What are electromagnetic waves? An electromagnetic wave is the process of propagation of an electromagnetic field in space.

Electromagnetic waves are the result of years of debate and thousands of experiments. Proof of the presence of forces of natural origin that can turn the current society. This is the actual acceptance of a simple truth - we know too little about the world we live in.

Physics is the queen among the natural sciences, able to answer questions about the origin of not only life, but the world itself. It gives scientists the ability to study the electric and magnetic fields, the interaction of which generates EMW (electromagnetic waves).

What is an electromagnetic wave

Not so long ago, the film “War of the Currents” (2018) was released on the screens of our country, where, with a touch of fiction, it tells about the dispute between the two great scientists Edison and Tesla. One tried to prove a benefit from direct current, the other - from the variable. This long battle ended only in the seventh year of the twenty-first century.

At the very beginning of the “battle”, another scientist, working on the theory of relativity, described electricity and magnetism as similar phenomena.

In the thirtieth year of the nineteenth century, the physicist English origin Faraday discovered the phenomenon electromagnetic induction and introduced the term of the unity of the electric and magnetic fields. He also claimed that movement in this field is limited by the speed of light.

A little later, the theory of the English scientist Maxwell told that electricity causes a magnetic effect, and magnetism causes the appearance electric field. Since both of these fields move in space and time, they form perturbations - that is, electromagnetic waves.

Simply put, an electromagnetic wave is a spatial perturbation of an electrical magnetic field.

Experimentally, the existence of EMW was proved by the German scientist Hertz.

Electromagnetic waves, their properties and characteristics

Electromagnetic waves are characterized by the following factors:

• length (wide enough range);
• frequency;
• intensity (or amplitude of oscillation);
• the amount of energy.

The main property of all electromagnetic radiation is the wavelength (in vacuum), which is usually specified in nanometers for the visible light spectrum.

Each nanometer represents a thousandth of a micrometer and is measured by the distance between two successive peaks (vertices).

The corresponding radiation frequency of a wave is the number of sinusoidal oscillations and inversely proportional to the wavelength.

Frequency is usually measured in Hertz. Thus, longer wavelengths correspond to a lower frequency of radiation, and shorter wavelengths correspond to a higher frequency of radiation.

The main properties of waves:

• refraction;
• reflection;
• absorption;
• interference.

electromagnetic wave speed

The actual speed of propagation of an electromagnetic wave depends on the material that the medium has, its optical density and the presence of such a factor as pressure.

Besides, various materials have different density of "packing" of atoms, the closer they are located, the smaller the distance and the higher the speed. As a result, the speed of an electromagnetic wave depends on the material through which it travels.

Similar experiments are carried out in the hadron collider, where the main instrument of influence is a charged particle. Study of electromagnetic phenomena occurs there at the quantum level, when light is decomposed into tiny particles - photons. But the quantum physics is a separate issue.

According to the theory of relativity, the highest speed of wave propagation cannot exceed the speed of light. The finiteness of the speed limit in his writings was described by Maxwell, explaining this by the presence of a new field - the ether. Modern official science has not yet studied such a relationship.

Electromagnetic radiation and its types

Electromagnetic radiation consists of electromagnetic waves, which are observed as fluctuations in electric and magnetic fields, propagating at the speed of light (300 km per second in a vacuum).

When EM radiation interacts with matter, its behavior changes qualitatively as frequency changes. Why is it converted to:

1. Radio emission. At radio frequencies and microwave frequencies, em radiation interacts with matter mainly in the form of a common set of charges that are distributed over a large number affected atoms.
2. Infrared radiation. Unlike low-frequency radio and microwave radiation, an infrared emitter usually interacts with dipoles present in individual molecules, which change at the ends as they vibrate. chemical bond at the atomic level.
3. Visible light emission. As the frequency increases in the visible range, photons have enough energy to change the bonded structure of some individual molecules.
4. Ultraviolet radiation. The frequency is increasing. There is now enough energy in ultraviolet photons (more than three volts) to doubly act on the bonds of molecules, constantly rearranging them chemically.
5. Ionizing radiation. At the highest frequencies and the smallest in wavelength. The absorption of these rays by matter affects the entire gamma spectrum. The most famous effect is radiation.

What is the source of electromagnetic waves

The world, according to the young theory of the origin of everything, arose thanks to an impulse. He released colossal energy, which was called a big explosion. This is how the first em-wave appeared in the history of the universe.

