Dark matter and dark energy. Dark matter

plays decisive role in the development of the universe. However, little is known about this strange substance yet. Professor Matthias Bartelmann - Heidelberg Institute for Theoretical Astrophysics - explains how dark matter research has been done, answering a series of questions from journalists.

and how does it arise?

I have no idea! So far, no one. It probably consists of heavy elementary particles. But no one knows if they are really particles. In any case, they are very different from anything we have known before.

Is it like discovering a whole new animal species?

Yes, that's right, that's a good comparison.

Who discovered dark matter and when?

In 1933, Fritz Zwicky considered the motion of galaxies in galaxy clusters, which depends on the total mass of the cluster. The researcher noticed that galaxies, given their calculated mass, move very quickly. This was the first hint of dark matter. No known matter could explain why the stars in galaxies stick together: they must, because of their high speed appeals fly apart.

Gravitational lens Photo: Wissensschreiber

What other evidence is there?

Pretty good evidence is the gravitational lens effect. Distant galaxies appear distorted to us, as light rays deviate from matter on their way. It's like looking through fluted glass. And the effect is stronger than it would be if only visible matter existed.

What does dark matter look like?

It cannot be seen, since there is no interaction of dark matter and electromagnetic radiation. This means that it does not reflect light and does not emit any radiation.

How do you study dark matter then? What instruments are needed for research?

We are not studying dark matter specifically, but only its manifestations, for example, the effect of a gravitational lens. I am a theorist. As a matter of fact, I just need my computer, a pen and a sheet of paper. But I also use data from large telescopes in Hawaii and Chile.

Is it possible to depict dark matter?

Yes, you can create a kind of map of its distribution. Just as the lines of hills show on geographical map the contours of the mountain, here you can see by the density of lines, where there is especially a lot of dark matter.

When did she appear?

Dark matter arose either directly at the Big Bang, or 10,000-100,000 years later. But we are still studying this.

How much dark matter is there?

Nobody can say for sure. But based on recent research, we believe that there is about seven to eight times more dark matter in the universe than visible matter.

Computer modeling shows the distribution of dark matter in the form of a web, and we see its accumulation in the brightest areas.
Photo: Volker Springel

Is there a relationship between dark energy and dark matter?

Probably not. Dark energy ensures the accelerated expansion of the universe, while dark matter holds galaxies together.

Where did she come from?

Dark matter is probably everywhere, only it is not evenly distributed - just like visible matter, it forms clumps.

What is the significance of dark matter for us and our worldview?

For Everyday life she doesn't matter. But in astrophysics it is very important, as it plays a decisive role in the development of the Universe.

What is our universe made of? 4.9% visible matter, 26.8% dark matter, 68.3% dark energy Photo: Wissensschreiber

What will she bring about in the future?

Probably nothing more. Previously, for the development of the universe, it was very important. Today, it only still holds individual galaxies together. And as the universe continues to expand, it becomes increasingly difficult for new structures of dark matter to emerge.

Will it be possible in the future to directly image dark matter using instruments?

Yes it is possible. For example, one can measure the vibrations that occur when dark matter particles collide with atoms in a crystal. The same happens in the particle accelerator: if elementary particles seem to fly in an unexpected direction for no reason, then an unknown particle may be to blame. Then this would be another proof of the existence of dark matter. Imagine: you are standing on a football field and there is a ball in front of you. He suddenly flies away for no apparent reason. He must have been knocked down by something invisible.

What interests you the most in your work?

I am attracted by the assumption that visible matter is only a small fraction of everything, and we have no idea of ​​the remainder.

Thank you for taking the time. We hope you will learn more about dark matter soon!

The term "dark matter" (or hidden mass) is used in various fields of science: in cosmology, astronomy, physics. We are talking about a hypothetical object - a form of the content of space and time, which directly interacts with electromagnetic radiation and does not pass it through itself.

Dark matter - what is it?

Since time immemorial, people have been concerned about the origin of the Universe and the processes that form it. In the age of technology, important discoveries have been made, and the theoretical base has been significantly expanded. In 1922, British physicist James Jeans and Dutch astronomer Jacobus Kaptein discovered that most of galactic matter is not visible. Then for the first time the term dark matter was named - this is a substance that cannot be seen by any of the known to mankind ways. The presence of a mysterious substance is given out by indirect signs - a gravitational field, gravity.

Dark matter in astronomy and cosmology

By assuming that all objects and parts in the universe are attracted to each other, astronomers were able to find the mass of visible space. But a discrepancy was found in the real and predicted weight. And scientists have found out that there is an invisible mass, which accounts for up to 95% of all unknown essence in the Universe. Dark matter in space has the following characteristics:

• affected by gravity
• affects other space objects,
• little interaction with the real world.

