The age of the Earth is determined by different methods. The most accurate of them is to determine the age of rocks. It consists of calculating the ratio of the amount of radioactive uranium to the amount of lead found in a given rock. The fact is that lead is the end product of the spontaneous decay of uranium. The speed of this process is known exactly, and it cannot be changed by any means. The less uranium left and the more lead accumulated in the rock, the older its age. The oldest rocks in the earth's crust are several billion years old. The earth as a whole apparently arose somewhat earlier than the earth's crust. The study of fossilized remains of animals and plants shows that over the past hundreds of millions of years, the radiation of the Sun has not changed significantly. According to modern estimates, the age of the Sun is about 5 billion years. The sun is older than the earth

There are stars that are much younger than the Earth, for example, hot supergiants. Based on the rate of energy consumption by hot supergiants, one can judge that the possible reserves of their energy allow them to spend it so generously only for a short time. This means that hot supergiants are young - they are 10 6 -10 7 years old.

Young stars are found in the spiral arms of the galaxy, as are the gaseous nebulae from which stars arise. The stars that did not have time to scatter from the branch are young. When they leave the branch, they grow old.

Stars of globular clusters, according to the modern theory of the internal structure and evolution of stars, are the oldest. They can be more than 10 10 years old. It is clear that star systems - galaxies must be older than the stars of which they are composed. Most of them must be at least 10 10 years old

In the stellar Universe, not only slow changes occur, but also rapid, even catastrophic ones. For example, over a period of about a year, an ordinary-looking star flares up as a “supernova” (§ 24.3), and during approximately the same time its brightness decreases.

As a result, it probably turns into a tiny star made of neutrons and rotating with a period on the order of a second or faster (a neutron star). Its density increases to the density of atomic nuclei (10 16 kg/m), and it becomes a powerful emitter of radio and x-rays, which, like its light, pulsate with the rotation period of the star. An example of this pulsar, as they are called, serves as a faint star at the center of the expanding Crab Radio Nebula ($24.3). A lot of remnants of supernova explosions in the form of pulsars and radio nebulae like the Crab nebula are already known.

The question of the origin of the solar system must be resolved together with the problem of the origin and development of stars. It is perhaps difficult to solve correctly without knowledge of how galaxies form and evolve.

From a cosmogonic point of view, data on the “age” of celestial bodies is as important as astronomical data in the proper sense of the word.

The problem of "age" may seem quite different from those we have just considered, since it relates to time, and we have hitherto seemed to be concerned only with space. But in reality the difference is not very big. In the previous paragraphs we saw how astronomers were able to gradually extend the laws discovered on Earth to all space where our eyes, armed with perfect telescopes, reach. With the help of these laws, scientists can quite satisfactorily explain the processes occurring in various stars and even in the most distant spiral nebulae.

True, astronomers observe celestial bodies from which light takes thousands and millions of years to reach us. Consequently, the phenomena that are being studied in these stars are not happening now, but happened exactly as many years ago as is necessary for the ray of light that tells us about this to travel from the heavenly body to us (just like a letter , sent, for example, from Moscow, brings us in Paris not the latest news, but several days late). Thus, to phenomena that occurred thousands and millions of years ago, one can successfully apply the laws that exist today on our planet and information about which was acquired on the basis of experience over only two or three centuries. *

* (The fact that we observe celestial bodies as they were many thousands and millions of years ago (since the light from them travels to us for thousands and millions of years) does not play a special role, because the evolutionary periods of celestial bodies are, as a rule, very long and are estimated at hundreds of millions and billions of years. (Editor's note))

Scientists, wanting to calculate the age of celestial bodies, proceed from the facts observed at the present time, and try to explain these facts on the basis of the supposed evolution of the world, in accordance with the laws of nature known to them. There is no doubt that the application of such a method cannot proceed without some difficulties, especially since the time periods under consideration here are thousands of times longer. Our knowledge of the laws of nature is and will always be only an approximation to reality, and nothing says that all the laws that are valid today can be applied without any changes to eras billions of years removed from ours. Nevertheless, it is a remarkable fact that various scientists, using entirely different methods, have arrived at consistent results regarding the age of the Earth. As for the age of stars, the same clarity has not yet been achieved on this issue, but nevertheless very important results have been obtained.