Currently, the sources of disturbance formation include:

• emv emits an artificial vibrator;
• the result of vibration of atomic groups or parts of molecules;
• if there is an impact on outer shell substances (at the atomic-molecular level);
• effect similar to light;
• during nuclear decay;
• consequence of electron deceleration.

Scale and application of electromagnetic radiation

Radiation scale means a wide range of wave frequency from 3·10 6 ÷10 -2 to 10 -9 ÷ 10 -14 .

Each part of the electromagnetic spectrum has a wide range of applications in our daily lives:

1. Waves of small length (microwaves). These electrical waves are used as a satellite signal because they are able to bypass the earth's atmosphere. Also, a slightly enhanced version is used for heating and cooking in the kitchen - this is a microwave oven. The principle of preparation is simple - under the action microwave radiation water molecules are absorbed and accelerated, causing the dish to heat up.
2. Long perturbations are used in radio technologies (radio waves). Their frequency does not allow clouds and atmosphere to pass through, thanks to which FM radio and television are available to us.
3. The infrared disturbance is directly related to heat. It is almost impossible to see him. Try to notice without special equipment a beam from the remote control of your TV, music center or radio in the car. Devices capable of reading such waves are used in the armies of countries (night vision device). Also in induction cookers in kitchens.
4. Ultraviolet is also related to heat. The most powerful natural "generator" of such radiation is the sun. It is because of the action of ultraviolet radiation that a tan forms on the skin of a person. In medicine, this type of wave is used to disinfect instruments, killing germs and.
5. Gamma rays are the most powerful type of radiation in which a short-wave disturbance with a high frequency is concentrated. The energy contained in this part of the electromagnetic spectrum gives the rays a greater penetrating power. Applicable in nuclear physics- peaceful, nuclear weapons - combat use.

The influence of electromagnetic waves on human health

Measuring the impact of emv on humans is the responsibility of scientists. But you do not need to be a specialist to assess the intensity of ionizing radiation - it provokes changes at the level of human DNA, which entails such serious diseases as oncology.

No wonder the detrimental impact of the Chernobyl disaster is considered one of the most dangerous for nature. Several square kilometers of the once beautiful territory have become a zone of complete exclusion. Until the end of the century, an explosion at the Chernobyl nuclear power plant is dangerous until the half-life of radionuclides ends.

Some types of emv (radio, infrared, ultraviolet) do not cause much harm to a person and are only discomfort. After all, the magnetic field of the earth is practically not felt by us, but the emv from mobile phone may cause headache(impact on the nervous system).

In order to protect your health from electromagnetism, you should simply use reasonable precautions. Instead of hundreds of hours playing a computer game, go out for a walk.

In 1864, James Clerk Maxwell predicted the possibility of the existence of electromagnetic waves in space. He put forward this statement based on the conclusions arising from the analysis of all the experimental data known at that time regarding electricity and magnetism.

Maxwell mathematically unified the laws of electrodynamics by linking electrical and magnetic phenomena, and thus came to the conclusion that electric and magnetic fields that change over time give rise to each other.

Initially, he emphasized the fact that the relationship between magnetic and electrical phenomena is not symmetrical, and introduced the term "vortex electric field”, offering his own, truly new explanation of the phenomenon of electromagnetic induction discovered by Faraday: “every change in the magnetic field leads to the appearance in the surrounding space of a vortex electric field with closed lines of force».

Fair, according to Maxwell, was the converse statement that "a changing electric field gives rise to a magnetic field in the surrounding space", but this statement remained at first only a hypothesis.

Maxwell wrote down a system of mathematical equations that consistently described the laws of mutual transformations of magnetic and electric fields, these equations later became the basic equations of electrodynamics, and became known as "Maxwell's equations" in honor of the great scientist who wrote them down. Maxwell's hypothesis, based on the written equations, had several extremely important conclusions for science and technology, which are given below.

Electromagnetic waves really exist

In space, transverse electromagnetic waves can exist, which are propagating over time. The fact that the waves are transverse is indicated by the fact that the vectors of magnetic induction B and electric field strength E are mutually perpendicular and both lie in a plane perpendicular to the direction of propagation of an electromagnetic wave.

The speed of propagation of electromagnetic waves in matter is finite, and it is determined by the electrical and magnetic properties material through which the wave propagates. In this case, the length of the sinusoidal wave λ is related to the speed υ by a certain exact relation λ = υ / f, and depends on the frequency f of the field oscillations. The speed c of an electromagnetic wave in a vacuum is one of the fundamental physical constants - the speed of light in a vacuum.