Dark matter - philosophy

A special place is occupied by dark matter in philosophy. This science is engaged in the study of the world order, the foundations of being, the system of visible and invisible worlds. A certain substance was taken as the fundamental principle, determined by space, time, and environmental factors. Discovered much later, the mysterious dark matter of the cosmos changed the understanding of the world, its structure and evolution. In a philosophical sense, an unknown substance, like a clot of space and time energy, is present in each of us, therefore people are mortal, because they consist of time that has an end.

What is dark matter for?

Only a small part of space objects (planets, stars, etc.) is visible matter. By the standards of various scientists, dark energy and dark matter occupy almost the entire space in the Cosmos. The former accounts for 21-24%, while energy takes 72%. Each substance of unclear physical nature has its own functions:

1. Black energy, which does not absorb or emit light, repels objects, causing the universe to expand.
2. Galaxies are built on the basis of the hidden mass, its force attracts objects in outer space, keeps them in their places. That is, it slows down the expansion of the universe.

What is dark matter made of?

dark matter in solar system- this is something that cannot be touched, examined and studied thoroughly. Therefore, several hypotheses are put forward regarding its nature and composition:

1. Not known to science the particles involved in gravity are a component of this substance. It is impossible to detect them with a telescope.
2. The phenomenon is a cluster of small black holes (no larger than the moon).

It is possible to distinguish two types of hidden mass, depending on the speed of its constituent particles, the density of their accumulation.

1. Hot. It is not enough for the formation of galaxies.
2. Cold. Consists of slow, massive clots. These components can be known to science axions and bosons.

Does dark matter exist?

All attempts to measure objects of unexplored physical nature have not been successful. In 2012, the movement of 400 stars around the Sun was investigated, but the presence of dark matter in large volumes was not proven. Even if dark matter does not exist in reality, it does exist in theory. With its help, the location of the objects of the Universe in their places is explained. Some scientists are finding evidence for the existence of hidden cosmic mass. Its presence in the universe explains the fact that clusters of galaxies do not scatter in different directions and stick together.

Dark matter - interesting facts

The nature of the hidden mass remains a mystery, but it continues to interest scientific minds around the world. Experiments are regularly conducted, with the help of which they try to investigate the substance itself and its side effects. And the facts about her continue to multiply. For example:

1. The acclaimed Large Hadron Collider, the world's most powerful particle accelerator, is running at high power to reveal the existence of invisible matter in space. The world community is waiting with interest for the results.
2. Japanese scientists create the world's first hidden mass map in space. It is planned to be completed by 2019.
3. Recently, theoretical physicist Lisa Randall suggested that dark matter and dinosaurs are related. This substance sent a comet to Earth, which destroyed life on the planet.

The components of our galaxy and the entire Universe are light and dark matter, that is, visible and invisible objects. If with the study of the first modern technology copes, the methods are constantly being improved, then it is very problematic to investigate hidden substances. Mankind has not yet come to understand this phenomenon. Invisible, intangible, but ubiquitous dark matter has been and remains one of the main mysteries of the Universe.

Dark matter is another of the discoveries of mankind, made "on the tip of a pen." No one has ever felt it, it does not radiate electromagnetic waves and does not interact with them. For more than half a century, there has been no experimental evidence for the existence of dark matter, only experimental calculations are given that allegedly confirm its existence. But on this moment- this is just a hypothesis of astrophysicists. However, it should be noted that this is one of the most intriguing and highly substantiated scientific hypotheses.

It all started at the beginning of the last century: astronomers noticed that the picture of the world they observe does not fit into the theory of gravity. Theoretically, galaxies, having a calculated mass, rotate faster than it should be.

This means that they (galaxies) have a much larger mass than the calculations from the observations made suggest. But if they do rotate, then either the theory of gravity is not correct, or this theory does not “work” on objects such as galaxies. Or there is more matter in the Universe than modern instruments can detect. This theory became more popular among scientists, and this intangible hypothetical substance was called dark matter.
From the calculations, it turns out that there is about 10 times more dark matter in the composition of galaxies than ordinary matter, and different matter interacts with each other only at the gravitational level, that is, dark matter manifests itself exclusively in the form of mass.
Some scholars suggest that some dark matter- this is an ordinary substance, but does not emit electromagnetic radiation. Such objects include dark galactic halos, neutron stars, and brown dwarfs, as well as other yet hypothetical space objects.

If you believe the findings of scientists, then ordinary matter (mainly contained in galaxies) is collected
around areas with the densest concentration of dark matter. On the resulting space
vein map, dark matter is an uneven network of giant filaments, since
changes that increase and intersect in places of galactic clusters.

