The first steps to discovering superconductivity

The article was written specifically for the 250th anniversary of the DISCOVERY of freezing mercury.

I

St. Petersburg Academy of Sciences, opened in 1725. just had to become at the same time a leader in the study of the physics of cold. “The nature of our locality is surprisingly favorable for conducting experiments with the cold,” wrote G.V. Kraft, one of the first Petersburg professors. However, he immediately warned that in the nature of the cold there is a lot of unknown. “Until now, the aforementioned qualities have been shrouded in such darkness that it took them several years to illuminate, and perhaps a whole life century was needed, and not only one, but many insightful gifts.” He was right. [ 1.]

The academies of England, Italy, France, Germany, Holland and even Sweden lay in a strip of mild climate. Technologically, it is easier to obtain high temperatures for experimental needs than cold. Even in antiquity, man could receive high temperatures sufficient for smelting iron ores. But before he learned to liquefy gases, getting low was very problematic. Only in 1665 physicist Boyle was able to reduce the temperature of the aqueous solution by only a few degrees. He achieved this by dissolving ammonia in water.

And why then did people need low temperatures? First of all, for scientists to calibrate thermometers used for meteorological measurements, where there are temperatures hitherto unknown to old-timers. It was the manufacturers of thermometers that began to select such substances and solvents that would lower the temperature of the solutions as much as possible. Such a composition was invented by the Dutch master of scientific instruments D. Fahrenheit. He recommended the use of crushed ice to which concentrated nitric acid would be added. In Russia, such a composition began to be called curious matter.

The winter of 1759-1760 in St. Petersburg turned out to be very icy. Already on December 14, “an extreme cold happened, which had never been noticed at the Academy before.” On this day, academician Joseph Adam Brown, with purely scientific goals, asked himself to clarify the question “How much can this natural cold be multiplied by art”. For this purpose, he used the composition of the Dutchman, though instead of crushed ice, he used street snow, with an ambient temperature. He placed the snow in a glass vessel, poured a little nitric acid and inserted a mercury thermometer into this noble matter. After some time, he took out the thermometer and “gladly found that it was not damaged, but the mercury was still”. [2]

What did Brown rejoice at? That the thermometer has not defrosted? No, he just began to suspect that mercury was frozen in the thermometer tube. And it was a sensation! Not a single scientific treatise of all times and peoples has reported that mercury can be solid. Here is what, for example, can be read in a textbook of that time for ore miners: “This mineral is no different in appearance from melted metals, but they freeze in such heat, from which many things catch fire, and mercury cannot freeze in the most severe frost” . Note that the author of the textbook, MV Lomonosov, does not even consider mercury to be metal. [3]

Title page of a printout of a report by Academician I.A. Brown at a public meeting of the St. Petersburg Academy of Sciences

The conviction of scientists of that time in this postulate was so great that on November 18, 1734, when the equestrian Cossack Salomatov, an observer at a weather station in Tomsk, reported the freezing of mercury in his barometer to academicians Gmelin and Miller, they simply did not believe this. They had a suspicion that an inexperienced Cossack simply spilled mercury, because “he didn’t carefully take it out and shake it, otherwise it could not happen, because, although the frosts were incomparably more severe, the mercury did not freeze.” Scientists were so sure of their innocence that instead of supposedly spilled six more mercury spools were sent to the Cossack. Of the academics, remember the name Miller, we will still meet her. [ 4 ]

But back to the St. Petersburg experiments. So, ”Brown wrote later,“ I was “sure that the mercury in the thermometer became solid and motionless from the cold and, therefore, froze”. It was all so unexpected that he decided to immediately report the news to his colleagues. Hurriedly gathered scientists decided that when conducting repeated experiments it was necessary to break the thermometer and visually verify the fait accompli. For this purpose, a new batch of thermometers was ordered at the academy workshop.

They could only start the experiments on December 25th, “for the required number of thermometers was soon impossible to do.” In addition to Brown, experiments were begun by academicians M.V. Lomonosov, F.U.T. Epinus, I.E. Zeiger and pharmacist I.G. Model. Each of the participants, repeating Brown's tricks, received from the broken thermometers columns of solid mercury in the form of a wire, “like silver”, and a mercury “bullet” at its end. The wires were easily bent, and the “bullet” was easily flattened by blows of the ax butt, because “it had the hardness of lead or tin”. Zeiger later said that he seemed to hear her ringing. All the properties of the metal were evident, therefore mercury was a metal, and the priority of the discovery of this fact belongs to Russia.

