An ECG is an electrocardiogram, a recording of the electrical signals of the heart. The fact that a potential difference arises in the heart upon excitation was shown as early as 1856, during the Dubois-Reymond era. The experiment proving this was set by Kelliker and Muller exactly according to Galvani’s recipe: a nerve running to the frog’s foot was laid on an isolated heart, and this “living voltmeter” responded with a jerking of the paw to each heart beat.

With the advent of sensitive electrical measuring instruments, it became possible to capture the electrical signals of a working heart by applying electrodes not directly to the heart muscle, but to the skin.

In 1887, it was for the first time possible to register a human ECG in this way. This was done by the English scientist A. Waller using a capillary electrometer ...

Despite the indisputable successes of the modern theory of electromagnetism, the creation on its basis of such areas as electrical engineering, radio engineering, electronics, there is no reason to consider this theory complete. The main drawback of the existing theory of electromagnetism is the lack of model concepts, a lack of understanding of the essence of electrical processes; hence the practical impossibility of further development and improvement of the theory. And from the limitations of the theory, many applied difficulties also follow.

There are no grounds for believing the theory of electromagnetism to be the height of perfection. In fact, the theory has accumulated a number of omissions and direct paradoxes for which very unsatisfactory explanations have been invented, or there are no such explanations at all.

For example, how to explain that two mutually motionless identical charges, which are supposed to be repelled from each other according to the Coulomb law, are actually attracted if they move together a relatively long abandoned source? ...

Attention factor affects the outcome of electrical injuries

The unresolved issue of what is primary in a fatal electric trauma - damage to the respiratory system or cardiac arrest - is largely due to the enormous role of the central nervous system, which unexpectedly confuses our ideas about the mechanism of action of electric current. In some cases, the central nervous system forces the irreversible development of pathological changes, in others, on the contrary, it creates defensive (protective) lines against them.

Experimental electrical trauma cannot provide an unambiguous interpretation of these mysterious circumstances. The main object of study is too complex - the person, and therefore the transfer of data obtained during the experimental electric trauma caused to the model, i.e., to the animal, is too conditional. It is conditional first of all because such a transfer does not take into account the state of the central nervous system of a person, the most important role of which in the outcome of electric shock is beyond doubt ...

Once in a second-hand bookstore, I came across a book by I. Perelman “Entertaining Physics” of the 1924 edition. Printed on brown paper (and where did the good paper come from after the Civil War), it had a subtitle - "Paradoxes, puzzles, tasks, experiments, intricate questions and stories from the field of physics." For some reason, this subtitle in subsequent editions from childhood of a book well known to me has disappeared. Just for the sake of curiosity, I wanted to find out what has changed in the book over the past 75 years. After all, at home I had the twenty-second edition of this widely known student youth book. But science and technology during this time did not stagnate.

My interest in Ya.I. Perelman was heated by the recently published book of G.I. Mishkevich about the life and work of an outstanding popularizer of science. “The singer of mathematics, the bard of physics, the poet of astronomy” was widely in demand in the country, recently agrarian and backward, and had just begun its journey into the number of advanced and cultural states of the world. And the role of Perelman in this development was far from the last. In his books, witty amusement, scientific certainty and even grace, even in his school years, helped the most talented part of the younger generation to choose their future life path in the service of science.

In a biography book, it was somehow noted in passing that Ya.I. Perelman in 1916 worked at a special meeting of the Russian government on fuel and, "in connection with the deplorable state of wood heating in Petrograd," he proposed the first time in our country to switch to summer time. The fact that by using the clock hands to save energy on lighting has long been known to everyone. But how firewood was saved, I could not understand.

This fact interested me so much that I decided to ask the author of the biography book about it. Moreover, in one of the stories of the book I bought, when calculating the energy consumption for a lightning discharge, the data between Perelman and subsequent editions, released after the death of the popularizer, differed almost a hundred times!

A letter was sent and the reply came and put everything in its place. As for saving firewood, the explanation was very clear ...

