Electric field potential. Equipotential surfaces.
Conductors and dielectrics in an electric field.
Electric capacity. Electrical capacity units. Flat
Capacitor.
Electric field. Coulomb's law.
Electric field strength.
Field lines of force.
According to modern scientific concepts, matter exists in two forms: in the form of matter and in the form of a field. There are not so many fields in nature. There are only such fields:
A) gravitational
B) electric
B) magnetic
D) nuclear
E) the field of weak interactions.
And there are no more fields in nature and cannot be.
All information about other types of fields (biological, torsion, etc.) is false, although supporters of these fields try to bring some kind of "scientific" theory under these concepts of non-existent fields, but as soon as the principle of the presumption of provability is used, these pseudoscientific theories endure crash. This should be taken into account by all medical specialists, since supporters of pseudoscientific theories impudently speculate on the concepts of non-existent fields: they sell for a lot of money all sorts of useless devices that supposedly cure all diseases by the method of “correction of the biofield or torsion field”. All kinds of "generators of torsion fields", "charged" amulets and other completely useless items are on sale. And only a solid knowledge of physics and other natural sciences will help knock the ground out from under the feet of those who profit from deceiving the population.
In this lecture, we will look at one of the real fields - electric field.
As you know, the field does not affect our senses, does not produce sensations, but nevertheless, it really exists and can be detected by appropriate devices.
How does it manifest itself?
Even in ancient Greece, it was discovered that amber, rubbed with wool, began to attract various small objects: specks, straws, dry leaves. If you rub a plastic comb on clean and dry hair, it will begin to attract hair. Why did the hair not attract before rubbing against the comb, but after friction began to attract? Yes, after friction, a charge appeared on the comb after friction. And they named him electric charge. But why was there no such charge before friction? Where did it come from after friction? Yes, the field exists around all bodies that have an electric charge. Through this field, the interaction between objects that are distant at a certain distance is transmitted.
Further research showed that electrically charged bodies can not only attract, but also repel. Hence, it was concluded that there are two types of electric charges. They were conventionally named positive (+)and negative (-). But these designations are purely conventional. With the same success, they could be called, say, black and white, or top and bottom, etc.
Charges of the same name are repelled, and unlike charges are attracted. The SI unit of electric charge is pendant (Cl). This unit is named after the French scientist C. Coulomb. This scientist has experimentally derived the law that bears his name:
F \u003d k ( q1q2)
F -force of attraction or repulsion between charges
q1and q2 -charge magnitudes
R -distance between charges
k -the proportionality coefficient is 9 * 10 9 Nm 2 / Cl 2
Is there the smallest charge? It turns out yes, it does. There is such an elementary particle, the charge of which is the smallest and less than which does not exist in nature. In any case, according to modern data. This particle is electron. This particle is in the atom, but not in its center, but moves in an orbit around the atomic nucleus. Electron has negative charge and its value is q \u003d e \u003d -1.6 * 10 -19 Cl. This quantity is called an elementary electric charge.
We now know what an electric field is. Now let's consider the question: and in what units should it be measured so that this unit is objective?
It turns out that the electric field has two characteristics. One of them is called tension.
To understand this unit, take a charge of +1 C and put it at one of the points of the field and measure the force with which the field acts on this charge. And the magnitude of this charge will be the field strength.
But, in principle, it is not necessary to take a charge of 1 C. You can take an arbitrary charge, but in this case, the tension will need to be calculated using the formula:
Here E- electric field strength. Dimension - N / CL.
However, according to the great Russian scientist Dmitry Ivanovich Mendeleev, "science begins as soon as they begin to measure." Experiments must be planned, the results of the obtained measurements must be processed, interpreted, and then scientifically substantiated not only the purity and reliability of the research methods used, but also the reliability of the measurement processing methods. In this case, it becomes necessary to use numerical methods, mathematical statistics, etc. The author, who is well acquainted with the theoretical substantiation of hypotheses, the practical design of experiments and the numerical processing of their results, knows in practice how thankless this is. Any person who is at least a little familiar with the theory of mathematical processing of measurement results or who has personal experience of experimental research has an excellent opportunity to question the purity of the experiment, the processing algorithms used, the size of the statistical sample, and, as a result, to doubt the result as a whole.
