Rostov branch

Department of Humanities, Socio-Economic and Natural Sciences

ABSTRACT

By discipline:

« Modern concepts

natural sciences"

On the topic of: " Evolution of the Universe »

Rostov-on-Don

Plan

Introduction

1. Basic concepts of cosmology

1.1 Assumptions of A. Einstein

1.2 Conclusions A.A. Friedman

1.3 Empirical law - Hubble's law

1.4 Hypotheses G.A. Gamova

1.5 CMB radiation by A. Penzis and R. Wilson

2. Hot Universe model

2.1 Big Bang cosmology

2.2 Dividing the initial stage of evolution into eras

2.3 Inflationary model of the Universe

3. Structure of the Universe

3.1 Metagalaxy

3.2 Galaxies

3.3 Stars

3.4 Solar system

Conclusion

Bibliography

Introduction

Looking at the sky dotted with stars, a person becomes delighted, not remaining indifferent to what he contemplates. “The abyss has opened and is full of stars. The stars have no number, the abyss has its bottom,” these beautiful lines by M.V. Lomonosov, figuratively and most fully describe the first impression that a person experiences while admiring the bewitching picture of the starry sky. There are many poems and songs written about stars. The stars and the endless heavenly space have always attracted and continue to attract everyone: the most ordinary person, the poet, and the scientist. But for scientists, the starry sky is not only a subject of delight and pleasure, but also a fascinating, inexhaustible object of research.

In clear weather on a moonless night, up to three thousand stars can be observed in the sky with the naked eye. But this is only a small part of the stars and other cosmic objects that make up the Universe.

Universe- this is the entire existing material world, limitless in time and space and infinitely diverse in the forms that matter takes in the process of its development.

1. Basic concepts of cosmology

Throughout the history of civilization, humanity has striven to understand the world around us and understand what place it occupies in the Universe. Universe- the largest material system. Its origin has interested people since ancient times. In the beginning, the Universe was “formless and empty,” as the Bible says. In the beginning there was a vacuum - modern physicists clarify. What are the origins of the Universe? How does it develop? What is its structure? Scientists from different times tried to answer these and other questions. However, even the greatest achievements of natural science of the twentieth century. do not allow us to give completely comprehensive answers.

1.1 Assumptions of A. Einstein

Nevertheless, it is generally accepted that the basic principles of modern cosmology - the science of the structure and evolution of the Universe - began to take shape after the creation in 1917. A. Einstein the first relativistic model based on the theory of gravity and claiming to describe the entire Universe. This model characterized the stationary state of the Universe and, as astrophysical observations showed, turned out to be incorrect.

1.2 Conclusions A.A. Friedman

An important step in solving cosmological problems was made in 1922 by a professor at Petrograd University A.A. Friedman(1888–1925). As a result of solving cosmological equations, he came to the conclusion: the Universe cannot, is in a stationary state - it must expand or contract.

1.3 Empirical law - Hubble's law

The next step was taken in 1924, when an American astronomer at the Mount Wilson Observatory in California E. Hubble(1889–1953) measured the distance to nearby galaxies (called nebulae at the time) and thereby discovered the world of galaxies. In 1929, at the same observatory, E. Hubble experimentally confirmed the theoretical conclusion of A.A. using the red shift of lines in the emission spectrum of galaxies. Friedman about the expansion of the Universe and established The empirical law is Hubble's law: the galaxy's retreat velocity V is directly proportional to the distance r to it, i.e. V=Hr, where H is the Hubble constant.

Over time, the Hubble constant gradually decreases - the recession of galaxies slows down. But such a decrease over the observed period of time is negligible. The reciprocal of the Hubble constant determines the lifetime (age) of the Universe. From the observational results it follows that the speed of galaxy recession increases by approximately 75 km/s for every million parsecs (1 parsec is equal to 3.3 light years; a light year is the distance traveled by light in a vacuum in 1 Earth year). At this rate, extrapolation to the past leads to the conclusion that the age of the Universe is about 15 billion years, which means that the entire Universe 15 billion years ago was concentrated in a very small area. It is assumed that at that time the density of matter in the Universe was comparable to the density of an atomic nucleus, and the entire Universe was a huge nuclear drop. For some reason, the nuclear droplet became unstable and exploded. This assumption underlies the big bang concept.

The product of the lifetime of the Universe and the speed of light determines the radius of the cosmological horizon - the limit of knowledge of the Universe through astronomical observations. Information about objects beyond the cosmological horizon has not yet reached us - we cannot look beyond the cosmological horizon. A simple calculation shows that the radius of the cosmological horizon is approximately 10 m. Obviously, this radius increases by about 300 thousand km every second. But such an increase is negligible compared to the radius of the cosmological horizon. To observe a noticeable expansion of the cosmological horizon, you need to wait billions of years.

The big bang concept assumes that the expansion of the universe occurred at the same rate starting from the moment the nuclear droplet exploded. Another hypothesis is currently being discussed - the hypothesis of a pulsating Universe: the Universe has not always expanded, but pulsates between finite limits of density. It follows from it that in some past the speed of removal of galaxies was less than now, and there were periods when the Universe contracted, that is, galaxies approached each other and at a greater speed, the greater the distance that separated them.