The economic efficiency of using thermoelectric refrigerators in comparison with other types of refrigerating machines increases the more, the smaller the volume of the cooled volume. Therefore, the most rational at the present time is the use of thermoelectric cooling for household refrigerators, in food liquid coolers, air conditioners, in addition, thermoelectric cooling is successfully used in chemistry, biology and medicine, metrology, as well as in commercial cold (maintaining the temperature in refrigerators) , refrigeration transport (refrigerators), and other areas

The effect of the appearance of thermoEMF in soldered conductors is widely known in the art, the contacts (junctions of junctions) between which are maintained at different temperatures (Seebeck effect). In the case when a constant current is passed through a circuit of two dissimilar materials, one of the junctions starts to heat up, and the other starts to cool. This phenomenon is called the thermoelectric effect or the Peltier effect ...

In the beginning of the twentieth century, fierce debates between specialists over the advantages and disadvantages of using direct and alternating current circuits for power supply. It so happened that preference was given to three-phase AC circuits. Industrialists, calculating the volume of capital costs for the creation of power supply systems, have chosen, it would seem, the most optimal option.

The decisive role in the ubiquity of three-phase AC networks was played by the simplicity of obtaining torque with a minimum number of phases. Against direct current, such arguments were put forward as the high cost and low reliability of engines, the complexity of energy conversion. But that was then. What now? The practical experience gained over many years of the development of the electric power industry gives, in my opinion, devastating results.

The first one. From the course of the theoretical foundations of electrical engineering it is known that in order to transfer maximum power to the load in alternating current circuits, the condition of equal source resistance to line resistance and load resistance must be met. It follows that the theoretically achievable efficiency for AC circuits is 33% ...

In 1951, the English scientist Lissman studied the behavior of the fish of the gymnasium. This fish lives in opaque opaque water in lakes and swamps of Africa and therefore can not always use sight for orientation. Lissman suggested that these fish, like bats, are used for orientation echolocation.

The amazing ability of bats to fly in complete darkness, without bumping into obstacles, was discovered a long time ago, in 1793, that is, almost simultaneously with the discovery of Galvani. Did it Lazaro Spallanzani - Professor at the University of Pavia (the one where Volta worked). However, experimental evidence that bats emit ultrasounds and are guided by their echoes was obtained only in 1938 at Harvard University in the USA, when physicists created equipment for recording ultrasounds.

Having tested the ultrasonic hypothesis of the orientation of the gymnasium experimentally, Lissman rejected it. It turned out that the gymnarch is oriented somehow differently. Studying the behavior of the gymnast, Lissman found out that this fish has an electric organ and begins to generate very weak current discharges in opaque water. Such a current is not suitable for either defense or attack. Then Lissman suggested that the gymnarch should have special organs for the perception of electric fields - sensor system ...

The author is most afraid that the inexperienced reader will not read the heading further. He believes the definition terms anode and cathode Every competent person knows that, solving a crossword puzzle, when asked about the name of the positive electrode, he immediately writes the word anode and everything fits in the cells. But there are not many things that are worse than half-knowledge.

Recently, in the Google search engine, in the “Questions and Answers” ​​section, I even found a rule by which its authors suggest remembering the definition of electrodes. Here it is:

«Cathode - negative electrode anode is positive. And remembering this is easiest if you count the letters in words. IN cathode as many letters as in the word “minus”, and in anode respectively, as much as in the term “plus”. The rule is simple, memorable, one would have to offer it to schoolchildren if it were correct. Although the desire of teachers to put knowledge in the heads of students using mnemonics (the science of memorization) is very commendable. But back to our electrodes.

To begin with, we take a very serious document, which is the LAW for science, technology, and, of course, school. It "GOST 15596-82. SOURCES OF THE CURRENT CHEMICAL. Terms and Definitions". There, on page 3, you can read the following: “The negative electrode of a chemical current source is an electrode that, when discharged, is anode". The same thing, “A positive electrode of a chemical current source is an electrode that, when discharged, is cathode". (Terms are highlighted by me. BH). But the texts of the rule and GOST contradict each other. What is the matter? ...