Universe - abstract. "Space exploration" report Message on the topic of the study of the universe
INTRODUCTION
The study of the Universe, even only part of it known to us, is a daunting task. To obtain the information that modern scientists have, it took the work of many generations. We know the structure of the universe in a vast volume of space, which light takes billions of years to cross. But the inquisitive thought of man strives to penetrate further. What lies beyond the observable region of the world? Is the universe infinite in volume? And its expansion - why did it start and will it always continue in the future? And what is the origin of the "hidden" mass? And finally, how did intelligent life originate in the universe?
Does it exist anywhere else besides our planet? There are no definitive and complete answers to these questions yet.
The universe is inexhaustible. The thirst for knowledge is also tireless, forcing people to ask more and more new questions about the world and persistently seek answers to them.
Perhaps that is why I chose this topic for the essay. The unknown has always attracted the attention of man. The universe, stars and planets are a perfect example of this.
This branch is quite well covered both by the achievements of science and the works of literature. However, in some matters, opinions are different, so it is worth reflecting on some topic of interest to you and drawing your own conclusions.
FOREWORD
The stars in the universe are grouped into giant star systems called galaxies. The number of stars in the Galaxy is about 1012 (trillion). Our galaxy is called the Milky Way. It includes the Sun, 9 large planets with their 34 satellites, more than 100 thousand small planets (asteroids), about 1011 comets, as well as countless small, so-called meteoroids (diameter from 100 meters to negligible dust particles).
The Milky Way, a bright silver band of stars, encircles the entire sky, making up the bulk of our Galaxy. In general, our Galaxy occupies a space resembling a lens or lentil when viewed from the side. The dimensions of the Galaxy were outlined by the arrangement of stars that are visible at great distances. The mass of our Galaxy is now estimated in various ways, it is approximately 2 * 1011 masses of the Sun (the mass of the Sun is 2 * 1030 kg), and 1/1000 of it is contained in interstellar gas and dust. The mass of the galaxy in Andromeda is almost the same, while the mass of the galaxy in Triangulum is estimated to be 20 times less. Our galaxy is 100,000 light years across. Through painstaking work, the Moscow astronomer V.V. Kukarin in 1944 found indications of the spiral structure of the Galaxy, and it turned out that we live in a space between two spiral branches, poor in stars. In some places in the sky with a telescope, and in some places even with the naked eye, one can distinguish close groups of stars connected by mutual gravity, or star clusters.
According to the currently accepted hypothesis, the formation of the solar system began about 4.6 billion years ago with the gravitational collapse of a small part of a giant interstellar gas and dust cloud. In general terms, this process can be described as follows:
- The trigger mechanism for the gravitational collapse was a small (spontaneous) compaction of the matter of the gas and dust cloud (possible reasons for which could be both the natural dynamics of the cloud, and the passage of a shock wave from a supernova explosion through the matter of the cloud, etc.), which became the center of gravitational attraction for the surrounding matter - center of gravitational collapse. The cloud already contained not only primary hydrogen and helium, but also numerous heavy elements (metals) left over from the stars of previous generations. In addition, the collapsing cloud had some initial angular momentum.
- In the process of gravitational compression, the size of the gas and dust cloud decreased and, due to the law of conservation of angular momentum, the speed of rotation of the cloud increased. Due to the rotation, the compression rates of the clouds parallel and perpendicular to the axis of rotation differed, which led to the flattening of the cloud and the formation of a characteristic disk.
- As a consequence of compression, the density and intensity of collisions of matter particles with each other increased, as a result of which the temperature of the matter continuously increased as it was compressed. The central regions of the disk were heated most strongly.
- Upon reaching a temperature of several thousand kelvins, the central region of the disk began to glow - a protostar was formed. The cloud matter continued to fall onto the protostar, increasing the pressure and temperature at the center. The outer regions of the disk remained relatively cold. Due to hydrodynamic instabilities, separate seals began to develop in them, which became local gravitational centers for the formation of planets from the substance of the protoplanetary disk.
- When the temperature in the center of the protostar reached millions of kelvins, a thermonuclear hydrogen burning reaction began in the central region. The protostar has evolved into an ordinary main sequence star. In the outer region of the disk, large clusters formed planets revolving around the central star in approximately the same plane and in the same direction.
Subsequent evolution
After the initial formation, the solar system has evolved significantly. Many satellites of the planets were formed from gas and dust disks orbiting the planets, while other satellites were presumably captured by the planets or were the result of collisions of the bodies of the solar system (according to one hypothesis, the Moon was formed this way). Collisions of the bodies of the solar system have always occurred, up to the present moment, which, along with gravitational interaction, was the main driving force of the evolution of the solar system. In the course of evolution, the orbits of the planets changed significantly, up to a change in their order - planetary migration took place. It is currently assumed that planetary migration explains much of the early evolution of the solar system.
Future
In about 5 billion years, the surface of the Sun will cool down, and the Sun itself will increase many times in size (its diameter will reach the diameter of the modern orbit of the Earth), turning into a red giant. Subsequently, the outer layers of the Sun will be ejected by a powerful explosion into the surrounding space, forming a planetary nebula, in the center of which only a small stellar core will remain - a white dwarf. At this stage, nuclear reactions will stop and in the future there will be a slow steady cooling of the Sun.
In the very distant future, the gravity of nearby stars will gradually destroy the planetary system. Some of the planets will be destroyed, others will be thrown into interstellar space. Ultimately, in trillions of years, the cooled Sun will most likely lose all of its planets, and alone will continue its orbit around the center of our Milky Way galaxy among many other stars.
Admiring the stars on a clear autumn night, we immediately notice a wide foggy strip passing through the whole sky - Milky Way is the name of our galaxy. We involuntarily think about other worlds that inhabit the cosmos, and admire the grandeur and grandiose beauty of the universe around us. How did planets, stars, galaxies originate?
At the beginning of the world, after the Big Bang, a myriad of formed particles scattered at great speeds and gradually turned into atoms of primary matter, which formed a huge cloud, billions of times greater than the mass of the Sun. This cloud began to thicken, the first atoms of hydrogen and helium appeared in it. As in any gas, turbulent flows arose in it, generating eddies. In these whirlwinds, hydrogen clusters appeared rotating at different speeds, which became more and more dense, shrinking around their center - the axis of rotation. The rotation speed increased with decreasing volume in accordance with the law of conservation of momentum. In this case, the centrifugal force acting along the equatorial plane increases, and the cloud is flattened, turning from a spherical shape into a lenticular or disk-shaped one. This is how galaxies are born.
The first stars appeared at the spherical stage of galaxy formation. They consisted only of hydrogen and helium. A thermonuclear reaction took place in them - the combination of two protons. Having used up their supply of hydrogen, these stars exploded and became supernovae. As a result of the explosion, new elements appeared, heavier than helium. This happened everywhere, the interstellar gas was replenished with new elements, from which, as a result of thermonuclear reactions, ever heavier ones were obtained.
The Milky Way is a spiral galaxy.
This is how our galaxy, the Milky Way, was formed. If you look at it "from above" from space, it looks like a disk with a spiral structure - arms, where young stars and regions with an increased density of interstellar gas are located. In the middle of the disk is a spherical bulge - the core of the galaxy. If you look at the map of the starry sky, then the center of our galaxy will be in the constellation Sagittarius. Astronomers were able to identify the closest spiral branches of the galaxy to Earth: the branches of Orion (where the solar system is located), Perseus and Sagittarius. The nearest branch to the core is the Karina (Kiel) branch, and the existence of a distant branch, the Centaur, is assumed. These spiral branches-sleeves got their names from the constellations in which they are located on the map of the starry sky.
If we look at a spiral galaxy through a good telescope, we will see that it looks like a fiery fireworks wheel. But what determines such a structure of galaxies? It would seem that there is nothing surprising in this. The famous scientist astronomer Carl Friedrich von Weizsäcker once said that if at first Milky Way if it looked like a cow, it would still have acquired a spiral structure. Some scientists have seriously begun to develop the "Weizsäcker galactic cow", and, indeed, according to calculations, it should have turned into a galactic spiral in about a hundred million years. And our Milky Way is much older - almost a hundred times. During this time, the beautiful spiral galaxy should have been transformed in such a way that the spirals form long threads that wrap around the center. But, as it turned out, not a single known galaxy has a filamentous structure and does not stretch, although spiral arms, consisting of stars and gas, constantly rotate around the center of the galaxy. An irresolvable contradiction? No, if we give up the idea that the interstellar matter is constantly located in one spiral arm and assume that a stream of gas and stars simply moves through these spiral arms. That is, the stars and gas move, rotating around the center, and the arms of the spiral are certain states of the structure of the galaxy, along which flows of cosmic matter and stars move. How can this be? Light a candle or gas burner. You will see flames in which a chemical combustion reaction of a substance takes place. The flame is a region of space that determines the state of the gas flow. Similarly, in spiral arms, the flow of stars and gas has a certain state, which is determined by the gravitational field.