Age of the Earth

The first methods used to determine the age of the Earth were “geological”. It was geology that first showed that the earth's crust did not have the same appearance throughout all centuries, but was constantly changing and undergoing gigantic catastrophes - uplift and subsidence.

The problem was to determine how long it took to form the earth's crust (as it is today). This time is called the “age of the Earth.”

The first methods of calculating the age of the Earth were based on the laws of geology. For example, it was noticed that the salt contained in sea water is carried into the sea by rivers, which dissolve ground salts along their path. Knowing, on the one hand, the quantity of salt carried by the various rivers, and the fluctuations of this quantity during geological periods, and, on the other hand, the total quantity of salt presently contained in the oceans, one can easily obtain an idea of ​​the time required for the accumulation of this quantity salts in the oceans.

It was also possible to determine the thickness of the various layers of soil that were gradually deposited as a result of river sediments on the bottom of the former seas. At the same time, other studies have made it possible to calculate the growth rate of these deposits. Simple division then gave the number of years required for their formation.

These various geological methods have led to the conclusion that the age of the Earth must be measured at least in the hundreds of millions of years.

Later, methods based on the study of the decay of radioactive elements, which is extremely regular, began to be used to determine the age of the Earth. For example, as a result of radioactive decay, uranium gradually turns into lead, and this process releases some helium (the gas used to fill airships). By the relationship between the amounts of uranium and lead contained in some rocks, the age of these rocks can be determined. Using such methods, not only the age of the Earth is estimated, but also the duration of the formation of individual layers of the earth's crust.

Analyzing the totality of the results obtained by this method, the English scientist Holmes determined that the most probable age of the earth's crust is 3 billion 300 million years. It goes without saying that there should be no illusions about the accuracy of this number; in any case, an error of several hundred million years is quite acceptable. It can only be stated that all estimates worth mentioning that have been obtained at present are between 3 and 5 billion years.

Let us add that these results completely satisfy biologists. Indeed, according to the latter, the evolution of living matter lasted approximately 500 million years.

Age of stars

a) Long and short time scales. The problem of determining the age of stars has generated much more heated debate. It was in connection with this problem that proponents of the long time scale (who estimate the duration of the evolution of celestial bodies in trillions of years) and proponents of the short scale (who count in billions of years) clashed with each other.

Despite the fact that the proponents of the short scale have gained some advantage (for example, in estimating the ages of the brightest stars in the Galaxy), their victory cannot be considered complete, and therefore it is necessary to highlight some of the details of this conflict, first mentioning the methods used to estimate the required time periods. These methods are of two types: some estimate the time of internal physical changes that lead to changes in stars, and try to determine the “life” of stars; others set themselves the task of calculating the time it took for stellar systems (clusters of stars, double stars) to establish the characteristics of their current state as a result of the mutual attraction of stars.

b) Sources of radiant energy from stars. Bethe's theory. When they talk about the “life” of a star, they mean the duration of such a state of the star, during which it detects its presence due to light and thermal radiation. Consequently, the problem of the possible lifespan of a star is closely related to the problem of the sources of the energy it emits. This energy is extremely great. For example, every square centimeter of the sun's surface continuously emits enough energy to run an eight-horsepower engine.

At first they wanted to explain the release of solar energy by ordinary combustion, then by the gradual compression of the Sun under the influence of gravitational forces. But these hypotheses led to the age of the Sun being too small: in accordance with the first hypothesis, it was estimated at thousands of years, in accordance with the second, at millions of years.

The theory currently accepted by all scientists is based on one of the fundamental results of the theory of relativity, discovered in 1905 simultaneously by Einstein and Langevin: “the mass of a body at rest is nothing more than a measure of the internal energy of this body.” In other words, matter (matter in a corpuscular state) can partially or even completely “disappear” (that is, go into another form of existence - into radiation), and this phenomenon is accompanied by the release of energy.

