ANALYSIS OF SPECTRA AND SPECTRAL ANALYSIS

D. S. Rozhdestvenskii, Leningrad

The somewhat fanciful title of my report is explained by the fact that I want at once to draw attention to its peculiarity: given the extreme abstraction of the main theme (the analysis of spectra has as its aim the construction of atoms on the foundations of quantum mechanics), the practicality of the second theme, inseparably connected with it, is this: spectral analysis is the analysis of ores by means of spectra; it is the geochemist’s eye in the search for the necessary metals in the bowels of the earth. Such is the antithesis in the structure of the State Optical Institute (GOI), and the aim of this report is to reflect its activity—at least in one of its many cross-sections. To make clear how this antithesis fits within GOI and how the chosen cross-section is oriented, I shall allow myself a brief introduction.

The time has passed when science was done first in academies, and then in universities, exclusively in a purely academic atmosphere. Now science has become directly and quickly profitable. The American General Electric Company, the Kodak firm, the Nela lamp company have each established its own science, its own multimillion institute. It has become obvious that a large institute, specialized on a technical problem, not only does not crowd out but surpasses the former university laboratory. Therefore, when the revolution moved toward the reconstruction of technology and science, and at the same time the war revealed with terrible clarity that today, without numerous optical instruments, people can successfully neither kill one another nor defend themselves from one another, the Optical Institute was founded. Its tasks are as follows:

1. To understand, calculate, build, and invent optical instruments: rangefinders, sights, microscopes, photographic cameras—their name is legion, since all life and all technology are permeated by optical instruments.

2. To create optical glass for instruments and to investigate methods for its processing.

3. To apply optical methods to the investigation of atoms and molecules.

Under the pressure of the rapid growth of technology in the country, it was necessary to add the following departments as well.

1. Department of photography—the study of emulsions, of development processes, of cinema, of the secrets of the latent image.

2. Department of illumination engineering.

In the first department—the instruments department—before the State Optical Institute there was practically a complete void. In 15 years it quickly mastered foreign technology, said its witty word, and continues to say it. In the second department—the glass department—there was an even greater void. Now foreign technology has been mastered and a weighty Stakhanovite word has been said; development is proceeding further. The fourth department—photography—has followed the same path and found new, fresh ideas. Of each of these technical departments one could speak at length and with interest. But their significance, their usefulness, is clear to every capitalist firm.

Something special must be said about the third department. The third department—abstract science—alongside the department of technology, whose tasks are clear, requires not justification but a profound understanding of its significance. A capitalist firm will not introduce it into its institutes.

Why should the communist state introduce it?

This distinction must be explained in my report, after S. I. Vavilov has given a vivid picture of the structure, purpose, and achievements of the State Optical Institute, of its four technical departments. My report will therefore concern, as its main subject, abstract science. Its principal trunk is the structure of the atom. We shall see below how from this trunk there extend, in still vague outlines, branches toward the great goal of the future—the mastery of solar energy.

In prehistoric times, before Bohr’s theory, 25 years ago, the following was believed: however the atom might be constructed, it consists of some positive heavy parts and light negative electrons; the latter are attached to the atom as if by rubber bands, springs, as if by elastic forces; hence the term quasi-elastic electrons. If this is so, then the atom can be studied by rocking the electrons with light waves. In Fig. 1 a photograph is shown illustrating this rocking. You see that in two places of the spectrum something catastrophic occurs. Here the light waves, having entered into close resonance with the electrons of the atom, smash it, just as a dynamo installed in a building, upon entering into resonance with the structure, destroys it, or as a regiment of soldiers, marching in step, rocks an elastic bridge and breaks it. Here in the photograph the curves give the course of the velocity of propagation of light in sodium vapor as a function of the period of the incident light wave. Near coincidence with the period of oscillation of the atom, the curve to the left of the sodium absorption line goes off, apparently, infinitely upward; on the other side, it rises, apparently, from infinitely below. The resonance theory says that for quasi-elastic electrons the branch of the curve must be a hyperbola on each side.

Hardly anyone examined these curves more carefully than I did, along and across, and my answer was: yes, these curves are hyperbolas, and consequently the electron has a quasi-elastic bond. Fortunately, my inherent skepticism forced me to add: however, the linearity of the equations governing the oscillations of the electron is sufficient to produce a hyperbola, without entering into consideration of the question of

To the article by D. S. Rozhdestvensky

Fig. 1. Anomalous dispersion of the sodium spectrum
without hooks

Fig. 2. Anomalous dispersion
of the sodium spectrum with hooks

Fig. 4. Anomalous dispersion of the entire Na spectrum

substance of the bond. But in my own thinking as well, following the most celebrated minds of that time, the working hypothesis was the quasi-elastic bond of the electron. And if so, then by a small change in the experiment—by inserting a glass plate into the interferometer with which the curves were obtained—it is easy to modify the curves so that they tell much about the structure of the atom. In Fig. 2 there is a photograph where one can see that near the sodium lines there has now appeared what I called “hooks.” This name has also entered the textbooks. By measuring the distance of a hook from the line, one can say how large, in the atom, is the number of electrons of a given period. For example, here one line corresponds to exactly twice as many electrons as the other. For different lines, in different atoms, there exist these integral, at first incomprehensible and mysterious, ratios. We shall encounter the hook method of the State Optical Institute more than once below.

Thus it is possible, by means of light, to investigate the atom. This investigation, and other analogous ones—the theory of Voigt, the phenomenon discovered by Zeeman—raised the quasi-elastic electron almost to infallibility. And yet it—though with glory and after a fierce battle—perished.

It perished because it proved unable to help even in approaching the question of the analysis of spectra. The spectrum of an atom, the lines scattered in it, as we shall see below, tell, to one who can read them, of all the details of the structure of the atom. But at that time they stood as a blank wall before the quasi-elastic electron. A small illustration, not chronologically exact—namely, the experiment of the student Terenin—will show this clearly. In front of a piano we take a note at full voice, break off, and listen: from the piano, a string resonating at the same tone will answer. The famous optician Wood directed yellow light waves onto sodium vapor, and the sodium atom sounded in response with the same yellow light—that line which we have just seen in the photograph. Terenin, developing Wood’s experiments, sent an ultraviolet line onto thallium vapor and, to his surprise, received in response, besides the ultraviolet, also a green one, which the vapor does not absorb. Hence it is clear that the model of the atom does not have exact quasi-elastic properties; in the atom there is no complete analogue of the elasticity of a string, but perhaps something altogether different.

But what?

During the period from 1913 to 1926 an exhaustive answer was gradually obtained, but we shall see that its character is not such as to give us great satisfaction. The chief figure in this work was the famous scientist Niels Bohr. From the very beginning he simply discarded everything that suggested elastic properties of the atom, and took up an immeasurably more essential side of the matter.

