we get closer to the relic radiation, we will see an interesting picture. Naturally, we will observe how galaxies will form and develop from the original cloud of hydrogen. When we reach one of these formed galaxies, we will understand that we have overcome not 1.375 kilometers at all, but all 4.57.

Downscaling

As a result, we will increase even more in size. Now we can place whole voids and walls in the fist. So we find ourselves in a rather small bubble, from which it is impossible to get out. Not only will the distance to objects on the edge of the bubble increase as they get closer, but the edge itself will drift infinitely. This is the whole point of the size of the observable universe.

No matter how big the Universe is, for the observer it will always remain a limited bubble. The observer will always be in the center of this bubble, in fact, he is its center. Trying to get to any object at the edge of the bubble, the observer will shift its center. As it gets closer to the object, this object will move farther and farther from the edge of the bubble and at the same time change. For example, from a shapeless hydrogen cloud it will turn into a full-fledged galaxy or further a galaxy cluster. In addition, the path to this object will increase as you approach it, as the surrounding space itself will change. Once we get to this object, we will only move it from the edge of the bubble to its center. At the edge of the Universe, the relic radiation will also flicker.

If we assume that the Universe will continue to expand at an accelerated rate, then being in the center of the bubble and winding time for billions, trillions and even higher orders of years ahead, we will notice an even more interesting picture. Although our bubble will also grow in size, its mutating components will move away from us even faster, leaving the edge of this bubble, until each particle of the universe wanders scattered in its lonely bubble without the ability to interact with other particles.

So, modern science does not have information about what the real dimensions of the Universe are and whether it has boundaries. But we know for sure that the observed Universe has a visible and true border, called the Hubble radius (13.75 billion light years) and the radius of particles (45.7 billion light years), respectively. These boundaries are completely dependent on the position of the observer in space and expand over time. If the Hubble radius expands strictly at the speed of light, then the expansion of the particle horizon is accelerated. The question of whether its acceleration of the particle horizon will continue further and will not change to compression remains open.