Since Maxwell declared the finiteness of the propagation velocity of an electromagnetic wave, this created a contradiction between his hypothesis and the long-range theory accepted at that time, according to which the propagation velocity of waves should have been infinite. Maxwell's theory was therefore called the theory of short-range action.

In an electromagnetic wave, the transformation of electric and magnetic fields into each other occurs simultaneously, therefore, the volumetric densities of magnetic energy and electrical energy are equal to each other. Therefore, the statement is true that the modules of the electric field strength and magnetic field induction are interconnected at each point in space by the following relationship:

electromagnetic wave in the process of its distribution creates a stream electromagnetic energy, and if we consider the area in a plane perpendicular to the direction of wave propagation, then in a short time a certain amount of electromagnetic energy will move through it. The electromagnetic energy flux density is the amount of energy carried by an electromagnetic wave through the surface of a unit area per unit of time. By substituting the values ​​of velocity, as well as magnetic and electrical energy, we can obtain an expression for the flux density in terms of the quantities E and B.

Since the direction of wave energy propagation coincides with the direction of the wave propagation velocity, the energy flux propagating in an electromagnetic wave can be specified using a vector directed in the same way as the wave propagation velocity. This vector is called the "Poynting vector" - in honor of British physicist Henry Poynting, who developed in 1884 the theory of the propagation of the energy flow of the electromagnetic field. Wave energy flux density is measured in W/sq.m.

When an electric field acts on a substance, small currents appear in it, which are an ordered movement of electrically charged particles. These currents in the magnetic field of an electromagnetic wave are subjected to the action of the Ampère force, which is directed deep into the substance. Ampere's force and generates as a result pressure.

This phenomenon was later, in 1900, investigated and confirmed experimentally by the Russian physicist Pyotr Nikolaevich Lebedev, whose experimental work was very important for confirming Maxwell's theory of electromagnetism and its acceptance and approval in the future.

The fact that an electromagnetic wave exerts pressure makes it possible to judge the presence of a mechanical impulse in an electromagnetic field, which can be expressed for a unit volume in terms of the volumetric density of electromagnetic energy and the speed of wave propagation in vacuum:

Since the momentum is associated with the movement of mass, such a concept as electromagnetic mass can be introduced, and then for a unit volume this ratio (in accordance with SRT) will take on the character of a universal law of nature, and will be valid for any material bodies, regardless of the form of matter. And the electromagnetic field is then akin to a material body - it has energy W, mass m, momentum p and a finite propagation velocity v. That is, the electromagnetic field is one of the forms of matter that actually exists in nature.

For the first time in 1888, Heinrich Hertz confirmed experimentally Maxwell's electromagnetic theory. He empirically proved the reality of electromagnetic waves and studied their properties such as refraction and absorption in various media, as well as the reflection of waves from metal surfaces.

Hertz measured the wavelength, and showed that the speed of propagation of an electromagnetic wave is equal to the speed of light. Hertz's experimental work was the last step towards the recognition of Maxwell's electromagnetic theory. Seven years later, in 1895, Russian physicist Alexander Stepanovich Popov used electromagnetic waves to create wireless communications.

In DC circuits, charges move at a constant speed, and electromagnetic waves in this case are not radiated into space. For radiation to take place, it is necessary to use an antenna in which alternating currents, that is, currents that quickly change their direction, are excited.

In its simplest form, an electric dipole is suitable for emitting electromagnetic waves. small size, whose dipole moment would change rapidly with time. It is such a dipole that is called today the "Hertzian dipole", the size of which is several times smaller than the wavelength it emits.

When emitted by a Hertzian dipole, maximum flow electromagnetic energy falls on a plane perpendicular to the axis of the dipole. No electromagnetic energy is emitted along the dipole axis. In the most important experiments of Hertz, elementary dipoles were used both for emitting and receiving electromagnetic waves, and the existence of electromagnetic waves was proved.

M. Faraday introduced the concept of a field:

an electrostatic field around a charge at rest

around moving charges (current) there is a magnetic field.

In 1830, M. Faraday discovered the phenomenon of electromagnetic induction: when the magnetic field changes, a vortex electric field arises.

Figure 2.7 - Vortex electric field

where,
- electric field strength vector,
- vector of magnetic induction.

An alternating magnetic field creates a vortex electric field.

In 1862 D.K. Maxwell put forward a hypothesis: when the electric field changes, a vortex magnetic field arises.

The idea of ​​a single electromagnetic field arose.

Figure 2.8 - Unified electromagnetic field.

The alternating electric field creates a vortex magnetic field.