At the moment when it became clear from the work of Rutherford and Moseley that the number of electrons is equal to the number of the atom, the position of the quasi-elastic electron became indefensible. In a piano there are as many tones as there are strings. Each electron corresponds at most to three strings. Consequently hydrogen—the atom No. 1—cannot have more than three lines, whereas it has almost a hundred. Iron—the atom

No. 26 gives thousands of lines instead of 78. It is this fact that must be explained first of all.

You know the famous Bohr model of the atom, which, gradually perfected, gained universal recognition. Even a single electron in a hydrogen atom can have an infinite number of orbits. The admissibility of these orbits is determined by exact conditions—the so-called quantization. Jumping from an outer orbit to an inner one, the electron loses energy, emitting it in a marvelous way in the form of monochromatic waves: the amount of energy lost is always exactly equal to one quantum. Conversely, if light falls on an atom and is absorbed, then exactly one monochromatic quantum is absorbed, and the electron is torn from one orbit and transferred to another.

This image of a one-electron atom—hydrogen or ionized helium—with different orbits, with different energy levels, almost at once won universal recognition: a long-standing problem had been solved, the energy levels of the atom and the lines of the hydrogen spectrum could be calculated with astonishing accuracy; a whole series of processes in X-rays and in ordinary rays corresponded exactly to this remarkable postulate of the emission or absorption of one monochromatic quantum of energy. The triumph of the picture, even if only for the simplest one-electron atom, was complete. But at what cost was this triumph achieved?

Let us think about the postulate of the departing and incoming monochromatic quantum. First of all, the theory of such an atom is concerned only with the energy balance; the very process of capture or emission of a quantum remains undisclosed. And nevertheless the essence of the method of giving off energy in separate quanta is sharply opposed to the swinging of a quasi-elastic electron. A monochromatic quantum has entered the atom; the electron has jumped to a level richer in energy—and can no longer absorb a quantum of the same period; the process is over. Formerly, however, the electron in the atom was for a long time set swinging by light—more and more strongly. In just the same way, formerly, in an atom with a strongly excited electron, the latter emitted radiation, continuously and gradually dying down. Now the picture has changed radically. An electron driven to an upper orbit lives on it for a certain time, and then breaks away from it all at once, firing off its quantum. It has a definite probability of emitting a quantum or, what is the same thing, an average lifetime in the orbit; and the brightness of the light source is determined not by the power of oscillations of electrons, but only by the number of excited atoms emitting their always identical quantum with a definite probability. And this probability is a new constant of the atom, replacing our former one: the number of resonating electrons in the atom. The concept of quanta is incompatible with the concept of a quasi-elastic electron.

These two concepts, each governing its own large circle of phenomena, formed two optics, and both optics entered into rivalry. But all sympathies here were already in advance on the side of the concept of quanta, and the defeat of the elastic electron was predetermined.

This is, to the highest degree, a peculiar defeat. The battle in its last stage is not over. And perhaps the quasi-elastic electron, like Proteus, by changing its form, will gain the upper hand at the last minute. At the end we shall see signs of this, but now let us follow the history of the battle, since the GOI took a lively part in it—now on one side, now on the other.

In the period from 1913 to 1918 the basic postulates of Bohr were mastered and accepted by all physicists as applied to one-electron atoms. As for many-electron atoms, one thing was clear: in them the entire complexity of the spectrum is produced by one, the outermost electron, jumping from orbit to orbit. But why are the spectra, even of the alkalis, the simplest atoms at least, twice as complicated as that of hydrogen, and if in the latter the electron theoretically gives an infinite number of lines, then for the former do we have a double infinity of lines?

This became clear immediately after Sommerfeld found a method for quantizing orbits with respect to a second variable. Following this, at the GOI at once, by comparing the energies of an atomic electron in distant orbits with the analogous energy of the hydrogen electron, all series of lines were distributed. All orbits at once became clear; the huge accumulated stores of numerical material on the analysis of spectra, until then purely empirical, began to speak in a distinct language. It was as if an explosion of understanding. Among us it occurred at the moment of the harshest blockade. The new scheme at once captivated minds, at once with tremendous enthusiasm directed work into the channel of the quantum atom, but it also sharpened among us the tragedy of two optics. Abroad the same process proceeded in parallel. The period 1919–1922 was filled among us with works on methods of quantization (Yu. A. Krutkov, student V. A. Fok, and others), on the assimilation of the general, only just indicated ideas about the structure of spectra and the structure of atoms in a long series of particular cases. Here too the above-mentioned riddle of Terenin became clear, who had produced a whole series of works on the excitation by means of light of luminescence in various atoms. The energy levels of the thallium atom are arranged in such a way (Fig. 3) that the light of the ultraviolet line 3776 raises an electron from the lower level \(2p_2\) to the upper \(2s\); from there it can fall back to \(2p_2\), emitting again the resonance line 3776, but it can also fall to the level \(2p_1\), which is somewhat higher than \(2p_2\), which will give the unexpected green line 5351. The green line is not absorbed at all, since normally there is no electron at \(2p_1\). Thus the riddle is resolved simply, a riddle that from the point of view of the quasi-elastic atom is insoluble. If, however, the electron is driven to \(2p_1\) by simpler methods—by collisions with other electrons—then the atom will absorb the green line as well.

Fig. 3. Levels of the thallium atom

Throughout all this time the two optics continued to exist side by side. It was precisely in the period 1922–1926 that they clashed in the most severe manner. The point is that at this time ideas about the structure of the atom had perhaps, more than ever, been cleared up and made more precise. Here Bohr took a new, bold step forward.

Using chemical analogies and the analysis of spectra—both X-ray and optical—with the aid of new methods of quantization and the so-called correspondence principle, he constructed a model of the atom in all its complexity: in principle, not only the orbits of the valence electron were outlined, but all the orbits of all the electrons, in all their complexity.

As the concept grew clearer, it was no longer permissible to preserve two contradictory optics. Bohr tried to crush the quasi-elastic electron, even at the cost of sacrificing the law of conservation of energy, by separating two moments in time: the jump of the electron from orbit to orbit without a change of energy, and the emission of energy in the form of waves. In this way he tried to save the very notion of a period, of a wave, the very principle of interference of light waves, since the threat was advancing from another side as well. A quantum that instantaneously flew out and, especially, instantaneously flew into an atom no longer in general appeared as a complex of waves, but seemed, as Einstein thought, to be some negligibly small lump of energy which flew out in one direction or another, i.e. not at all like a group of waves propagating in all directions from a drop that has fallen into water, and even less like a group of waves being drawn in from all sides toward a center—an analogue of the absorption of light. For such absorption no time is required—the quantum must pop out instantaneously. But then where is the very notion of a period, of a wave, of interference?

Here lies an acute tragedy, which cannot be overcome by the most ingenious mechanisms. All these mechanisms, like Bohr’s palliatives, had no success, and no possibility was found of devising how a quantum interferes.

Especially tragic was our position at the GOI. Our instrument of investigation is the interferometer; but interference is incomprehensible. We study the velocity of propagation of light through matter, in other words, through an assemblage of atoms; but without interference this process too is incomprehensible. Finally, we clearly treat the atom as quasi-elastic, which is strictly forbidden. It was truly not easy to find the right path in this collision of the old and the new optics.