If we imagine a huge number of stars forming a rotating disk, we will see that where the density of stars is greater, they tend to get even closer, but the centrifugal force complicates the process, and the balance in such a rotating disk is very unstable. This situation was simulated on a computer, and it turned out that as a result, spiral regions of increased density of stars are formed. Those. the stars themselves form spiral arms that do not become filamentous and do not stretch. Moreover, the stars flow through these spiral regions. Once in the sleeve, they approach, leaving - they diverge. The same thing happens with interstellar gas. Once in the spiral arm, the gas condenses, and conditions are created for the formation of new stars. Therefore, young stars form in this region. Among them are bright blue stars that cause the cosmic gas and dust to glow, ionizing them. Luminous clouds of ionized gas are created, allowing us to enjoy the beautiful spectacle of spiral galaxies.
The stars in the central part of the galaxy are mostly made up of red giants that formed almost simultaneously with the galaxy. At the very center, the presence of a supermassive black hole (Sagittarius A) is assumed, around which another medium-mass black hole possibly rotates. Their gravitational interaction is the center of gravity of the entire galaxy and controls the movement of stars.
According to the latest scientific data, the diameter milky way- about 100,000 light years (approximately 30,000 parsecs), and the average thickness of our disk is about 1000 light years. According to modern estimates, the number of stars in the galaxy ranges from 200 billion to 400 billion.
In the Universe, in addition to spiral galaxies, there are other types: elliptical, barred galaxies, dwarf, irregular, and others.
Galaxies are combined into clusters, which can include several hundred galaxies. These clusters, in turn, can combine into superclusters. Our Galaxy belongs to the Local (Local) group, which includes the constellation Andromeda. In total, there are about 40 galaxies in the Local Group, and it itself is part of the Virgo supercluster. So our vast galaxy Milky Way with billions of stars is just a small island in the boundless ocean of the universe.
The evolution of even one star cannot be traced over the lifetime of several generations of people. The life of the shortest-lived stars is estimated in millions of years. Mankind does not live that long. Therefore, the ability to trace stellar evolution from the beginning - the birth of a star - to its end lies in comparing the chemical and physical characteristics of stars at different stages of development.
The main indicator of the physical properties of a star is its luminosity and color. According to these characteristics, the stars were grouped into groups called sequences. There are several of them: the main sequence, the sequence of supergiants, bright and weak giants. There are also subgiants, subdwarfs and white dwarfs.
These funny names reflect the different stages of the state of the star, which it goes through in the process of its evolution. The two astronomers Hertzsprung and Ressel have compiled a diagram that relates the surface temperature of a star to its luminosity. The temperature of a star is determined by its color. It turned out that the hottest stars are blue, the coldest are red. When Hertzsprung and Ressel placed stars with known physical characteristics - luminosity-color (temperature) on the diagram, it turned out that they are located in groups. It turned out quite a funny picture, where the place of a star on it determined at what stage of evolution this star is.
Most of the stars (almost 90%) were on the main sequence. This means that the star spends the main part of its life in this place of the diagram. The diagram also shows that the smallest stars - dwarfs - are at the bottom, and the largest - supergiants - at the top.
Three paths for the development of stellar evolution
The time allotted for the life of a star is determined primarily by its mass. The mass of a star also determines what it will become when it ceases to be one. The greater the mass, the shorter the life of the star. The most massive - supergiants - live only a few million years, while most stars of medium fatness - about 15 billion years.
All stars, after the source of energy due to which they live, burn with a bright flame, begin to quietly cool down, decrease in size and shrink. They shrink to the state of a massive compact object with a very high density: a white dwarf, a neutron star and a black hole.
Stars with low mass can withstand compression because gravity is relatively low. They are compressed into a small white dwarf and remain in this stable state until their mass increases to a critical value.
If the star's mass is greater than the critical value, then it continues to shrink until the electrons "stick together" with protons, forming a neutron substance. Thus, a small neutron ball with a radius of several kilometers is obtained - a neutron star.
If the star's mass is so huge that gravity continues to compress even neutron matter, then a gravitational collapse occurs, after which a black hole forms in place of the giant star.
What is a white dwarf? Something that didn't become a neutron star or a black hole.
This is what medium and small stars turn into at the end of their evolution. Thermonuclear reactions have already ended, however, they remain very hot dense balls of gas. The stars slowly cool down, glowing with bright white light. The fate of a white dwarf awaits our Sun, as its mass is below critical. The critical mass is 1.4 solar masses. This value is called the Chandrasekhar limit. Chandrasekhar is an Indian astronomer who calculated this value.
The state of a neutron star ends the evolution of such stars, the masses of which exceed the solar mass by several times. A neutron star is the result of a supernova explosion. With a mass 1.5-2 times greater than the sun, it has a radius of 10-20 km. A neutron star rotates rapidly and periodically emits streams of elementary particles and electromagnetic radiation. Such stars are called pulsars. The state of a neutron star is also determined by its mass. The Oppenheimer-Volkov limit is a value that determines the maximum possible mass of a neutron star. To be stable in this state, it is necessary that its mass does not exceed three solar masses.
If the mass of a neutron star exceeds this value, then the monstrous force of gravity compresses it so in the arms of collapse that it becomes a black hole.
A black hole is what happens when the gravitational contraction of massive bodies is unlimited, i.e. when a star shrinks to such an extent that it becomes completely invisible. Not a single ray of light can leave its surface. And here there is also an indicator that determines the state of a space object as a black hole. This is the gravitational radius, or Schwarzschild radius. It is also called the event horizon, since it is impossible to describe or see what happens inside a sphere with such a radius at the site of a collapsed star.
Maybe inside this sphere there are beautiful bright worlds or an exit to another Universe. But for a simple observer, this is just a gap in space, which twists around itself the light coming from other stars and absorbs cosmic matter. By the way other space objects behave next to it, we can make assumptions about its properties.
For example, it can be assumed that the most massive black holes are located in the place where the brightest glow of star clusters is observed. By attracting stellar matter and other space objects to themselves, black holes make them glow, surrounding themselves with a bright luminous halo - a quasar. Darkness cannot exist without light, and light exists because of darkness. This proves the evolution of stars.
BLACK HOLES.
Black holes amaze the imagination: they stop time, captivate light, form holes in space itself. Even light becomes a prisoner of the gravitational sarcophagus.
There are about a billion black holes in our galaxy alone. Nowadays, astrophysicists use black holes to explain mysterious phenomena quite often. The physics and astrophysics of black holes have received wide recognition from the scientific community.
It is believed that the existence of such space objects as black holes, was first substantiated by A. Einstein. The general theory of relativity predicted the possibility of unlimited gravitational compression of massive cosmic bodies to a state of collapse, after which these bodies can only be detected by their gravity.
In fact, people started talking about black holes long before the advent of the theory of relativity.
And it was in the time of I. Newton, who, as everyone knows, discovered the law of universal gravitation. According to this law, everything is subject to gravity, even a beam of light is deflected in the field of attraction of massive bodies. Actually, the history of black holes in the scientific world begins with the realization of this fact.
It began with the work of the English priest and geologist John Michell, who in his article came to the conclusion about the possibility of the existence of black holes based on reasoning about the behavior of a cannonball depending on its speed. As a result, he came to the conclusion that there could be a very small but very heavy star, and that "the speed of its escape" was greater than the speed of light; then the light from its surface will not reach the observer, and it will be possible to detect it only by the force of its attraction. At first glance, the course of reasoning does not shine with iron logic, but perhaps this is just such a case when they try to clothe intuitive insight in the fabric of logic, which this time was quite full of holes due to lack of scientific knowledge.
The famous Frenchman Pierre Laplace wrote in 1795 in his book Exposition of the System of the World:
“A luminous star with a density equal to the density of the Earth and a diameter 250 times greater than the diameter of the Sun does not allow a single light beam to reach us because of its gravity; therefore it is possible that the brightest celestial bodies in the universe turn out to be invisible for this reason. Laplace did not prove his brilliant statement in any way, he simply knew it. However, the scientific world does not take seriously such fundamental things without calculations, formulas and other evidence. Laplace had to work hard, and a few years later he gave his prediction a scientific justification, made on the same classical Newton's law of universal gravitation. These proofs also cannot be considered rigorous, since we already know that Newton's laws do not quite correspond to reality on the scale of the universe and quantum mechanics. But, in those days, it was Newton's theory that was the most advanced, science could not offer anything better, and therefore scientists had to look for the truth where there was light - under the lantern of the classical laws of mechanics.
Black holes in the mysterious light of mysticism
Those interested in occult knowledge and practicing magicians and wizards know that if an object exists, then there is information about it, regardless of whether its presence in nature has been discovered or not yet. Example: the electromagnetic field took place before scientists wrote about it.