However, there is also “the other side of the coin”. It lies in the fact that a professionally staged experiment makes it possible to make significant progress in understanding the phenomenon under study, to confirm or refute the hypotheses put forward, to obtain reliable and repeatable knowledge about the object of research. That is why a group of researchers under the leadership of the author for several years carried out scientific research of the properties of such a completely unscientific phenomenon as seida discovered by us.
2. How to carry out scientific research of seids
2.1. The essence of the scientific method
In order to carry out precisely scientific research, and not any others, we first figure out what a scientific method is in general. The essence of the scientific method was quite clearly formulated by Isaac Newton in his works "Optics" and "Mathematical Principles of Natural Philosophy", and has not changed over the past three centuries.
The scientific method includes the study of phenomena, systematization and correction of the acquired knowledge. Inferences and conclusions are made using rules and principles of reasoning based on empirical (observable) and measurable data about the object of research. To explain the observed phenomena, hypotheses and are being built theory,on the basis of which conclusions, assumptions and forecasts are formulated. The obtained forecasts are verified by experiments or collection of new facts, and then corrected based on the newly received data. Thus, the development of scientific ideas about the world takes place.
According to the scientific method, the source of data are observations and experiments... To perform scientific research, you must first select object and subjectresearch, property or set of studied properties, to accumulate empirical and experimental data. Then formulate one or several scientific hypotheses, perform their experimental verification, process the experimental materials, formulate the conclusions obtained, and thereby confirm, refute or correct the hypotheses put forward. After confirmation and correction, the proposed hypothesis becomes reliable knowledge, after refutation becomes false knowledge (delusion)and discarded.
2.2. How they write about seids
The scientific method includes ways to obtain new knowledge about any phenomenon, incl. and about megaliths. However, in most publications about seids in the Russian North, there is no serious reasoned confirmation of the hypotheses put forward about the properties and purpose of seids. This applies to both official scientific and popular publications. Experimental verification is usually replaced by fairly general reasoning about the unusual properties of seids. There is no clear description and systematization of the studied properties. The list of observed and studied properties can vary significantly from one region or complex to another. There is no quantitative assessment of the studied properties.
Modern methods of researching megaliths are reduced mainly to identifying artifacts, i.e. objects that do not fit into the concept of the traditional history of the development of our civilization, the emotional literary description of their unusualness, as well as the description of various kinds of myths, legends and traditions, which, according to the authors of the publications, have at least some relation to the seids. These legends wander from one author to another without any attempt to verify and confirm them. At the same time, it is not substantiated whether the nationalities in which these legends were recorded have a relation to the creation of seids, or simply accidentally live in the same territory. Naturally, for different authors such "sacred knowledge" is completely different and often opposed to each other.
Professional research of seids is not carried out by official science. The level of argumentation, even in peer-reviewed scientific publications, often leaves much to be desired. In order not to be unfounded, I will give only a few quotes from the article. " ... The statements of amateurs and journalists about the "cult" buildings in Vottovaara are colored with biased, usually unfounded ideas about the origin and functions of these objects, although deliberate hoaxes are also likely to strike the imagination of gullible readers. Trusting them is impossible and should not be ...». « ... The intellectual drunkenness of the authors of such information is amazing ...». «… We are dealing with clearly biased explanations and conjectures hidden in them, mixed with a considerable amount of fantasy».
Let me remind you that this is the argumentation of a "scientific" article published in the official collection of the KarRC RAS. For some reason, the authors forget to clearly state on the basis of what scientific methods of research of seids such conclusions were made. They also forget to give the results of experimental testing of their hypotheses. But after reading this article, one gets the feeling that the next publication about the actually existing, confirmed and measurable properties of seids will be called heresy and the Holy Inquisition will be summoned to the author's house. And if such argumentation of "scientists" has passed scientific review and was published in the official collection of the Russian Academy of Sciences, then what can we expect from "uneducated" researchers ?!