The experiments in St. Petersburg made a sensation in the scientific world. Newspapers and private correspondence of scientists were far ahead of official reports from the Academy and therefore serious distortions were made, especially about the role of the main characters. The name of the discoverer was not named correctly, which led to a big scandal in the Academy. At the initiative of Lomonosov, a special investigation was organized by the Office. They found the culprit - it was Academician Miller, who "wrote to Leipzig on behalf of the Academy and without her knowledge, supposedly the beginning of this experiment came from professors Zeiger and Epinus, and Brown, allegedly on occasion, had to find a pearl grain as a rooster." For this, Miller was sharply criticized by colleagues at a meeting of the Office. The case for science is almost typical. [ 5 ]

Followed by the responses of other scientists. “The discovery of Professor Brown of the greatest importance,” wrote Leonard Euler, “and it gave me particular pleasure because I always believed that heat is the true cause of the liquid state of mercury.”

The results of the winter experiments by the Chancellery of the Academy were recognized so important that their results were decided to be published in the public meeting of the Academy at the solemn celebration of the namesake of Empress Elizabeth Petrovna. The opening reports were instructed to be made by the main characters of the opening: I.A. Brown in German and M.V. Lomonosov in Russian. The first report was called “On the amazing cold, the art produced”, the second - “Reasoning about the hardness and liquid of bodies”. The texts of the reports were decided to be issued in separate stampings, which were then printed in the amount of 412 copies each and can now be found in the main libraries of the country.

Brown's merits in the history of physics are now revered by descendants. But what was the merit of Lomonosov is not known to either compatriots or foreign scientists. And there is something to read about. But, before we talk about this, we’ll give another review on the discovery of Russian scientists, made back in 1763: “The most remarkable of all the discoveries over the past three years is the establishment of the fact of mercury melting.” [6]. These words belong to one of the founders of the science of electricity, the great American B. Franklin. His main work, “Experiments and Observations of Electricity,” was well known to Russian scientists, repeatedly quoted by G.V. Rikhman and M.V. Lomonosov in their writings.

III

Franklin's work is a collection of his letters addressed to other scholars. Here, the experiments conducted by the author in the New World and the theoretical constructions of the author are described in sequence. He was one of the first who began to widely apply the now familiar to electricians the term conductor, introduced by the English scientist T. Desagulier. In one of these letters, 1751.you can read the following: the only difference between conductors and non-conductors is "only that some of them conduct electrical substance, while others do not." And further: “Only metals and water are ideal conductors. Other bodies carry out only insofar as they contain impurities of metals and water. ” [7]

Later, a footnote was made to this letter, published in Franklin’s collected works, that this rule is not always respected and the author cites the case when the English scientist “Wilson discovered that wax and melting resin acquire the ability to conduct”. However, Franklin himself had come across a strange fact: “A dry piece of ice or an icicle in an electric circuit prevents a shock, which could not be expected, since water perfectly transfers it.” Here we are talking about the shock electric shock of the experimenter when a charged Leiden bank is discharged through it. The ice behaved in a chain like an insulator. [7, p. 37.]

Now we are well aware that metals have electronic conductivity, other substances - ionic, which is very dependent on their temperature.

So maybe in this way to test mercury? After all, if frozen mercury will conduct electricity, then it is definitely metal. Only the Big Scientist could ask himself such a question. And we still do not know whether he was only going to find out this question, but such an experience was made by our great compatriot M.V. Lomonosov. A brief description of this experiment can be found in the third volume of the Complete Works of his works. A drawing of this experiment is also given there. I must say that the figure does not depict an electric machine and an electric pointer (electrometer), but their presence is implied by the text. [8. p.407]

Lomonosov’s own drawings for experiments on freezing mercury. Figure 5 shows a ball of frozen mercury and its degree of deformation after forging. Figure 6 shows the experience of the electrical conductivity of mercury and a hot iron wire. 7 shows a frozen tube of a mercury thermometer. Air bubbles appear.

A U-shaped glass tube with mercury was dropped into a glass vessel with freezing material, into which iron wires were frozen on both sides. One wire was in contact with the conductor of an electric machine, the other with an electroscope. When the generator began to generate electricity, the electrometer immediately showed its presence on a wire located after frozen mercury. Liquid and frozen mercury turned out to be conductive, like all the metals known at that time. The last point in the proof that mercury is a metal was put precisely by M.V. Lomonosov. The exact date of this event is unknown, but it was in January 1760. We note one more subtlety of the experiment. In the section of the electric circuit between the solid mercury and the electrometer, the experimenter glows red-hot iron wire with candles. The conclusion is unequivocal: “Electric force acts through frozen mercury and through hot iron.”

