Moscow

There can be no doubt that interest in Friedmann's personality will increase over the years, and then the many “desert areas” in his biography will disappear, giving place to cultivated “plots” densely populated with events. One such remaining “desert area” is the time that Friedmann spent in Moscow before leaving for Perm. It is known that the Central Aeronavigational Station in April 1917 moved from Kiev to Moscow – together with the personnel and the various services (workshop, instrument store, etc.), and the laboratory. Friedmann was appointed a member of the commission for the construction of an aviation instrument plant. By this time in Moscow several buildings had been prepared for the future plant on the site of former Georgian bath houses. The plant was called “Aviapribor” (aviation instruments); it had started earlier, in 1915, as a workshop for repairing aeronavigational instruments. Friedmann dealt with this very workshop, and he recommended N. N. Andreyev, an acquaintance of his, for a job there. Andreyev started to work there and got in touch with Nikolai Zhukovsky. Later he reminisced that in his first talk with Zhukovsky “Friedmann's name was a key to his heart and he immediately got warmer,” and gave an instruction to render Andreyev all possible assistance. Andreyev was interested in wind tunnels necessary for solving the important problem of graduating instruments for continuous automatic recording of wind speed and direction.

In the summer of 1917, Friedmann was appointed head of one of the departments in the plant. The department heads formed a council which operated under the plant's management and collaborated with it in framing the plant's policy, and made technological and organizational decisions.

In fact, in the year 1808, an English chemist JOHN DALTON showed that the relative proportions of various chemical elements which are needed to form more complicated chemical compounds can always be expressed by the ratio of integral numbers, and he interpreted this empirical law as due to the fact that all compound substances are built up from a varying number of particles representing simple chemical elements. The failure of medieval alchemy to turn one chemical element into another supplied a proof of apparent indivisibility of these particles, and without much hesitation they were christened by the old Greek name: ‘atoms’. Once given, the name stuck, and although we know now that these ‘Dalton's atoms’ are not at all indivisible, and are, in fact, formed by a large number of still smaller particles, we close our eyes to the philological inconsistency of their name.

Thus the entities called ‘atoms’ by modern physics are not at all the elementary and indivisible constituent units of matter imagined by Democritus, and the term ‘atom’ would actually be more correct if it were applied to such much smaller particles as electrons and protons, from which ‘Dalton's atoms’ are built. But such a change of names would cause too much confusion, and nobody in physics cares much about philological consistency anyway! Thus we retain the old name of ‘atoms’ in Dalton's sense, and refer to electrons, protons, etc. as ‘elementary particles’.

In the winter of 1938 I wrote a short, scientifically fantastic story (not a science fiction story) in which I tried to explain to the layman the basic ideas of the theory of curvature of space and the expanding universe. I decided to do this by exaggerating the actually existing relativistic phenomena to such an extent that they could easily be observed by the hero of the story, C. G. H. Tompkins, a bank clerk interested in modern science.

I sent the manuscript to Harper's Magazine and, like all beginning authors, got it back with a rejection slip. The other half-a-dozen magazines which I tried followed suit. So I put the manuscript in a drawer of my desk and forgot about it. During the summer of the same year, I attended the International Conference of Theoretical Physics, organized by the League of Nations in Warsaw. I was chatting over a glass of excellent Polish miod with my old friend Sir Charles Darwin, the grandson of Charles (The Origin of Species) Darwin, and the conversation turned to the popularization of science. I told Darwin about the bad luck I had had along this line, and he said: ‘Look, Gamow, when you get back to the United States dig up your manuscript and send it to Dr. C. P. Snow, who is the editor of a popular scientific magazine Discovery published by the Cambridge University Press.’

One weekend Maud went away to visit her aunt in Yorkshire, and Mr Tompkins invited the professor to have dinner with him in a famous sukiyaki restaurant. Sitting on the soft cushions at a low table, they were enjoying all the delicacies of the Japanese kitchen and sipping sake from little cups.

‘Tell me,’ said Mr Tompkins. ‘The other day I heard Dr Tallerkin saying in his lecture that the protons and the neutrons in a nucleus were held together by some kinds of nuclear forces. Are those the same forces which hold electrons in an atom?’