This hypothesis was first proposed by the French physicist Jean Perrin in 1919, who had in mind the significant release of energy in the process of converting hydrogen into helium. It was picked up and brought to its most extreme consequences (the “complete destruction” of matter as a result of its transformation into energy) by various scientists, in particular, the English astronomer Jeans. *

* (In fact, what is happening is not the “destruction” of matter, not its transformation into energy, but the transformation of one form of matter - substance - into another - radiation. (Editor's note))

The energy released through such processes is colossal. With the complete transformation of coal into radiation, three billion times more energy can be obtained than during its normal combustion, and Jeans quite rightly said that a small piece of coal the size of a pea is enough to travel on the largest ocean steamer from Europe to America and back .

Let us note, for comparison, that the decay of uranium, which occurs in a conventional atomic bomb and which corresponds to only a partial conversion of the substance into radiation, releases two and a half million times more energy than the combustion of the same amount of coal. As for the conversion of hydrogen into helium, which takes place in a hydrogen bomb, this releases 10 million times more energy than the combustion of the same amount of coal.

Some types of transformation of matter (matter in corpuscular form) into radiation, which until recently we have never observed on Earth, occur inside stars, where temperatures on the order of millions of degrees reign.

Assuming that the star undergoes a transformation of the entire amount of matter of which it consists, it can be calculated that the energy released during this process can support its radiation, i.e., the star has something to “live on” for trillions of years. For example, the Sun, under this assumption, can live another 10 trillion years, and if it was “born” as a red giant of normal size, then this “birth” occurred about eight trillion years ago.

Proponents of a long time scale, such as Jeans, supported the hypothesis of the complete decay of matter, which leads to periods of time that fit into their cosmogonic hypotheses. At the same time, supporters of the short scale, who, on the basis of various considerations, believed that these periods of time were too long, adhered to the point of view of Jean Perrin.

It seemed that resolving this controversial issue would be difficult, but shortly before the 1939 war, advances in atomic chemistry, in particular the discoveries of Frédéric and Irene Joliot-Curie, shed some light on the problem. The creation of a cyclotron, with which it was possible to expose matter to significant electric and magnetic fields, made it possible to partially realize in laboratories conditions similar to those that exist inside stars. Indeed, in these devices it was possible to accelerate charged particles to such speeds that they acquired energy comparable to that which they (on average) have when located at the center of a star such as the Sun at a temperature of millions of degrees.

Thanks to this extremely powerful tool, scientists were able to create a theory of the transformations of matter inside stars; it was developed by the American astrophysicist Bethe.

An essential agent of these transformations is hydrogen. The final result of the combination of these nuclear reactions is the transformation of four hydrogen nuclei into one helium nucleus. *

* (Atoms of various chemical elements consist of a central nucleus with a positive electrical charge and a certain number of electrons, negatively charged, and the total charge of electrons in an ordinary (electrically neutral) atom is numerically equal to the charge of the nucleus. The amount of positive charge on the nucleus determines the so-called atomic number of a chemical element. If we arrange the chemical elements in increasing order of their atomic numbers, then we get the well-known classification of elements according to their atomic weights (Mendeleev's periodic system). Let us also add that the nuclei of atoms themselves have a complex structure, different for different elements, that the phenomena inside atoms obey very specific laws, and that, contrary to the opinion that existed some time ago, atoms in their structure are not at all like a miniature solar system.)

As for the duration of these processes, the transformation of hydrogen into helium, corresponding to the loss of only 1/14 of the mass (converted into radiation), takes a much shorter period of time than that obtained in hypotheses based on the assumption of the complete conversion of matter into radiation. According to the new point of view, the stars we observe began to emit light only a few billion years ago.

Some stars - white and blue giants, whose mass reaches twenty solar masses - radiate so intensely that they cannot exist in this state for more than several tens of millions of years, so they probably have not yet traveled a very long “life path”.