1.4 Hypotheses G.A. Gamova

With the development of natural science and especially nuclear physics, various hypotheses are put forward about physical processes at different stages of cosmological expansion. One of them was proposed in the late 40s. XX century G.A. Gamov(1904–1968), a theoretical physicist who emigrated from the Soviet Union to the USA in 1933, and is called the hot Universe model. It examines the nuclear processes that occurred at the initial moment of expansion of the Universe in very dense matter with an extremely high temperature. As the Universe expanded, dense matter cooled.

Two conclusions follow from this model:

The matter from which the first stars were born consisted mainly of hydrogen (75%) and helium (25%);

In today's Universe, weak electromagnetic radiation should be observed, which has preserved the memory of the initial stage of the development of the Universe, and therefore is called relic radiation.

1.5 CMB radiation by A. Penzis and R. Wilson

With the development of astronomical means of observation, and in particular, with the birth of radio astronomy, new possibilities for understanding the Universe emerged. In 1965, American astrophysicists A. Penzias and R. Wilson experimentally discovered cosmic microwave background radiation. CMB radiation is background isotropic cosmic radiation with a spectrum close to that of a black body with a temperature of about 3 K.

In 2000, it was reported that an important step had been taken towards understanding the earliest stage of the evolution of the Universe. A new state of matter - quark - gluon plasma - has been obtained at the European Nuclear Research Laboratory in Geneva. It is assumed that the Universe was in this state in the first 10 μs after the big bang. Until now, it has been possible to characterize the evolution of matter at a stage no earlier than three minutes after the explosion, when the nuclei of atoms have already formed.

2. Hot Universe model

Universe is the totality of everything that exists. The Earth, Moon, Sun and all the planets and stars form the Universe. The universe is full of great and exciting secrets and riddles that scientists are trying to unravel. Many have put forward theories regarding its origin. They argue that the Universe did not always exist, but had its beginning.

Based on studies of stars and galaxies, scientists have noticed that they are separating from each other at high speed. This suggests that they were connected at some point. An experiment proposed to explain the beginning of the universe is that a balloon is painted with small spots. As the balloon is inflated, the distance between the spots increases and the spots also become larger. In this experiment, the spots represent the galaxies, and the inflation of the balloon represents the expansion of the Universe.

2. 1 Big Bang Cosmology

Belgian astronomer Georges Lamaitre, who studied stars, suggested that 15 billion years ago the Universe was small and very dense. He called this state of the Universe a “cosmic egg.” According to his calculations, the radius of the Universe in its original state was equal to 10 cm, which is close in size to the radius of an electron, and its density was 10 g/cm, i.e. the Universe was a micro-object of negligible size.

The Universe moved from its initial state to expansion as a result big bang, i.e. all the matter that was part of the “cosmic egg” burst out at high speed and scattered in all directions.

Cosmology is a science that asks fundamental questions. What is the Universe? How old is she? How was it formed? What will happen to her in the future? Even five hundred years ago, it was generally accepted in cosmology that the center of the Universe was the Earth. It is now clear that the Earth is just a particle of the huge Universe formed as a result of the Big Bang. But the Earth is a planet on which many living beings have evolved, and explaining this fact is very important for any model of the cosmos.

Cosmology has been of interest all over the world since ancient times; the sky was observed with the naked eye. In those days they tried to understand how the stars, the Sun and the planets moved. The studies mixed logical thinking, traditional ideas and religion. More than 400 years ago, the heliocentric model of the world of Nicolaus Copernicus became widespread (it was later refined by Johannes Kepler and Isaac Newton). At the beginning of the 17th century, Galileo Galilei, using the first optical telescopes, discovered many stars and planets. The quality of observations improved with increasing telescope sizes, and in the mid-19th century, spectroscopy revolutionized the study of the starry sky.
Spectroscopy has allowed astronomers to analyze the composition of stars, planets, and tenuous clouds of gas and dust in interstellar space. The results of observations developed into new physical theories. At the beginning of the 20th century, science took a big leap forward thanks to Einstein's general theory of relativity. He described how the Universe works in general and at the same time made it possible to use the theory to describe individual details of various models. To select the right model, many observations must be made. Over the course of the 20th century, the range of observations expanded from visible light to radio waves, infrared, ultraviolet, x-rays, gamma rays and even neutrinos. By 1970, Belennaya's model, based on the Big Bang theory, gained general acceptance. The Aztec calendar stone, 3.6 m in diameter, depicts the calendar and cosmological ideas of the Aztecs. The central part is the current era. The four previous eras are shown around it, and the 20 days of the Aztec month are depicted around the edges.
Egyptian cosmology. It is believed that the corridors of the Cheops pyramid in Giza point towards some stars in the sky. Another hypothesis: the location of the three large pyramids at Giza corresponds to the three stars of the “belt” of the constellation Orion.
The model is based on three basic scientific facts: the expansion of the Universe, the existence of cosmic background radiation, and the relative abundance of light elements. Recently, using large telescopes with new detectors, scientists have determined the distribution of galaxies in the Universe and discovered distant exploding stars. This suggests that after the Big Bang, the expansion of the Universe accelerates. The results of all observations prove that the “most reasonable” of the proposed models of the Universe is one in which ordinary matter is dominated by invisible “dark matter” and the mysterious “dark energy”. But to substantiate it in detail, new theories and more detailed observations are needed.