One thing here seems firm—the integral relations of the numbers of electrons, as given by hooks in the old language. Even if it is not very clear what these integers signify, in any case this is a firm law. And all efforts were directed toward proving that the law really was firm, purely atomic, that the relations obtained, like radioactivity, depend neither on temperature nor on the density of the gas. This we succeeded in doing, and Turoverov and I (he died without completing the experiment) proved that the integral relations do not change even at the temperature of a voltaic arc, while V. K. Prokofiev, who was still

as a student at the State Optical Institute, began work with an interferometer, found them unchanged even at such a density of potassium vapors that in his interferometer there fell a potassium metallic rain.

At this time the State Optical Institute had grown very strong. It had acquired a powerful technical base and had created such magnificent workshops—mechanical and optical—that it could itself build a fluorite interferometer, which for many years formed the basis of further investigations not only at the State Optical Institute but also abroad, where in Germany Ladenburg’s school worked with it until the coming of fascism, which scattered it throughout the world.

This encounter between quasi-elastic and quantum optics, although it did not lead to final solutions, nevertheless greatly helped to clarify several questions.

First of all, the suspicion was dispelled that the quasi-elastic theory was correct even from a purely classical point of view. Only, in pointing to the photograph, I said: light destroyed the atom. This is incorrect. When the periods nearly coincide, light unusually strongly rocks the elastic electron, and the latter emits a wave opposite in phase to the incident one: a retardation of the phase velocity and absorption take place. But if the atom is broken and then restored, the phase relation is lost; the emitted wave becomes random in phase relative to the incident one (the technical term is “incoherent”), and then the absorption goes into the scattering of light in all directions. Thus the question arises whether or not the atom breaks under resonant irradiation. If it does not, then the quasi-elastic theory is possible. If it does, then we in essence have a scheme of the atom with two energy levels, growing directly out of classical mechanics. Thus the old atom began to show features of the Bohr, quantum atom. We shall see further on that this is indeed so, although in this period it had not been proved whether resonant emission is coherent with the incident wave or not.

Three more very important properties of the atom were discovered at this time. First, Kramers showed that the linearity of the equations does not contradict the quantum atom and, consequently, the hyperbolicity of the interference curves, of which we spoke above, cannot serve as a pure criterion of the quasi-elasticity of the atom: my skepticism was justified in the most unexpected way. I shall not mention Kramers’s second discovery, since it will not concern us. We shall defer the third property of the atom until the account of the next period, from 1926, the period of Schrödinger’s wave mechanics, when its significance appeared with particular concreteness.

Allow me to show you a spectrogram (Fig. 4) with hooks, which is sufficiently conclusive on the question of the structure of the atom and for which, as has already been said, we at the State Optical Institute had long been preparing. A. N. Filippov completed the work on the fluorite interferometer and, together with V. K. Prokofiev, investigated the sodium atom. You see—this is not one or two lines; these are all the lines of one series, down to the weakest and even the region beyond the lines. In order to understand the significance of this spectrogram, we

Let us pass to the language of Schrödinger’s wave mechanics, which, beginning in 1926, victoriously took the place of the former Bohr theory, developing, supplementing, and justifying it.

As is known, in de Broglie’s hypothesis, in Schrödinger’s theory, and, let us say simply, in reality, in direct experiment, the electron has turned into a wave. The electron in the atom is a standing wave. Besides the fundamental “tone,” in quotation marks, it has “overtones”—to be sure, in no case harmonic ones, as for a string, but, on the contrary, very complex, cacophonically constructed ones. Here they are compressed toward the boundary of the series. And the hooks indicate the intensity of the “overtones.”

For knowing the atom in numbers, the photograph contains in principle everything. The position in the spectrum and the hooks exhaust the atom. But here, properly speaking, its study only begins.

However, first let us bring this picture into agreement with everything that was said earlier.

What is the state of the question of the quasi-elastic properties of the electron? What, in the new theory, is the quantum of light?

Does the interference of light dare still to exist?

First of all, somewhat earlier, in 1925, it became clear that all the “overtones” together correspond in sum to one electron, and if we apply our method of hooks, as before, before Bohr, then, adding all the numbers for all the sodium lines, we obtain the number—unity. This is known as the sum rule and was verified in detail by Prokofiev and Filippov.

But what does it mean that “the sum of the overtones corresponds to one electron”?

It means that the electron may be regarded in two ways. Either it is a wave and forms standing waves, or, what is the same thing, it appears in the guise of a particle and then it moves around the nucleus along a definite orbit at a definite energy level and has a definite probability of jumping from one orbit to another, as we said at the beginning.

But after all, we previously counted the electrons according to the principle of resonance, and resonance requires an elastic electron set into oscillation by light. This is contradicted by the very concept of light as a quantum of energy.

Just as the nature of the electron is dual, so too is the nature of light dual. Light is both a wave, and light is also a quantum—a particle. As a wave, light interferes, and our use of the interferometer is entirely legitimate. As soon as Schrödinger’s equation had been constructed, Schrödinger himself applied it to the dispersion of light, to that process in which light, acting on atoms, on the electrons in atoms, propagates in a medium filled with atoms—in a word, to the process that gives rise to anomalous dispersion and to those hooks with which we have been operating all the time. Here all the properties of the phenomena proved to be reproduced as though the electron were quasi-elastic. But at the same time the nature of the orbits and of Bohr’s equations revealed itself in full triumph, with all the rules of quantization. Ele-

electron gives also those coherent waves which change the speed of light. It gives also those incoherent resonance waves which it emits, having been flung by the incident quantum onto the upper orbit. The equations give an astonishing harmony and accord between the old and the new—at what price, we shall now see—but from now on the work, the ardent work, proceeds without inner tragedy, without two optics, which have now merged into one.

What, then, is the work now, when, it would seem, everything has been solved and the equations numerically, mathematically predict everything?

Although the principle of the construction of atoms is known, the equations have been drawn up, it is as impossible to solve them as it is to solve to the end the three-body problem in astronomy. The mathematical difficulties are too great. However, what is impossible in the solar system is much more accessible in the atom, since one can experiment with the atom. The joint work of experimentalists (spectra and cryogenics) and of the most experienced mathematicians will undoubtedly make it possible to master the construction of the atom as the engineer masters the construction of a building, i.e. to calculate and predict.

Therefore, since 1926 the GOI has taken up especially intensively the development and application of its method and has already applied it to sodium, potassium, lithium, rubidium, caesium, thallium, zinc, cadmium, calcium, strontium, barium, silver, and mercury.

Thallium has been investigated especially extensively, since it is convenient on it to study quantitatively the phenomenon of an empty (metastable) orbit upon change of the vapor temperature, which was first found by Terenin, while still a student. As has already been noted, it is impossible to drive an electron onto this orbit by light, but this occurs, in sufficiently strong collisions of atoms, the more often the higher the temperature, according to Boltzmann’s law. Boltzmann’s law has been verified at the GOI, and now, conversely, from the number of electrons on a metastable orbit it is possible to determine the temperature of the gas, which is at times very important.