We should now show how the Russell diagram can be interpreted using Bethe's theory. We will return to this issue a little later, when we present the latest cosmogonic theories. Let us note, however, now that if the nuclear reactions proposed by Bethe make it possible to well explain the observed facts regarding main sequence stars, then in relation to the giants it turns out to be necessary to assume the existence of other nuclear transformations, which are far from fully established. As for white dwarfs, it was only in 1946 that the French astronomer Schatzmann was able to clarify our understanding of the processes occurring inside these stars.

Age of the Galaxy

Among the various methods for estimating the age of the stars that make up our Galaxy, statistical methods have also been used. In this case, the influence on double stars of the attraction of neighboring stars, produced on average over very long periods of time, was taken into account. It is possible, for example, knowing the current distance between the stars of a pair, to approximately estimate the period of time that has elapsed since the formation of the stars of the pair, if, of course, we assume that both stars of the pair have a common origin (as is currently believed) and if we know the average values ​​of distances of masses and velocities of neighboring stars. One can also estimate the time required for some globular clusters, which have low densities, to dissipate due to the attraction of passing stars.

These calculations are quite delicate and it is easy to make mistakes. For example, Jeans, studying some pairs of stars, came to the conclusion that the age of these pairs should be several trillion years. In this he found confirmation of his views about a long time scale. However, in reality, as V.A. Ambartsumyan proved a few years later, the age of these pairs does not exceed several billion years.

Typically, the most recent calculations for both binary stars and globular clusters result in estimates of billions of years. But one cannot quite definitely conclude from this that this is exactly what the actual age of our Galaxy should be. This conclusion would be valid only if all pairs of stars, all globular clusters that we know, were formed simultaneously with our Galaxy. Ambartsumyan's recent work, on the contrary, has shown that new stars are continuously forming in the Milky Way. Therefore, nothing prevents us from assuming that, along with the double stars and globular clusters that we now know, there also existed other pairs and other globular clusters that have now completely dissipated and turned into single stars. Consequently, we can only say that the actual age of the Milky Way is no less than several billion years.

Preliminary considerations about the evolution of galaxies

Is it possible to go further and try to estimate the time of the complete evolution of a galaxy in the same way as we determined the duration of the entire “life” of a star? Of course, this problem is much more complex. However, when comparing different known types of galaxies, some interesting data can still be obtained (Fig. 7). Indeed, a simple comparison of the shapes of galaxies makes us suspect that we are dealing here with different stages of evolution. True, the question now arises in which direction this evolution is going: from spherical to spiral nebulae or vice versa.

Rice. Evolution of a spiral nebula according to Hubble. (The observer is in the equatorial plane.) The darker areas in Figures IV and V correspond to areas where dark matter is present.

First, the first hypothesis put forward by Hubble was accepted, which corresponded, roughly speaking, to the evolution of a liquid rapidly rotating mass (flattening and then ejection of matter in a tangent direction). But observations have shown that, on the one hand, elliptical nebulae have dimensions of the same order as spiral nebulae, and on the other hand (Baade's work in 1943), they are “overpopulated” with stars, but are devoid of any traces of scattered matter. Therefore, most scientists are inclined to believe that galaxies evolve in the opposite direction, that is, their evolution begins with an irregularly shaped galaxy and ends with a giant globular cluster. In this scheme, the spiral shape of the galaxy is only an intermediate stage, quite close to the beginning of the evolutionary path and, therefore, contrary to what was previously thought, our Galaxy should be relatively “young”.

Rice. View of a spiral nebula with formed arms. (The observer is located on the axis of rotation of the nebula)

As for estimates of the total lifespan of one galaxy, they are still very unreliable, but not lower than tens of billions of years. Finally, the distribution of galaxies in clusters indicates, according to some astronomers (for example, Zwicky), that the age of galaxy clusters is tens of trillions of years.

Thus, contrary to the premature conclusions of some supporters of the short scale, the following idea clearly emerges: in astronomy there is not a single time scale, but there are many scales. * The age of the planets of the solar system differs from the lifespan of most stars in the Milky Way, and the latter, apparently, cannot be estimated at the same value as the age of large clusters of galaxies.