And this conclusion was new for science of that time. It was at this time that world science began to understand the dependence of the electrical conductivity of all bodies on their temperature. In 1762 Franklin will describe the experience of Charles Cavendish (father of the well-known Henry Cavendish), who conducted a study on the electrical conductivity of glass depending on its temperature. It turned out that a fairly strongly heated ordinary glass becomes conductive. It was much easier to organize this experience than Lomonosovsky. After all, it was much easier to heat a glass tube with electrodes soldered into glass than to freeze mercury. But this experience, Franklin, calling it “very witty,” adds: “It remains only to wish this noble philosopher to inform humanity more about his experiences.” Of course, Lomonosov’s experiment on the electrical conductivity of frozen mercury was repeatedly repeated by others, but later, since in Western countries experiments on freezing mercury could be carried out only after decades. [7. p.206]

The sensation about the opening in St. Petersburg soon subsided, no one could repeat the experiments in hot pursuit and the results of the electrical experiment were forgotten for a long time not only in the West but also in Russia.Lomonosov apparently prepared a full description of this experiment for his “Theory of Mathematics, which was mathematically stated,” which he worked on since 1756, but remained incomplete. After the events described by the great scientist in 1762 and 1763, he “nearly brought to the grave” the disease, and he lived only until 1765. In addition, major troubles at the academy did not give time for creative work in the last years of life. Of course, his work remained in print in the amount of 412 copies. Alas, an unworthy science story happened to her.

In "History of the Imperial Academy of Sciences", written by academician P.P. Pekarsky in 1873. You can read the following. “This work of our academician suffered a strange fate - it was forgotten to be included in the most common editions of collected works, so it was then reprinted only once in the 1778 edition and which is now a bibliographic rarity. It is not surprising that Lomonosov’s “Reasoning” regarding hardness and body fluid is not found in any review of later scholars. ” [8], [9]. (Italic our B.Kh.)

Indeed, the fate is more than strange. Given that M.V. Lomonosov had many enemies, it can be assumed that the strangeness was deliberate. Among his worst enemies, the Brockhaus and Efron encyclopedia also lists the already familiar Academician G.F. Miller, who served in the period from 1757 to 1765 as the permanent secretary of the St. Petersburg Academy. We remember that he did not respond to the message about the freezing of mercury in 1734, then he gives incorrect information abroad, for which he had great troubles. It can be assumed that for reasons unknown to us, it was he who could make this work not catch the eye of the publishers. After all, he kept correspondence between the academy and the minutes of all meetings, and their archives and to carry out the deed would not have caused him difficulty. Moreover, the same encyclopedia writes about Miller as if he “did not always turn out to be impeccable in his relations with his members”.

Academician V.I. Vernadsky, describing Miller, writes that he “was not the creator of the new in theoretical and scientific thought, like Euler or Lomonosov, but like them, he was imbued with a deep understanding of the scientific method, he mastered it expertly.” Perhaps it was just an envy of talent and this is just our guess. But what happened happened. [10]

IV

The misadventures of this work of Lomonosov do not end there. In the period from 1768 to 1900, seven editions of his collected works were published and this work was not included in any of them. Only in the fifth volume of the academic publication in 1902. this work of a scientist saw the light. However, the text was printed only in Russian and drawings and drawings were not reproduced, without which the text of the “Reasoning” was incomprehensible. So, one of his most interesting works fell out of sight of researchers of Lomonosov’s work.

Since 1940, the USSR Academy of Sciences begins to publish Lomonosov collections, which contain newly found materials and articles on his scientific activities. In some, the cryogenic experiments of Brown and Lomonosov are also understood. There is no new information about electrical experience in them. [11, 12] Finally, to the 250th anniversary of the birth of Russian physicists (they were the same age) of M.V. Lomonosov and G.V. Rikhman, A. A. Alekseev’s book “The Emergence of the Science of Electricity in Russia” was published. In this experience is not mentioned at all. But the question inexorably arises, what are the goals set by the researcher, starting cryogenic electrical experiments. Is there anything you can find on the issue of interest to us? [ thirteen ]

Surely there was something in the archives of the scientist. But this archive “at the highest command” was sealed by Count G. Orlov and himself ordered it to be sorted. It is not well known where and where but the finds are possible. The remaining documents can be found in the 11-volume Complete Works of the scientist.There are few Russian scientists whose work would be pursued by historians of science as broadly and persistently as Lomonosov and all his works were reviewed and revised, and there was little hope of finding something new. But he who seeks finds.