The work is still far from having turned—and perhaps will not turn to the end—into a mass, routine investigation of atoms; separate new, incomprehensible features still appear. As an example let us again take thallium. So far I have not yet spoken of one property of the quantum atom which has no analogue at all with the quasi-elastic atom. It is possible by light to transfer electrons from the fundamental orbit to an infinitely high one, i.e. to remove them to infinity—in the language of elasticity this means to break them off. But one can do even more: one can shoot out the electron, in other words, remove it to infinity, endowing it with a large velocity; to fit such a process into the scheme of the quasi-elastic electron is in any case not simple and, at first glance, impossible. But for quantum theory, even in its original form, this side of the question presents no difficulty: beyond the end of a series of lines, where, as we see, the lines crowd together toward a definite boundary, there follows continuous absorption; the last line corresponds to an electron at infinity without velocity; continuous absorption corresponds to the additional velocity of the shot-

of the ejected electron; it is continuous because all velocities of the emitted electrons are possible, and there is no discreteness in the levels of kinetic energy. Wave mechanics also deals easily with this question. The electron’s “overtones” include the entire infinite space around the atom, and the properties of this standing wave embrace also the velocity (energy) of the electron moving away from the atom. Therefore the continuous spectrum is automatically included in that sum rule which corresponds to unity on our interferometer. But in the case of thallium, if one adds up all the serial electrons, the sum amounts to only one quarter, and the remaining three quarters can in no way be ascribed to the continuous spectrum, however strong it may be here. The law is incorrect. But through recognizing the incorrectness of old laws, new laws are discovered. This, however, is already connected with theoretical work on the hooks.

After Prokof’ev and Filippov obtained the spectrogram with hooks demonstrated here, Prokof’ev attempted to calculate theoretically those probabilities of electron transitions which give the hooks experimentally. The attempt, which improved the method already proposed by the Japanese scholar Sugiura, was crowned with success in the first approximation and showed that this question can and must be taken up far more closely. It passed into the hands of a major specialist in quantum mechanics and in calculations—V. A. Fock, likewise a former student of the State Optical Institute and now a corresponding member of the Academy of Sciences. At the present session he will report in detail precisely on these works of his. They complete our program. The atom, experimentally probed, is subjected to mathematical treatment in order to derive as many consequences as possible concerning its properties and concerning its possibilities of combining with other atoms. And Fock indicated how to do this by fundamentally modifying Hartree’s method. The result of his calculation of energy levels and transition probabilities is already considerably more accurate than Hartree’s. Here the ultimate goal, of course, is to calculate all the properties of the atom from the fundamental equations. Beyond such knowledge of the atom there could be nothing more. Naturally, here the many-body problem is considerably facilitated by the fact that many electrons can be collected into groups or layers, whose significance lies chiefly in screening the nucleus; and therefore the calculations are simplest here for the monovalent alkali metals.

At the State Optical Institute, V. A. Fock organized a systematic calculation of atoms, and a whole series of works yielded valuable results. Here I shall mention only the solution of the riddle posed by the thallium atom. The sum rule had been stated without taking into account a special kind of forces which, as it is customary to say, have no analogue in classical mechanics—the so-called exchange forces. Fock was the first to prove that between the valence electron and the remaining atom there can be so great a coupling through exchange forces that it will distort the sum rule in a way no one expected, and will produce precisely the anomaly that experiment found in the thallium atom.

Thus, the work on the structure and calculation of atoms is proceeding very intensively, both experimentally and theoretically. In recent years a theory of the interferometer has been developed, which serves for investigations by the hook method. In addition, the method itself is being carefully studied; apparently it can be made a precision method for counting electrons, and sometimes also for measuring temperature.

Before finishing our survey of the work of the State Optical Institute, in order to characterize it more fully, we should note certain features of that temporary finale with which, for the time being, the struggle between the quasi-elastic atom and Bohr’s atom has ended.

Above we dwelt on Schrödinger’s theory of dispersion. But this is not the last stage of theoretical thought. Schrödinger’s theory considers the fate of Bohr’s atom under the action of an incident wave. However, this method is no longer permissible. The incident wave itself is part of that system which we must embrace with Schrödinger’s equation. And if we do this, we obtain, as Dirac indicated, the laws of emission, absorption, and dispersion in their most perfect and consistent form.

What, then, is the result?

The light wave is transformed theoretically into a harmonic oscillator and exchanges quanta with the electron of the atom. The features of the quasi-elastic vibrator, almost vanished in the electron of the atom, have unexpectedly appeared, dimly, in the light wave. Whenever a wave—whether in this image the electron appears or a quantum of light—acts, it acts as a particle. When this wave propagates, it may be regarded as a wave, but as a phantom wave, not a reality, but a probability wave.

Yet here there is no danger for the experimental physicist. He is always, and in essence, a skeptic, since he always operates with numbers. If equations, however they may have appeared, give correct predictions, give numbers obtained in experiment, then this is already a real, reliable achievement. This, and precisely this, is directly useful and practically necessary. A correct and convenient scheme of explanations will someday be found. For the time being it evokes a feeling of deep dissatisfaction. What is simple in it is complex; work with it proceeds, though confidently, yet laboriously and slowly.

However, my purpose today is not to insist on these enthusiasms. I mention them only in order to emphasize more sharply the atmosphere of abstractness in which physics now has to work.

The line of work just outlined, in which I have taken the greatest part up to recent times, does not exhaust even the questions of the analysis of spectra for the knowledge of the atom. In the Optical Institute there is still a considerable field of research headed by Prof. S. E. Frisch. His group has analyzed a number of spectra, and from the moment when the study of the atomic nucleus developed, it has taken an active part in the analysis of spectra, since the influence of the nucleus is reflected in them. It is reflected only in the very fin—

details, so that the investigation consists of jewelry-like work—analysis of the super-fine structure of spectral lines. From this it has already been possible to draw a number of conclusions concerning the structure of the nucleus by means of the formalisms of wave mechanics.

Work on the structure of atoms lies at the center of modern physics and astrophysics, and it would be superfluous to discuss its importance.

However, it seems essential to outline—in broad terms in the work of the GOI—those lines along which the practical use of the abstractions attained is taking place and will take place. First, it will be shown below that physics in the USSR must be strengthened four- to fivefold, and in such a case one must clearly see the practical goals toward which we are striving. Second, the scheme of the Optical Institute, which is not characteristic of a capitalist state, will stand out more clearly. Third, we shall feel out the strong and weak points of the GOI.

Fig. 5. V. K. Prokofiev’s ultraviolet spectrograph with a sylvine prism

Let us trace, with regard to practical applications, only these three lines—and very briefly—in order of increasing importance and decreasing definiteness. We shall no longer be dealing with the analysis of spectra, but with spectral analysis. First—the simplest chemical analysis, based on knowledge of the spectra of elements. Second—new lighting technology: gas-discharge lamps. This line did not succeed at the GOI. Third—photochemistry and its obscure, but grandiose future.