Sky observation. As a result of the Big Bang at the birth of the Universe, relict radiation was formed. A special spacecraft studies it and forms a map of micro-oscillations that disrupt the even glow of cosmic background radiation. The color reflects changes in temperature and density in the ancient Universe that led to the formation of galaxy clusters.
Space telescope. The Hubble Space Telescope is located outside the Earth's atmosphere - this location allows us to study the Universe in detail without distorting the Earth's atmosphere. Its principle involves the use of various types of devices. The production of IR optics and optical materials is carried out using the same technique. Only professionals who are aces in physics and chemistry can perform high-quality work. The materials they produce are very often used both on land and in space. The Hubble telescope is maintained by astronauts arriving on the space shuttle. Radio telescopes. The world's largest radio telescope complex is located in the US state of New Mexico; it consists of 27 antennas. They are capable of producing images with a resolution equal to that of one large radio telescope with a cross section of 36 km.

• Expansion of the Universe

• Cosmological models
  • Friedman equation

History of cosmology

Early forms of cosmology were religious myths about the creation (cosmogony) and destruction (eschatology) of the existing world.

China

Renaissance

The cosmology of Nicholas of Cusa, set out in the treatise, is innovative About learned ignorance. He assumed the material unity of the Universe and considered the Earth to be one of the planets, also in motion; celestial bodies are inhabited, like our Earth, and every observer in the Universe can with equal reason consider himself motionless. In his opinion, the Universe is limitless, but finite, since infinity can only be characteristic of God alone. At the same time, Kuzan retains many elements of medieval cosmology, including the belief in the existence of celestial spheres, including the outer one - the sphere of fixed stars. However, these “spheres” are not absolutely round, their rotation is not uniform, and the axes of rotation do not occupy a fixed position in space. As a result, the world does not have an absolute center and a clear boundary (probably, it is in this sense that Kuzantz’s thesis about the boundlessness of the Universe should be understood).

The first half of the 16th century was marked by the emergence of a new, heliocentric system of the world of Nicolaus Copernicus. Copernicus placed the Sun at the center of the world, around which the planets revolved (including the Earth, which also rotated around its axis). Copernicus still considered the universe to be limited to the sphere of fixed stars; Apparently, he also retained his belief in the existence of celestial spheres.

A modification of the Copernican system was the system of Thomas Digges, in which the stars are located not on one sphere, but at different distances from the Earth to infinity. Some philosophers (Francesco Patrizi, Jan Essensky) borrowed only one element of Copernicus’s teachings - the rotation of the Earth around its axis, also considering the stars scattered in the Universe to infinity. The views of these thinkers bear traces of the influence of Hermeticism, since the region of the Universe outside the solar system was considered by them to be an immaterial world, the habitat of God and angels.

A decisive step from heliocentrism to an infinite Universe evenly filled with stars was made by the Italian philosopher Giordano Bruno. According to Bruno, when observed from all points, the Universe should look approximately the same. Of all the thinkers of the New Age, he was the first to suggest that the stars are distant suns and that physical laws are the same throughout the infinite and boundless space. At the end of the 16th century, the infinity of the Universe was also defended by William Gilbert. In the mid to second half of the 17th century, these views were supported by René Descartes, Otto von Guericke and Christiaan Huygens.

The emergence of modern cosmology

A. A. Fridman

The emergence of modern cosmology is associated with the development in the 20th century of Einstein's general theory of relativity (GR) and particle physics. Einstein published the first study on this topic, based on general relativity, in 1917 under the title “Cosmological considerations for the general theory of relativity.” In it he introduced 3 assumptions: the Universe is homogeneous, isotropic and stationary. To ensure the latter requirement, Einstein introduced an additional “cosmological term” into the gravitational field equations. The solution he obtained meant that the Universe has a finite volume (closed) and positive curvature.

Age of the Universe

The age of the Universe is the time that has passed since the Big Bang. According to modern scientific data (WMAP 9 results), it is 13.830 ± 0.075 Ga. New data from the European Space Agency's powerful Planck satellite show the age of the Universe to be 13.798 ± 0.037 billion years (68% confidence interval).

Age of the Universe as a function of cosmological parameters

The modern estimate of the age of the Universe is based on one of the most common models of the Universe, the so-called standard cosmological ΛCDM model.

The main stages of the development of the Universe

Of great importance for determining the age of the Universe is the periodization of the main processes occurring in the Universe. The following periodization is currently accepted:

• The earliest epoch for which there is any theoretical assumption is the Planck time ( 10 −43 after the Big Bang). At this time, the gravitational interaction separated from the other fundamental interactions. According to modern ideas, this era of quantum cosmology lasted until a time of the order of 10 −11 s after the Big Bang.
• The next era is characterized by the birth of the initial quark particles and the separation of types of interactions. This era lasted until the Time of Order 10 −2 s after the Big Bang. At present, there are already possibilities for a fairly detailed physical description of the processes of this period.
• The modern era of standard cosmology began 0.01 seconds after the Big Bang and continues to this day. During this period, the nuclei of the primary elements were formed, stars, galaxies, and the solar system arose.