Dark matter is divided into several classes: hot, warm and cold (this depends on the speed of the particles of which it consists). This is how hot, warm and cold dark matter is isolated. It is cold dark matter that is of greatest interest to astronomers, since it can form stable objects, for example, entire dark galaxies.
The theory of dark matter also fits into the Big Bang theory. Therefore, scientists suggest that 300 thousand years after the explosion, first in huge number particles of dark matter began to cluster, and after that, by the force of gravity, particles of ordinary matter gathered on them and galaxies formed.
These surprising findings mean that the mass of ordinary matter is only a few percent of gross weight universe!!!

That is, the world we see is only a small part of what the Universe actually consists of. And we cannot even imagine what this huge “something” is.

Everything that we see around us (stars and galaxies) is no more than 4-5% of the total mass in the Universe!

According to modern cosmological theories, our Universe consists of only 5% of ordinary, so-called baryonic matter, which forms all observable objects; 25% of dark matter registered due to gravity; and dark energy, which makes up as much as 70% of the total.

The terms dark energy and dark matter are not entirely successful and represent a literal, but not semantic translation from English.

In the physical sense, these terms mean only that these substances do not interact with photons, and they could just as well be called invisible or transparent matter and energy.

Many modern scientists are convinced that research aimed at studying dark energy and matter will probably help answer the global question: what awaits our Universe in the future?

Clumps the size of a galaxy

Dark matter is a substance that most likely consists of new, still unknown particles in terrestrial conditions and has properties inherent in the most ordinary matter. For example, it is also capable, like ordinary substances, of gathering into clumps and participating in gravitational interactions. But the size of these so-called clumps can exceed an entire galaxy or even a cluster of galaxies.

Approaches and methods for studying dark matter particles

At the moment, scientists around the world are trying in every possible way to detect or artificially obtain particles of dark matter under terrestrial conditions, using specially designed high-tech equipment and many different research methods, but so far all the work has not been crowned with success.

One method involves conducting experiments at high-energy accelerators, commonly known as colliders. Scientists, believing that dark matter particles are 100-1000 times heavier than a proton, suggest that they will have to be generated by the collision of ordinary particles accelerated to high energies by means of a collider. The essence of another method is to register dark matter particles that are all around us. The main difficulty in registering these particles is that they exhibit very weak interaction with ordinary particles, which, in their essence, are, as it were, transparent to them. And yet, dark matter particles very rarely, but collide with the nuclei of atoms, and there is a certain hope, sooner or later, to register this phenomenon.

There are other approaches and methods for studying dark matter particles, and which of them will be the first to succeed, only time will tell, but in any case, the discovery of these new particles will be a major scientific achievement.

Substance with antigravity

Dark energy is an even more unusual substance than the same dark matter. It does not have the ability to gather into clumps, as a result of which it is evenly distributed absolutely throughout the Universe. But its most unusual property at the moment is anti-gravity.

The nature of dark matter and black holes

Thanks to modern astronomical methods, it is possible to determine the rate of expansion of the Universe at the present time and to model the process of its change earlier in time. As a result, information was obtained that at the moment, just as in the recent past, our Universe is expanding, while the rate of this process is constantly increasing. That is why the hypothesis of antigravity of dark energy appeared, since the usual gravitational attraction would have a slowing down effect on the process of "recession of galaxies", restraining the rate of expansion of the Universe. This phenomenon does not contradict general theory relativity, but at the same time, dark energy must have a negative pressure - a property that none of the substances known at the moment has.

Candidates for the role of "Dark Energy"

The mass of galaxies in the Abel 2744 cluster is less than 5 percent of its total mass. This gas is so hot that it only shines in the X-ray range (red in this image). The distribution of invisible dark matter (which makes up about 75 percent of the mass of this cluster) is colored blue.

One of the proposed candidates for the role of dark energy is the vacuum, whose energy density remains unchanged during the expansion of the Universe and thus confirms the negative pressure of the vacuum. Another alleged candidate is the "quintessence" - a previously unknown super-weak field, allegedly passing through the entire Universe. There are also other possible candidates, but not one of them has so far contributed to obtaining an accurate answer to the question: what is dark energy? But it is already clear that dark energy is something completely supernatural, remaining the main mystery of the fundamental physics of the XXI century.

To date, the mystery of where the dark matter came from has not been solved. There are theories that suggest that it is composed of low temperature interstellar gas. In this case, the substance cannot give any radiation. However, there are theories that counter this idea. They say that the gas is able to heat up, which leads to the fact that they become ordinary "baryon" substances. In favor of this theory is the fact that the mass of gas in the cold state cannot eliminate the deficit that occurs in this case.

