Theory big bang

The Big Bang Theory states that all physical universe- matter, energy and even 4 dimensions of space and time arose from a state of infinite values ​​of density, temperature and pressure. The universe originated from a volume smaller than a point and continues to expand. The Big Bang theory is now generally accepted as it explains both of the most significant facts of cosmology: the expanding universe and the existence of cosmic background radiation.

This event took place between 13 and 20 billion years ago. You can use the known laws of physics and calculate backwards all the states in which the Universe was, starting from 10-43 seconds after the Big Bang. During the first million years, matter and energy in the universe formed an opaque plasma, sometimes called a primordial fireball. By the end of this period, the expansion of the universe caused the temperature to drop below 3000 K, so that protons and electrons could combine to form hydrogen atoms. At this stage, the Universe became transparent to radiation. The density of matter now became higher than the density of radiation, although before the situation was reversed, which determined the rate of expansion of the Universe. The microwave background radiation is all that remains of the highly cooled radiation from the early universe.

Beginning of Star Formation This image shows an idea of ​​what the very young universe (less than 1 billion years old) looked like when stars began to form, converting the original hydrogen into countless stars.

The first galaxies began to form from primordial clouds of hydrogen and helium only after one or two billion years. The term "Big Bang" can be applied to any model of an expanding universe that in the past was the hot and dense Large Magellanic Cloud, the galaxy that accompanies our own. It is visible to the naked eye as a hazy, elongated region of the sky. It is located at a distance of 160,000 light years and covers an area of ​​20,000 light years. Its visible part is a tenth of the Milky Way

The Hourglass Nebula is a young planetary nebula about 8000 light-years distant from us. The image was taken at three different wavelengths to reflect the gaseous composition of the nebula. Nitrogen is shown in red, hydrogen in green, and doubly ionized oxygen in blue. The exact formation process is still unclear

The Crab Nebula is one of the most interesting objects in the sky. It is the remnants of a huge stellar explosion. It has been displayed in all wavelengths from radio to gamma rays. The central star - a pulsar - is a rapidly rotating neutron star. It spins so fast that an impulse is seen every 0.033 seconds. At optical wavelengths, this central star is 16th magnitude and out of reach of all but the most powerful telescopes.

The Milky Way is our own galaxy as seen from within. The galaxy is a giant star system of approximately 200 billion stars The Milky Way galaxy is approximately 100,000 light-years across and contains over 100 billion stars. The galaxy has the shape of a lens with a diameter of 80,000 light years and a thickness of ~ 30,000 light years.

This image shows a spiral galaxy. Elliptical galaxies are formed as a result of collisions between spiral galaxies.

Collision of Our Galaxy In about three billion years, our Galaxy will collide with Andromeda, as astronomers have known for almost a century that the two galaxies are approaching each other at a speed of 500,000 kilometers per hour.

According to this theory, the entire observable space is expanding. But what happened at the very beginning? All matter in the Cosmos at some initial moment was squeezed literally into nothing - compressed into a single point. It had a fantastically huge density - it is almost impossible to imagine, it is expressed by a number in which there are 96 zeros after one - and an equally unimaginably high temperature. Astronomers have called this state a singularity. For some reason, this amazing balance was suddenly destroyed by the action gravitational forces- it's hard to even imagine what they must have been like at the infinitely huge density of "primary matter"! What was there before the Big Bang?

Mysteries of the Big Bang Theory 1. As the Big Bang theory says, the Universe arose from a point with zero volume and infinitely high density and temperature. This state, called a singularity, defies mathematical description. 2. The big bang theory cannot explain the existence of galaxies. Modern versions of cosmological theories predict only the appearance of a homogeneous cloud of gas. 3. The problem of “missing mass”. By measuring the light energy emitted milky way, we can roughly determine the mass of our galaxy. It is equal to the mass of one hundred billion suns. However, by studying the interaction patterns of the same Milky Way with the nearby Andromeda galaxy, we find that our galaxy is attracted to it as if it weighs ten times more

Presentation on the topic "The Big Bang Theory" on astronomy in powerpoint format. This presentation for schoolchildren explains what the Big Bang Theory is about and its mysteries.