* (A similar pattern is observed in the microcosm. The duration of “life” is different for different types of “elementary” particles: for some (for example, an electron) it is practically infinite, for others (mu-mesons) it is only 10-14 seconds. However, as the latest data show, for various celestial bodies the difference in “lifetimes” is apparently much smaller. (Editor's note))

In most modern textbooks, encyclopedias and reference books, the age of the Sun is estimated at 4.5-5 billion years. The same amount of time is allotted to him to “burn out.”

In the first half of the 20th century, the development of nuclear physics reached such a level that it became possible to calculate the efficiency of various thermonuclear reactions. As was established in the late 1930s, under the physical conditions existing in the central region of the Sun and stars, reactions can occur that lead to the union of four protons (nuclei of a hydrogen atom) into the nucleus of a helium atom. As a result of such unification, energy is released and, as follows from calculations, this way ensures the glow of the Sun for billions of years. Giant stars, which use their nuclear fuel (protons) more profusely, should have a much shorter lifetime than the Sun - only tens of millions of years. From this, in those same years, the conclusion was made about the birth of such stars in our time. Regarding smaller stars like the Sun, many astronomers continued to hold the view that they, like the Sun, were all formed billions of years ago.

At the end of the 40s V.A. Ambartsumyan took a completely different approach to the problem of determining the age of stars. It was based on the extensive observational data available at that time on the distribution of stars of various types in space, as well as on the results of our own studies of the dynamics of stars, that is, their movements in the gravitational field created by all the stars in the Galaxy.
V.A. On this basis, Ambartsumyan made two most important conclusions not only for astrophysics, but also for the entire natural sciences:

1. Star formation in the Galaxy continues to this day.
2. Stars are born in groups.

These conclusions depend neither on assumptions about the mechanism of star formation, which in those years was not established with certainty, nor on the nature of the sources of stellar energy. They are based on what V.A. Ambartsumyan discovered a new type of star clusters, which he called stellar associations.

Before the discovery of stellar associations, astronomers knew of two types of stellar groups in the Galaxy - open (or open) clusters and globular clusters. In open clusters the concentration of stars is not very significant, but they still stand out against the background of the star field of the Galaxy. A cluster of another type - a globular one - is distinguished by a high degree of concentration of stars and, with insufficiently good resolution, appears to be a single body. Such a cluster consists of hundreds of thousands of stars, creating a strong enough gravitational field that keeps it from quickly disintegrating. It can exist for a long time - about 10 billion years. The open cluster contains several hundred stars and, although it is a gravitationally bound system, this connection is not very strong. The cluster can disintegrate, as shown by V.A. Ambartsumyan's calculations for several hundred million years.

Scientists from NASA have determined the age of our Universe with unprecedented accuracy. Astronomers estimate it to be 13.7 billion years old, and the first stars appeared 200 million years after the Big Bang. From this moment on, the Universe continuously expands, disperses and cools... until complete non-existence.

Previously, astrophysicists believed that our world was from 8 to 20 billion years old, then they settled on the range of 12-15 billion, reserving the right to a 30% error. The current estimate has a margin of error of 1%. As for the “gestation period” of the first star, it was previously assumed to lie within the range of 500 million to a billion years.
Even more interesting is the qualitative composition of the matter of the Universe. It turns out that only 4% of matter consists of atoms, which are subject to the known laws of electromagnetism and gravity. Another 23 percent consists of so-called “dark matter” (scientists know little about its properties). Well, as much as 73% of everything that exists is the very mysterious “dark energy” or “antigravity”, which prompts the Universe to expand. It turns out that we know that we know nothing by 96%.
The day was the first natural unit of time that regulated work and rest. At first, the day was divided into day and night, and only much later into 24 hours.

The sidereal day is determined by the period of rotation of the Earth around its axis relative to any star.
True noon occurs at different times on different meridians of the Earth, and for convenience, the convention is to divide the globe into time zones that pass through 15 degrees of longitude, starting from the Greenwich meridian. This is the London meridian of 0 degrees longitude, and the belt is called zero (Western European).

A second is a generally accepted unit of time; the human heart beats with a period of approximately 1 second. Historically, this unit is associated with dividing the day into 24 hours, 1 hour into 60 minutes, 1 minute into 60 seconds.