There are so many questions in the theories about dark matter that it is worth understanding this in a little more detail.

What is dark matter?

The question of what is dark matter appeared about 80 years ago. As early as the beginning of the 20th century. At that time, the Swiss astronomer F. Zwicky came up with the idea that the mass of all galaxies in reality is greater than the mass of all those objects that can be seen with their own gases through a telescope. All the numerous clues hinted at the fact that there is something unknown in space that has an impressive mass. It was decided to give the name "dark matter" to this inexplicable substance.

This invisible substance occupies at least a quarter of the entire universe. The peculiarity of this substance is that its particles do not interact well with each other and with other ordinary substances. This interaction is so weak that scientists can't even register it. In fact, there are only signs of influence from particles.

The study of this issue is being conducted by the biggest minds around the world, so even the biggest skeptics in the world believe that it will be possible to capture particles of matter. The most desirable goal is to do this in a laboratory setting. Work is underway in mines at great depths, such conditions for experiments are necessary in order to exclude interference from particles of rays from space.

It is likely that a lot of new information will be obtained thanks to modern accelerators, in particular, with the help of the Large Hadron Collider.

Particles of dark matter have one strange feature - mutual annihilation. As a result of such processes, gamma radiation, antiparticles and particles (such as the electron and positron) appear. Therefore, astrophysicists are trying to find traces of gamma radiation or antiparticles. For this, various ground and space installations are used.

Evidence for the existence of dark matter

The very first doubts about the correctness of the calculations of the mass of the Universe, as already mentioned, were shared by the astronomer from Switzerland F. Zwicky. To begin with, he decided to measure the speed of the galaxies from the Coma Cluster moving around the center. And the result of his work somewhat puzzled him, because the speed of movement of these galaxies turned out to be higher than he expected. In addition, he pre-calculated this value. But the results didn't match.

The conclusion was obvious: the actual mass of the cluster was much larger than the apparent one. This could be explained by the fact that most of the matter that is in this part of the universe cannot be seen, and it is also impossible to observe it. This substance manifests its property only in the form of a mass.

A number of gravitational experiments have confirmed the presence of an invisible mass in galaxy clusters. In the theory of relativity there is some interpretation of this phenomenon. If you follow it, then each mass is capable of deforming space, in addition, like a lens, it bends a direct stream of light rays. The galaxy cluster causes a distortion, its influence is so strong that it becomes noticeable. The most distorted view of the galaxy, which is located directly behind the cluster. This distortion is used to calculate how the matter is distributed in this cluster. This is how real mass is measured. It invariably turns out to be several times larger than the mass of visible matter.

Four decades after the work of the pioneer in this field, F. Zwicky, the astronomer from America, V. Rubin, took up this issue. She studied the speed with which the substance that is located at the edges of galaxies rotates around the center of the galaxy. If you follow Kepler's laws regarding the laws of gravity, then there is a certain relationship between the speed of rotation of galaxies and the distance to the center.

But in reality, the measurements showed that the rotation speed did not change with increasing distance to the center. Such data could be explained in only one way - the matter of the galaxy has the same density both in the center and along the edges. But the visible matter had a much greater density in the center and was characterized by rarefaction at the edges, and the lack of density could only be explained by the presence of some substance that is not visible to the eye.

To give an explanation for the phenomenon, it is necessary that this very invisible substance in galaxies be almost 10 times more than the substance that we can see. It is this unknown substance that has received the name "dark matter", or "dark matter". To date, for astrophysicists, this phenomenon remains the most interesting mystery.

There is another argument in favor of evidence for the existence of dark matter. It follows from calculations that describe the process of how galaxies formed. It is believed that this began about 300,000 years after the Big Bang occurred. The calculation results show that the attraction between the fragments of matter that appeared during the explosion could not compensate kinetic energy from scattering. That is, matter could not be concentrated in galaxies, but we can see this today.

This inexplicable fact is called the paradox of the galaxy, it was cited as an argument that destroys the Big Bang theory. But you can look at it from the other side. After all, particles of the most ordinary matter could be mixed with particles of dark matter. Then the calculations become correct, but how galaxies were formed, in which a lot of dark matter has accumulated, and particles of ordinary matter have already joined them due to gravity. After all, ordinary matter makes up a small fraction of the entire mass of the universe.

Visible matter has a relatively low density compared to dark matter because it is 20 times denser. Therefore, those 95% of the mass of the Universe, which are missing according to the calculations of scientists, this is dark matter.

However, this led to the conclusion that the entire visible world, which was studied up and down, is so familiar and understandable, only a small addition to what it really consists of.

All galaxies, planets and stars are just a small piece of what we have no idea about. This is what is on display, and the real is hidden from us.