‘Oh, no!’ answered the professor. ‘Nuclear forces are something quite different. Atomic electrons are attracted to the nucleus by ordinary electrostatic forces first studied in detail by a French physicist, CHARLES AUGUSTIN DE COULOMB, toward the end of the eighteenth century. They are comparatively weak and decrease in inverse proportion to the square of the distance from the centre. Nuclear forces are quite different. When a proton and a neutron come close to each other but not yet in direct contact, there are practically no forces between them. But as soon as they come into contact, there appears an extremely strong force which holds them together. It is like two pieces of adhesive tape which do not attract each other at even a small distance but stick together like brothers as soon as they come in touch with each other. Physicists call these forces ‘strong interaction’.

Mr Tompkins was very amused about his adventures in the relativistic city, but was sorry that the professor had not been with him to give any explanation of the strange things he had observed: the mystery of how the railway brakeman had been able to prevent the passengers from getting old worried him especially. Many a night he went to bed with the hope that he would see this interesting city again, but the dreams were rare and mostly unpleasant; last time it was the manager of the bank who was firing him for the uncertainty he introduced into the bank accounts… so now he decided that he had better take a holiday, and go for a week somewhere to the sea. Thus he found himself sitting in a compartment of a train and watching through the window the grey roofs of the city suburb gradually giving place to the green meadows of the countryside., He picked up a newspaper and tried to interest himself in the Vietnam conflict. But it all seemed to be so dull, and the railway carriage rocked him pleasantly….

When he lowered the paper and looked out of the window again the landscape had changed considerably. The telegraph poles were so close to each other that they looked like a hedge, and the trees had extremely narrow crowns and were like Italian cypresses. Opposite to him sat his old friend the professor, looking through the window with great interest. He had probably got in while Mr Tompkins was busy with his newspaper.

Ladies and Gendemen:

Today I am going to discuss the problem of curved space and its relation to the phenomena of gravitation. I have no doubt that any one of you can easily imagine a curved line or a curved surface, but at the mention of a curved, three-dimensional space your faces grow longer and you are inclined to think that it is something very unusual and almost supernatural. What is the reason for this common ‘horror’ for a curved space, and is this notion really more difficult than the notion of a curved surface? Many of you, if you will think a little about it, will probably say that you find it difficult to imagine a curved space because you cannot look on it ‘from outside’ as you look on a curved surface of a globe, or, to take another example, on the rather peculiarly curved surface of a saddle. However, those who say this convict themselves of not knowing the strict mathematical meaning of curvature, which is in fact rather different from the common use of the word. We mathematicians call a surface curved if the properties of geometrical figures drawn on it are different from those on a plane, and we measure the curvature by the deviation from the classical rules of Euclid. If you draw a triangle on a flat piece of paper the sum of its angles, as you know from elementary geometry, is equal to two right angles.

When, that morning at breakfast, Mr Tompkins told the professor about his dream the previous night, the old man listened rather sceptically.

‘ The collapse of the universe,’ said he, ‘would of course be a very dramatic ending, but I think that the velocities of mutual recession of galaxies are so high that present expansion will never turn into a collapse, and that the universe will continue to expand beyond any limit with the distribution of galaxies in space becoming more and more diluted. When all the stars forming the galaxies burn out because of the exhaustion of nuclear fuel, the universe will become a collection of cold and dark celestial aggregations dispersing into infinity.’

‘ There are, however, some astronomers who think otherwise. They suggest the so-called steady state cosmology, according to which the universe remains unchanging in time: it has existed in about the same state as we see it today from infinity in the past, and will continue so to exist to infinity in the future. Of course it is in accordance with the good old principle of the British empire to preserve the status quo in the world, but I am not inclined to believe that this steady state theory is true. By the way, one of the originators of this new theory, a professor of theoretical astronomy at Cambridge University, wrote an opera on the subject which will have its premiere in Covent Garden next week. Why don't you reserve tickets for Maud and yourself and go to hear it? It may be quite amusing.’

The next lecture which Mr Tompkins attended was devoted to the interior of the nuclei which make the pivot point for the revolution of atomic electrons.