Scientists-occultists differ from scientists-materialists in that they are in no hurry to make their knowledge public in the hope of receiving the Nobel Prize and recognition of a grateful humanity. They, for a reason incomprehensible to mere mortals, carefully encrypt what they managed to draw from the cosmic storehouse of information and secretly transmit it to specially selected initiates. However, one way or another, this knowledge seeps into the world in the form of incomprehensible symbols, legends, fairy tales, etc.
The famous occult writer Gustav Meyrink has a short story "The Black Ball", an excerpt from which is given below:
“A velvet-black round body hung motionless in space.
In general, this thing was not at all like a ball, more like a gaping hole. It was nothing but a real hole.
It was absolute, mathematical nothingness!
And so it happened - immediately there was a sharp howling sound, which became louder and louder - the air of the hall began to be sucked into the ball. Scraps of paper, gloves, ladies' veils - everything rushed along with the stream.
And when one of the officers of the civil militia poked a saber into a black hole, the blade disappeared into it, as if dissolved.
.......
The crowd, which did not understand what was happening, and only heard a terrible, ever-growing rumble, rushed out in fear of an inexplicable phenomenon.
Only two Indians remained.
The whole universe, which was created by Brahma, which is supported by Vishnu and destroyed by Shiva, will gradually fall into this ball, - solemnly announced Rajendralalamitra. - That's what trouble we brought, brother, going to the West!
Well, what's in that! muttered the Gosain. “Someday we are all destined to go to that world, which is the denial of being.”
What is the exact description of the properties black hole according to modern ideas! And this story was written even before the advent of A. Einstein's theory of relativity ...
I would also like to add that in the story a black ball appears as a material embodiment of the thought-form of one of those present ... Isn't this the occultist's hint at the causes of black holes?
Modern ideas about the properties of a black hole.
What does modern physics say about the properties of black holes? It turns out that a black hole is determined by only one parameter - mass. And it is practically indestructible. For example, if it occurs to someone to shoot it with nuclear weapons in order to somehow change it or “tear it to shreds”, then its mass will simply increase by the mass of these same bombs and that’s it. The black hole will simply become more massive. But it turned out, not everything is so simple. A black hole is not just a gluttonous monster that consumes everything and everything. It can "evaporate" little by little due to mixed Hawking radiation. That is, a black hole can turn any body that has fallen into it into information and “give it away” in the form of a stream of various radiations and quarks. Such objects are discovered by astronomers, they are called pulsars. Thus, it can be concluded that black holes are characterized not only by their mass, but also by the information they contain.
How do black holes form?
Black holes are born from very large and beautiful stars - red giants, the mass of which exceeds the solar mass by more than ten times. The evolution of such stars is very fast. After a few million years, all hydrogen “burns out”, turning into helium, which, in turn, as a result of combustion, turns into carbon, carbon into other, heavier elements, etc. The rate of transformation also increases. Finally, iron atoms appear.
On this, the stellar nuclear reactor stops its work. Energy is no longer released from iron nuclei. They themselves begin to capture electrons from the surrounding gas. The central region of the star, consisting of gaseous iron, begins to decrease due to the compaction and absorption of electrons by the iron nuclei. Finally, a dense iron core forms in the center of the star. Further, it all depends on how much iron is obtained in this star. If its mass was 1.5 solar masses, then an irreversible process begins, which leads to collapse.
The fact is that iron atoms are so tightly pressed against each other that they simply flatten out. Protons and electrons combine with each other to form neutrons. When protons and electrons combine, an unimaginable amount of energy is released, which sweeps the outer part of the star. Then you can observe the explosion of a supernova, which means the end of the star. After the explosion, a neutron core remains in place of a massive giant. Further development of events inevitably leads to the formation of a black hole.
Chandrasekhar limit and Schwarzschild radius.
This is the classic way black holes form. A neutron star can come from a white dwarf - a star from the class of very dense and hot stars. The number equal to 1.4 solar masses also plays a big role here - the Chandrasekhar limit. As soon as the mass of the white dwarf reaches this value, the process of "collapse" of the star, described above, begins. A white dwarf turns into a neutron star in a minute.
Any ray of light emerging from the surface of such a star is bent in space, it travels almost parallel to the surface of the star. Several times, turning around in a spiral around it, the beam can escape into outer space. Now imagine a neutron star with a mass equal to three solar and a radius of 8.85 km. In this case, not a single ray will be able to escape from the surface of the star, it will be so bent in the field of the star that it will return back. That's what they are, black holes!
The radius to which the body must be compressed so that light cannot leave it is called the Schwarzschild radius or event horizon. Do you want to become a black hole? Then you'll have to shrink to 0,000... just 21 centimetres, and no one will see you! But your mass will remain - turn on your imagination and imagine what you could do in such a state. Probably, calmly seep through the earth, to the very center ... But let's return to space.
White and gray holes .
A white hole is an object that is the opposite of a black hole. The matter of the white hole is pushed out and scattered in space. If the matter is not compressed, but expands from under the Schwarzschild sphere, then this object is a white hole. Gray holes combine the properties of black and white holes.
The term "white hole" appears at a symposium on relativistic astrophysics in 1969. The famous English scientist R. Penrose made a presentation at this symposium "Black holes and white holes". Ya. B. Zeldovich and I. D. Novikov in 1971 introduced the concept of “gray hole”.
The nature of the formation of massive black holes is now clear. Massive stars, consuming their nuclear fuel and shrinking, must necessarily reach their gravitational radius and turn into black holes. For a black hole to form in this way, the mass of the star must be at least twice the mass of the Sun. The gravitational force of a less massive body is not enough to form a black hole.
PULSARS.
Pulsars are talking black holes.
In 1967, pulsars were discovered - neutron stars that emit narrowly directed streams of elementary particles. These radiations are periodic pulses of the electromagnetic spectrum. For the first time they were recorded as radio emissions. Their clear periodicity led the astronomers who discovered these impulses to the idea that the signals are sent by "green men" - aliens in order to enter into long-awaited contact with earthlings. Immediately everyone was classified and began to decipher the message. As a result of research, confirmed by other facts, it was concluded that these signals belong to a rotating neutron star, or black hole. Due to the periodicity of the pulses, these space objects were called pulsars.
How does the radiation visible in the X-ray spectrum escape from the embrace of a black hole? It is believed that neutrons are not so stable on the surface of a pulsar. They can even decay into protons and electrons, which, in turn, give rise to other elementary particles. In a strong magnetic field, electrons accelerate along the lines of force, and at the poles of the pulsar, where gravity is the least, they break out into outer space. This representation explains the periodicity of the sent pulses. But on the other hand, a black hole can gradually evaporate due to the emission of elementary particles. So far, no traces of evaporated black holes have been found in space.
Black holes - eaters of stellar matter
But with the help of an X-ray telescope, it was discovered how the stellar gas broke away from the star in the form of a luminous cloud and flowed into the dark region of outer space, where it became invisible, in other words, disappeared. The conclusion suggests itself.
This star, traveling through the galaxy, approached the black hole and ended up in its gravitational field. The most unstable elements of the trapped star, the surface stellar matter and the circumstellar gas, were the first to crawl towards it. The gaseous substance, warming up, approaches the black hole in a spiral, thus highlighting its location. This region is called the "accretion disk" and is very similar in appearance to a spiral galaxy.
QUASARS.
The light from quasars points to black holes.
In 1963, quasars (quasi-stellar sources) were discovered - the most powerful sources of radio emission in the Universe with a luminosity hundreds of times greater than the luminosity of galaxies and sizes ten times smaller than them. It was assumed that quasars are the nuclei of new galaxies and, therefore, the process of galaxy formation continues to this day.
The brightest discovered objects in the universe, quasars, also owe their origin to black holes. Particularly massive black holes attract nearby space objects so strongly that, approaching it in a crowd, they begin to glow like 10 galaxies combined. The quasar is notable for its variable brightness, which probably corresponds to the periodicity of the rotation of the huge neutron star around which it was formed. Although no one can say exactly what quasars are.
I would like to point out an interesting fact. When the existence of black holes was deduced from Einstein's theory of relativity, many astronomers enthusiastically searched space for confirmation of this assumption. And they found enough facts and objects confirming this theory. At present, when enough facts and observations have accumulated that indicate the presence of black holes in space, their very existence is being questioned by many astronomers. Thus, representatives of homo sapiens, like black holes, are the most mysterious objects in the universe.
CONCLUSION
After the work done, the following conclusions can be drawn:
The degree of knowledge of the universe is extremely small.
Celestial bodies are like living beings: they have their own stages of development, signs that determine the age of a particular celestial body.
The Universe is evolving, turbulent processes took place in the past, are taking place now and will take place in the future.
The significance of this topic in natural science is obvious - it determines everything. The Universe is the beginning, the continuation and the end of everything (although we can say that the Universe has no end, it just reborn from time to time). The exploration of outer space turned the worldview of man, influenced further scientific activity.