Electromagnetic field- this is a special form of matter - a combination of electric and magnetic fields. Variable electric and magnetic fields exist simultaneously and form a single electromagnetic field. It is material:

It manifests itself in action on both resting and moving charges;

It spreads at a high but finite speed;

It exists independently of our will and desires.

At the charging speed, zero, there is only an electric field. At a constant charge rate, an electromagnetic field is generated.

With the accelerated movement of the charge, an electromagnetic wave is emitted, which propagates in space with a finite speed .

The development of the idea of ​​electromagnetic waves belongs to Maxwell, but Faraday already knew about their existence, although he was afraid to publish the work (it was read more than 100 years after his death).

The main condition for the emergence of an electromagnetic wave is the accelerated movement of electric charges.

What is an electromagnetic wave, it is easy to imagine the following example. If you throw a pebble on the surface of the water, then waves diverging in circles are formed on the surface. They move from the source of their occurrence (perturbation) with a certain speed of propagation. For electromagnetic waves, disturbances are electric and magnetic fields moving in space. A time-varying electromagnetic field necessarily causes an alternating magnetic field, and vice versa. These fields are interconnected.

The main source of the spectrum of electromagnetic waves is the Sun star. Part of the spectrum of electromagnetic waves sees the human eye. This spectrum lies within 380...780 nm (Fig. 2.1). In the visible spectrum, the eye perceives light differently. Electromagnetic oscillations with different wavelengths cause the sensation of light with different colors.

Figure 2.9 - Spectrum of electromagnetic waves

Part of the spectrum of electromagnetic waves is used for the purposes of radio and television broadcasting and communications. The source of electromagnetic waves is a wire (antenna) in which oscillation occurs electric charges. The process of formation of fields, which began near the wire, gradually, point by point, captures the entire space. The higher the frequency alternating current passing through the wire and generating an electric or magnetic field, the more intense the radio waves of a given length created by the wire.

Radio(lat. radio - emit, emit rays ← radius - beam) - a type of wireless communication in which radio waves freely propagating in space are used as a signal carrier.

radio waves(from radio...), electromagnetic waves with a wavelength > 500 µm (frequency< 6×10 12 Гц).

Radio waves are electric and magnetic fields that change over time. The speed of propagation of radio waves in free space is 300,000 km/s. Based on this, you can determine the length of the radio wave (m).

λ=300/f, where f - frequency (MHz)

The sound vibrations of the air created during a telephone conversation are converted by a microphone into electrical vibrations of sound frequency, which are transmitted by wires to the subscriber's equipment. There, at the other end of the line, with the help of the phone's emitter, they are converted into air vibrations perceived by the subscriber as sounds. In telephony, the means of communication are wires; in radio broadcasting, radio waves.

The "heart" of the transmitter of any radio station is a generator - a device that generates oscillations of a high, but strictly constant frequency for a given radio station. These radio frequency oscillations, amplified to the required power, enter the antenna and excite in the surrounding space electromagnetic oscillations of exactly the same frequency - radio waves. The speed of removal of radio waves from the antenna of the radio station is equal to the speed of light: 300,000 km / s, which is almost a million times faster than the propagation of sound in air. This means that if a transmitter was turned on at a certain moment in time at the Moscow Broadcasting Station, then its radio waves would reach Vladivostok in less than 1/30 s, and the sound during this time would have time to propagate only 10-11 m.

Radio waves propagate not only in the air, but also where there is none, for example, in outer space. In this they differ from sound waves, for which air or some other dense medium, such as water, is absolutely necessary.

electromagnetic wave is an electromagnetic field propagating in space (oscillations of vectors
). Near the charge, the electric and magnetic fields change with a phase shift p/2.

Figure 2.10 - Unified electromagnetic field.

At a large distance from the charge, the electric and magnetic fields change in phase.

Figure 2.11 - In-phase change in electric and magnetic fields.

The electromagnetic wave is transverse. The direction of the speed of the electromagnetic wave coincides with the direction of movement of the right screw when turning the handle of the vector gimlet to the vector .

Figure 2.12 - Electromagnetic wave.

Moreover, in an electromagnetic wave, the relation
, where c is the speed of light in vacuum.

Maxwell theoretically calculated the energy and speed of electromagnetic waves.

Thus, wave energy is directly proportional to the fourth power of frequency. This means that in order to more easily fix the wave, it is necessary that it be of high frequency.

Electromagnetic waves were discovered by G. Hertz (1887).