An important milestone in the history of the development of the Universe in this era is considered the era of recombination, when the matter of the expanding Universe became transparent to radiation. According to modern ideas, this happened 380 thousand years after the Big Bang. Currently, we can observe this radiation in the form of the cosmic microwave background, which is the most important experimental confirmation of existing models of the Universe.

WMAP

Microwave radiation map built by WMAP

The information collected by WMAP allowed scientists to construct the most detailed map to date of temperature fluctuations in the distribution of microwave radiation on the celestial sphere. Previously, it was possible to construct a similar map using data from NASA's COBE apparatus, but its resolution was significantly - 35 times - inferior to the data obtained by WMAP.

WMAP data showed that the temperature distribution of the CMB across the celestial sphere follows completely random fluctuations with a normal distribution. The parameters of the function describing the measured distribution are consistent with the model of the Universe, consisting of:

• 4% from ordinary substance,
• 23% from so-called dark matter (possibly from hypothetical heavy supersymmetric particles) and
• 73% from even more mysterious dark energy, causing the accelerated expansion of the Universe.

WMAP data suggests that dark matter is cold (that is, it consists of heavy particles, not neutrinos or any other light particles). Otherwise, light particles moving at relativistic speeds would blur small density fluctuations in the early Universe.

Among other parameters, determined from WMAP data (based on ΛCDM-model, that is, the Friedmann cosmological model with the Λ-term and cold dark matter in English. Cold Dark Matter :

• age of the Universe: (13.73 ± 0.12)·10 9 years;
• Hubble constant: 71 ± 4 km/s/Mpc;
• baryon density at present: (2.5 ± 0.1)·10−7 cm−3;
• flatness parameter of the Universe (ratio of total density to critical): 1.02 ± 0.02;
• the total mass of all three types of neutrinos:<0,7 эВ.

Based on Planck TT, TE, EE+lensing+BAO+JLA+H0 review

• 100θMC= 1.04077 ± 0.00032
• Ω b h 2 = 0.02225 ± 0.00016
• Ω c h 2 = 0.1198 ± 0.0015
• τ=0.079 ± 0.017
• ln(10 10 As)=3.094 ± 0.034
• ns = 0.9645 ± 0.0049
• H0 = 67.27 ± 0.66
• Ω m =0.3089 ± 0.0062
• Ω Λ = 0.6911 ± 0.0062
• Σm v< 0.17
• Ω k =0.0008 −0.0039 +0.0040
• w=−1.019 −0.08 +0.075

Video on the topic

see also

Notes

1. , p. 103.
2. On the influence of Hermetic literature on Bradwardin, see the work.
3. , With. 2-17 and especially p. 14.

History of cosmology

Early forms of cosmology were religious myths about the creation (cosmogony) and destruction (eschatology) of the existing world.

China

Renaissance

The cosmology of Nicholas of Cusa, set out in the treatise, is innovative About learned ignorance. He assumed the material unity of the Universe and considered the Earth to be one of the planets, also in motion; celestial bodies are inhabited, like our Earth, and every observer in the Universe can with equal reason consider himself motionless. In his opinion, the Universe is limitless, but finite, since infinity can only be characteristic of God alone. At the same time, Kuzan retains many elements of medieval cosmology, including the belief in the existence of celestial spheres, including the outer one - the sphere of fixed stars. However, these “spheres” are not absolutely round, their rotation is not uniform, and the axes of rotation do not occupy a fixed position in space. As a result, the world does not have an absolute center and a clear boundary (probably, it is in this sense that Kuzantz’s thesis about the boundlessness of the Universe should be understood).

The first half of the 16th century was marked by the emergence of a new, heliocentric system of the world of Nicolaus Copernicus. Copernicus placed the Sun at the center of the world, around which the planets revolved (including the Earth, which also rotated around its axis). Copernicus still considered the universe to be limited to the sphere of fixed stars; Apparently, he also retained his belief in the existence of celestial spheres.

A modification of the Copernican system was the system of Thomas Digges, in which the stars are located not on one sphere, but at different distances from the Earth to infinity. Some philosophers (Francesco Patrizi, Jan Essensky) borrowed only one element of Copernicus’s teachings - the rotation of the Earth around its axis, also considering the stars scattered in the Universe to infinity. The views of these thinkers bear traces of the influence of Hermeticism, since the region of the Universe outside the solar system was considered by them to be an immaterial world, the habitat of God and angels.

A decisive step from heliocentrism to an infinite Universe evenly filled with stars was made by the Italian philosopher Giordano Bruno. According to Bruno, when observed from all points, the Universe should look approximately the same. Of all the thinkers of the New Age, he was the first to suggest that the stars are distant suns and that physical laws are the same throughout the infinite and boundless space. At the end of the 16th century, the infinity of the Universe was also defended by William Gilbert. In the mid to second half of the 17th century, these views were supported by René Descartes, Otto von Guericke and Christiaan Huygens.

