Chapter two “...And it stands on three pillars...” Faith is the extrapolation of truth through authority, the unsubstantiated perception of verbal information as

How much does a gram of light cost? The increase in body mass is closely related to the work done on it: it is proportional to the work that is needed to set the body in motion. In this case, there is no need to spend work only on setting the body in motion. Any

Alexander Friedman: “The Universe does not stand still” In the spring of 1922, an appeal “To the physicists of Germany” appeared in the main physics journal of that time, Zeitschrift für Physik. The Board of the German Physical Society reported on the difficult situation of colleagues in Russia, who

108. Could life exist elsewhere in the solar system? Space is harsh. Vacuum, cold and heat, deadly ultraviolet (UV) radiation and high energy particles are all harmful to living cells. If it is too hot, complex molecules break down, and if

An experience that should not be repeated “I want to tell you a new and terrible experience, which I advise you not to repeat yourself,” wrote the Dutch physicist van Musschenbroeck to the Parisian physicist Reaumur and further reported that when he took left hand glass jar with electrified

The world is not fully created: the heavens are always being updated, astronomers are always adding new ones to the old stars. If I discovered a star, I would call it Friedman - better means I can’t find it to make everything clearer.

Friedman! Until now, he is an inhabitant of only a few bookshelves - an amateur mathematician, a young meteorologist and a military aviator on the German front somewhere, and later - the organizer of the University of Perm at the dawn Soviet power. Member of Osoaviakhim. Having caught typhus in the Crimea, unfortunately, he did not return from Crimea. Died. And they forgot about him. Only a quarter of a century later they remembered the man and seemed to revive him: “Young, full of boldness, he did not think without ideas. It is a fact that in some ways he went further than Einstein himself: sensing the inconstancy of forms in this hurricane world, he saw galaxies scattering in the curvature of space.” – “Expansion of the Universe? We need to figure this out!”

They begin to bicker.

But the fact is undeniable: this Friedman was a scientist with a very enviable future. Oh, shine a new star above the horizon, Friedman!

Some inaccuracies do not at all spoil the poems of Leonid Martynov, dedicated to the mathematician, physicist, meteorologist Alexander Alexandrovich Fridman, who succeeded despite short life, leave a noticeable mark on world science.

Academician P. L. Kapitsa argued that Friedman was one of the best Russian scientists. “If it had not been for his death from typhoid fever at the age of 37... he certainly would have done much more in physics and mathematics and would have achieved the highest academic ranks. At a young age, he was already a professor and was world famous among specialists in the theory of relativity and meteorology. In the 1920s, while in Leningrad, I often heard reviews of Friedman as an outstanding scientist from professors Krutkov, Fredericks, and Bursian.”

While still a high school student, Friedman (together with Ya. D. Tumarkin) published two short articles on number theory. Both received an approving review from the famous mathematician D. Hilbert. Friedman’s widow wrote: “...In childhood, the most severe punishment, which pacified his rebellious temper: he was left without an arithmetic lesson, and he remained that way for the rest of his life. While still a student he published several mathematical studies; one of them was awarded a Gold Medal from the Faculty of Physics and Mathematics.” The widow was referring to work on number theory - again done with Tumarkin.

In 1910, Friedman graduated from St. Petersburg University and was retained at the mathematics department to prepare for a professorship. At the same time, he taught classes in higher mathematics at the Institute of Railways and the Mining Institute. For many years, Friedman maintained a trusting relationship with his teacher, Academician Steklov. The correspondence of scientists is of undoubted value, since it allows not only to see their interests, but also to understand the atmosphere that reigned in mathematics of that era.

“Dear Vladimir Andreevich,” Friedman wrote in 1911, “I had to remember the saying that you spoke about this spring: “Do as you know, you will regret it anyway.”

The fact is that I decided to get married.

I already told you in general outline about his bride. She is taking a course (mathematics); her name is Ekaterina Petrovna Dorofeeva; a little older than me; I think that marriage will not have an adverse effect on my studies...”

In the same letter, Friedman reported:

“...Our classes are with Yak. Dove. (with Yakov Davidovich Tamarkin, a student of V.A. Steklov and friend of Friedman) are going, it seems, quite favorably. They, of course, consist solely of reading the courses and articles recommended by you for the master's exam. We have already finished hydrodynamics and are starting to study the theory of elasticity. We have several questions, but it’s better to find out when we meet with you.”

