Radiation is a physical process that results in the transfer of energy using electromagnetic waves. The reverse process of radiation is called absorption. Let us consider this issue in more detail, and also give examples of radiation in everyday life and nature.
Physics of radiation occurrence
Any body consists of atoms, which, in turn, are formed by nuclei, charged positively, and electrons, which form electron shells around the nuclei and are negatively charged. Atoms are designed in such a way that they can be in different energy states, that is, they can have both higher and lower energy. When an atom has the lowest energy, we speak of its ground state; any other energy state of the atom is called excited.
The existence of different energy states of an atom is due to the fact that its electrons can be located at certain energy levels. When an electron moves from a higher level to a lower one, the atom loses energy, which it emits into the surrounding space in the form of a photon, the carrier particle of electromagnetic waves. On the contrary, the transition of an electron from a lower to a higher level is accompanied by the absorption of a photon.
There are several ways to transfer an electron of an atom to a higher energy level, which involve the transfer of energy. This can be either the impact of external electromagnetic radiation on the atom in question, or the transfer of energy to it by mechanical or electrical means. In addition, atoms can receive and then release energy through chemical reactions.
Electromagnetic spectrum
Before moving on to examples of radiation in physics, it should be noted that each atom emits certain portions of energy. This happens because the states in which an electron can be in an atom are not arbitrary, but strictly defined. Accordingly, the transition between these states is accompanied by the emission of a certain amount of energy.
It is known from atomic physics that photons generated as a result of electronic transitions in an atom have energy that is directly proportional to their oscillation frequency and inversely proportional to the wavelength (a photon is an electromagnetic wave, which is characterized by propagation speed, length and frequency). Since an atom of a substance can only emit a certain set of energies, this means that the wavelengths of the emitted photons are also specific. The set of all these lengths is called the electromagnetic spectrum.
If the wavelength of a photon lies between 390 nm and 750 nm, then we speak of visible light, since a person can perceive it with his own eyes; if the wavelength is less than 390 nm, then such electromagnetic waves have high energy and are called ultraviolet, x-ray or gamma radiation. For lengths greater than 750 nm, photons have low energy and are called infrared, micro- or radio radiation.
Thermal radiation of bodies
Any body that has some temperature different from absolute zero emits energy, in this case we talk about thermal or temperature radiation. In this case, temperature determines both the electromagnetic spectrum of thermal radiation and the amount of energy emitted by the body. The higher the temperature, the more energy the body emits into the surrounding space, and the more its electromagnetic spectrum shifts to the high-frequency region. Thermal radiation processes are described by the Stefan-Boltzmann, Planck and Wien laws.
Examples of radiation in everyday life
As was said above, absolutely any body emits energy in the form of electromagnetic waves, but this process cannot always be seen with the naked eye, since the temperatures of the bodies around us are usually too low, so their spectrum lies in a low-frequency region invisible to humans.
A striking example of radiation in the visible range is an electric incandescent lamp. Passing along a spiral, the electric current heats the tungsten filament to 3000 K. Such a high temperature leads to the fact that the filament begins to emit electromagnetic waves, the maximum of which falls on the long-wavelength part of the visible spectrum.
Another example of radiation in everyday life is a microwave oven, which emits microwaves that are invisible to the human eye. These waves are absorbed by objects containing water, thereby increasing their kinetic energy and, as a result, temperature.
Finally, an example of radiation in the infrared range in everyday life is the radiator of a heating battery. We do not see its radiation, but we feel this heat.
Natural emitting objects
Perhaps the most striking example of radiation in nature is our star - the Sun. The temperature on the surface of the Sun is about therefore its maximum radiation occurs at a wavelength of 475 nm, that is, it lies within the visible spectrum.
The sun heats up the planets around it and their satellites, which also begin to glow. Here it is necessary to distinguish between reflected light and thermal radiation. Thus, our Earth can be seen from space in the form of a blue ball precisely due to reflected sunlight. If we talk about the thermal radiation of the planet, then it also occurs, but lies in the region of the microwave spectrum (about 10 microns).
Besides reflected light, it is interesting to give another example of radiation in nature, which is associated with crickets. The visible light they emit has nothing to do with thermal radiation and is the result of a chemical reaction between atmospheric oxygen and luciferin (a substance found in insect cells). This phenomenon is called bioluminescence.