The emergence of modern cosmology

A. A. Fridman

The emergence of modern cosmology is associated with the development in the 20th century of Einstein's general theory of relativity (GR) and particle physics. Einstein published the first study on this topic, based on general relativity, in 1917 under the title “Cosmological considerations for the general theory of relativity.” In it he introduced 3 assumptions: the Universe is homogeneous, isotropic and stationary. To ensure the latter requirement, Einstein introduced an additional “cosmological term” into the gravitational field equations. The solution he obtained meant that the Universe has a finite volume (closed) and positive curvature.

Age of the Universe

The age of the Universe is the time that has passed since the Big Bang. According to modern scientific data (WMAP 9 results), it is 13.830 ± 0.075 Ga. New data from the European Space Agency's powerful Planck satellite show the age of the Universe to be 13.798 ± 0.037 billion years (68% confidence interval).

Age of the Universe as a function of cosmological parameters

The modern estimate of the age of the Universe is based on one of the most common models of the Universe, the so-called standard cosmological ΛCDM model.

The main stages of the development of the Universe

Of great importance for determining the age of the Universe is the periodization of the main processes occurring in the Universe. The following periodization is currently accepted:

• The earliest epoch for which there is any theoretical assumption is the Planck time ( 10 −43 after the Big Bang). At this time, the gravitational interaction separated from the other fundamental interactions. According to modern ideas, this era of quantum cosmology lasted until a time of the order of 10 −11 s after the Big Bang.
• The next era is characterized by the birth of the initial quark particles and the separation of types of interactions. This era lasted until the Time of Order 10 −2 s after the Big Bang. At present, there are already possibilities for a fairly detailed physical description of the processes of this period.
• The modern era of standard cosmology began 0.01 seconds after the Big Bang and continues to this day. During this period, the nuclei of the primary elements were formed, stars, galaxies, and the solar system arose.

An important milestone in the history of the development of the Universe in this era is considered the era of recombination, when the matter of the expanding Universe became transparent to radiation. According to modern ideas, this happened 380 thousand years after the Big Bang. Currently, we can observe this radiation in the form of the cosmic microwave background, which is the most important experimental confirmation of existing models of the Universe.

WMAP

Microwave radiation map built by WMAP

The information collected by WMAP allowed scientists to construct the most detailed map to date of temperature fluctuations in the distribution of microwave radiation on the celestial sphere. Previously, it was possible to construct a similar map using data from NASA's COBE apparatus, but its resolution was significantly - 35 times - inferior to the data obtained by WMAP.

WMAP data showed that the temperature distribution of the CMB across the celestial sphere follows completely random fluctuations with a normal distribution. The parameters of the function describing the measured distribution are consistent with the model of the Universe, consisting of:

• 4% from ordinary substance,
• 23% from so-called dark matter (possibly from hypothetical heavy supersymmetric particles) and
• 73% from even more mysterious dark energy, causing the accelerated expansion of the Universe.

WMAP data suggests that dark matter is cold (that is, it consists of heavy particles, not neutrinos or any other light particles). Otherwise, light particles moving at relativistic speeds would blur small density fluctuations in the early Universe.

Among other parameters, determined from WMAP data (based on ΛCDM-model, that is, the Friedmann cosmological model with the Λ-term and cold dark matter in English. Cold Dark Matter :

• age of the Universe: (13.73 ± 0.12)⋅10 9 years;
• Hubble constant: 71 ± 4 km/s/Mpc;
• baryon density at present: (2.5 ± 0.1)⋅10 −7 cm −3 ;
• flatness parameter of the Universe (ratio of total density to critical): 1.02 ± 0.02;
• the total mass of all three types of neutrinos:<0,7 эВ.

Based on Planck TT, TE, EE+lensing+BAO+JLA+H0 review

• 100θMC= 1.04077 ± 0.00032
• Ω b h 2 = 0.02225 ± 0.00016
• Ω c h 2 = 0.1198 ± 0.0015
• τ=0.079 ± 0.017
• ln(10 10 As)=3.094 ± 0.034
• ns = 0.9645 ± 0.0049
• H0 = 67.27 ± 0.66
• Ω m =0.3089 ± 0.0062
• Ω Λ = 0.6911 ± 0.0062
• Σm v< 0.17
• Ω k =0.0008 −0.0039 +0.0040
• w=−1.019 −0.08 +0.075

Notes

1. , p. 103.
2. On the influence of Hermetic literature on Bradwardin, see the work.
3. , With. 2-17 and especially p. 14.
4. , p. 105-106.
5. , With. 31-45.
6. WMAP Cosmological Parameters(English) . NASA. Goddard Space Flight Center. Retrieved March 22, 2013. Archived March 22, 2013.
7. N° 7-2013: PLANCK REVEALS AN ALMOST PERFECT UNIVERSE(English) .
8. Planck Collaboration. Planck 2013 results. XVI. Cosmological parameters (English) // ArXiv/astro-ph. - 2013. - Bibcode: 2013arXiv1303.5076P. - arXiv:1303.5076.
9. P.A.R.Ade et al. (Planck Collaboration) (22 March 2013).