BIBLIOGRAPHY
1. Dagaev M.M., Charugin V.M. Book for reading on astronomy. - M .: Education, 1988.
2. Gorelov A.A. KSE.- M.: VLADOS, 2003.
3. Novikov I.D. Evolution of the Universe. - M.: Nauka, 1990.
Laplace Pierre. Statement of the system of the world [transl. O. Borisenko] M.: Enlightenment, 1980.
Meyrink Gustav. Ring of Saturn: a collection [transl. from Austrian I. Steblova.].-M.: ABC Classics, 2004.-832s.
Gorelov A.A. KSE: Proc. A manual for students of higher educational institutions. - M .: Humanitarian Publishing Center VLADOS, 2003. - 512 pp.: ill.
The Universe is a collection of galaxies, their clusters, stars, planets, planetoids, comets, asteroids, cosmic dust and gases, all matter known to man (visible and dark), energy (including dark) and radiation. In this blog, most often I will talk about the Universe as a subject of astronomical and cosmological study. In a visual sense, there are more dark areas in the universe than lit areas. According to one version, the visible Universe is a ball, a sphere with a diameter of 90-93 billion light years. On the other hand, it is a disk of about the same diameter. In any case, we are talking about huge distances. The universe is multicenter and heterogeneous. There are approximately 170 billion galaxies in the Universe, which in places gather into large clusters. In other places there are voids. But there is no single center of accumulations of matter and energy, there is no single center from which it expands after the Big Bang.
The universe is made up of matter and energy. The universe is expanding at an accelerating rate. Expansion has led to the fact that there are more voids than accumulations of matter and energy. The density of matter in the universe is 10 −29 g/cm 3 (for comparison, the density of pure water under normal conditions is 1 g/cm 3). The universe is about 13.73 billion years old, its average temperature is -270°C, and it is decreasing as the stars cool down. According to modern ideas, the universe had a beginning and will have an end. All formations and cosmic bodies in the Universe move at great speeds. The Universe is constantly changing: galaxies, stars, planets are born and destroyed in it. At the present stage of life, the Universe has boundaries that a person cannot overcome - for example, the speed of light and absolute temperature zero.
How the universe was studied
Since ancient times, man has been worried about how the world works, where its boundaries are, what forces act and win in it. Space explorers first explored our solar system. Then they discovered galaxies, then their clusters. In accordance with modern theories, space and time have their limits, but we study them gradually, expanding our understanding of the world. Perhaps these boundaries will expand as we study, and some restrictions will be lifted.
The ancient Greeks were the first to systematically explore the boundaries of our world. Not feeling the movement of the Earth around the Sun and its movement inside the galaxy with the entire solar system, they considered the Earth to be the fixed center of the universe, around which the stars, the Sun and the Moon move. The Greeks understood that objects raised above the ground fall down. In order for the Earth not to fall, it must rest on something. Thales of Miletus considered the world ocean to be such a support, Anaximenes - compressed air. Anaximander of Miletus, Parmenides and Ptolemy believed that the Earth does without support, as it lies in the center of the universe, and there is no reason for it to fall somewhere. Their views also diverged on the shape of the Earth. Anaximander considered the Earth cylindrical, Leucippus flat. The fact that the Earth is a ball was first guessed by Pythagoras. Also considered Plato and Aristotle. Their ideas about the world became the basis for scientists for many centuries. Although already among the Greek scientists there were those who tried to put the Sun in the center of the world. But they were in the minority. Greek philosophers also tried to explain what elements the world consists of. Aristotle said that the sky is a dome on which the stars are fixed. The space of the dome is divided into sublunar and supralunar worlds. Sublunar light contains 4 primary elements - earth, water, wind and fire. The supralunar light is the place where there is the fifth element (ether) and where the gods live. But the ancient Greek gods, unlike the Christian god, were not inclined to interfere in the affairs of scientists. Greek scientists also argued about what is closer to the Earth - the Sun, the Moon or the stars, where meteorites come from. Anaxagoras came to the conclusion that meteorites are made up of the same material as the Earth. The Greeks considered other planets of the solar system to be deities. Despite the fallacy of the geocentric model of the world, Anaxagoras and other philosophers laid the foundations of modern astronomy.
Aristotle Pythagoras
In the Middle Ages, the Christian Church seriously interfered in European astronomy. Instead of scientific arguments, she accepted the opinions of theologians, evaluating them according to the benefits for the harmony of beliefs, and not according to logic and evidence. After the 2nd century BC, mysticism or religious dogmatism became dominant in philosophy, so astrology took the place of astronomy. The anthropocentrism of Christian beliefs, which consisted in the fact that the Earth was created by God for people, perceived the geocentric system much better. Medieval astronomers in India, Judea, the Latin countries and the Islamic East also more often relied on the work of Aristotle and Ptolemy. The decline in medieval European science did not allow scientists not only to refute the works of the Greeks mathematically, but even simply to understand them. The geocentric system existed for many centuries, until the Polish astronomer Nicolaus Copernicus again confidently announced the heliocentric system of the world. He clearly said that the Earth rotates around its axis in a day and around the Sun in a year. The new system easily explained the backward movement of the planets, which was incomprehensible before (when the planet at some point begins to move in the opposite direction across the sky). From that moment a new scientific revolution began.
Copernicus
Nicolaus Copernicus believed that the Earth and other planets of the solar systems move around the Sun uniformly. He outlined his theory in the book of 1543 "On the rotation of the celestial spheres." He relatively accurately calculated the distance from the Sun to the planets of the solar system.
The famous painting by J. Matejko. 1873
Nicolaus Copernicus on a Polish 1000 zloty note
In 1572, a supernova (Tycho Brahe) lit up in the sky. She was visible even during the day. Looking at it, Thomas Digges (Oxford, England) began to doubt that the sky is a sphere. The new star was clearly beyond it. But it was still necessary to comprehend the absence of the "firmament" and to abandon the intermediate geo-heliocentric system of the world. The most significant contribution to these processes was the contribution of Johannes Kepler and Galileo Galilei. Johannes Kepler proved that the Sun is located in the geometric center of the star-planetary system. He also understood how the periods of revolutions of the planets and the sizes of their orbits are related: the squares of the periods of revolutions of the planets are related as the cubes of the semi-major axes of their orbits. Based on these discoveries, new, more accurate tables of planetary motions were compiled.
At the same time, the Italian physicist, mathematician, astronomer and philosopher Galileo Galilei worked with Johannes Kepler. He was the first to use a telescope to observe celestial bodies. In 1609, looking at the Milky Way through a telescope, he saw that it was created by individual stars. He described mountains on the Moon and 4 moons of Jupiter. He described his discoveries in The Starry Messenger (1610). His discoveries made the construction of telescopes popular and at the same time dealt a heavy blow to astrology, destroying some of its traditions. Galileo discovered the phases of Venus, spots on the Sun (described in the book "Letters on Sunspots") and the rotation of the Sun around its axis. With his discoveries and the nature of the debater, he made many enemies in church circles and was accused of heresy by the Inquisition. In 1616, Pope Paul V officially called heliocentrism a dangerous heresy. The book of Copernicus "On the rotation of the celestial spheres" was included in the list of banned. The authority of Galileo protected him from persecution, but he could no longer openly defend the works of Copernicus. Galileo made a mistake in interpreting comets, considering them to be optical phenomena. But even this mistake contributed to the further development of science, the understanding of the relativity of motion and inertia.
Isaac Newton put an end to the debate about the validity of the heliocentric system, which lasted more than a century and a half. In 1687, he derived Kepler's laws from the law of universal gravitation.
In the late 18th century, William and Caroline Herschel created a new generation of telescopes. They took Isaac Newton's telescope as a basis, but replaced the glass mirrors with metal ones. Using a new telescope on March 13, 1781, William Herschel discovered Uranus, for which he received the honorary title of Astronomer Royal. In 1785 he published the first map of the galaxy. In 1789, the astronomer discovered Saturn's moons Mimas and Enceladus, then Uranus' moons Titania and Oberon. We also owe his talent for the discovery of infrared radiation (hereinafter referred to as IR). He also saw nebulae but could not explain them.
Astronomers continued to work on measuring the distance to stars. The parallax method accurately measured the distance from the Earth to the Sun, but it turned out that this method was limited to a distance of 300 million km. Another method was needed. It was proposed by Henrietta Leavitt, a research fellow at Harvard University. She made a discovery: the brightness of a star depends on the distance to it. This helped measure the distance to many stars and nebulae. In honor of G. Leavitt, an asteroid and a crater on the Moon were named.