In the summer of 1935, on the initiative of A. P. Solovov, the head of a geological prospecting party that was setting out for Khapcherang in search of tin, a qualified chemist-spectroscopist from the GOI, Yu. M. Tolmachev, was sent with the party, with a spectrograph of the type shown in Fig. 5 and with all the devices for obtaining a spark and an arc. During the two months of the expedition’s work, 2,500 analyses were carried out, about 40 per day. Every sample was analyzed without delay, and an answer was obtained instantly: whether there was tin

or not, and in what approximate quantity. It was not for nothing that at the beginning of the report I called spectral analysis the eyes of the geochemist. By means of it he sees how much tin there is in the samples extracted, and can at once draw a conclusion. The spectrograph works 60 times faster and as many times more cheaply than chemical analysis. Moreover, the method is so simple that in the second half of the expedition’s work the analyses were already being carried out by girls completely unacquainted with physics. As a result, the tin was found precisely thanks to the spectrograph; in its honor the first lode of tin that was found was named “spectral.” It is obvious that the application of spectral analysis provides, in the search for the required elements, a method of exceptional value.

Let us dwell somewhat on the properties of the method of spectral analysis, and then draw conclusions from the experience of the present summer.

The significance of spectral analysis is determined by its colossal sensitivity, which is expressed by the number \(10^{-5}\). This means that by spectral reactions one can detect in a substance an impurity amounting to \(1/100000\) of the weight of the substance itself, or to \(0.001\%\). Seventy years ago, at the time of the discovery of spectral analysis, this was an astounding sensitivity. It is known that it is almost impossible to get rid of the sodium line in the flame of a burner, or of the calcium line in the spectrum of a spark, into which sodium and calcium get with the dust. Nevertheless, these are still enormous quantities, such as one-millionth or one ten-millionth of a gram, in other words, \(10^{13}\)—\(10^{14}\) atoms, whereas now it is possible to follow the fate of a single \(\alpha\)-particle or of a single ion of a substance. The point of view in the evaluation of sensitivity has changed radically in recent decades, but in practice the state of the question has not changed. Excessive sensitivity is not needed in most cases; what is needed is a sensitivity only considerably exceeding the sensitivity of chemical analysis.

But even here the question of sensitivity is debatable. Physicists remember well how easily and elegantly, a few years ago, in Haber’s laboratory, the old alchemical question of the transformation of mercury into gold was decided in the negative. In doing so, the accuracy of the analysis was brought to \(10^{-9}\), and thus the sensitivity of the spectroscope was surpassed 10,000 times. An analyst who touches his gold spectacles with his hands will find this gold in his analysis.

However, how much time does such an analysis take?

The strength of spectral analysis lies not in its incredible sensitivity, but in a very great sensitivity, exceeding the normal methods of chemistry hundreds of times, combined with unusual rapidity and ease. The spectroscopist works for half an hour or an hour where the chemist requires several days’ work. Here is an example from the practice of optical-glass production. The scourge of optical glass is iron oxides, which from the sand, from the chamotte of the pot, get into the glass and color it. But there is another scourge, which until now has been unknown:

since, coloring glass 30 times more strongly than iron, it is present in quantities too small for the chemists to detect. This is chromium oxide. A prolonged spectro-photometric study led the GOI to suspect its presence in thousandths of a percent. The factory chemists refused to verify or refute this discovery of the new enemy, since doing so required too great an expenditure of time. Emission spectral analysis quickly confirmed the discovery.

At gold placers it is sometimes advantageous to work such places where spectral analysis, owing to its limited sensitivity, will show zero gold. In such a case, combining spectral analysis with the simplest chemical manipulations quickly increases the sensitivity. Thus, if for gold the spectral sensitivity is normally \(10^{-5}\), and for platinum it is 5 times less, then with the aid of the so-called “micro-docimastic” method of Gaber it becomes equal to \(10^{-6}\) and surpasses all practical requirements. Gaber’s method consists merely in fusing \(0.5\) g of the substance under investigation with alkali and lead acetate, whereby all impurities of the precious metals are concentrated in a small drop of lead weighing \(3.5\) mg, and the latter is then subjected to ordinary spectral analysis.

Hence the enormous importance of spectral analysis is clear for the chemist and geochemist in prospecting and exploration parties, in the search for and extraction of precious elements, and, finally, in qualitative chemical analysis in general. The extraordinary simplicity of the apparatus and manipulations, and the minimal requirements as to theory, ought long ago to have attracted chemists to spectral analysis.

And nevertheless the method of spectral analysis is hardly used at all in the USSR. Yet all chemists unanimously speak of the effectiveness of the method, and those who have once learned it no longer abandon it. There are three reasons for the unpopularity of spectral analysis. The first is the high price of a spectrograph. The second is the absence of instruments in the USSR. Most of the sensitive spectral lines are in the ultraviolet part of the spectrum, and therefore the spectrograph must have quartz optics; but homogeneous quartz of the required dimensions does not exist in the USSR. It is found only in Brazil and Madagascar. The third reason is that chemists are not taught spectral analysis in higher educational institutions.

Now, however, when the value of the method was revealed so vividly in the summer of 1935, all obstacles must be removed. Not a single expedition should now set out without a spectrograph and without an experienced analyst-spectroscopist; otherwise it sets out blind—without eyes. Geologists themselves must master the method in order to have a clear idea of its significance.

As for quartz prisms in spectrographs, the GOI has conquered niggardly nature. It has learned to crystallize sylvine in large single crystals. Sylvine is even better than quartz. Fig. 6 shows a sylvine crystal (on the right) and, cut from sylvine,

prism (on the left). Figures 7 and 8 show samples of spectrographs manufactured at the GOI for the visible spectrum (Fig. 7) and vacuum spectrographs—for the far ultraviolet. On the basis of this model, industry

Fig. 6. Sylvite crystal and prism made of sylvite

Fig. 7. S. E. Frisch spectrograph

Fig. 8. V. M. Chulanovskii vacuum spectrograph for the far ultraviolet

must manufacture spectrographs by the hundreds. It must also prepare the remaining apparatus. In two years it is possible to manufacture several hundred sets.

Here there is still no entirely new special ultraviolet spectrograph for tin—compact, portable, intended for expeditions; it is still in the construction stage in the workshops of the GOI.

If there are no chemist-spectroscopists, then systematic training in spectroscopy must be organized for all analytical chemists in higher educational institutions, for example at Leningrad University, alongside the GOI. Two or three dozen can easily be trained in one month. Geologists must be trained in spectral analysis in the same way.

Physicists and chemist-spectroscopists must develop simple standard methods of analysis for all elements under diverse conditions, something that has already been done for several years at the Optical Institute.