Fragments from the presentation

• The Big Bang Theory states that the entire physical universe - matter, energy and even 4 dimensions of space and time - arose from a state of infinite values ​​of density, temperature and pressure. The universe originated from a volume smaller than a point and continues to expand. The Big Bang theory is now generally accepted as it explains both of the most significant facts of cosmology: the expanding universe and the existence of cosmic background radiation.
• This event took place between 13 and 20 billion years ago. You can use the known laws of physics and calculate backwards all the states in which the Universe was, starting from 10-43 seconds after the Big Bang.
• During the first million years, matter and energy in the universe formed an opaque plasma, sometimes called a primordial fireball.
• By the end of this period, the expansion of the universe caused the temperature to drop below 3000 K, so that protons and electrons could combine to form hydrogen atoms. At this stage, the Universe became transparent to radiation. The density of matter now became higher than the density of radiation, although before the situation was reversed, which determined the rate of expansion of the Universe.
• The microwave background radiation is all that remains of the highly cooled radiation from the early universe.

Beginning of star formation

• This image shows an idea of ​​what the very young universe (less than 1 billion years old) looked like when stars began to form, converting the original hydrogen into countless stars.
• The first galaxies began to form from primordial clouds of hydrogen and helium only after one or two billion years. The term "Big Bang" can be applied to any model of an expanding universe that was hot and dense in the past.
• The Large Magellanic Cloud is the galaxy that accompanies our own. It is visible to the naked eye as a hazy, elongated region of the sky. It is located at a distance of 160,000 light years and covers an area of ​​20,000 light years. Its visible part is a tenth of the Milky Way
• The Hourglass Nebula is a young planetary nebula about 8000 light-years distant from us. The image was taken at three different wavelengths to reflect the gaseous composition of the nebula. Nitrogen is shown in red, hydrogen in green, and doubly ionized oxygen in blue. The exact formation process is still unclear
• The Crab Nebula is one of the most interesting objects in the sky. It is the remnants of a huge stellar explosion. It has been displayed in all wavelengths from radio to gamma rays. The central star - a pulsar - is a rapidly rotating neutron star. It spins so fast that an impulse is seen every 0.033 seconds. At optical wavelengths, this central star is 16th magnitude and out of reach of all but the most powerful telescopes.
• The Milky Way is our own galaxy as seen from within. The galaxy is a giant star system of approximately 200 billion stars The Milky Way galaxy is approximately 100,000 light-years across and contains over 100 billion stars. The galaxy has the shape of a lens with a diameter of 80,000 light years and a thickness of ~ 30,000 light years.

Collision of our Galaxy

In about three billion years, our Galaxy will collide with Andromeda, as astronomers have known for almost a century that both galaxies are approaching each other at a speed of 500,000 kilometers per hour.

What happened before the Big Bang?

• According to this theory, the entire observable space is expanding. But what happened at the very beginning? All matter in the Cosmos at some initial moment was squeezed literally into nothing - compressed into a single point. It had a fantastically huge density - it is almost impossible to imagine, it is expressed by a number in which there are 96 zeros after one - and an equally unimaginably high temperature. Astronomers have called this state a singularity.
• For some reason, this amazing balance was suddenly destroyed by the action of gravitational forces - it's hard to even imagine what they should have been with an infinitely huge density of the "primary matter"!

Mysteries of the Big Bang Theory

1. According to the big bang theory, the universe emerged from a point with zero volume and infinitely high density and temperature. This state, called a singularity, defies mathematical description.
2. The big bang theory cannot explain the existence of galaxies. Modern versions of cosmological theories predict only the appearance of a homogeneous cloud of gas.
3. The problem of "missing mass". By measuring the light energy emitted by the Milky Way, we can approximately determine the mass of our galaxy. It is equal to the mass of one hundred billion Suns. However, by studying the patterns of interaction of the same Milky Way with the nearby Andromeda galaxy, we will find that our galaxy is attracted to her as if she weighs ten times as much

slide 1

In accordance with Friedman's solutions to Einstein's equations, 13–17 billion years ago, at the initial moment of time, the radius of the Universe was equal to zero. All the energy of the Universe, all its mass was concentrated in the zero volume. The density of energy is infinite, and the density of matter is also infinite. Such a state is called singular. In 1946, Georgy Gamov and his colleagues developed physical theory initial stage expansion of the universe, explaining the presence in it chemical elements synthesis at very high temperatures and pressures. Therefore, the beginning of the expansion according to Gamow's theory was called the "Big Bang". Gamow's co-authors were R. Alfer and G. Bethe, so sometimes this theory is called "α, β, γ-theory".

slide 2


Most scientists believe that the Universe began with an event that took place 13-17 billion years ago, the Big Bang. DIAGRAM "From the Big Bang to the present day." The upper part depicts hot dense clumps of matter that have turned into galaxies. Radiation and elementary particles, which make up atoms and, finally, plants and animals on our Earth.