But it is precisely the lack of professional research that does not allow formulating well-founded conclusions about the real properties and purpose of megaliths. The scientific vacuum formed at the suggestion of the RAS “scientists” is filled with very unconvincing definitions of seids as some “sacred” or “cult” complexes, the exact purpose of which defies human logic and can only be explained by the “mythological consciousness” of their primitive creators.
« Physics - Grade 10 "
What is the mediator that carries out the interaction of charges?
How to determine which of the two fields is stronger? Suggest ways to compare fields.
Electric field strength.
The electric field is detected by the forces acting on the charge. It can be argued that we know everything we need about the field if we know the force acting on any charge at any point in the field. Therefore, it is necessary to introduce such a characteristic of the field, the knowledge of which will make it possible to determine this force.
If we alternately place small charged bodies at the same point of the field and measure the forces, it will be found that the force acting on the charge from the side of the field is directly proportional to this charge. Indeed, let the field be created by a point charge q 1. According to Coulomb's law (14.2), a force proportional to the charge q acts on a point charge q. Therefore, the ratio of the force acting on the charge placed at a given point of the field to this charge for each point of the field does not depend on the charge and can be considered as a characteristic of the field.
The ratio of the force acting on a point charge placed at a given point of the field to this charge is called electric field strength.
Like force, field strength - vector quantity; it is denoted by the letter:
Hence, the force acting on the charge q from the side of the electric field is equal to:
Q. (14.8) 
The direction of the vector coincides with the direction of the force acting on the positive charge, and opposite to the direction of the force acting on the negative charge.
The unit of tension in SI is N / Kl.
Electric field lines of force.
The electric field does not affect the senses. We do not see him. However, we can get some idea of \u200b\u200bthe field distribution if we draw the field strength vectors at several points in space (Fig. 14.9, a). The picture will be more visual if you draw continuous lines.
Lines tangent at each point of which coincides with the vector of the electric field strength are called power lines or field strength lines (Figure 14.9, b).
The direction of the lines of force allows you to determine the direction of the intensity vector at different points of the field, and the density (number of lines per unit area) of the lines of force shows where the field strength is greater. So, in Figures 14 10-14.13, the density of field lines at points A is greater than at points B. It is obvious that A\u003e B.
One should not think that the lines of tension exist in reality like stretched elastic threads or cords, as Faraday himself assumed. Lines of tension help only to visualize the distribution of the field in space. They are no more real than the meridians and parallels on the globe.
Lines of force can be made visible. If the elongated crystals of an insulator (for example, quinine) are mixed well in a viscous liquid (for example, in castor oil) and charged bodies are placed there, then near these bodies the crystals will line up in chains along the lines of tension.
The figures show examples of lines of tension: a positively charged ball (see Fig. 14.10), two oppositely charged balls (see Fig. 14.11), two like-charged balls (see Fig. 14.12), two plates, the charges of which are equal in magnitude and are opposite in sign (see fig. 14.13). The last example is especially important.
Figure 14.13 shows that in the space between the plates, the lines of force are basically parallel and are at equal distances from each other: the electric field is the same at all points.
An electric field, the strength of which is the same at all points, is called homogeneous.
In a limited area of \u200b\u200bspace, the electric field can be considered approximately uniform if the field strength inside this area changes insignificantly.
The lines of force of the electric field are not closed, they start at positive charges and end at negative ones. The lines of force are continuous and do not intersect, since intersection would mean the absence of a certain direction of the electric field strength at a given point.
The space surrounding the charge that is the source is directly proportional to the amount of that charge and inversely to the square of the distance from that charge. The direction of the electric field, according to the accepted rules, is always from a positive charge towards a negative charge. This can be imagined as if you place a test charge in the region of space of the electric field of the source and this test charge will either repel or attract (depending on the sign of the charge). An electric field is characterized by its intensity, which, being a vector quantity, can be represented graphically in the form of an arrow having a length and direction. Anywhere the direction of the arrow indicates the direction of the electric field strength E, or simply - the direction of the field, and the length of the arrow is proportional to the numerical value of the electric field strength in this place. The further the region of space is from the source of the field (charge Q), the shorter the length of the tension vector. Moreover, the length of the vector decreases with distance n times from some place in n 2 times, that is, inversely proportional to the square.