The applications of spectral analysis to industry are far broader than was indicated above. For the first time Prof. G. S. Landsberg, in the laboratories of Moscow State University, organized the construction of spectroscopes and spectrographs for special industrial purposes; the GOI followed him. But I shall not dwell on these works, since the case of the summer of 1935 showed an application of spectral analysis of exceptionally important character, and at the same time an extremely typical one. Its typicality consists in the fact that here we have a problem in which physics accounts for only 20%, while the remaining 80% lies in the precision of state organization.

If I had the opportunity, I would convene representatives of spectral analysis, the optical industry, chemistry, and geology, and charge them with organizing matters so that within 2 years there would not be a single prospecting or exploration party without a spectrograph and an experienced spectroscopist. The scale of this undertaking is on the order of several million rubles, and its effectiveness, undoubtedly, exceeds this figure many times over.

I turn to the second application, the scale of which is determined by hundreds of millions and by a much greater saturation with the methods of science, down to the very greatest subtleties of quantum mechanics. These are gas-discharge light sources.

Quantum theory, by its very essence, in its basic postulates guarantees a 100% yield in the conversion of electrical energy into light energy, whereas in ordinary incandescent lamps this yield is considerably below 10%.

This is shown by Bohr’s postulates, and it is confirmed by the famous experiments of Franck and Hertz.

Let us take as a light source sodium vapor in a vacuum at low pressure, and suppose that in the same tube there are electrons in an electric field. We accelerate the electrons in the electric field exactly enough so that the energy they acquire upon striking an atom is entirely used to transfer an electron of the atom from the ground level to the next, higher one. The striking electron then comes to a stop, and the electron of the atom shortly thereafter flies back and emits all the energy received as the yellow line. A 100% yield is achieved.

In practice this yields gains, for example, of fivefold; hence the worldwide saving of one hundred million is clear.

The mechanism of the glow of such lamps is connected with the most intricate atomic processes. One must not waste energy either in the ultraviolet or in the infrared part of the spectrum. In essence, only sodium vapor gives an ideal gas, practically with a single line, as our method of hooks shows. But the yellow light of sodium gives a sinister illumination, deadening faces. To obtain white light, a second gas must be mixed in. The laws of the transfer of energy from some atoms to others, the laws of emission of resonance light, the distribution of the atom’s electrons over metastable orbits—here a mass of considerations plays a role, and inventions in this field require the most profound knowledge of spectroscopy, wave mechanics, and optics.

Moreover, it is necessary to create electrons and not to lose their energy in vain in those complex processes that take place in Langmuir’s famous “plasma.” At present cadres of people are being trained who specially study these processes in gas tubes and master them, mastering all the techniques of vacuum technology.

There are still no satisfactory gas-discharge lamps, although many streets and roads abroad are already illuminated by a very unpleasant yellow light.

Nevertheless, it is clear that this problem of cheap white light will soon be solved. The entire lighting-engineering world has been working on it for five years now.

Unfortunately, the GOI is not working on this problem. Technically it is very difficult and requires creative work, as well as specialists in lamp technology. The work has been assigned to the VEI. There a huge laboratory has been set up with a large number of technicians. The GOI tried to organize similar work at its own institute, on a small scale, in order to put its spectroscopic power into action, but the cadres of lamp technicians in the USSR are too scanty; a practical laboratory did not succeed, and the GOI had to limit itself to a few works in this field, involuntarily sterile, far from major technology, although they did elucidate interesting processes of the interaction of atoms.

In this field, as we have seen, the concept of spectral analysis is far from being as elementary and simple as it is at first sight, and it is not always possible here to distinguish spectral analysis from the analysis of spectra.

This is still more the case in the third application of spectral analysis—in photochemistry.

What does technology gain from knowledge of atoms? Of course, the practical gain is very great and in very diverse directions, but the main gain is not direct, but indirect. The laws of the structure of the atom provide the basis for studying the laws of the structure of molecules. And why are molecules needed? Knowledge of molecules necessarily includes knowledge of how atoms are bound and the ability to build and dis—

destroy molecules. This is chemistry, but chemistry not in the pre-Bohr, empirical sense, guided only by phenomenological laws of thermodynamics, but concrete chemistry, understanding the process in the finest details and controlling atoms as a driver controls an automobile. Chemistry of the kind that wave mechanics is creating, having an image of how, for example, the six hydrogens of benzene are each connected with each of the six carbons. This is the chemistry of Pauling, Heitler, London, Slater, Van Vleck, and many others, able to understand and calculate the bond between atoms from their electric fields. It is hardly necessary to continue further on the question of what chemistry is needed for.

The era of theoretical chemistry on the basis of quantum mechanics arose some ten years ago, immediately after the study of molecular spectra began and, from this, of molecular structure. This branch, molecular spectroscopy, is represented in the SOI by two groups.

Fig. 9. Two-layer radiometer of the Optical Institute:
1 — transparent window for radiation; 2 — concave mirror; 3 — measured flux of infrared radiation; 4 — evacuated bulb; 5 — two-layer plate; 6 — bismuth; 7 — quartz, coefficient of expansion \(\simeq 0\).

In Fig. 8 one sees a spectrograph, built in the strong group of Prof. V. M. Chulanovskii, which studies the nitrogen molecule in the most extreme ultraviolet region of the spectrum, where a vacuum must be created in the apparatus, since the rays are absorbed by air. Fig. 9 depicts a receiver of unusual sensitivity for infrared rays, invented in the young group of M. L. Veingerov, who directs collaborators working on molecules and infrared rays [in Fig. 2: 1 — transparent window for radiation, 2 — concave mirror, 3 — measured flux of infrared radiation, 4 — evacuated bulb, 5 — two-layer plate, 6 — bismuth, 7 — quartz (coefficient of expansion \(\simeq 0\)].

Veingerov’s group shakes atoms in a molecule with light and deals, for example, with such questions as the rectilinear arrangement of three atoms in the carbon dioxide molecule and the angular arrangement in the water molecule—in general, the external structure of the molecule. At present it is occupied with the structure of the bromine molecule. Prof. Chulanovskii’s group is trying to determine which electrons, for example, in the nitrogen molecule belong to the atoms and which are used as the bond between two atoms.

But all these groups of the spectroscopic sector of the SOI, atomic and molecular, despite their absolute and practical significance, are nevertheless only preparatory for that group which is now engaged in photochemistry. This is the group of A. N. Terenin.

By exploding an atom with light, he, while still a student, vividly illustrated

notion of the empty orbital of thallium. Exploding the simplest molecules by light, such as sodium iodide, he was one of the first to see distinctly, from the cross section of the decay products, and to illustrate the significance for the chemical bond of that electron which the sodium atom so readily gives up and which the halide—iodine—so readily attaches to itself.

The bonding methods and decay products of diatomic and triatomic molecules became clear after light analysis, spectral analysis, applied in the strictest manner to atoms and groups of atoms.