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The earliest universe was a fireball of radiation. The universe consisted of a mixture of exotic particles that cooled rapidly as the tiny world expanded. When the age of the universe reached one millionth of a second, most of the energy turned into protons. In the next thousandth of a second, electrons formed and merged with protons to form electrons. During the first quarter of an hour, the protons managed to react with rapidly decaying neutrons, and the nuclei of the helium atom appeared. A million years later, the temperature dropped to 4000 K, which kept the electrons in their orbits. Atoms are formed. The universe became transparent and light was able to travel freely.

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Young Universe

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  The universe is expanding from a state of infinite density. In the singular state, the usual laws of physics do not apply: a theory that combines the theory of relativity and quantum physics, has not yet been built. Apparently everything fundamental interactions at such high energies are indistinguishable from each other. And from what radius of the Universe does it make sense to talk about the applicability of the laws of physics? The answer is from the Planck length: starting from the moment of time tP = RP/c = 5∙10–44 s, where G is the gravitational constant, h is the Planck constant, c is the speed of light. Most likely, it is through tP gravitational interaction separated from the rest. In 1992, the anisotropy of the relic radiation was discovered - a slight temperature deviation (by 30 μK) from the average value of 2.725 K in various directions in the sky. The discovery of the CMB anisotropy also confirms the theory of the Hot Universe and the Big Bang.

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  The Big Bang Theory Singularity is a special state of matter characterized by its infinitely high density (5 · 1096 kg/m3) concentrated in a point volume. 1946 Georgy Gamow and his colleagues developed the Big Bang theory (1904-1968),

  Slide 7
  

  Conclusion of Friedman's calculations: The universe cannot be stationary. It either expands or contracts

  Slide 8
  

  Slide 9
  

  The Big Bang About 15-17 billion years ago, the explosive expansion of the universe began. Era of Expansion A short explosive period of expansion. The universe grows from an atom to an apple. The explosive expansion stops when the force begins to transform into matter and energy. The Age of Radiation Energy exists in the form of electromagnetic fields - visible light, X-rays and radio waves. Quarks combine to form protons and neutrons, which later stick together to form the nuclei of atoms. Light nuclei - helium, deuterium and lithium - are formed in the third minute of the life of the Universe. Time in seconds 10¯⁴⁰ 10¯³⁰ 10¯²⁰ 10¯¹⁰ 10° Second after explosion year 10¹ 10¹°years We are here 10²° Star Age Electrons combine with existing nuclei, mainly hydrogen and helium. From this raw material, over the next billion years, the first generation of stars condenses. Galaxies are born The solar system and the sun formed 4.6 million years ago. Humans appeared only 100,000 years before the present.

  Slide 10
  

  New Year, January 1, 0h00m00s - Big Bang and the emergence of the Metagalaxy January 1, noon, the first atoms formed March The first galaxies formed April Our Galaxy formed June The formation of galaxies was basically completed September The emergence of the Sun and the Solar system October The emergence of life (microorganisms) November Microbiota, the emergence of photosynthesis December 1-5 Formation of an oxygen atmosphere 15 The first multicellular organisms 20 The emergence of invertebrates 26 The first dinosaurs 27 The first mammals 28 The first birds 29 The extinction of dinosaurs 30 The first primates December 31, 14h Ramapithecus 22h30m The first people New Year January 1, 00h00m03s - XXI century. One year and the UNIVERSE

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"We hope to put the whole universe into a simple and short formula that can be printed on T-shirts." L. Lerdman

All attempts to create a physical model of the origin of the Universe are based on three postulates: All natural phenomena can be exhaustively described by physical laws expressed in mathematical form; These physical laws are universal and independent of time and place; All the basic laws of nature are simple.

Fridman Alexander Alexandrovich Friedman and Georges Lemaitre in 1927 managed to prove that Einstein's equations also allow such a solution: initially the entire Universe was concentrated at one point (conventionally called "daddy-atom") and then it begins to expand, and this is how galaxies appear and stars in them.

Hubble Edwin In 1929 he managed to confirm in practice the theories of Friedman and Lemaitre. However, this was done in 1929 by the outstanding astronomer Edwin Hubble. With his careful measurements, he proved that the long-known nebulae, previously thought to be just clouds of gas, are actually galaxies. And what is most interesting, these galaxies are moving away from us at speeds, the greater the farther they are.

Irregular Cigar Galaxy in the constellation Big Dipper(M82) (top) and a spiral galaxy in the constellation Triangulum (M33) (bottom), which were mistaken for nebulae in the early 20th century before Hubble proved they were actually galaxies. (photo taken later).