section of astronomy, physics. the doctrine of the development of the Universe as a whole, based on its general properties: homogeneity, isotropy, expansion of its observable part. The greatest distribution in the present day. The theory of a hot Universe, whose origins are associated with the Big Bang theory, came into being. F.M.Dyagilev

Excellent definition

Incomplete definition ↓

COSMOLOGY

from Greek ?????? – the world, the Universe, as well as structure, order, as opposed to chaos, and ????? - word, doctrine) - the doctrine of the Universe as a whole and of the entire astronomical universe. observations of a region of the Universe as part of this whole. K. developed as a branch of astronomy. It is often also considered as a branch of physics or philosophy. Actually modern. K. is a frontier science at the intersection of astronomy, physics and philosophy. The most general provisions of K. are directly related to philosophy. character, therefore K. was and is an arena for the struggle of worldviews. The first naive cosmologists. ideas arose in ancient times as a result of man’s attempts to understand his place in the universe. These views are characterized by anthropomorphism and anthropocentrism. The process of K.'s formation took place in the order of interconnected development, on the one hand, of abstract thinking, and on the other, of means and methods of observation. Mn. K.'s general questions were posed by philosophers. thought long before it became possible to approach the solution of these questions by means of astronomy and physics. These are, for example, the question of whether the Universe is a single whole or a multitude of parts. worlds, the question of the finitude or infinity of the Universe, posed by ancient Greek. philosophers. The idea of ​​the Universe as a single, eternal and natural process is already present in Heraclitus (see A5, 10; B 30, 65, 76, 90, Diels9). The first attempt to imagine the structure of the Universe as a whole based on observations. data – geocentric. world system (see Heliocentric and geocentric world systems). The most important cosmological ideas of this system: immobility and central position of the Earth in the Universe, spaces. the limitations of the latter, the fundamental difference in physical nature of the “earthly” and “heavenly”. These cosmological ideas were overcome only by heliocentric ones. system of the world. Already J. Bruno concluded from it that the Universe is limitless; This conclusion was obtained by the physicist. justification in Newton's theory of gravitation: a static limited Universe is incompatible with the law of universal gravitation. As for the ideas about the opposition of “earthly” and “heavenly,” it was undermined by the very conclusion that the Earth is just one of the planets, i.e. part of the "heavenly"; telescopic Galileo's discoveries, Newton's law of universal gravitation and spectral analysis showed the complete unity of physical science. laws and chemistry composition of "earthly" and "heavenly". As the means and methods of astronomy developed, the part of the Universe covered by observations expanded, and the cosmic. the role of the Earth seemed more and more modest. The systems of Ptolemy and Copernicus (in their original form) were essentially the K. of the solar system. Only gradually did it become clear what a vanishingly small fraction of the volume of the “stellar universe” - the Galaxy - is covered by the solar system: the Sun is only one of approximately 100 billion stars in this system. Determining the extent of the Galaxy took approx. 150 years. Although Wright, Lambert and Kant in the 50s and 60s. 18th century conjectured not only that all visible stars form a limit. disk-shaped system, but also that there are many such systems, even in the beginning. 20th century among astronomers there were widespread ideas that our Galaxy was the entire material Universe (the unlimited nature of space itself was usually not questioned). When it was finally proven that there are a huge number of star systems, generally similar to ours, the tendency again appeared to only push back the boundaries of the Universe, without abandoning the very concept of a boundary. Now the system of galaxies—the Metagalaxy—was taken to be the Universe. Scientific In its development, calculus went through two major stages—Newtonian and relativistic. The prerequisites for the emergence of scientific K. was a rejection of geocentrism, the creation of classical. mechanics and the discovery of the law of universal gravitation. Since the time of Newton, cosmology. the problem could no longer be posed speculatively, but as a physical one. task. Initially, due to the dominance of mechanistic. worldview, it was reduced to the problem of the behavior of an infinite system of masses controlled by the forces of universal gravity. The specific image of the mass system that Newtonian K. operated on was the stellar system. The beginning of a new one, modern. stage in the development of quantum theory is associated, on the one hand, with the creation of the general theory of relativity and the first relativistic models of the world (1917–22), on the other hand, with the establishment of stellar nature and extragalactic. positions of spiral "nebulae" (1917–24). Comparison of theoretical and observe. conclusions became possible after Hubble's discovery of the red shift law in 1929, and in a specific way cosmological. the system of masses became a system of galaxies. This new stage began with attempts to overcome, on the basis of a new theory of gravity, those cosmological difficulties, which were inherited from the classic. (pre-relativistic) physics (see Cosmological paradoxes). It seemed that there was an infinite Universe with a uniform (on average) distribution of gravitating and radiating masses (stars) with non-zero spaces. mass density cannot exist. The solution could formally be sought in one of three directions: either to abandon the assumption of uniform (chaotic) ) distribution of space masses, either from the assumption of an infinite volume of space in the Universe, or, finally, to assume that Newton’s law of gravity is satisfied only approximately. The possibility