It is known that MV Lomonosov translated into Russian the first textbook for the university “Wolfian Experimental Physics”. It was published in 1746. and it was required to reprint it - “for sale everything is at a loss”. In March 1760 It was decided to publish it by second embossing. Lomonosov understood that between the editions the textbook was pretty outdated. The textbook was urgently needed, but there was little time. Therefore, it was decided to make additions to the existing text. According to the author of the “additions,” they should “explain the actions and changes that depend on the subtlest insensitive particles, the components of the body.” Under these particles, the modern reader can understand atoms and molecules, and even electrons, but all together this should reflect Lomonosov’s system of views on the physics of phenomena.

The fact that the work on the report at the Academy and the writing of the “Additions” was parallel at the same time is proved by the calendar. The date of reading the report is September 6, 1760, and the text of the “Additions” was signed by Lomonosov on September 15 of the same year. [ 14 ]

Now we give the physical views of that time on electricity in general: “Electrical substance consists of extremely small particles, since it is able to penetrate ordinary matter, even the most dense metals, with great ease and freedom.” [7, p.53] The fact that electricity moves with extremely high speed was well known immediately after the invention of the Leiden can, that is to Franklin.

Now the time has come to quote from the “Additions” of Lomonosov, undoubtedly related to the winter experiments of January 1760. We specifically highlight them in bold.

“The newly found electrical experiments show that extraneous matter, moving at great speed in the wells of cold bodies, does not kindle them”, that is, does not heat. There is no mystery here, it’s clear and clear that extraneous matter Is an electric substance, and cold bodies are frozen mercury. Recall that Lomonosov was a supporter of the kinetic theory of heat, and there you can read that "The motion of particles, the constituent bodies there is a heat cause". [5, p. 436].

That's all that was found. But it is worth a lot. Now it is clear that the experimenter, as a supporter of the kinetic theory of heat, expected an increase in the temperature of mercury. Due to the fact that he could not have thermometers for such temperatures, he apparently was waiting for the melting of mercury. That did not happen. Hence this conclusion.

It should be said that the science of that time had no idea about the movement of electric charges (electric current). Lomonosov believes that during the operation of an electric machine, electric substance moves through mercury all the time. It wasn’t. Through the frozen mercury, only a small amount of electricity was needed to charge the wire leaving the mercury. Otherwise, Lomonosov’s conclusion would mean that frozen mercury has superconductivity.

Superconductivity of mercury at temperatures much lower than that found by Lomonosov in 1911. Leiden professor Kamerling-Onnes. This happened 150 years after the experiments in St. Petersburg and produced the same sensation as the then in the scientific world. The Nobel Prize rightly crowned the work of the Dutch scientist and outlined the development of physics in the coming years. But the path to such a discovery began in Russia, and almost no one remembers this.

V

This year marks 250 years of mercury freezing experiments. Not only this event requires us to pay attention to this fact. In 2011 marks the three hundredth anniversary of the birth of the great Russian scientist. The anniversary of Lomonosov will certainly be celebrated by the scientific community and this is our contribution to this event.Nevertheless, I would like to note such an unsightly fact in our country as a neglect of our scientists. Almost everyone knows the discoverer of the electric arc, Russian physicist V.V. Petrov. But not everyone knows what became known about this discovery in their homeland after almost a hundred years, and then by accident. We also learn about this experiment of Lomonosov, only in a quarter of a millennium!

I would like to give an example of old and good England. There in 1700. a certain Wall, rubbing a piece of amber, found that the spark arising from this reminds him of lightning. He was an absolute amateur in electricity and could not repeat his experience in the presence of scientists, but in the textbooks on the history of the physics of electricity and lightning protection, he is always remembered not only by the British.

It is known that the works of Lomonosov almost did not affect the development of world science, because he did not create his own school. But this is not the fault, but the trouble of Lomonosov. Among the reasons here are attention to domestic science. And she deserves it! Here, for example, such words about the great Russian scientist were cited by V.I. Vernadsky: “In his ideas and areas of his work, we meet extremely often and extremely many predictions, predictions, before which our mind stops in thought and wonder, since we are not used to treating the data of the history of science in the way we handle other phenomena and facts. ” Our find only confirms these words. [10, p. 323]

I must say that a mystical curse always hung over the description of this experience of Lomonosov. Our attempts to report to the editorial office of magazines about our historical find did not find even a polite answer, for example, such that the editorial portfolio was full, etc. Only the journal "Electricity" advised to forward the article to a physical journal. We also mention a curious case when the editor of the Russian department of one of the popular science journals on the life of science, when asked whether she received such a text, simply replied that their email was broken these days. Apparently, she believes that only Papuans live outside the Moscow Ring Road.

No one will respect us if we do not respect ourselves.