Ionizing radiation (hereinafter referred to as IR) is radiation whose interaction with matter leads to the ionization of atoms and molecules, i.e. this interaction leads to the excitation of the atom and the separation of individual electrons (negatively charged particles) from atomic shells. As a result, deprived of one or more electrons, the atom turns into a positively charged ion - primary ionization occurs. II includes electromagnetic radiation (gamma radiation) and flows of charged and neutral particles - corpuscular radiation (alpha radiation, beta radiation, and neutron radiation).
Alpha radiation refers to corpuscular radiation. This is a stream of heavy positively charged alpha particles (nuclei of helium atoms) resulting from the decay of atoms of heavy elements such as uranium, radium and thorium. Since the particles are heavy, the range of alpha particles in a substance (that is, the path along which they produce ionization) turns out to be very short: hundredths of a millimeter in biological media, 2.5-8 cm in air. Thus, a regular sheet of paper or the outer dead layer of skin can trap these particles.
However, substances that emit alpha particles are long-lived. As a result of such substances entering the body with food, air or through wounds, they are carried throughout the body by the bloodstream, deposited in organs responsible for metabolism and protection of the body (for example, the spleen or lymph nodes), thus causing internal irradiation of the body . The danger of such internal irradiation of the body is high, because these alpha particles create a very large number of ions (up to several thousand pairs of ions per 1 micron of path in tissues). Ionization, in turn, determines a number of features of those chemical reactions that occur in matter, in particular in living tissue (the formation of strong oxidizing agents, free hydrogen and oxygen, etc.).
Beta radiation(beta rays, or stream of beta particles) also refers to the corpuscular type of radiation. This is a stream of electrons (β- radiation, or, most often, just β-radiation) or positrons (β+ radiation) emitted during the radioactive beta decay of the nuclei of certain atoms. Electrons or positrons are produced in the nucleus when a neutron converts to a proton or a proton to a neutron, respectively.
Electrons are significantly smaller than alpha particles and can penetrate 10-15 centimeters deep into a substance (body) (cf. hundredths of a millimeter for alpha particles). When passing through matter, beta radiation interacts with the electrons and nuclei of its atoms, expending its energy on this and slowing down the movement until it stops completely. Due to these properties, to protect against beta radiation, it is enough to have an organic glass screen of appropriate thickness. The use of beta radiation in medicine for superficial, interstitial and intracavitary radiation therapy is based on these same properties.
Neutron radiation- another type of corpuscular type of radiation. Neutron radiation is a flow of neutrons (elementary particles that have no electrical charge). Neutrons do not have an ionizing effect, but a very significant ionizing effect occurs due to elastic and inelastic scattering on the nuclei of matter.
Substances irradiated by neutrons can acquire radioactive properties, that is, receive so-called induced radioactivity. Neutron radiation is generated during the operation of particle accelerators, in nuclear reactors, industrial and laboratory installations, during nuclear explosions, etc. Neutron radiation has the greatest penetrating ability. The best materials for protection against neutron radiation are hydrogen-containing materials.
Gamma rays and x-rays belong to electromagnetic radiation.
The fundamental difference between these two types of radiation lies in the mechanism of their occurrence. X-ray radiation is of extranuclear origin, gamma radiation is a product of nuclear decay.
X-ray radiation was discovered in 1895 by the physicist Roentgen. This is invisible radiation capable of penetrating, although to varying degrees, into all substances. It is electromagnetic radiation with a wavelength of the order of - from 10 -12 to 10 -7. The source of X-rays is an X-ray tube, some radionuclides (for example, beta emitters), accelerators and electron storage devices (synchrotron radiation).
The X-ray tube has two electrodes - the cathode and the anode (negative and positive electrodes, respectively). When the cathode is heated, electron emission occurs (the phenomenon of the emission of electrons by the surface of a solid or liquid). Electrons escaping from the cathode are accelerated by the electric field and strike the surface of the anode, where they are sharply decelerated, resulting in X-ray radiation. Like visible light, X-rays cause photographic film to turn black. This is one of its properties, fundamental for medicine - that it is penetrating radiation and, accordingly, the patient can be illuminated with its help, and since Tissues of different density absorb X-rays differently - we can diagnose many types of diseases of internal organs at a very early stage.