An atomic second is a time interval during which almost 10 billion vibrations of a Cs atom take place - (9,192,631,830).

A calendar is a system for reporting long periods of time, in which a certain order of counting days in a year is established and the beginning of the report is indicated.

Determining age by spectrum

At first glance, it may seem that in order to determine the composition of the Sun or a star, it is necessary to extract at least a little of its matter. However, this is not true. The composition of a celestial body can be determined by observing the light coming to us from it using special instruments. This method is called spectral analysis and is of great importance in astronomy.
The essence of this method can be understood as follows. Let us place an opaque barrier with a narrow slit in front of the electric lamp, a glass prism behind the slit, and a white screen somewhat further away. A heated solid metal filament glows in an electric lamp. A narrow beam of white light cut by a slit, passing through a prism, is decomposed into its component colors and gives a beautiful color image on the screen, consisting of sections of different colors that continuously transform into each other - this is the so-called continuous light spectrum, similar to a rainbow. The type of spectrum of a heated solid does not depend on its composition, but only on the temperature of the body.
A different situation occurs when substances glow in a gaseous state. When gases glow, each of them glows with a special, unique light. When this light is decomposed using a prism, a set of colored lines, or a line spectrum, characteristic of each given gas is obtained (Fig. 1). This is, for example, the glow of neon, argon and other substances in gas-discharge tubes, or so-called cold light lamps.

Spectrum of arrivals. Photo: NASA

Spectral analysis is based on the fact that each given substance can be distinguished from all others by its emission spectrum. When spectral analysis of a mixture of several substances, the relative brightness of individual lines characteristic of each substance can be used to determine the relative content of a particular impurity. Moreover, the accuracy of the measurements is such that it makes it possible to determine the presence of a small impurity, even if it is only one hundred thousandth of the total amount of the substance. Thus, spectral analysis is not only a qualitative, but also an accurate quantitative method for studying the composition of a mixture.
By pointing telescopes at the sky, astronomers study the patterns of movement of stars and the composition of the light they emit. Based on the nature of the movement of celestial bodies, the size of stars, their mass, etc. are determined. Based on the composition of the light emitted by celestial bodies, the chemical composition of stars is determined using spectral analysis. The relative abundance of hydrogen and helium in the star under study is determined by comparing the brightness of the spectra of these substances.

Since the development of a star is accompanied by the continuous transformation of hydrogen into helium inside it, the older the star, the less hydrogen and more helium in its composition. Knowing their relative abundance allows us to calculate the age of the star. However, this calculation is not at all simple, because during the evolution of stars, their composition changes and their mass decreases. Meanwhile, the rate at which the conversion of hydrogen into helium occurs in a star depends on its mass and composition. Moreover, depending on the initial mass and initial composition, these changes occur at different rates and in slightly different ways. Thus, in order to correctly determine the age of a star from the observed quantities - luminosity, mass and composition, it is necessary to restore to some extent the history of the star. This is what makes all the calculations quite complicated, and their results not very accurate.

Nevertheless, corresponding measurements and calculations have been made for many stars. According to A. B. Severny, the Sun contains 38% hydrogen, 59% helium, and 3% other elements, including about 1% carbon and nitrogen. In 1960, D. Lambert, based on data on the mass, luminosity and composition of the Sun, as well as detailed calculations of its supposed evolution, obtained the age of the Sun equal to 12 * 109 years.
When studying the history of the development of celestial bodies, there is neither the need nor the opportunity to follow any one star from its birth to its old age. Instead, many stars can be studied at different stages of their development. As a result of such research, it was possible to clarify not only the present, but also the past and future of the stars and, in particular, our Sun.
At first, the Sun was very wasteful in its mass and energy and relatively quickly transitioned to its modern state, characterized by a calmer and more even existence, in which only extremely slow changes in its luminosity, temperature and mass occur. At this already “mature” age, the Sun will exist for many more billions of years.