A closed oscillatory circuit does not radiate electromagnetic waves: all the energy of the electric field of the capacitor is converted into the energy of the magnetic field of the coil. The oscillation frequency is determined by the parameters of the oscillatory circuit:
.

Figure 2.13 - Oscillatory circuit.

To increase the frequency, it is necessary to decrease L and C, i.e. turn the coil to a straight wire and, as
, reduce the area of ​​​​the plates and spread them to the maximum distance. This shows that we get, in essence, a straight conductor.

Such a device is called a Hertz vibrator. The middle is cut and connected to a high frequency transformer. Between the ends of the wires, on which small spherical conductors are fixed, an electric spark jumps, which is the source of the electromagnetic wave. The wave propagates in such a way that the electric field strength vector oscillates in the plane in which the conductor is located.

Figure 2.14 - Hertz vibrator.

If the same conductor (antenna) is placed parallel to the emitter, then the charges in it will oscillate and weak sparks will jump between the conductors.

Hertz discovered electromagnetic waves in an experiment and measured their speed, which coincided with the one calculated by Maxwell and equal to c=3. 10 8 m/s.

An alternating electric field generates an alternating magnetic field, which, in turn, generates an alternating electric field, that is, an antenna that excites one of the fields causes the appearance of a single electromagnetic field. The most important property of this field is that it propagates in the form of electromagnetic waves.

The propagation velocity of electromagnetic waves in a lossless medium depends on the relatively dielectric and magnetic permeability of the medium. For air, the magnetic permeability of the medium is equal to one, therefore, the speed of propagation of electromagnetic waves in this case is equal to the speed of light.

The antenna can be a vertical wire powered by a high frequency generator. The generator expends energy to accelerate the movement of free electrons in the conductor, and this energy is converted into an alternating electromagnetic field, that is, electromagnetic waves. The higher the generator current frequency, the faster the electromagnetic field changes and the more intense the wave healing.

Connected to the antenna wire are both an electric field, the lines of force of which begin at positive and end at negative charges, and a magnetic field, the lines of which close around the current of the wire. The shorter the oscillation period, the less time remains for the energy of the bound fields to return to the wire (that is, to the generator) and the more it passes into free fields, which propagate further in the form of electromagnetic waves. Effective radiation of electromagnetic waves occurs under the condition of commensurability of the wavelength and the length of the radiating wire.

Thus, it can be determined that radio wave- this is an electromagnetic field not associated with the emitter and channel-forming devices, freely propagating in space in the form of a wave with an oscillation frequency of 10 -3 to 10 12 Hz.

Oscillations of electrons in the antenna are created by a source of periodically changing EMF with a period T. If at some moment the field at the antenna had a maximum value, then it will have the same value after a while T. During this time, the electromagnetic field that existed at the initial moment at the antenna will move to a distance

λ = υТ (1)

The minimum distance between two points in space where the field has the same value is called wavelength. As follows from (1), the wavelength λ depends on the speed of its propagation and the period of oscillation of the electrons in the antenna. As frequency current f = 1 / T, then the wavelength λ = υ / f .

The radio link includes the following main parts:

Transmitter

Receiver

The medium in which radio waves propagate.

The transmitter and receiver are controllable elements of the radio link, since it is possible to increase the transmitter power, connect a more efficient antenna, and increase the sensitivity of the receiver. The medium is an uncontrolled element of the radio link.

The difference between a radio communication line and wired lines is that wired lines use wires or cables as a connecting link, which are controlled elements (you can change their electrical parameters).

Electromagnetic waves, according to physics, are among the most mysterious. In them, the energy actually disappears into nowhere, appears from nowhere. There is no other similar object in all of science. How do all these miraculous transformations take place?

Maxwell electrodynamics

It all started with the fact that the scientist Maxwell back in 1865, relying on the work of Faraday, derived the equation of the electromagnetic field. Maxwell himself believed that his equations described the torsion and tension of waves in the ether. Twenty-three years later, Hertz experimentally created such perturbations in the medium, and succeeded not only in reconciling them with the equations of electrodynamics, but also in obtaining the laws governing the propagation of these perturbations. A curious tendency has arisen to declare any perturbations that are electromagnetic in nature as Hertzian waves. However, these radiations are not the only way to carry out energy transfer.

Wireless connection

To date, to options implementation of such wireless communication include:

Electrostatic coupling, also called capacitive;

induction;

current;

Tesla connection, that is, the connection of electron density waves along conductive surfaces;

The widest range of the most common carriers, which are called electromagnetic waves - from ultra-low frequencies to gamma radiation.