of solving the problem in the first of these directions was considered in 1908–22 by Charlier (in general terms, the idea was put forward in the 18th century by Lambert). This is the so-called hierarchical diagram of the structure of the Universe, based on the idea of ​​​​a strict regularity of structure and spaces. space distributions systems: defined the number of stars forms a system (galaxy) of the first order, defined. the number of which, in turn, forms a system (galaxy) of the second order, etc. to infinity. The Universe is a system of an infinitely high order of complexity. If the quantities characterizing each of the systems (linear dimensions, masses, densities) are related by definition. relations, then such an infinite system is free from cosmological. paradoxes. As the size of the system tends to infinity, its density tends to zero. However, such a scheme seemed too artificial. The search for a solution in the second direction within the framework of Newtonian physics also seemed little promising. Since the time of Riemann it has been known that infinite space can be either finite or infinite. However, the first of these possibilities was presented only mathematically. abstraction. The idea of ​​Mach et al. about the possibility of a spatially finite Universe therefore did not receive recognition. A third possibility was considered by Neumann in 1895; he showed that gravitational the paradox is eliminated if we assume that at large distances the gravitational force decreases faster than according to the inverse square law (or, equivalently, that at large distances, along with the attractive forces, still unknown repulsive forces act, weakening gravitational effects). However, no data existed to support such assumptions. In 1917, Einstein made an attempt to apply cosmology to the solution. problem of the relativistic theory of gravity he created - the general theory of relativity. It turned out that if we proceed from the assumption that the Universe is static, then within the framework of the new theory of gravity difficulties arise, similar to those that occur in the classical theory. (Newtonian) theory. Therefore, Einstein modified the gravitational equations of the general theory of relativity by introducing the so-called. cosmological member. This modification meant the assumption of the existence of unknown repulsive forces affecting large distances. Solution of gravity equations with cosmology. term under the assumption of a statistically homogeneous and isotropic distribution of matter gives a closed (finite) space. Dr. static (pseudostatic) model was built by de Sitter. In 1922–24, A. A. Friedman showed that there are no sufficient grounds for such a modification of the gravitational equations: the “cosmological term” can correspond not only to repulsion, but also to attraction, and, most importantly, the usual Einstein equations also have a cosmological . solutions free from these difficulties. But the space of such models is not static; the curvature of space changes over time, the space is deformed. After the discovery of Hubble, it turned out, however, that this is not a disadvantage, but an advantage of the new models: the Metagalaxy is not static. system, and Friedman's models can be considered as theoretical. explanation of the effect of galaxies "scattering away". However, the simplest relativistic models, if we consider them as models of the Universe as a whole, lead to fundamental difficulties, which were used by fideism and idealism to “justify” the idea of ​​​​creating the world out of nothing or primordial chaos, moreover, in a very near, astronomically speaking. scale, past – 2–10 billion years. From view K. itself and astronomy, the assumption underlying isotropic homogeneous models, and the widespread idea that a galaxy or cluster of galaxies is the highest, most complex structural formation, followed by the Universe itself, has greatly delayed the study of the structure of the Metagalaxy. Up to the 40s. The prevailing view was that galaxies were randomly distributed, and the detected inhomogeneities were considered as inhomogeneities of a local nature (see Cosmological postulate). To overcome the difficulties associated with the simplest models, attempts were made to abandon the basic simplifying assumption of a uniform distribution of matter and construct more complex - inhomogeneous anisotropic models. This task will be eliminated. mathematical difficulties. However, the results already obtained show that along this path it is apparently possible to overcome all the basics. difficulties of modern times K. without some radically new physics. theories. However, with the transition to significantly larger scales (system of metagalaxies), modern. theoretical K.'s basis may turn out to be insufficient, just as Newtonian physics turned out to be insufficient to explain the phenomena of metagalactics. scale. There are also attempts to find a solution to the cosmology. problems outside the framework of general relativity. These include the theory of "kinematic relativity" in English. Milne's astrophysics, created in the 30s. Milne's scheme is extremely artificial and has not received widespread use. Dr. cosmological theories, e.g. Jordan also do not have much influence. The “stationary universe” model of Bondi, Gold and Hoyle (1948) is much more popular among Western scientists. Currently time it is usually considered as an alternative to relativistic models of the “dynamic Universe”. The idea of ​​this model is this. The universe has existed and will exist forever without k.