Gamow Georgy Antonovich Gamow proved that the father-atom did not just suddenly begin to expand into the entire Universe (the so-called "cold model"), it had to explode. He calls this model "Big Bang" ohm "(very simple for that time attitude towards foreign language), the Big Bang, and sets it out first in a note in 1946, and then in a 1948 article "The Origin of the Chemical Elements", written with his student Ralph Alfer.

Main question in Gamow's theories was the following: if such an explosion took place, then already quite early stages should have arisen penetrating the whole world electromagnetic radiation, whose distribution should have corresponded to the temperature at the moment of emission (many billions of degrees). But as the Universe expanded, the frequencies of this primary (it was called "relic") radiation should have decreased due to the Doppler effect, and by now, according to Gamow, correspond to a temperature of about three to four degrees Kelvin, i.e. be concentrated in the region of wavelengths of several centimeters. In 1965, A. Penzias and R. Wilson, who designed antennas for radio electronics, discovered electromagnetic radiation uniformly traveling in all directions, corresponding to a temperature of 3 Kelvin! As it turned out, this was not a hardware failure at all, but exactly the radiation that Gamow was talking about! But Nobel Prize They gave Penzias and Wilson, not Gamow.

Data from the NASA probe - WMAP, which hovered at the Lagrange point (the point of gravitational equilibrium between the Sun and the Earth) at a distance of 1.5 million km from us. The resulting "picture" is actually a snapshot of the afterglow of the Big Bang, formed by the temperature distribution of the cosmic microwave background.

Stephen Hawking b.1942 To date, the theory has subsequently been interpreted many times, translated and supplemented by many scientists. The main contribution to solving the problems of the Big Bang Theory was made by Stephen Hawking, and the contribution was not theoretical, but very practical - more than two thousand pages of calculations and equations devoted to describing the appearance of particles and galaxies.

Big Bang Theory Time - billions of years ago. Initial density kg/m 3. The volume of the "daddy-atom" was infinitely small.

Decrease in temperature T as a function of time t. In order for a photon to turn (materialize) into a particle and an antiparticle with mass m o and rest energy m o c 2, it must have energy 2 m o c 2. In the previous relation, we can replace the photon energy hn kinetic energy particles kT Or…

10 32 10 32 18 Evolution of the Universe: pre-Galactic period Time after the Big Bang Characteristic temperatures (K) Characteristic distances (cm) Stage/Event 10 32 10 32 10 32 10 32 title="(!LANG: Evolution of the Universe: pre-Galactic period Time after the Big Bang Characteristic temperatures (K ) Characteristic distances (cm) Stage/Event 10 32

C Hadron era. Birth and annihilation of hadrons and leptons from the lepton era. Creation and annihilation of leptons c2 · Separation of neutrinos. The Universe becomes transparent for neutrinos (antineutrinos) with ~ Prestellar fusion of helium. 10 years Radiation era. Dominance of radiation over matter years The beginning of the era of Substance. Matter begins to dominate over radiation 3 · Separation of matter and radiation. The universe becomes transparent to radiation. Time after Big Bang Characteristic temperatures (K) Characteristic distances (cm) Stage/Event

Modern cosmology has three ways to solve the problems of the Big Bang Theory: Completely abandon the Big Bang Theory. Use for the development of Theory a huge amount of human, machine and financial resources. Find a fundamentally new (and reliable) alternative, which is a modified version of the Big Bang Theory.

Three different models can be specified for which both of Friedman's fundamental assumptions hold. In the first type of model (discovered by Friedman himself), the universe expands slowly enough that, due to the gravitational attraction between different galaxies, the expansion of the universe slows down and eventually stops. After that, the galaxies begin to approach each other, and the Universe begins to shrink. On fig. 1 shows how the distance between two neighboring galaxies changes with time. It rises from zero to a certain maximum, and then falls back to zero. In the model of the second type, the expansion of the Universe is so fast that the gravitational attraction, although it slows down the expansion, cannot stop it. On fig. 2 shows how the distance between galaxies changes in this model. The curve goes out of zero, and eventually the galaxies move away from each other with constant speed. There is, finally, a model of the third type, in which the expansion rate of the Universe is just enough to avoid shrinking to zero (collapse). In this case, the distance between the galaxies is also zero at first (Fig. 3), and then it increases all the time. True, the galaxies "run away" at a slower and slower speed, but it never drops to zero. Three different models can be specified for which both of Friedman's fundamental assumptions hold. In the first type of model (discovered by Friedman himself), the universe expands slowly enough that, due to the gravitational attraction between different galaxies, the expansion of the universe slows down and eventually stops. After that, the galaxies begin to approach each other, and the Universe begins to shrink. On fig. 1 shows how the distance between two neighboring galaxies changes with time. It rises from zero to a certain maximum, and then falls back to zero. In the model of the second type, the expansion of the Universe is so fast that the gravitational attraction, although it slows down the expansion, cannot stop it. On fig. 2 shows how the distance between galaxies changes in this model. The curve starts from zero, and eventually the galaxies move away from each other at a constant speed. There is, finally, a model of the third type, in which the expansion rate of the Universe is just enough to avoid shrinking to zero (collapse). In this case, the distance between the galaxies is also zero at first (Fig. 3), and then it increases all the time. True, the galaxies "run away" at a slower and slower speed, but it never drops to zero.