A more useful means of visualizing the vector nature of an electric field is to use such a concept as, or simply - lines of force. Instead of drawing countless vector arrows in space surrounding the charge-source, it turned out to be useful to combine them in lines, where the vectors themselves are tangent to points on such lines.
As a result, it is successfully used to represent the vector picture of the electric field electric field lines, which leave the charges of a positive sign and enter the charges of a negative sign, and also extend to infinity in space. Such a representation allows the mind to see an electric field invisible to the human eye. However, such a representation is also convenient for gravitational forces and any other non-contact long-range interactions.
The model of electric field lines includes an infinite number of them, but too high density of the image of field lines reduces the ability to read the patterns of the field, therefore their number is limited to readability.
Rules for drawing electric field lines
There are many rules for drawing up such models of electrical lines of force. All these rules are created in order to communicate the greatest information content when visualizing (drawing) an electric field. One way is to draw lines of force. One of the most common ways is to surround more charged objects with more lines, that is, more line density. Objects with a higher charge create stronger electric fields and therefore the density (density) of lines around them is greater. The closer the source is to the charge, the higher the density of the lines of force, and the greater the value of the charge, the denser the lines around it.
The second rule for drawing electric field lines involves drawing lines of a different type, such as those that intersect the first lines of force. perpendicular... This line type is called equipotential lines, and in the volumetric representation one should speak of equipotential surfaces. This type of line forms closed contours and each point on such an equipotential line has the same value of the field potential. When any charged particle crosses such perpendicular power lines lines (surfaces), then they speak of the commission of work. If the charge moves along equipotential lines (surfaces), then although it moves, no work is done. A charged particle, finding itself in the electric field of another charge, begins to move, but in static electricity only stationary charges are considered. The movement of charges is called an electric current, while the charge carrier can do work.
It is important to remember that electric field lines do not intersect, and lines of another type are equipotential and form closed contours. In the place where the intersection of lines of two types takes place, the tangents to these lines are mutually perpendicular. Thus, something like a curved coordinate grid, or a lattice, is obtained, the cells of which, as well as the points of intersection of lines of different types, characterize the electric field.
Dotted lines are equipotential. Arrow lines - electric field lines of force
Electric field consisting of two or more charges
For solitary single charges electric field lines represent radial beams going out of charges and going to infinity. What will be the configuration of the field lines for two or more charges? To complete such a pattern, it is necessary to remember that we are dealing with a vector field, that is, with vectors of the electric field strength. To depict a picture of the field, we need to add the strength vectors from two or more charges. The resulting vectors will represent the total field of several charges. How in this case can you build lines of force? It is important to remember that each point on the line of force is single point contact with the electric field strength vector. This follows from the definition of tangent in geometry. If, from the beginning of each vector, a perpendicular is constructed in the form of long lines, then the mutual intersection of many such lines will depict the very sought line of force.
For a more accurate mathematical algebraic image of the lines of force, it is necessary to draw up the equations of the lines of force, and the vectors in this case will represent the first derivatives, the lines of the first order, which are tangents. Such a task is sometimes extremely complex and requires computer calculations.
First of all, it is important to remember that the electric field from many charges is represented by the sum of the strength vectors from each charge source. it the basis to perform the construction of lines of force in order to visualize the electric field.
Each charge introduced into the electric field leads to a change, even slight, in the pattern of the lines of force. Such images are sometimes very attractive.
Electric Field Lines as a Way to Help the Mind See Reality
The concept of an electric field arose when scientists tried to explain the long-range action that occurs between charged objects. The concept of an electric field was first introduced by the 19th century physicist Michael Faraday. It was the result of Michael Faraday's perception invisible reality in the form of a picture of lines of force characterizing long-range action. Faraday did not think within the framework of one charge, but went further and expanded the boundaries of the mind. He suggested that a charged object (or mass in the case of gravity) affects space and introduced the concept of a field of such influence. Considering such fields, he was able to explain the behavior of charges and thereby revealed many secrets of electricity.
