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HOW THEY SEE THE INVISIBLE
People incredibly quickly get used to the most amazing achievements of science and technology. Is it possible to introduce cognition today with a story about a television, a jet plane, or an artificial Earth satellite? Even the lunar rover - this amazing creation of modern science and technology - has taken a common place in our imagination next to an electronic computer, a nuclear power plant and the mechanism for transmitting hereditary characteristics from generation to generation. We are spoiled by the abundance of new wonderful opportunities that the modern scientific and technological revolution continuously puts at the disposal of man and scientist. Almost nothing can surprise you anymore. But this, in general, is bad. For without surprise there is no interest, and without interest there is no desire to truly learn something, to study it, to explore it yourself.
But let’s cut ourselves off from this “all-importance” for a minute and think about this question. Atoms consist of electrons and atomic nuclei. Atomic nuclei are formed from protons and neutrons. What are the sizes of these particles? The radius of a proton or neutron is of the order of cm. Consequently, any of these particles, roughly speaking, is contained in a volume of the order of cm. The dot that comes at the end of the previous phrase has a radius approximately equal to a quarter of a millimeter. A sphere with such a radius will have a volume of the order of cm. Therefore, it would be possible to measure elementary particles in it! How small these particles must be to decrease in such a gigantic quantity inside our point. Neither the eye nor the microscope, even with the highest magnification, can notice them. But you have all seen clear photographs of traces of such particles in textbooks and popular books. They were obtained using cloud chamber signs. Look at them carefully, and a new world will open before you. Here, for example, are photographs of the traces left by electrons. One trace of length, they pass through the chamber, slightly bending in the magnetic field penetrating it. These electrons have high energy. Other traces were short, highly curved, and their remaining electrons had a small amount of energy. Some traces, as it were, will disperse at the end - a collision has occurred with an atom, ending with the removal of one of the electrons from its shell.
Remember how they discovered the invisible man, the hero of Herbert Wallace’s one-shot novel? The pursuer saw traces of bare feet, right before his eyes, appearing one after another in the snow. The man was invisible, but traces of him remained. Also here - the particles are invisible, but the trace of their destructive work is present.
Looking at a photograph of a person unknown to us, we can learn very little about him in essence. Unless we can establish the gender and roughly estimate the age. A photograph will not tell us whether he is pure or not, whether he likes music, what his profession is, whether he has children and, if so, how he feels about them.
Another thing is photographs of traces of elementary particles in a cloud chamber. By studying them, we can accurately determine the nature of the particles, establish their energies, patterns, the nature of interaction with each other, the interaction of other energies, protons or electrons, one cannot help but admire the perfection with which all the details of their short, but full of dramatic life events are recorded. The Wilson chamber has become a helpless assistant in a wide variety of studies. This device is in some ways the highest court of cassation, which
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the experimenter can trust completely. No person endowed with the most brilliant talent of scientific foresight could have predicted all the capabilities of this instrument, possessing such tempting powers and inexhaustible possibilities.
In 1970, the Atomizdat publishing house published an interview with the popular science book by I. M. Bekkerman “The Invisible Leaves a Trace”*). It contains a detailed story about how the Wilson chamber was created and how amazing discoveries were made using this chamber. The undoubted advantage of the book is that I. M. Bekkerman introduces the reader not only to instruments and research, scientific ideas and the way to implement them. The book also tells about the author of these ideas and devices, the remarkable English physicist Charles Thomson Rhys Wilson. Reading the book, we learned interesting details of his life, we see what enormous work and direction the creation of his camera required. Telerb, everything seems surprisingly simple to us. “Condensation of supersaturated vapor on charged parts!” - a modern physicist will say. But in those days when Wilson began the research season, no one could say almost anything about either the mechanism of vapor condensation or the nature of the charged particles. In 1895, Wilson began to study the conditions for the formation of fog, and only in 1911 his “fog chamber” was born.
The book traces in detail the fate of the cloud chamber - how the Soviet physicists P. L. Kapitsa and D. V. Skobeltsyn placed it in a magnetic field (which made it easy to determine the sign of the charge of the part by the characteristics of their paths), how the Japanese physicist Shimzu and the English physicist Blackett automated its work, how it was forced to work much faster, to study minimator lightning - electrical discharges in gases, etc.
The appearance of some of the high energies created by modern accelerators of charged particles has necessitated a radical reconstruction of the cloud chamber. In order to prevent particles from leaving the field of view of the camera, it was necessary to sharply increase the density of the substance in the path of the particles. Cloud chambers with high pressures of gas filling them are created to take into account. But even at a pressure of 200 amps, the particles travel only a small fraction of their path in the chamber. This means that many events happen to them outside the camera and no traces remain. It was necessary to replace the supersaturated steam that fills the general Wilson chambers with a superheated liquid one, in which charged particles form gas bubbles along the path. Just like fog droplets, these bubbles in a boiling liquid form around charged particles. The first such “bubble” chamber was created by the American physicist Donald Glaser. It is sometimes called an “anti-Wilson chamber”, since in Wilson’s chamber the supersaturated steam condenses into droplets of liquid, and in Glezer’s chamber bubbles of steam appear in overheated liquid.
And again, talking about the birth of chamber bubbles, the author traces in detail the train of thought of Donald Glaser, step by step, with logical inevitability, he leads the reader to the final goal.
In the book by I.M. Bekkerman we talk about complex ss
temporary research in the field of particle physics. But the author surprisingly chooses the material and quite clearly presents the essence of the matter, the main thing is in the research he covers.
The events described in the book come close to the present day, to the problems that physicists intend to solve at the most powerful accelerator of charged particles near Moscow, near the city of Serpukhov in the young scientific center of Protvino. A huge live-hydrogen bubble chamber “Mirabelle”, created by French scientists for our accelerator, is mounted there. The chamber diameter is 1.6 m, length 4.5 m. All of it with the necessary supports is over 200 tons. Moreover, there is a magnet weighing 1150 tons, inside of which a camera is placed. What a huge distance separates Mirabelle from the first Wilson camera, which easily fit inside a small suitcase! But this path was covered in a little more time than a vole.
Wilson died this year from the first and only serious illness in his life. Until his last days, he worked hard, showing deep interest in the study of new, unknown natural phenomena.
《Of all the great scientists of our century, he was, perhaps, the most gentle and calm, the most indifferent to honors and glory. He drew his boundless passion for this from his exceptional love for the natural world, in admiration for its beauty.” This is how the outstanding researcher of cosmic rays, the English physicist Blackett, assessed the outstanding English physicist Charles Thomson Rhys Wilson, the creator of the “foggy chamber” signs.
V. A. Leshkovce