Later they learned that the Universe began with the Big Bang, that the galaxy is not a strip of stars, but a disk that constantly and rapidly rotates. The solar system is also a conditional disk inside the galaxy. Once it was a real disk of dust and gas. The sun and the planets of the solar system formed in a disk-shaped cloud of gases and dust. And now the orbits of all the planets of the solar system lie in the plane of the conditional disk. Orbital movement has balanced the force of gravity and the force of the explosion from birth in the center of the solar disk. The trajectory of planetary motion obeys the same laws of physics as the motion of objects in our macrocosm. In the microcosm, at the level of elementary particles, other laws operate. I will talk about this in more detail later. Here it is appropriate to talk a little about Edwin Hubble.
Astronomer Edwin Hubble made several important discoveries. He discovered that there is not a single galaxy in the universe, but many. He made this discovery using the 100-inch Hooker telescope at the Mount Wilson Observatory (Los Angeles, California, USA). He realized that the Cepheids (pulsating variable stars) he had identified in the Andromeda and Triangulum nebulae were too far away to be part of the Milky Way. These Cepheids were later named the Hubble Cepheids. E. Hubble's description of the Andromeda nebula later helped establish the size of the universe.
The second important discovery was that most galaxies are moving away from each other. It turned out that several galaxies are moving in our direction, and within the calculated timeframe, these galaxies will collide with the Milky Way. But all other galaxies are rapidly moving away from us. Moreover, the farther away the galaxies are from us, the faster they move away from us. But how did he prove it? E. Hubble studied the movement of galaxies, fixing their light waves. If a galaxy approaches, its light waves shrink and turn blue. If removed, the waves expand and turn red. The phenomenon of changing the length, and with it the color of the waves, is called the Doppler effect. The "redshift" of the spectrum showed that most galaxies are moving away from each other. By the way, this also confirms that the Big Bang really was.
In 1998, a work was published in which it was proved that the expansion rate of the Universe is increasing due to dark energy. In 100 billion years, if we are alive, we will see only the rare stars of the Milky Way, and the Universe around will become dim and empty.
The universe consists of the same 92 chemical elements that are present in the periodic table of D.I. Mendeleev - from hydrogen +1 to uranium +92. The properties of chemical elements depend on the serial number (charge). Today, this dependence is defined as follows: the properties of chemical elements, as well as the forms and properties of the simple substances and compounds they form, are in a periodic dependence on the magnitude of the charges of the nuclei of their atoms. The variety of forms of visible matter is also determined by the abundance of elements. The higher it is, the more chances there are for chemical interactions. The most common element in the universe is hydrogen (75%). This is followed by helium (23%), oxygen (1%), carbon (0.5%), neon (0.13%), iron (0.11%), nitrogen (0.1%), silicon (0. 07%), sulfur (0.05%), etc. The prevalence of carbon, as well as its ability to create chains and multiple bonds, largely explains the origin of carbon-based biological life. Some of the elements are part of gases, some are halogens or metals. For example, Ca +20 and Na +11 in their pure form are silvery metals. But in this form we usually do not see them. But if we are talking about the Earth, then it is clear how exactly we learned about the composition of the soil, atmosphere, water in the oceans, etc. Even before the flight to the planets of the solar system, scientists knew that the atmosphere of Venus is filled with sulfur, and the soil of Mars is filled with iron. When they got to them, it was confirmed and clarified. But it will probably take us a very long time to even get to the nearest star systems. The closest Proxima Centauri is 4.22 light years away. So how do we know what elements it consists of? Thanks to spectral analysis. To study the individual spectra of elements allowed their combustion. Barium burns with green fire, copper with blue, and strontium with red. Thus, we answered another important question about the primary elements of the Universe. True, the questions did not end there.
Exploring the universe 2
Formation of the Universe 3
Evolution of the Universe 4
Galaxies and the Structure of the Universe 4
Classification of galaxies 5
Structure of the Universe. 7
Conclusion 9
Introduction
Many religions, such as Jewish, Christian and Islamic, believed that the universe was created by God and quite recently. For example, Bishop Ussher calculated the date of four thousand four hundred years for the creation of the universe by adding the age of people in the Old Testament. In fact, the date of biblical creation is not that far from the date of the end of the last Ice Age, when the first modern man appeared.
On the other hand, some people, for example, the Greek philosopher Aristotle, Descartes, Newton, Galileo, preferred to believe that the Universe existed and should have always existed, that is, forever and infinitely. And in 1781 the philosopher Immanuel Kant wrote an unusual and very obscure work, The Critique of Pure Reason. In it, he made equally correct arguments that the universe had a beginning, and that it did not exist. No one in the seventeenth, eighteenth, nineteenth, or early twentieth centuries believed that the universe could evolve over time. Newton and Einstein both missed the chance of predicting that the universe could either contract or expand.
Exploring the Universe
The great German scientist, philosopher Immanuel Kant (1724-1804) created the first universal concept of the evolving Universe, enriching the picture of its even structure, and presented the Universe as infinite in a special sense. He substantiated the possibility and significant probability of the emergence of such a universe solely under the action of mechanical forces of attraction and repulsion. Kant tried to find out the further fate of this Universe at all its scale levels, starting with the planetary system and ending with the nebula world.
For the first time, fundamentally new cosmological consequences of the general theory of relativity were revealed by the outstanding mathematician and theoretical physicist Alexander Fridman (1888-1925). Speaking in 1922-24. he criticized Einstein's findings that the universe is finite and shaped like a four-dimensional cylinder. Einstein made his conclusion based on the assumption of the stationarity of the Universe, but Friedman showed the groundlessness of his original postulate.
Friedman gave two models of the universe. Soon, these models found surprisingly accurate confirmation in direct observations of the movements of distant galaxies in the effect of "redshift" in their spectra.
By this, Friedman proved that the matter in the Universe cannot be at rest. With his conclusions, Friedman theoretically contributed to the discovery of the need for the global evolution of the Universe.
The formation of the universe
Modern astronomical observations indicate that the beginning of the universe, approximately ten billion years ago, was a giant fireball, hot and dense. Its composition is very simple. This fireball was so hot that it consisted only of free elementary particles that were moving rapidly, colliding with each other.
There are several theories of evolution. The pulsating universe theory claims that our world came into being as a result of a gigantic explosion. But the expansion of the universe will not continue forever, because. gravity will stop it.
According to this theory, our Universe has been expanding for 18 billion years since the explosion. In the future, the expansion will slow down completely, and there will be a stop. And then the Universe will begin to shrink until the matter contracts again and a new explosion occurs.
Stationary explosion theory: According to it, the Universe has neither beginning nor end. She is always in the same state. A new whirlpool is constantly being formed to replace matter with receding galaxies. For this reason, the Universe is always the same, but if the Universe, the beginning of which was laid by the explosion, expands to infinity, then it will gradually cool down and completely die out.
But so far, none of these theories has been proven, because. at the moment there is no exact evidence of at least one of them.
However, it is worth noting another theory (principle).
The anthropic (human) principle was first formulated in 1960 by Iglis G.I. , but he is, as it were, an unofficial author of it. And the official author was a scientist named Carter.
The Anthropic Principle states that the Universe is the way it is because there is an observer, or he must appear at a certain stage of development. As proof, the creators of this theory cite very interesting facts. This is the criticality of fundamental constants and the coincidence of large numbers. It turns out that they are completely interconnected and their slightest change will lead to complete chaos. The fact that such a clear coincidence and even one can say a pattern exists gives this certainly interesting theory a chance to live.
Evolution of the Universe
The process of evolution of the universe is very slow. After all, the Universe is many times older than astronomy and human culture in general. The origin and evolution of life on earth is only an insignificant link in the evolution of the universe. And yet, research carried out in our century has lifted the curtain that closes the distant past from us.
The universe is usually divided into four eras: hadron, lepton, photon and stellar.
Galaxies and the Structure of the Universe
Galaxies have been the subject of cosmogonic research since the 1920s, when their real nature was reliably established. And it turned out that these are not nebulae; not clouds of gas and dust that are not far from us, but huge stellar worlds that lie at very large distances from us. Discoveries and research in the field of cosmology in recent decades have clarified much of what concerns the prehistory of galaxies and stars, the physical state of the rarefied matter from which they formed in very distant times. All modern cosmology is based on one fundamental idea - the idea of gravitational instability. Matter cannot remain uniformly dispersed in space, because the mutual attraction of all particles of matter tends to create in it concentrations of various scales and masses. In the early Universe, gravitational instability strengthened initially very weak irregularities in the distribution and motion of matter, and at a certain epoch led to the emergence of strong inhomogeneities: "pancakes" - protoclusters.
The breakup of layers of protoclusters into separate clusters also occurred, apparently due to gravitational instability, and this gave rise to protogalaxies. Many of them turned out to be rapidly rotating due to the swirling state of the substance from which they were formed. The fragmentation of protogalactic clouds as a result of their gravitational instability led to the emergence of the first stars, and the clouds turned into star systems - galaxies. Protogalaxies, which had a fast rotation, turned into Spiral galaxies, in which the rotation was slow or completely absent, turned into elliptical or irregular galaxies. In parallel with this process, the formation of a large-scale structure of the Universe took place - superclusters of galaxies arose, which, connecting with their edges, formed a kind of honeycomb.