One of the most important achievements of Faraday was his proposed new interpretation of how force is transmitted from one body to another. Instead of acting at a distance, he imagined lines of force piercing space. During the 1830s and 1840s, Faraday continued to develop his idea of \u200b\u200bmagnetic and electrical lines of force. But since this new idea had no mathematical form, most scientists rejected it. However, there were two important exceptions - William Thomson and James Clerk Maxwell.
Thomson gave a mathematical interpretation to the Faraday lines of force and showed that the concept of lines of force is consistent with the theory of heat and mechanics; thus, the mathematical foundation of field theory was laid. Faraday recognized the importance of the support of these "two very talented gentlemen and outstanding mathematicians"; he said: "for me it is a source of great pleasure and support - to feel that they confirm the validity and universality of the idea I have proposed."
For Faraday, the idea of \u200b\u200blines of force naturally followed from his experiments with magnets. When he threw needle-shaped iron filings on a sheet of paper lying on a piece of magnet, he noticed that the sawdust line up in lines going in a certain direction, depending on their position relative to the magnet.
He thought that the magnetic poles were connected by magnetic lines and that these lines are made visible by iron filings that line up parallel to the lines. For Faraday, these lines were real, though invisible. Faraday extended his idea of \u200b\u200blines of force to electric forces; he believed that gravity could be interpreted in a similar way. Instead of claiming that the planet in some unknown way knows how it should orbit around the Sun, Faraday introduced the concept of a gravitational field that controls the planet in orbit. The sun generates a field around itself, and the planets and other celestial bodies feel the influence of the field and behave accordingly. In the same way, charged bodies generate electric fields around them, and other charged bodies sense this field and react to it. There are also magnetic fields associated with magnets.
Newton believed that the main objects are particles connected by forces; and the space between them is empty. Faraday imagined both particles and fields interacting with each other; and this is a completely modern point of view. This is not to say that particles are more real than fields. We usually draw fields as lines indicating the direction of force at each point in space.
The tighter the lines are, the greater the strength. Take the sun's gravity as an example. We can say that, coming from all sorts of directions, all lines of force end in the Sun. We can draw spheres of different radii centered on the Sun, with each line of force crossing each sphere. The area of \u200b\u200bthe spheres increases as the square of their radius, so the line density decreases in inverse proportion to the square of the distances.
Thus, the idea of \u200b\u200blines of force leads us directly to Newton's law of gravity (and also to the Coulomb inverse square law for an electric field of a constant charge; 
When using the idea of \u200b\u200ba force field (like a gravitational field), there are a few simple rules to follow.
1. Gravitational acceleration occurs along the force field passing through the body.
2. The amount of acceleration is proportional to the line density at a given point.
3. Lines of force can end only where there is mass. The number of lines ending at a given point is proportional to the mass of that point.
Now it is easy to prove a statement that Newton had to work hard on. Comparing accelerations on the surface of the Earth and in the orbit of the Moon, Newton assumed that the Earth acts on all bodies as if all its mass is concentrated in its center. Why?
Let's assume, for simplicity, that the Earth is perfectly round and symmetrical. Then all parts of its surface will be equally covered by the incoming lines of force. According to the third) ’rule, the number of lines of force depends on the mass of the Earth. If all mass were concentrated in the center of the planet, all these lines would continue to the center. Thus, the gravitational field of the Earth
does not depend on how the mass is distributed under its surface if there is spherical symmetry. In particular, the entire mass of the Earth concentrated at its center creates exactly the same gravity as the real Earth.
Exactly the same reasoning applies to the electric field. But since there are two types of electric charge, positive and negative, then when the sign of the charge changes, the direction of the lines of force changes to the opposite. Lines of force begin at a positive charge and end at a negative one.