-l. stages of catastrophic evolution. It has always expanded, is expanding and will continue to expand, but the density of matter remains unchanged due to the constant emergence of matter. In the original version of the theory, matter arises from nothing; in the version developed by Hoyle, the source of the substance is physical. a “creative” field of an as yet unknown nature, and the tensor of this field is introduced into the field equations of the general theory of relativity. Here the theory can be considered as a special case of relativistic cosmology. theories. K. also deals with the “thermodynamics of the Universe” (see Entropy, Thermal Death of the Universe). A boundary problem of cosmogony, astrophysics, and nuclear physics is the problem of nucleogenesis, i.e. chemical origin elements. In connection with the discovery of antiparticles in K., the problem of “anti-worlds” began to be discussed - hypothetically. space objects built from antimatter (antiparticles). This, however, is only a small part of the more general problem of the symmetry of the Universe. K.'s problems also include the problem of the prevalence of organic. life in the Universe (at present this is a boundary problem of cosmogony, astrophysics and biochemistry). Modern t.zr. is that life in the Universe, although not universal, is far from exclusive. phenomenon. A number of existing cosmological concepts developed under the influence of positivism. This affected, first of all, the desire to develop philosophy independently of philosophy, and further, in the unfounded. claims to obtain an immediate and finally comprehensive solution to the question of the structure of the Universe as a whole. Hence the desire to consider cosmological. models not as the next steps in the endless process of cognition of the infinite Universe, but as they will end. The result is not as sketchy. model of the Metagalaxy, but as an adequate model of the entire Universe. This finally manifested itself in ignoring dialectics. inconsistencies of the Universe. The object of K. - the Universe - is at the same time extremely universal (for there is nothing that is not included in the Universe) and at the same time extremely individual (for, apart from it, nothing exists at all). Therefore, for example, in general terms, the question of which features of the Universe are individual, which are special and which are universal, without further clarification is meaningless: the most general properties of the Universe are also its individual properties that are not inherent in any other object . But since we always observe not directly s.l. “properties of the Universe as a whole” (for example, its extent or the curvature of its space-time continuum), but only the properties of certain. space system as its part, then the question of the separation of individual, special and general properties acquires decisive importance in the knowledge of the Universe. So, if the Universe is homogeneous, as cosmologically states. postulate, then, depending on the selection of data, one can obtain, for example, a conclusion about its finiteness in space or time, that the age of the Universe as a whole is less than the age of its component parts, etc. If it is heterogeneous (in the broad sense), i.e. one can assume, for example, that in some other metagalaxies a different law of gravity operates, this would mean that we observe only isolated and special properties of cosmic objects. systems that do not reflect the general features of the structure of the Universe; then the share of what is known in the Universe does not exceed its known share, and even with no matter how rapid the progress of knowledge, we will always know only an infinitesimal part of the Universe and will never be able to say anything about the Universe as a whole. Dr. in words, we would have to conclude that the Universe as an object is unknowable, and the object K. does not exist. The dialectic here is that the infinite (in space-time and inexhaustibility of properties) all-encompassing Universe is the unity and interpenetration of mutually exclusive opposites: homogeneity and heterogeneity, discontinuous and continuous, unified and diverse, finite and infinite, symmetrical and asymmetrical, reversible and irreversible . Cognizing the finite, we always cognize some features of the infinite; from a part we can draw certain conclusions about the whole, but we cannot simply transfer the properties of one to another. Problems of modern times Problems must be solved through the joint efforts of astronomy, physics, and philosophy. Sov. science has a definition in this regard. success. Until recently, we paid incomparably less attention to cosmic physics than to other branches of astronomy, which is explained, firstly, by the fact that until recently the USSR did not have the super-powerful instruments necessary for work in the field of extragalactic space. astronomy. Secondly, in the conditions of dogmatism generated by the personality cult of Stalin, theoretical. basis of modern K. - the theory of relativity - was subjected to a number of philosophers and departments. nihilistic physicists criticism, and relativistic K. was considered by them as completely idealistic. Now that both of these obstacles have been overcome, Sov. The Union, which occupies a leading position in space exploration, also has all the prerequisites to take a major step forward in theoretical science. understanding its general laws. See also the articles Infinity, Space and Time, Universe, Universal Gravity. Lit.: Shklovsky I. S., Photometric. paradox for the radio emission of a metagalaxy, "Astronomical Journal", 1953, v. 30, no. 5, p. 495–508; Extragalactic astronomy and K. Tr. sixth meeting on cosmogony June 5–7, 1957, M., 1959; Zelmanov A.L., K., TSB, 2nd ed., vol. 23; by him, K., in the collection: Astronomy in the USSR for thirty years (1917–1947), M.–L., 1948 (bibl. available); him, Towards the formulation of cosmological. problems, in the book: Tr. Second Congress of the All-Union Astronomy and Geodesy. about 25–31 Jan. 1955, M., 1960; Naan G.I., About modern times. cosmological state science, in the book: Issues. cosmogony, vol. 6, M., 1958; his, On the infinity of the Universe, "Questions of Philosophy", 1961, No. 6; McVitty G.K., General Theory of Relativity and K., M., 1961; Landau L.D. and Lifshitz E.M., Field Theory, 4th ed., M., 1962; Ambartsumyan V.?., Problems of extragalactic. research, in: Vopr. cosmogony, vol. 8, M., 1962, p. 3–26; Robertson H. P., Relativistic cosmology, "Rev. of Modern Physics", 1933, v. 5, No. 1; ?olman R. S., Relativity, thermodynamics and cosmology, Oxf., 1934; Heckmann O. H. L., Sch?cking?., Newtonsche und Einsteinsche Kosmologie, Handbuch der Physik, hrsg. von S. Fl?gge, Bd 53, V.–G?tt.–Hdlb., 1959; ?ondi?., Cosmology, 2 ed., Camb., 1960. G. Haan. Tallinn.