In 1913, Friedman passed the exams for a master's degree in pure and applied mathematics. Having become interested in mathematical aerology, he got a job at the Aerological Observatory in the city of Pavlovsk, but at the end of the summer of 1914 the First World War began. Friedman volunteered to join an aviation detachment operating on the Northern Front. Starting as a private, he quickly rose to the rank of corporal, and in the summer of 1915 he received his first officer rank- ensign. Friedman not only established air navigation and aerological services on the Northern Front, but also took part in combat missions more than once as an observer pilot.

“...My life flows quite smoothly,” he wrote to Steklov on February 5, 1915, “except for such accidents as: the explosion of shrapnel at 20 steps, the explosion of the fuse of an Austrian bomb in half a step, which ended almost safely for me, and falling on my face and head that ended in a rupture upper lip and headaches. But, of course, you get used to all this, especially when you see things around you that are a thousand times heavier...”

After the October Revolution, Friedman returned to teaching.

In 1918, he was given the position of extraordinary professor at the department of theoretical mathematics of the young Perm University.

Friedman taught at Perm University for two years.

Only in 1920 did he return to Petrograd.

In a hungry, cold capital, a young scientist got a job at the Main Physical Observatory. At the same time, he gave lectures at several universities, including Petrograd University. In 1922 Friedman brought out general equation to determine the speed vortex, which later became fundamental in the theory of weather forecasting. At the Naval Academy, he gave a course of lectures “Experience in the hydromechanics of a compressible fluid,” solving a complex problem about the movement of a liquid or gas at very high speeds, when the liquid or gas cannot in principle be considered ideal and their compressibility must be taken into account. In those same years, together with L.V. Keller, he indicated a system of characteristics of the structure of a turbulent flow and constructed a closed system of equations, connecting the pulsations of speed and pressure at two points of the flow at different times. In 1925, for research purposes, he ascended in a balloon with the famous Soviet stratonaut P. Fedoseenko to a record height for that time - 7.4 kilometers.

Particular attention was drawn to Friedman's two small works on cosmology - “On the Curvature of Space” (1922), and “On the Possibility of a World with Constant Negative Curvature” (1924), published in the Berlin Physical Journal. In these works Friedman showed that geometric properties The universe on a large scale must change dramatically over time, that is, all such changes must be of the nature of “expansion” or “compression.” A few years later, the American astronomer Hubble actually discovered the effect of the recession of galaxies - a consequence of the expansion of the Universe.

Before Friedman’s work, the belief in a static Universe was so great that even Einstein, when developing the general theory of relativity, introduced into his equations the so-called cosmological constant - a kind of “anti-gravity” force, which, unlike other forces, was not generated by any physical source , but was embedded in the very structure of space-time.

On September 18, 1922, Einstein published “Remarks on the work of A. Friedman “On the curvature of space.” The summary of this remark read: “...The results regarding the non-stationary world contained in the mentioned work seem to me suspicious.” However, already on May 31, 1923, having understood the work of the Russian scientist, Einstein hastened to announce: “... In the previous note, I criticized Friedman’s work. However, my criticism, as I became convinced... was based on an error in calculations. I think Friedman's results are correct."

Friedman proved that the matter of the Universe does not necessarily have to be at rest. The Universe cannot be stationary, he believed. The universe must either expand or contract.

In arguing this, Friedman proceeded from two assumptions.

Firstly, he pointed out, the Universe looks absolutely the same everywhere, no matter in what direction we observe it, and, secondly, this statement always remains valid, no matter from what place we observe the Universe.

The models considered by Friedman said that at some point in time in the past, naturally - cosmic time, that is, billions and billions of years distant from us (time that the human brain finds it difficult to perceive as something real), the distance between all galaxies should was equal to zero. At this moment (usually called Big bang) the density of the Universe and the curvature of space should have been infinite. Since mathematicians cannot actually handle infinitely large quantities, this meant that, according to general relativity, there had to be a point in the Universe at which none of the laws of that theory itself could apply.

Such a point is called singular.

Analyzing the concept of singularity, the French mathematician Lemaitre proposed calling the state of such a high concentration of matter a “primary atom.” He wrote: “The word “atom” should be understood here in its original form, Greek meaning. An atom is something so simple that nothing can be said about it and not a single question can be asked about it. Here we have a completely incomprehensible beginning. Only when the atom decayed into large number fragments, filling the space of a small but not exactly zero radius, physical concepts began to take on meaning."