Facts, firmly and forever established and proven by the Big Bang Theory: At the moment of "birth" all the matter of the universe was concentrated in one point, which had an infinitely large mass and an infinitely small volume; As a result of the expansion (or explosion) of this point, first elementary particles began to form, and then the first material macro-bodies.

Facts proving the Big Bang Theory: Removal from each other of galaxies, with speeds increasing, the farther they are from each other, which was discovered by Hubble; CMB radiation, discovered by Penzias and Wilson; Mathematical calculations of the formation of substances, derived by S. Hawking and other mathematicians; General theory Einstein's relativity.

The Big Bang Theory claims that the entire physical universe - matter, energy and even 4 dimensions of space and time arose from a state of infinite values ​​of density, temperature and pressure. The universe originated from a volume smaller than a point

and continues to expand. The Big Bang Theory is now generally accepted as it explains both of the most significant facts of cosmology: the expanding universe

and the existence of cosmic background radiation.

This event took place between 13 and 20 billion years ago. You can use the known laws of physics and calculate backwards all the states in which the Universe was, starting from 10-43 seconds after the Big Bang.

During the first million years, matter and energy in the universe formed an opaque plasma, sometimes called a primordial fireball.

By the end of this period, the expansion of the universe caused the temperature to drop below 3000 K, so that protons and electrons could combine to form hydrogen atoms. At this stage, the Universe became transparent to radiation. The density of matter now became higher than the density of radiation, although before the situation was reversed, which determined the rate of expansion of the Universe.

The microwave background radiation is all that remains of the highly cooled radiation from the early universe.

First

galaxies

began to form from primordial clouds of hydrogen and helium only after one or two billion years. The term "Big Bang" can be applied to any model of an expanding universe that was hot and dense in the past.

The Large Magellanic Cloud is the galaxy that accompanies our own. It is visible to the naked eye as a hazy, elongated region of the sky. It is located at a distance of 160,000 light years and covers an area of ​​20,000 light years. Its visible part is a tenth of the Milky Way

Hourglass Nebula

A young planetary nebula about 8000 light-years distant from us.

The image was taken at three different wavelengths to reflect the gaseous composition of the nebula. Nitrogen is shown in red, hydrogen in green, and doubly ionized oxygen in blue. The exact formation process is still unclear

Crab Nebula

is one of the most interesting objects in the sky. It is the remnants of a huge stellar explosion. It has been displayed in all wavelengths from radio to gamma rays. The central star - a pulsar - is a rapidly rotating neutron star. It spins so fast that an impulse is seen every 0.033 seconds. At optical wavelengths, this central star is 16th magnitude and out of reach of all but the most powerful telescopes.

Milky Way

This is our own galaxy as seen from within. The galaxy is a giant star system of approximately 200 billion stars The Milky Way galaxy is approximately 100,000 light-years across and contains over 100 billion stars. The galaxy has the shape of a lens with a diameter of 80,000 light years and a thickness of ~ 30,000 light years.

Elliptical galaxies are formed as a result of collisions between spiral galaxies.

This image shows a spiral galaxy

clash

galaxies

In about three billion years, our Galaxy will collide with Andromeda, as astronomers have known for almost a century that both galaxies are approaching each other at a speed of 500,000 kilometers per hour.

What happened before the Big Bang?

According to this theory, the entire observable space is expanding. But what happened at the very beginning? All matter in the Cosmos at some initial moment was squeezed literally into nothing - compressed into a single point. It had a fantastically huge density - it is almost impossible to imagine, it is expressed by a number in which there are 96 zeros after one - and an equally unimaginably high temperature. Astronomers have called this state a singularity.

For some reason, this amazing balance was suddenly destroyed by the action of gravitational forces - it's hard to even imagine what they should have been with an infinitely huge density of the "primary matter"!