By breaking up an oxygen molecule into atoms, ordinary and excited, Terenin in recent years—he is, of course, no longer now a student, as he was in the first years of the existence of the GOI, he is a Corresponding Member of the Academy of Sciences—has traced the reaction of the combination of both atoms with hydrogen into water and with carbon monoxide into carbon dioxide. In more complex molecules, a light wave makes it possible to capture and cause reactions involving hydroxyl radicals in alcohols, cyanogen in organic compounds, and amine. From the way the glow spreads from the site of reaction, one can learn how energy is transferred within rather complex molecules. Terenin’s laboratory is among the scientific world one of those that respond most rapidly to every new request of photochemistry, and it is coming closer than any other to the most important object, on which the forces of researchers are increasingly being concentrated. And its significance is still greater than that of quantum chemistry, however important the latter may be directly and practically.

Everyone knows the trivial fact that all energy on earth comes from the sun, that light rays, beginning with the infrared and ending with the ultraviolet, bring heat to the earth and, through the green plant, energy in the form of life, as well as the energy needed for our life in the form of coal.

Perhaps it is less well known to the general public, or, if known, then insufficiently appreciated, that of the entire solar spectrum only a narrow red band is used—the band absorbed by chlorophyll—while the rest of the energy is wasted.

What does it mean—wasted? After all, the sun warms us! Open the valve on the boiler of a locomotive and let out the steam. It will warm the earth, but it will do no work: it has been wasted. The sun is a boiler at 6000°. Its high temperature, the high possible coefficient of utilization of its energy—lie in the abundance of ultraviolet rays, in the abundance of enormous, easily assimilable quanta. We blindly and stupidly watch this precious energy pour past us onto the earth, doing no work, supplying us with no energy. And how much of it there is! Lovers of large numbers have long calculated that the power of solar radiation—according to Volkhovstroi—for every inhabitant of the earth. Only an insignificant part of it, and not a very effective one, is intercepted by the green plant and transformed into me, into you, into life, into the energy of coal. And all this solely because we do not know how to handl-

associated with this form of energy, with the light wave—we do not know photochemistry.

From these simple considerations it is clear what significance, for us, is possessed by the abstractness or concreteness of wave mechanics, by the understanding or non-understanding of the structure of the atom, by the knowledge or ignorance of photochemistry. It is clear that we must learn to bind the energy of the sunbeam, as the green plant does; in other words, we must above all study the photoreaction—the assimilation of carbon dioxide by chlorophyll. Chemist-biologists have worked much on this, but the most important, optical side of the question remains closed until wave mechanics gives us the possibility of mastering it. As we have seen, experiment is already approaching complex organic molecules. But, beyond any doubt, our knowledge of atoms, of molecules, of light processes, is still far from sufficient. Let us first of all note that spectroscopy and photochemistry are an analysis of processes, chiefly in the gaseous medium, the simplest for the experimenter. But photosynthesis in the green plant takes place, apparently, in a colloidal medium. The transfer of the laws of optical phenomena in gases to liquids and solids is especially complex. In the Optical Institute, these and analogous questions are being dealt with, with great success, by the luminescence group, carrying out the ideas of S. I. Vavilov.

He has just spoken himself about its work, and I shall not dwell on it here. I shall note only that the composition of the groups of our scientific department has been chosen so that all stages of the problem of photochemistry have their workers. And, probably, the time will come when it will be possible to discuss the possibility of posing the solar problem. For its solution will give humanity such stores of energy that a new era will arrive, incomparable in anything with the old.

This may be called fantasy. It is indeed fantasy, but it is beyond doubt that this fantasy will someday be realized. The only question is when.

From 1913 to 1925 quantum mechanics conquered the atom. From 1922 to 1935 all the essential mysteries of the structure of molecules were discovered. For some 10 years now, chemistry and photochemistry have been advancing with rapid steps on the foundations of wave mechanics. One may think that in 10–20 years the problem of harnessing solar energy will become concrete, and then the second half of the twentieth century will inevitably, and must, be the era of photochemistry, just as the second half of the nineteenth was the era of electricity.

But this new era, in its scale, will surpass the old many times over. Here the question will be not only of a new form of energy, but also of the fact that it will become free, like the air we breathe.

Against the background of this series of works, after their near and distant aims—at least the chief ones—have become clear, allow me a few words of self-criticism and criticism of the existing state of affairs in science, in physics, in optics. This is all the more appropriate since

today, as it were, a review of physics is being carried out. And this is all the more appropriate for me, since I have already withdrawn from the front ranks of fighters and consciously work only in such fields where experience sometimes has greater significance than intuition, and therefore, from my side, my outlook may perhaps be somewhat broader and more impartial.

First of all I ask that I not be blamed if my report creates the impression of a certain overestimation of the scientific activity of the GOI. It is built on the work of the GOI, and therefore it may have seemed to you that we stand at the head of world scientific events and that all eyes are directed toward us. This is not so.

On the international scale we are a small group of scientists who have contributed their noteworthy page to the great era of the structure of the atom and the molecule. We did not have leaders of this era, since leaders are created at a rate of one in a thousand, under a fortunate combination of personal qualities and external surroundings. But precisely this background of thousands did not exist in the USSR; it has only now begun to be created, and in the GOI we already have a chance for the promotion of leaders in the field of luminescence, in the field of photochemistry, in the field that may be called “atom-building.”

The chief merits of the GOI are not in the scientific sector alone. First of all, the GOI performed a great technical task: first, together with the Lensos, by fully providing the country with optical glass, and, secondly, by creating the scientific basis for the optical industry. Then the GOI realized a new type of scientific institute, in which large-scale technology and abstract science are extraordinarily happily combined. We have seen that \(4/5\) of it is technology, while spectroscopy develops on the fertile, rich soil of this technology and in turn abundantly fertilizes it. It seems to me that at present this is one of the few institutes of the true type, leading science in a communist country, since precisely in a communist country there must be abstract science with distant but great aims.

For a month now the GOI has entered upon a new path, the path of much closer unity with the optical industry. The government has transferred the GOI to the jurisdiction of VOOMP, and, undoubtedly, the GOI must now ideologically head the optical industry with full responsibility. One may welcome this act as a first experiment which, we hope, will yield firm results.

But here it is proper to draw attention to the fact that the GOI owes its scientific strength precisely to its complex composition; that the GOI is precisely the right type of scientific institute in a socialist country, where technology must be supported by abstract science and conversely. Consequently, it must be emphasized that, in directing the GOI, VOOMP assumes the obligation to support not only the service part of the GOI, but also the scientific nucleus that animates it.

Recently it has often been heard that science among us has lagged behind industry. This is undoubtedly so, and it would be strange if it were not.

if it were otherwise. In our country a grandiose experiment has been carried out, with deafening success. Industry has grown furiously, but all resources were concentrated on it. Science did not accomplish so grandiose an ascent. True, the development of physics may be considered almost infinite in comparison with the prewar level, since in the denominator of the ratio there stands almost zero; and, undoubtedly, Soviet power gave an enormous impetus to physics in general. However, if 8 years ago scientific optotechnics at the GOI was excessive for the optical industry of that time, now it is far from sufficient. The equipment at the GOI, which was excellent 10 years ago, is now meager.