Then, due to the accumulation of a large amount of helium, the transparency of the Sun will decrease and, accordingly, its heat transfer will decrease. This will lead to even greater heating of the Sun. By this time, the reserves of hydrogen “fuel” in the Sun will almost dry up, so after a relatively short flare-up of the Sun, its relatively rapid fading will begin. However, all this will not happen to our Sun soon, no less than in ten billion years.

There are stars in which the hydrogen content is much greater than in our Sun, and also those in which there is very little hydrogen. V. A. Ambartsumyan, B. A. Vorontsov-Velyaminov and B. V. Kukarkin showed that there are young stars in the Galaxy, for example, a number of supergiants, whose age does not exceed only one or ten million years, as well as old stars, age which are much greater than the age of our Sun.

Our Galaxy is a gigantic cluster of stars interconnected by gravitational forces and thus united into a common system. The distances separating us from the Sun and other stars are enormous. Therefore, to measure them, astronomers introduced specific units of length. The distance from the Earth to the Sun is called the astronomical unit of length. As you know, 1 a. e. = 149.6 million km. The distance that light travels in one year is called a light year: 1 light year. year = 9.46x10 12 km = 10 13 km. The distance at which the radius of the earth's orbit is visible at an angle of 1 second is called second parallax or abbreviated as parsec (pc). Thus, 1 pc = 3.26 st. years = 3.085x10 13 km.

Our Galaxy has the shape of a very flat disk. It contains about 1013 stars. The sun is one of them. This entire system rotates slowly, but not like a solid body, but rather like a semi-liquid, viscous body. The angular velocity of rotation of the Galaxy decreases from its center to the periphery so that at 8 kiloparsecs from the center the period of revolution is about 212 million years, and in the region of the Sun, that is, at a distance of 10 kiloparsecs from the center, it is 275 million years. It is this period that is usually called the galactic year.
Obviously, the age of the Galaxy should be determined by the oldest of its constituent stars. In 1961, G. Arp studied a number of the oldest stars. For the oldest open cluster NGC 188, he obtained an age value of 16x10 9 years, and for one of the oldest globular clusters, M5, the age was 20x10 9 years. According to estimates by F. Hoyle and others, the age of some stars close to the Sun: 8 Eridani and u Hercules A, is (10-15)x10 9 years.

At present, the age of the Galaxy has been determined by other methods, and somewhat different results have been obtained. A consideration of these methods and a comparison of the results obtained with their help is of great interest and is given below.

Modern theories of the internal structure of celestial bodies, as well as planetary cosmogony, use the results of studies of the age of rocks, solar neutrinos or other data obtained from studying the outer layer of a celestial body as the initial, experimental basis for estimating the age of celestial bodies.

Since, based on the model of vortex cosmogony, celestial bodies were created through the accumulation of cosmic matter, the conclusion follows that each inner layer must have its own age, exceeding the age of the outer layer of the same planet or star. Consequently, from studies of external rocks or any radiation emanating from these rocks, it is impossible to estimate the age of the internal substance or the celestial body as a whole.

Based on vortex gravity and the creation of celestial bodies, it is permissible to determine the age of planets by simply dividing the mass of the planet by the corresponding annual increase in the mass of this planet.

Taking into account the above, the age of the Earth is 15.6 billion years.

DARK MATTER

As is known, in the middle of the last century, when studying the structure of the galaxy, a discrepancy between the distribution of stars and the distribution of gravitational potential was discovered.

Scientific opinion was divided into two groups.

Some scientists have argued that Newton's theory of gravity, derived from observations of planets in the solar system, is not true on larger astronomical scales

Most researchers agree that part of the matter (30%) does not emit photons, so it is not visible. But it is this matter that balances the gravitational potential in the galaxy. Invisible matter is called dark matter.

Obviously, the theory of vortex gravity has no difficulty in explaining this astronomical “paradox,” since the force of universal gravity does not depend on the masses of stars, but only on the speed of vortex rotation and the pressure gradient of the galactic ether. The magnitude of vortex gravity in any galaxy can be determined in accordance with Chap. 2.1. The resulting value of the gravitational force completely balances the centrifugal forces of stars and, thus, there is no need to use hypothetical dark matter.