Friedman's work caused a lot of unrest among physicists.

The idea that time once had a beginning did not appeal to many, wrote American astrophysicist Hawking. But I didn’t like this idea precisely because it contained some, albeit vague, hint of the intervention of divine forces. It is no coincidence that the Big Bang model was grasped by catholic church. In 1951, the Pope officially declared that the Big Bang model was fully consistent with the Bible.

Cosmologist W. Bonnor commented on this fact:

“Some scientists identified the singularity with God and thought that at that moment the universe was born. It seems to me highly inappropriate to force God to solve our scientific problems. There is no place for such supernatural intervention in science. And anyone who believes in God and associates a singularity in differential equations with him risks losing the need for him when mathematics improves.”

“The view I take is that the universe has an unlimited past and future. This may seem as puzzling as the assumption that her story is finite. However, in scientific terms, this point of view is a methodological foundation, and nothing else. Science should not arbitrarily accept hypotheses that limit the scope of its research.”

“Sometimes they say,” wrote Academician Kapitsa, “that Friedman did not really believe in his own theory and treated it only as a mathematical curiosity. He allegedly said that his job was to solve equations, and other specialists—physicists—should understand the physical meaning of the solutions. This ironic statement about his work by a witty man cannot change our high appreciation of his discovery. Even if Friedman was not sure that the expansion of the Universe, resulting from his mathematical calculations, exists in nature, this in no way detracts from his scientific merit. Let us recall, for example, Dirac’s theoretical prediction of the positron. Dirac also did not believe in the real existence of the positron and treated his calculations as a purely mathematical achievement, convenient for describing certain processes. But the positron was discovered, and Dirac, without even realizing it, turned out to be a prophet. No one is trying to diminish his contribution to science because he himself did not believe in his prophecy.”

An obituary written by Friedman's widow said:

“Excelsior (above) was the motto of his life.

He was tormented by a thirst for knowledge.

Having chosen mechanics, this paradise of mathematical sciences (according to Leonardo da Vinci), he could not limit himself to it and sought and found new branches, studied deeply, in detail and was forever tormented by the insufficiency of his knowledge. “No, I’m ignorant, I don’t know anything, I need to sleep even less, not do anything extraneous, since this whole so-called life is a complete waste of time.” He tormented himself deliberately, because he saw that he did not have enough time to embrace with his gaze the wide horizons that opened up to him while studying new science. Always ready to modestly learn from anyone who knew more than him, he was aware that in his work he was following new paths, difficult, unexplored by anyone, and he loved to quote the words of Dante: “The waters that I am entering have never been crossed by anyone.”

In 1931, posthumously, Friedman's research was awarded the. V.I. Lenin.

Speech at the session of the Department of Physical and Mathematical Sciences of the USSR Academy of Sciences, dedicated to the 75th anniversary of the birth of A. A. Friedman

Alexander Friedman is one of our best scientists. If it had not been for his death from typhoid fever at the age of 37, he would still be with us today. Of course, he would have done much more in physics and mathematics and would have achieved the highest academic ranks. At a young age, he was already a professor and was world famous among specialists in the theory of relativity and meteorology. In the 1920s, while in Leningrad, I often heard reviews of Friedman as an outstanding scientist from professors Krutkov, Fredericks, and Bursian.

Friedman made one of the most significant theoretical discoveries in astronomy - he predicted the expansion of the Universe.

From Friedman's solution of Einstein's cosmological equations, the possibility of changing the radius of curvature of our world over time followed. A few years after the publication of Friedman's work, the American astronomer Hubble discovered the recession of galaxies - a consequence of the expansion of the Universe. Thus, Friedman “at the tip of his pen” discovered an amazing phenomenon on a cosmic scale.

In this regard, it is sometimes said that Friedman did not really believe in his own theory and treated it only as a mathematical curiosity. He allegedly said that his job was to solve equations, and other specialists - physicists - should understand the physical meaning of the solutions.

This ironic statement about his work by a witty man cannot change our high appreciation of his discovery. Even if Friedman was not sure that the expansion of the Universe, resulting from his mathematical calculations, exists in nature, this in no way detracts from his scientific merit. Let us recall, for example, Dirac’s theoretical prediction of the positron. Dirac also did not believe in the real existence of the positron and treated his calculations as a purely mathematical achievement, convenient for describing certain processes. But the positron was discovered, and Dirac, without even realizing it, turned out to be a prophet. No one is trying to downplay his contribution to science because he himself did not believe in his prophecy.