Classification of galaxies
Edwin Powell Hubble (1889-1953), an eminent American astronomer-observer, chose the simplest method of classifying galaxies by appearance. And it must be said that although later reasonable assumptions were made by other researchers on the classification, the original system derived by Hubble still remains the basis for the classification of galaxies.
In the 20-30s. XX century Hubble developed the basics of the structural classification of galaxies - giant star systems, according to which there are three classes of galaxies.
spiral galaxies
Spiral galaxies "spiral" - are characterized by two relatively bright branches arranged in a spiral. The branches come out either from the bright core (denoted - S), or from the ends of the light jumper crossing the core (denoted - SB).
Spiral galaxies are perhaps even the most picturesque objects in the universe. As a rule, a galaxy has two spiral branches, originating at opposite points in the core, developing in a similar symmetrical manner, and ending in opposite regions of the periphery. However, examples of more than two spiral arms in a galaxy are known. In other cases, there are two spirals, but they are unequal - one is much more developed than the second. In spiral galaxies, light-absorbing dust matter is present in greater quantities. It ranges from several thousandths to a hundredth of their total mass. Due to the concentration of dusty matter towards the equatorial plane, it forms a dark band in galaxies that are turned to us with an edge and have the form of a spindle.
The representative is the M82 galaxy in the constellation B. Ursa, does not have a clear outline, and consists mainly of hot blue stars and gas clouds heated by them. M82 is located at a distance of 6.5 million light years from us. Perhaps about a million years ago, a powerful explosion occurred in its central part, as a result of which it acquired its current form.
elliptical galaxies
Elliptical galaxies "elliptical" (denoted - E) - having the shape of ellipsoids. Elliptical galaxies are outwardly inexpressive. They look like smooth ellipses or circles with a gradual circular decrease in brightness from the center to the periphery. As a rule, they do not contain cosmic dust, which is how they differ from spiral galaxies, in which there is a large amount of light-absorbing dust matter. Outwardly, elliptical galaxies differ from each other mainly in one feature - greater or lesser compression.
Representative - the ring nebula in the constellation Lyra is located at a distance of 2100 light years from us and consists of luminous gas surrounding the central star. This shell was formed when an aging star shed its gaseous covers, and they rushed into space. The star shrank and passed into a state comparable in mass to the Sun, and in size to the Earth.
Irregular galaxies
Irregular (irregular) "irregular" (denoted - I) - having irregular shapes. The types of galaxies listed so far were characterized by the symmetry of forms and by a certain character of the pattern. But there are a large number of irregularly shaped galaxies. Without any pattern of structural structure.
The irregular shape of the galaxy may be due to the fact that it did not have time to take the correct shape due to the low density of matter in it or because of its young age. There is another possibility: the galaxy may become irregular due to shape distortion as a result of interaction with another galaxy. Apparently, both of these cases occur among irregular galaxies, and this may be related to the division of irregular galaxies into 2 subtypes.
Irregular galaxies of subtype I I are characterized by a relatively high surface, brightness and complexity of the irregular structure. The French astronomer Vakuler in some galaxies of this subtype, for example, the Magellanic clouds, found signs of a spiral destroyed structure.
Irregular galaxies of the subtype designated I II are characterized by a very low surface and brightness. This feature distinguishes them from the environment of galaxies of all other types. At the same time, it prevents the detection of these galaxies, as a result of which only a few subtype I II galaxies located relatively close were identified.
Representatives of irregular galaxies - the Large Magellanic Cloud. It is located at a distance of 165,000 light years and, thus, is the closest galaxy to us of a relatively small size, next to it is a smaller galaxy - the Small Magellanic Cloud. Both of them are satellites of our galaxy.
Subsequent observations showed that the described classification is not sufficient to systematize the entire variety of shapes and properties of galaxies. Thus, galaxies were discovered that, in a sense, occupy an intermediate position between spiral and elliptical galaxies (denoted - So). These galaxies have a huge central cluster and a flat disk surrounding it, but no spiral arms.
Structure of the Universe.
With the appearance of hydrogen atoms, the stellar era begins, or rather, the era of protons and electrons.
The universe enters the stellar era in the form of hydrogen gas with a huge amount of light and ultraviolet photons. Hydrogen gas has expanded in different parts of the universe at different rates. Its density was also not the same. It formed huge clumps, many millions of light years across. The mass of such cosmic hydrogen clumps was hundreds of thousands, and even millions of times greater than the mass of our present Galaxy. The expansion of the gas inside the clumps proceeded more slowly than the expansion of rarefied hydrogen between the clumps themselves. Later, supergalaxies and clusters of galaxies were formed from individual sections with the help of their own attraction. So, the largest structural units of the Universe - supergalaxies - are the result of the uneven distribution of hydrogen, which occurred in the early stages of the history of the Universe.
The stars in the universe are grouped into giant star systems called galaxies. The stellar system, in which, as an ordinary star, our Sun is located, is called the Galaxy.
The number of stars in the galaxy is about 10 12 (trillion). The Milky Way, a bright silvery band of stars, encircles the entire sky, making up the bulk of our galaxy. The Milky Way is brightest in the constellation Sagittarius, where the most powerful clouds of stars are found. It is least bright in the opposite part of the sky. From this it is easy to conclude that the solar system is not located in the center of the Galaxy, which is visible from us in the direction of the constellation Sagittarius. The farther from the plane of the Milky Way, the fewer faint stars there are and the less far the star system stretches in these directions.
The dimensions of the Galaxy were outlined by the arrangement of stars that are visible at great distances. The diameter of the Galaxy is approximately equal to 3000 pc (Parsec (pc) - the distance with which the semi-major axis of the Earth's orbit, perpendicular to the line of sight, is visible at an angle of 1 ''; 1 Parsec = 3.26 light years = 206265 AU = 3 * 10 13 km.) or 100,000 light years, but it does not have a clear boundary.
In the center of the galaxy there is a core with a diameter of 1000-2000 pc - a giant dense cluster of stars. It is located at a distance of almost 10,000 pc (30,000 light years) from us in the direction of the constellation Sagittarius, but is almost completely hidden by a dense curtain of clouds, which prevents visual and ordinary photographic observations of this most interesting object of the Galaxy.
The mass of our galaxy is now estimated in different ways, equal to 2 * 10 11 solar masses (the mass of the Sun is 2 * 10 30 kg.), And 1/1000 of it is contained in interstellar gas and dust. In 1944 V.V. Kukarin found indications of the spiral structure of the galaxy, and it turned out that we live between two spiral arms.
In some places in the sky with a telescope, and in some places even with the naked eye, one can distinguish close groups of stars connected by mutual gravity, or star clusters.
There are two types of star clusters: open and globular.
In addition to stars, the Galaxy also includes diffuse matter, extremely diffuse matter consisting of interstellar gas and dust. It forms nebulae. Nebulae are diffuse and planetary. They are bright because they are illuminated by nearby stars.
There is nothing unique and unique in the Universe in the sense that there is no such body, such a phenomenon in it, the basic and general properties of which would not be repeated in another body, by other phenomena.
Conclusion
The discovery of diverse evolutionary processes in various systems and bodies that make up the Universe made it possible to study the patterns of cosmic evolution on the basis of observational data and theoretical calculations.
One of the most important tasks is to determine the age of space objects and their systems. Since in most cases it is difficult to decide what should be considered and understood as the “moment of birth” of a body or system, then two parameters are used to determine the age:
the time during which the system is already in the observable state
total lifetime of the given system from the moment of its appearance
Obviously, the second characteristic can be obtained only on the basis of theoretical calculations. Usually the first of these quantities is called age, and the second - lifetime.
The fact of the mutual removal of the galaxies that make up the metagalaxy indicates that some time ago it was in a qualitatively different state and was denser.
Our days are justifiably called the golden age of astrophysics - remarkable and most often unexpected discoveries in the world of stars are now following one after another. The solar system has recently become the subject of direct experimental, and not just observational, research. Flights of interplanetary space stations, orbital laboratories, expeditions to the Moon brought a lot of new specific knowledge about the Earth, near-Earth space, planets, and the Sun.
The study of the Universe, even only part of it known to us, is a daunting task. To obtain the information that modern scientists have, it took the work of many generations.
Examination on the course "Concepts of modern natural science" _________________________________________________________________________________
PLAN: Sizes and distances Types of galaxies Elliptical galaxies Spiral galaxies Irregular galaxies Needle galaxies Radio galaxies
Ministry of Education of the Russian Federation Russian State University of Innovative Technologies and Entrepreneurship Northern Branch.