Ladies and Gentlemen—said the professor—

Digging deeper and deeper into the structure of matter, we will now try to penetrate with our mental eye into the interior of the atomic nucleus, the mysterious region occupying only one thousand billionth part of the total volume of the atom itself. Yet, in spite of the almost incredibly small dimensions of our new field of investigation we shall find it full of very animated activity. In fact, the nucleus is after all the heart of the atom, and, in spite of its relatively small size, contains about 99*97% of total atomic mass.

Entering the nuclear region from the thinly populated electronic atmosphere of the atom, we shall be surprised at once by the extremely overcrowded state of the local population. Whereas electrons of atomic atmosphere move, on the average, distances exceeding by a factor of several hundred thousand their own diameters, the particles living inside the nucleus would literally be rubbing elbows with one another, if only they had elbows. In this sense the picture represented by the nuclear interior is very similar to that of an ordinary liquid, except that instead of molecules we encounter here much smaller and also much more elementary particles known as protons and neutrons.

From early childhood onwards we grow accustomed to the surrounding world as we perceive it through our five senses; in this stage of mental development the fundamental notions of space, time and motion are formed. Our mind soon becomes so accustomed to these notions that later on we are inclined to believe that our concept of the outside world based on them is the only possible one, and any idea of changing them seems paradoxical to us. However, the development of exact physical methods of observation and the profounder analysis of observed relations have brought modern science to the definite conclusion that this ‘classical’ foundation fails completely when used for the detailed description of phenomena ordinarily inaccessible to our everyday observation, and that, for the correct and consistent description of our new refined experience, some change in the fundamental concepts of space, time, and motion is absolutely necessary.

The deviations between the common notions and those introduced by modern physics are, however, negligibly small so far as the experience of ordinary life is concerned. If, however, we imagine other worlds, with the same physical laws as those of our own world, but with different numerical values for the physical constants determining the limits of applicability of the old concepts, the new and correct concepts of space, time and motion, at which modern science arrives only after very long and elaborate investigations, would become a matter of common knowledge. We may say that even a primitive savage in such a world would be acquainted with the principles of relativity and quantum theory, and would use them for his hunting purposes and everyday needs.

Ladies and Gentlemen:

Tonight I will request your special attention, since the problems which I am going to discuss are as difficult as they are fascinating. I am going to speak about new particles, known as ‘positrons’, possessing more than unusual properties. It is very instructive to notice that the existence of this new kind of particle was predicted on the basis of purely theoretical considerations several years before they were actually detected, and that their empirical discovery was largely helped by the theoretical preview of their main properties.

The honour of having made this prediction belongs to a British physicist, Paul Dirac, of whom you have heard and who arrived at his conclusions on the basis of theoretical considerations so strange and fantastic that most physicists refused to believe them for quite a long time. The basic idea of Dirac's theory can be formulated in these simple words: ‘There should be holes in empty space.’ I see you are surprised; well, so were all physicists when Dirac uttered these significant words. How can there be a hole in an empty space? Does this make any sense? Yes, if one implies that the so-called empty space is actually not so empty as we believe it to be. And, in fact, the main point of Dirac's theory consists in the assumption that the so-called empty space, or vacuum, is actually thickly populated by an infinite number of ordinary negative electrons packed together in a very regular and uniform way.

Ladies and Gentlemen:

In a very primitive stage of development the human mind formed definite notions of space and time as the frame in which different events take place. These notions, without essential changes, have been carried forward from generation to generation, and, since the development of exact sciences, have been built into the foundations of the mathematical description of the universe. The great NEWTON perhaps gave the first clear-cut formulation of the classical notions of space and time, writing in his Principia:

So strong was the belief in the absolute correctness of these classical ideas about space and time that they have often been held by philosophers as given a priori, and no scientist even thought about the possibility of doubting them.

However, just at the start of the present century it became clear that a number of results, obtained by most refined methods of experimental physics, led to clear contradictions if interpreted in the classical frame of space and time. This fact brought to one of the greatest contemporary physicists, ALBERT EINSTEIN, the revolutionary idea that there are hardly any reasons, except those of tradition, for considering the classical notions concerning space and time as absolutely true, and that they could and should be changed to fit our new and more refined experience.