Dirac later predicted the existence of individual magnetic poles, which were not found, although at one time Fermi thought that they could really exist, but this was a mistake. It is unknown whether he believed that they would be found. But if this happens, scientists will give Dirac credit for the power of his theory.

Friedman did not live to see his calculations confirmed by direct observation. But we now know that he was right. And we are obliged to give a fair assessment of the remarkable result of this scientist.

Friedman's name has so far been in undeserved oblivion. This is unfair and needs to be corrected. We must perpetuate this name. After all, Friedman is one of the pioneers of Soviet physics, a scientist who made a great contribution to domestic and world science.

FRIEDMAN, ALEXANDER ALEKSANDROVICH(1888–1925), Russian and Soviet mathematician and geophysicist, creator of the theory of the non-stationary Universe. Born June 16, 1888 in St. Petersburg. In school and student years was interested in astronomy. In 1906 he published his first math work in one of the leading scientific journals in Germany “Mathematical Annals” (“Mathematische Annalen”). In 1906 he entered the mathematical department of the Faculty of Physics and Mathematics of St. Petersburg University, from which he graduated in 1910. He was retained at the department of pure and applied mathematics to prepare for the professorship. Until the spring of 1913, Friedman studied mathematics - he led practical classes at the Institute of Railway Engineers, and lectured at the Mining Institute. In 1913 he entered the Aerological Observatory in Pavlovsk near St. Petersburg and began to study dynamic meteorology (now this field of science is called geophysical hydrodynamics). In the spring of 1914, he was sent on a business trip to Leipzig, where at that time the famous Norwegian meteorologist Wilhelm Freeman Koren Bjerknes (1862–1951), the creator of the theory of fronts in the atmosphere, lived. In the summer of the same year, Friedman flew on airships, taking part in preparations for the observation solar eclipse in August 1914.

With the outbreak of World War I, Friedman volunteered to join an aviation detachment. In 1914–1917 he participated in the organization of air navigation and aerological services on the Northern and other fronts. Participated as an observer in combat missions.

In 1918–1920 – professor at Perm University. From 1920 he worked at the Main Physical Observatory (from 1924 the Main Geophysical Observatory named after A.I. Voeikov), at the same time from 1920 he taught in various educational institutions Petrograd. From 1923 – editor-in-chief"Journal of Geophysics and Meteorology". Shortly before his death, he was appointed director of the Main Geophysical Observatory.

Friedman's main works are devoted to the problems of dynamic meteorology (theory atmospheric vortices and wind gustiness, theory of discontinuities in the atmosphere, atmospheric turbulence), hydrodynamics of compressible fluid, atmospheric physics and relativistic cosmology. In July 1925, for scientific purposes, he flew in a balloon together with the pilot P.F. Fedoseenko, reaching a record altitude of 7400 m at that time. Friedman was one of the first to master the mathematical apparatus of Einstein’s theory of gravity and began teaching a course in tensor calculus at the university as an introductory part to course of general theory of relativity. His book was published in 1923 The world as space and time(reissued in 1965), which introduced general public with new physics.

Friedman predicted the expansion of the Universe. The first non-static solutions of Einstein's equations obtained by him in 1922–1924 while studying relativistic models of the Universe laid the foundation for the development of the theory of the non-stationary Universe. The scientist studied non-stationary homogeneous isotropic models with a space of positive curvature filled with dusty matter (with zero pressure). The nonstationarity of the considered models is described by the dependence of the radius of curvature and density on time, and the density varies in inverse proportion to the cube of the radius of curvature. Friedman identified the types of behavior of such models allowed by the gravitational equations, and Einstein's model of a stationary Universe turned out to be a special case. Refuted the opinion that the general theory of relativity requires the assumption of the finiteness of space. Friedman's results demonstrated that Einstein's equations do not lead to a single model of the Universe, whatever the cosmological constant. From the model of a homogeneous isotropic Universe it follows that as it expands, a red shift proportional to the distance should be observed. This was confirmed in 1929 by E.P. Hubb based on astronomical observations: the spectral lines in the spectra of galaxies turned out to be shifted towards the red end of the spectrum.