Ministry of Education of the Russian Federation Moscow State Open University Department of Management and Economic Policy Examination
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P V P Sh No. 2 “Report on astronomy” Topic: “Study of Galaxies” The work was completed by: Elena Nasretdinova Accepted by the teacher: Evtodiev I.G.
Professional Management Institute
Faculty of Finance and Credit
Specialty Finance and Credit
Discipline Concept
modern natural science
Essay
on the topic of:
Universe
Student Ivanova E.A.
Group UFTZ-51/8-F-Vs-2
Moscow - 2010
Origin of the Universe 3
Expanding Universe Model 5
Evolution and structure of galaxies 10
Astronomy and cosmonautics 12
Literature 14
Origin of the Universe
At all times, people wanted to know where and how the world originated. When mythological ideas dominated in culture, the origin of the world was explained, as, say, in the Vedas, by the disintegration of the first man Purusha. The fact that this was a general mythological scheme is also confirmed by Russian apocrypha, for example, the Pigeon Book. The victory of Christianity confirmed the idea of God's creation of the world out of nothing.
With the advent of science in its modern sense, mythological and religious ideas are being replaced by scientific ideas about the origin of the universe. It is necessary to separate three close terms: being, the universe and the Universe. The first is philosophical and denotes everything that exists, being. The second one is used both in philosophy and in science, without having a specific philosophical load (in terms of opposing being and consciousness), and designates everything as such.
The meaning of the term Universe is narrower and has acquired a specifically scientific sound. The Universe is a place of human settlement, accessible to empirical observation. The gradual narrowing of the scientific meaning of the term Universe is quite understandable, since natural science, unlike philosophy, deals only with what is empirically verifiable by modern scientific methods.
The universe as a whole is studied by a science called cosmology, i.e. space science. The word is also not accidental. Although everything outside the Earth's atmosphere is now called space, this was not the case in ancient Greece. The cosmos was then accepted as "order", "harmony", as opposed to "chaos", "disorder". Thus, cosmology, at its core, as befits a science, reveals the orderliness of our world and is aimed at finding the laws of its functioning. The discovery of these laws is the goal of studying the Universe as a single ordered whole.
This study rests on several premises. First, the universal laws of the functioning of the world formulated by physics are considered to be valid in the entire Universe. Secondly, the observations made by astronomers are also recognized as being extended to the entire Universe. And, thirdly, only those conclusions are recognized as true that do not contradict the possibility of the existence of the observer himself, i.e. man (the so-called anthropic principle).
The conclusions of cosmology are called models of the origin and development of the Universe. Why models? The fact is that one of the basic principles of modern natural science is the idea of the possibility of conducting a controlled and reproducible experiment on the object under study at any time. Only if it is possible to carry out an infinite, in principle, number of experiments, and all of them lead to the same result, on the basis of these experiments they make a conclusion about the existence of a law to which the functioning of a given object is subject. Only in this case the result is considered quite reliable from a scientific point of view.
This methodological rule remains inapplicable to the Universe. Science formulates universal laws, and the universe is unique. This is a contradiction that requires considering all conclusions about the origin and development of the Universe not as laws, but only as models, i.e. possible explanations. Strictly speaking, all laws and scientific theories are models, since they can be replaced in the process of development of science by other concepts, but models of the Universe, as it were, are more models than many other scientific statements.
Expanding Universe Model
The most commonly accepted model in cosmology is the model of a homogeneous isotropic non-stationary hot expanding universe, built on the basis of general relativity and the relativistic theory of gravity created by Albert Einstein in 1916. This model is based on two assumptions: 1) the properties of the Universe are the same at all its points (homogeneity) and direction (isotropy); 2) the best known description of the gravitational field is the Einstein equations. From this follows the so-called curvature of space and the relationship of curvature with the density of mass (energy). The cosmology based on these postulates is relativistic.
An important point of this model is its non-stationarity. This is determined by two postulates of the theory of relativity: 1) the principle of relativity, which states that in all inertial systems all laws are preserved regardless of the speed with which these systems move uniformly and rectilinearly relative to each other; 2) experimentally confirmed constancy of the speed of light.
From the acceptance of the theory of relativity it followed as a consequence (the first to notice this was the Petrograd physicist and mathematician Alexander Alexandrovich Fridman in 1922) that curved space cannot be stationary: it must either expand or contract. This conclusion was ignored until the discovery by the American astronomer Edwin Hubble in 1929 of the so-called "redshift".
Redshift is a decrease in the frequencies of electromagnetic radiation: in the visible part of the spectrum, the lines are shifted towards its red end. The Doppler effect discovered earlier said that when any source of vibrations moves away from us, the frequency of vibrations perceived by us decreases, and the wavelength increases accordingly. When emitted, “reddening” occurs, i.e., the lines of the spectrum are shifted towards longer red waves.
So, for all distant light sources, the redshift was fixed, and the farther the source was, the more so. The redshift turned out to be proportional to the distance to the source, which confirmed the hypothesis about their removal, i.e. about the expansion of the Metagalaxy - the visible part of the Universe.
The redshift reliably confirms the theoretical conclusion about the non-stationarity of a region of our Universe with linear dimensions of the order of several billion parsecs over at least several billion years. At the same time, the curvature of space cannot be measured, remaining a theoretical hypothesis.
An integral part of the model of the expanding Universe is the idea of the Big Bang, which occurred about 12 -18 billion years ago. “In the beginning there was an explosion. Not the explosion that we are familiar with on Earth, which starts from a certain center and then spreads, capturing more and more space, but an explosion that occurred simultaneously everywhere, filling all space from the very beginning, with each particle of matter rushing away from any other particles ”(Weinberg S. The first three minutes. A modern view on the origin of the Universe.-M., 1981).
The initial state of the Universe (the so-called singular point): infinite mass density, infinite curvature of space, and explosive expansion that slows down over time at a high temperature, at which only a mixture of elementary particles (including photons and neutrinos) could exist. The hotness of the initial state was confirmed by the discovery in 1965 of the relic radiation of photons and neutrinos, formed at an early stage of the expansion of the Universe.
An interesting question arises: from what was the Universe formed? What was that from which it arose. The Bible states that God created everything out of nothing. Knowing that the laws of conservation of matter and energy were formulated in classical science, religious philosophers argued about what the biblical “nothing” meant, and some, for the sake of science, believed that nothing meant the initial material chaos ordered by God.
Surprising as it may seem, modern science admits (it admits, but does not assert) that everything could be created from nothing. "Nothing" in scientific terminology is called a vacuum. Vacuum, which physics of the 19th century considered to be emptiness, according to modern scientific concepts, is a peculiar form of matter, capable of “giving birth” to material particles under certain conditions.
Modern quantum mechanics admits (this does not contradict the theory) that the vacuum can come into an "excited state", as a result of which a field can form in it, and from it (which is confirmed by modern physical experiments) - matter.
From the modern scientific point of view, the birth of the Universe “out of nothing” means its spontaneous emergence from vacuum, when a random fluctuation occurs in the absence of particles. If the number of photons is zero, then the field strength does not have a definite value (according to Heisenberg's "uncertainty principle"): the field constantly fluctuates, although the average (observed) value of the strength is zero.
Fluctuation is the appearance of virtual particles that are continuously born and immediately destroyed, but also participate in interactions, like real particles. Due to fluctuations, the vacuum acquires special properties that are manifested in the observed effects.
So, the Universe could be formed from "nothing", i.e. from the excited vacuum. Such a hypothesis, of course, is not a decisive confirmation of the existence of God. After all, all this could happen in accordance with the laws of physics in a natural way without outside interference from any ideal entities. And in this case, scientific hypotheses do not confirm or refute religious dogmas that lie on the other side of empirically confirmed and refuted natural science.
The amazing in modern physics does not end there. Responding to a journalist's request to state the essence of the theory of relativity in one sentence, Einstein said: “It used to be believed that if all matter disappeared from the Universe, then space and time would be preserved; The theory of relativity states that together with matter, space and time would also disappear. Transferring this conclusion to the model of the expanding Universe, we can conclude that before the formation of the Universe there was neither space nor time.
Note that the theory of relativity corresponds to two versions of the model of the expanding Universe. In the first of them, the curvature of space-time is negative or equals zero in the limit; in this variant, all distances increase indefinitely with time. In the second version of the model, the curvature is positive, space is finite, and in this case, expansion is replaced by contraction over time. In both versions, the theory of relativity is consistent with the current empirically confirmed expansion of the universe.
An idle mind inevitably asks questions: what was there when there was nothing, and what is beyond the limits of expansion. The first question is obviously contradictory in itself, the second goes beyond the scope of a particular science. The astronomer may say that, as a scientist, he has no right to answer such questions. But since they nevertheless arise, possible substantiations of the answers are formulated, which are not so much scientific as natural-philosophical.