On a world scale physics in the USSR stands in 5th place, behind France. But here the question is not the place, but the fact that our scientific output is 4–5 times smaller in absolute figures than in any of the three countries: Germany, America, and England, whereas in industry we have everywhere moved far away from such ratios. At the GOI, optical glass, in terms of its servicing by scientific personnel, is placed, perhaps, better than anywhere else in the world. Optotechnics, with the rapid development of the optical industry, has insufficient personnel; the work of creating them lies ahead both at the GOI and in factory laboratories.

However, for optotechnics the situation is relatively much better than for spectroscopy. In spectroscopy, as in the rest of physics, scientific work must be strengthened 4–5 times, if we do not wish to hold industry back in its further qualitative development. The personnel are so scanty that a whole series of works cannot be undertaken.

Work on gas-discharge lamps failed at the GOI precisely because of the absence of personnel. Work on atoms, molecules, photochemistry—much of which we are justly proud of—is microscopically small on the world scale, is unfit for the greatness of the USSR, and does not ensure for it a dominant position in the technology of the future.

Of course, the new personnel must not be absorbed by the GOI, which must not expand without limit. New institutes must be created and university laboratories strengthened.

I think that physics is not in particularly unfavorable conditions—it has developed very rapidly of late—and that what has been said about it applies on average to the other sciences as well. What is needed is a general increase in the intensity of scientific activity severalfold.

If science at the present moment takes up \(1/2\%\) of all the country’s energy, then a fourfold increase means \(2\%\).

Consequently, \(2\%\) of the entire population, about 3 million citizens, must work wholly and continuously in order to provide the means and possibilities for strengthening science. Is this really necessary? Is this really possible?

On the one hand, it is already quite clear in my scheme that it is necessary to introduce spectral analysis into geological prospecting—

...—this is a million-ruble undertaking, which does not require new scientific discoveries, but only the organized introduction of something already prepared.

On the other hand, as if it were clear, one cannot evade work on gas-discharge lamps. This is a hundred-million-ruble undertaking, one that requires persistent scientific work with all the subtleties of quantum mechanics. Of course, before the revolution this question would not even have been raised. The Germans are inventing and importing for us... But now—is such a formulation of the question permissible?

On the third hand, the future gigantic technology in 10–15 years’ time—the utilization of solar energy, photochemistry—is a multi-billion-ruble undertaking; perhaps one can wait with it? Quite recently in the USSR we devoted more attention to industry than to remote scientific problems. But industry has now already advanced far ahead at unprecedented rates; should science be held back? For if science is held back now, then in 10–15 years it, in turn, will greatly retard the development of industry, which will require new forms and new objects. I feel that now, when the USSR has moved forward on a gigantic scale, when it is preparing to stand at the head of the nations, there can be no question of cutting back such fields of work as photochemistry. A collective of people that has become conscious of its power—the victorious proletariat with the Party at its head—cannot but move forward with ever more rapid steps.

However important it may be to move forward with an upsurge toward the conquest of science, one must immediately give oneself an account of how difficult this task is. Purposeful science—this question has not been solved anywhere in the world. In a capitalist state it essentially cannot be solved. What the difficulty is—this will again be clarified by the history of the development of the question of applying spectrum analysis.

Let us take gas-discharge lamps again. Who is to decide how and where to organize this creative technical task; how, for example, to make use of the spectroscopic power of the GOI and at the same time properly distribute the still-fluid personnel of lamp technicians, without harming other current minor tasks? Recently, in the physics group of the Academy of Sciences, there was a meeting devoted to lighting engineering. All the physicists clearly saw that work in the USSR is moving in this field at a snail’s pace, and they clearly know what must be done in order to set it going at full speed. But those present at that meeting had no authority. And the resolution was drafted precisely with the psychology of people who do not dispose of the destinies of science.

Let us take photochemistry. I am deeply convinced that it is precisely here, in the utilization of the immeasurable solar energy pouring down for free, that the future of nations lies, and not in the atomic nucleus, as many think, or at least not yet in the nucleus. But if I am right, and in 15–20 years we shall have to set about a new grandiose task, then measures must be taken now so that in preparing for these solar events we do not lose a single minute.

The Academy of Sciences, in the session of the physics group, recognized work on photochemistry and related fields as exceptionally important and adopted...

corresponding resolutions. The Presidium sent these resolutions to the appropriate chapters.

For the time being, that is where the matter stopped.

Can the Academy of Sciences, and, of course, in particular the GOI, be blamed for the fact that the fulfillment of the two indicated tasks—of primary and even overwhelming importance—is not moving at a proper pace? Yes, it can and should. So long as science in our country is not organized, stubborn pressure is needed, the unrelenting and tireless pursuit of a clear task is needed; even heroism in persistence is needed. I read with enthusiasm the speech of Academician T. D. Lysenko at the meeting of the shock workers of productivity. It is an epic speech. After a tremendous discovery—vernalization—the academician throws himself into the midst of thousands of collective farms in order to realize it there. When he has found a new variety of useful plant, he devotes all his energy to multiplying this variety not in 10 years, but in 2 years, in 1 year. This is truly a revolutionary epic, this is heroism. I remember how, in the same manner—the scales were different—the GOI in 1923 obtained from the government an optical-glass plant, and the personnel of the GOI spent days and nights together with the workers of the plant in order to give the country optical glass—and they did give it. And indeed the very organization of the GOI and the organization of the Physico-Technical Institute in the first decade of the revolution proceeded in the same epic style. This entire revolutionary epic is needed; heroism is necessary.

However, new epochs are created not only by the heroism of individual persons, but by organization; and only the organization of industry, with the iron hand of the leader, summed up the whole revolutionary pathos of the country, the heroism of individual units.

How, then, should the organization of science be carried out?

This question has practically not yet been solved. It is now being solved in our country, the only country where it has been posed and where it will inevitably be solved, since in it are concentrated new forms and new tempos of forward movement both of industry and of culture. On the one hand, it is enormous—let us recall, after all, that the issue may be energy given as a gift, and this, possibly, will overturn all social relations. On the other hand, on this scale it is nevertheless small—this is now only two percent of all energy.

This is not the time or place to touch upon what has already been successfully or unsuccessfully undertaken toward the resolution of this enormous problem. My aim was concretely, using the example of the GOI, to show what tasks are now being solved and are again arising in our Union, and to what organizational questions they inevitably lead. The solution of these questions, raised in masses from all sides, must be in another instance.

Nevertheless, let us try for a minute to imagine that the form of organization of science has been found, that 10 years have already passed—the period in which a capable student develops into a scholar with a European name. Let us try to imagine that every new undertaking in science is rapidly, without friction, introduced into industry; that the profound thought of the luminaries of science, who will then undoubtedly appear among thousands of new scholars, since the proletariat conceals within itself

still infinite unused forces—that this profound idea will find immediate resonance and realization in technology and industry. In short, let us imagine that the USSR will stand at the head of world science, just as it will, not today but tomorrow, stand at the head of world industry.

Then, by that very fact, the world communist proletarian revolution will be assured.