It is worth considering these types of connections in more detail.

Electrostatic bond

The two dipoles are coupled electrical forces in space, which is a consequence of Coulomb's law. From electromagnetic waves given type communication is distinguished by the ability to connect dipoles when they are located on the same line. With increasing distances, the strength of the connection attenuates, and a strong influence of various interferences is also observed.

inductive coupling

Based on magnetic stray fields of inductance. Observed between objects that have inductance. Its application is quite limited due to short-range action.

Current connection

Due to the spreading currents in a conducting medium, a certain interaction can occur. If currents are passed through the terminals (a pair of contacts), then these same currents can be detected at a considerable distance from the contacts. This is what is called the effect of current spreading.

Tesla connection

The famous physicist Nikola Tesla invented communication using waves on a conductive surface. If in some place of the plane the density of the charge carrier is disturbed, then these carriers will begin to move, which will tend to restore equilibrium. Since the carriers have an inertial nature, the recovery has a wave character.

Electromagnetic connection

The radiation of electromagnetic waves is distinguished by a huge long-range action, since their amplitude is inversely proportional to the distance to the source. It is this method of wireless communication that is most widely used. But what are electromagnetic waves? First you need to make a short digression into the history of their discovery.

How did electromagnetic waves "appear"?

It all started in 1829, when the American physicist Henry discovered perturbations in electrical discharges in experiments with Leyden jars. In 1832, the physicist Faraday suggested the existence of such a process as electromagnetic waves. Maxwell created his famous equations of electromagnetism in 1865. At the end of the nineteenth century, there were many successful attempts to create wireless communication using electrostatic and electromagnetic induction. The famous inventor Edison came up with a system that allowed passengers railway send and receive telegrams while the train is moving. In 1888, G. Hertz unequivocally proved that electromagnetic waves appear using a device called a vibrator. Hertz carried out an experiment on the transmission of an electromagnetic signal over a distance. In 1890, French engineer and physicist Branly invented a device for recording electromagnetic radiation. Subsequently, this device was called the "radio conductor" (coherer). In 1891-1893, Nikola Tesla described the basic principles for the implementation of signal transmission over long distances and patented a mast antenna, which was a source of electromagnetic waves. Further merits in the study of waves and the technical implementation of their production and application belong to such famous physicists and inventors as Popov, Marconi, de Maur, Lodge, Mirhead and many others.

The concept of "electromagnetic wave"

An electromagnetic wave is a phenomenon that propagates in space with a certain finite speed and is an alternating electric and magnetic field. Since magnetic and electric fields are inextricably linked with each other, they form an electromagnetic field. It can also be said that an electromagnetic wave is a perturbation of the field, and during its propagation, the energy that the magnetic field has is converted into the energy of the electric field and vice versa, according to Maxwell's electrodynamics. Outwardly, this is similar to the propagation of any other wave in any other medium, but there are also significant differences.

What is the difference between electromagnetic waves and others?

The energy of electromagnetic waves propagates in a rather incomprehensible medium. To compare these waves and any others, it is necessary to understand what propagation medium in question. It is assumed that the intra-atomic space is filled with electric ether - a specific medium, which is an absolute dielectric. All waves during propagation show the transition of kinetic energy into potential energy and vice versa. At the same time, these energies have shifted the maximum in time and space relative to each other by one fourth full period waves. In this case, the average wave energy, being the sum of the potential and kinetic energy is a constant. But with electromagnetic waves, the situation is different. The energies of both the magnetic and electric fields reach their maximum values ​​simultaneously.

How is an electromagnetic wave generated?

The matter of an electromagnetic wave is an electric field (ether). The moving field is structured and consists of the energy of its movement and the electric energy of the field itself. So potential energy waves associated with the kinetic and in-phase. The nature of an electromagnetic wave is a periodic electric field that is in a state forward movement in space and moving with the speed of light.

Displacement currents

There is another way to explain what electromagnetic waves are. It is assumed that displacement currents arise in the ether during the movement of inhomogeneous electric fields. They arise, of course, only for a stationary outside observer. At the moment when such a parameter as the electric field strength reaches its maximum, the displacement current at a given point in space will stop. Accordingly, at a minimum of tension, the reverse picture is obtained. This approach clarifies the wave nature electromagnetic radiation, since the energy of the electric field is shifted by one-fourth of the period with respect to the displacement currents. Then we can say that the electrical disturbance, or rather the energy of the disturbance, is transformed into the energy of the displacement current and vice versa and propagates in a wave manner in a dielectric medium.