Thus, a distinction is made between the terms "infinite" and "limitless". An example of infinity, which is not unlimited, is the surface of the Earth: we can walk on it indefinitely, but, nevertheless, it is limited by the atmosphere above and the earth's crust below. The universe can also be infinite, but limited. On the other hand, there is a point of view according to which there can be nothing infinite in the material world, because it develops in the form of finite systems with feedback loops, by which these systems are created in the process of transforming the environment.
But let us leave these considerations to the realm of natural philosophy, because in natural science, ultimately, the criterion of truth is not abstract considerations, but empirical testing of hypotheses.
What happened after the Big Bang? A clot of plasma was formed - a state in which elementary particles are located - something between a solid and a liquid state, which began to expand more and more under the action of a blast wave. 0.01 sec after the start of the Big Bang, a mixture of light nuclei (2/3 hydrogen and 1/3 helium) appeared in the Universe. How were all the other chemical elements formed?
Evolution and structure of galaxies
The poet asked: “Listen! After all, if the stars are lit, it means that someone needs it? We know that stars are needed to shine, and our Sun provides the energy necessary for our existence. Why are galaxies needed? It turns out that galaxies are also needed, and the Sun not only provides us with energy. Astronomical observations show that a continuous outflow of hydrogen occurs from the nuclei of galaxies. Thus, the nuclei of galaxies are factories for the production of the main building material of the Universe - hydrogen.
Hydrogen, whose atom consists of one proton in the nucleus and one electron in its orbit, is the simplest "brick" from which more complex atoms are formed in the interior of stars in the process of atomic reactions. Moreover, it turns out that it is not by chance that the stars have a different size. The greater the mass of a star, the more complex atoms are synthesized in its interior.
Our Sun, as an ordinary star, produces only helium from hydrogen (which is given by the nuclei of galaxies), very massive stars produce carbon - the main "brick" of living matter. That's what galaxies and stars are for. What is the earth for? It produces all the necessary substances for the existence of human life. Why does man exist? Science cannot answer this question, but it can make us think again about it.
If someone needs the “ignition” of stars, then maybe someone needs a person? Scientific data help us formulate an idea about our purpose, about the meaning of our life. When answering these questions, turning to the evolution of the Universe means thinking cosmically. Natural science teaches us to think cosmically, at the same time, not breaking away from the reality of our existence.
The question of the formation and structure of galaxies is the next important question of the origin of the Universe. It is studied not only by cosmology as the science of the Universe - a single whole, but also by cosmogony (Greek "gonea" means birth) - a field of science that studies the origin and development of cosmic bodies and their systems (distinguish between planetary, stellar, galactic cosmogony) .
A galaxy is a giant cluster of stars and their systems that have their own center (core) and a different, not only spherical, but often spiral, elliptical, oblate, or even irregular shape. There are billions of galaxies, and in each of them there are billions of stars.
Our galaxy is called the Milky Way and consists of 150 billion stars. It consists of a core and several spiral branches. Its dimensions are 100 thousand light years. Most of the stars in our galaxy are concentrated in a giant "disk" about 1500 light-years thick. The Sun is located at a distance of about 30 thousand light years from the center of the galaxy.
The galaxy closest to ours (to which a light beam runs 2 million years) is the Andromeda Nebula. It is named so because it was in the constellation Andromeda in 1917 that the first extragalactic object was discovered. Its belonging to another galaxy was proved in 1923 by E. Hubble, who found stars in this object by spectral analysis. Later, stars were also discovered in other nebulae.
And in 1963, quasars (quasi-stellar radio sources) were discovered - the most powerful sources of radio emission in the Universe with a luminosity hundreds of times greater than the luminosity of galaxies and sizes ten times smaller than them. It was assumed that quasars are the nuclei of new galaxies and, therefore, the process of galaxy formation continues to this day.
Astronomy and astronautics
Stars are studied by astronomy (from the Greek "astron" - star and "nomos" - law) - the science of the structure and development of cosmic bodies and their systems. This classical science is experiencing its second youth in the 20th century due to the rapid development of observational technology - its main research method: reflecting telescopes, radiation receivers (antennas), etc. In the USSR in 1974, a reflector with a mirror diameter of 6 m came into operation in the Stavropol Territory, collecting light millions of times more than the human eye.
Astronomy studies radio waves, light, infrared, ultraviolet, x-rays and gamma rays. Astronomy is divided into celestial mechanics, radio astronomy, astrophysics and other disciplines.
Astrophysics, a part of astronomy that studies the physical and chemical phenomena that occur in celestial bodies, their systems and in outer space, is gaining particular importance at the present time. Unlike physics, which is based on experiment, astrophysics is based mainly on observations. But in many cases, the conditions in which matter is found in celestial bodies and systems differ from those available to modern laboratories (ultrahigh and ultralow densities, high temperatures, etc.). Thanks to this, astrophysical research leads to the discovery of new physical laws.
The intrinsic value of astrophysics is determined by the fact that at present the main attention in relativistic cosmology is transferred to the physics of the Universe - the state of matter and physical processes occurring at different stages of the expansion of the Universe, including the earliest stages.
One of the main methods of astrophysics is spectral analysis. If a beam of white sunlight is passed through a narrow slit and then through a glass trihedral prism, then it breaks up into its component colors, and an iridescent color strip with a gradual transition from red to violet appears on the screen - a continuous spectrum. The red end of the spectrum is formed by the rays that deviate the least when passing through a prism, the violet - the most deviated. Each chemical element corresponds to well-defined spectral lines, which makes it possible to use this method to study substances.
Unfortunately, short-wave radiation - ultraviolet, X-ray and gamma rays - do not pass through the Earth's atmosphere, and here science comes to the aid of astronomers, which until recently was considered primarily technical - astronautics (from the Greek "nautike" - the art of navigation), providing space exploration for the needs of mankind with the use of aircraft.
Cosmonautics studies problems: theories of space flights - calculations of trajectories, etc.; scientific and technical - the design of space rockets, engines, onboard control systems, launch facilities, automatic stations and manned spacecraft, scientific instruments, ground-based flight control systems, trajectory measurement services, telemetry, organization and supply of orbital stations, etc.; medical and biological - the creation of onboard life support systems, compensation for adverse events in the human body associated with overload, weightlessness, radiation, etc.
The history of astronautics begins with the theoretical calculations of a man's exit into unearthly space, which were given by K.E. Tsiolkovsky in his work "Investigation of world spaces with reactive devices" (1903). Work in the field of rocket technology began in the USSR in 1921. The first launches of liquid fuel rockets were carried out in the USA in 1926.
The main milestones in the history of astronautics were the launch of the first artificial Earth satellite on October 4, 1957, the first manned flight into space on April 12, 1961, the lunar expedition in 1969, the creation of orbital manned stations in low Earth orbit, and the launch of a reusable spacecraft.
Work was carried out in parallel in the USSR and the USA, but in recent years there has been a unification of efforts in the field of space exploration. In 1995, the Mir-Shuttle joint project was implemented, in which the American Shuttle ships were used to deliver astronauts to the Russian orbital station Mir.
The ability to study at orbital stations cosmic radiation, which is delayed by the Earth's atmosphere, contributes to significant progress in the field of astrophysics.
Bibliography
1. Einstein A., Infeld L. The evolution of physics. M., 1965.
2. Heisenberg V. Physics and Philosophy. Part and whole. M., 1989.
3. A brief moment of triumph. M., 1989.
You can use the "Space Exploration" report for children in preparation for the lesson.
"Space exploration" report
Even in ancient times, people, observing the sky, used various measuring instruments that made it possible to determine the position of bodies in the sky.
But the invention of the telescope helped people study space. With the help of telescopes, people were able to discover many celestial bodies. These are various planets, stars, black holes, dwarfs, nebulae, quasars, comets and the like.
Today, in many countries of the world there are huge observatories where scientists conduct space research.
In the fifties of the last century, artificial satellites of the Earth were launched into space, in 1961 a man visited space for the first time. They became the Soviet cosmonaut Yuri Gagarin. In 1969, American astronauts landed on the moon.
Telescopes launched into the orbit of the Earth, allow you to look into the distant corners of the universe.
Among the most famous telescopes, which made many discoveries and opened the veil of deep space, was the Hubble telescope. The telescope was put into orbit in 1990. Astronomers began to find the first planets outside our native solar system two years after its launch.
Now, with the help of automatic spacecraft, scientists are conducting space research, such devices carry out flights to the planets of the solar system.
Spacecraft that are designed to carry out work in deep space are sent there irrevocably. Often their flight lasts for years, and during this period they transmit various information to Earth, which they received during the flight.
The number of vehicles sent into deep space is very small. An example is the spacecraft Voyager-1 and Voyager-2, which were launched in 1977. Both devices have energy and fuel to operate almost until 2020-2025. Voyager 1 will move away from the Sun by about 19 billion km during this time, and Voyager 2 by almost 15 billion km. After -6-10 years, communication with the devices will almost certainly cease, they will become dead piles of metal.