It is an especial pleasure to me that George Gamow's two gems—concerning the two adventures of Mr Tompkins in the wonderful worlds conjured up when the speed of light is made small or Planck's constant large—are now reprinted in paperback. Whilst, with hindsight, one may find details to quibble about, the excitement of these deeply delightful tales remains as fresh with me as it was some fifty years ago when I first encountered them. Though physics has moved on in many ways, the basic physics of relativity and quantum theory has not changed. By his ingenuity and narrative skills, Gamow is able to transform some of the puzzling and obscure mysteries of this basic physics—a physics which, indeed, is still modern—into magical and enthralling stories for children.

I remember reading (or being read) the Tompkins stories as a quite young child, and I am sure that their magic was responsible, to a very considerable extent, for the great excitement that fundamental physics has held for me for the rest of my life. I still vividly recall the tigers of the quantum jungle, and the old woodcarver's boxes of mysterious coloured balls (the nucleons), the relativistically flattened bicycle, and the professor calling out ‘Just lie down and observe’ as he and Mr Tompkins see their miniature universe collapse inwards upon them. It was Mr Tompkins who made the new physics vivid and real for me as a child and I am sure that he will continue to do the same for a great many others.

During many months of unusual adventures, in the course of which the professor tried to introduce Mr Tompkins to the secrets of physics, Mr Tompkins became more and more enchanted by Maud and finally, and rather sheepishly, made a proposal of marriage. This was readily accepted, and they became man and wife. In his new role of father-in-law, the professor considered it his duty to enlarge the knowledge of his daughter's husband in the field of physics and of its most recent progress.

One Sunday afternoon Mr and Mrs Tompkins were resting in armchairs in their comfortable flat, she being engulfed in the latest issue of Vogue, he reading an article in Esquire

‘Oh,’ Mr Tompkins exclaimed suddenly, ‘here is a chance game system which really works!’

‘Do you really think, Cyril, that it will?’ asked Maud, raising her eyes reluctantly from the pages of the fashion magazine. ‘Father has always said that there can't be such a thing as a surefire gambling system.’

A few days later, while finishing his dinner, Mr Tompkins remembered that it was the night of the professor's lecture on the structure of the atom, which he had promised to attend. But he was so fed up with his father-in-law's interminable expositions that he decided to forget the lecture and spend a comfortable evening at home. However, just as he was getting settled with his book, Maud cut off this avenue of escape by looking at the clock and remarking, gently but firmly, that it was almost time for him to leave. So, half an hour later, he found himself on a hard wooden bench in the university auditorium together with a crowd of eager young students.

‘Ladies and gentlemen,’ began the professor, looking at them gravely over his spectacles, ‘In my last lecture I promised to give you more details concerning the internal structure of the atom, and to explain how the peculiar features of this structure account for its physical and chemical properties. You know, of course, that atoms are no longer considered as elementary indivisible constituent parts of matter, and that this role has passed now to much smaller particles such as electrons, protons, etc.

‘The idea of elementary constituent particles of matter, representing the last possible step in divisibility of material bodies, dates back to the ancient Greek philosopher DEMOCRITUS who lived in the fourth century B.C. Meditating about the hidden nature of things, Democritus came to the problem of the structure of matter and was faced with the question whether or not it can exist in infinitely small portions.

After dinner on their first evening in the Beach Hotel with the old professor talking about cosmology, and his daughter chatting about art, Mr Tompkins finally got to his room, collapsed on to the bed, and pulled the blanket over his head. Botticelli and Bondi, Salvador Dali and Fred Hoyle, Lemaître and La Fontaine got all mixed up in his tired brain, and finally he fell into a deep sleep….

Sometime in the middle of the night he woke up with a strange feeling that instead of lying on a comfortable spring mattress he was lying on something hard. He opened his eyes and found himself prostrated on what he first thought to be a big rock on the seashore. Later he discovered that it was actually a very big rock, about 30 feet in diameter, suspended in space without any visible support. The rock was covered with some green moss, and in a few places little bushes were growing from cracks in the stone. The space around the rock was illuminated by some glimmering light and was very dusty. In fact, there was more dust in the air than he had ever seen, even in the films representing dust storms in the middle west. He tied his handkerchief round his nose and felt, after this, considerably relieved. But there were more dangerous things than the dust in the surrounding space. Very often stones of the size of his head and larger were swirling through the space near his rock, occasionally hitting it with a strange dull sound of impact.