Gamma radiation is of intranuclear origin. It occurs during the decay of radioactive nuclei, the transition of nuclei from an excited state to the ground state, during the interaction of fast charged particles with matter, the annihilation of electron-positron pairs, etc.
The high penetrating power of gamma radiation is explained by its short wavelength. To weaken the flow of gamma radiation, substances with a significant mass number (lead, tungsten, uranium, etc.) and all kinds of high-density compositions (various concretes with metal fillers) are used.
Previously, people, in order to explain what they did not understand, came up with various fantastic things - myths, gods, religion, magical creatures. And although a large number of people still believe in these superstitions, we now know that there is an explanation for everything. One of the most interesting, mysterious and amazing topics is radiation. What is it? What types of it exist? What is radiation in physics? How is it absorbed? Is it possible to protect yourself from radiation?
general information
So, the following types of radiation are distinguished: wave motion of the medium, corpuscular and electromagnetic. Most attention will be paid to the latter. Regarding the wave motion of the medium, we can say that it arises as a result of the mechanical movement of a certain object, which causes a successive rarefaction or compression of the medium. Examples include infrasound or ultrasound. Corpuscular radiation is a flow of atomic particles such as electrons, positrons, protons, neutrons, alpha, which is accompanied by natural and artificial decay of nuclei. Let's talk about these two for now.
Influence
Let's consider solar radiation. This is a powerful healing and preventive factor. The set of accompanying physiological and biochemical reactions that occur with the participation of light is called photobiological processes. They take part in the synthesis of biologically important compounds, serve to obtain information and orientation in space (vision), and can also cause harmful consequences, such as the appearance of harmful mutations, the destruction of vitamins, enzymes, and proteins.
About electromagnetic radiation
In the future, the article will be devoted exclusively to him. What does radiation do in physics, how does it affect us? EMR is electromagnetic waves that are emitted by charged molecules, atoms, and particles. Large sources can be antennas or other radiating systems. The wavelength of the radiation (oscillation frequency) together with the sources is of decisive importance. So, depending on these parameters, gamma, x-ray, and optical radiation are distinguished. The latter is divided into a number of other subspecies. So, this is infrared, ultraviolet, radio radiation, as well as light. The range is up to 10 -13. Gamma radiation is generated by excited atomic nuclei. X-rays can be obtained by decelerating accelerated electrons, as well as by their transition from non-free levels. Radio waves leave their mark as they move alternating electric currents along the conductors of radiating systems (for example, antennas).
About ultraviolet radiation
Biologically, UV rays are the most active. If they come into contact with the skin, they can cause local changes in tissue and cellular proteins. In addition, the effect on skin receptors is recorded. It affects the whole organism in a reflex way. Since it is a nonspecific stimulator of physiological functions, it has a beneficial effect on the body’s immune system, as well as on mineral, protein, carbohydrate and fat metabolism. All this manifests itself in the form of a general health-improving, tonic and preventive effect of solar radiation. It is worth mentioning some specific properties that a certain wave range has. Thus, the influence of radiation on a person with a length of 320 to 400 nanometers contributes to the erythema-tanning effect. In the range from 275 to 320 nm, weakly bactericidal and antirachitic effects are recorded. But ultraviolet radiation from 180 to 275 nm damages biological tissue. Therefore, caution should be exercised. Prolonged direct solar radiation, even in the safe spectrum, can lead to severe erythema with swelling of the skin and a significant deterioration in health. Up to increasing the likelihood of developing skin cancer.
Reaction to sunlight
First of all, infrared radiation should be mentioned. It has a thermal effect on the body, which depends on the degree of absorption of rays by the skin. The word “burn” is used to describe its effect. The visible spectrum affects the visual analyzer and the functional state of the central nervous system. And through the central nervous system and onto all human systems and organs. It should be noted that we are influenced not only by the degree of illumination, but also by the color range of sunlight, that is, the entire spectrum of radiation. Thus, color perception depends on the wavelength and influences our emotional activity, as well as the functioning of various body systems.
Red color excites the psyche, enhances emotions and gives a feeling of warmth. But it quickly tires, contributes to muscle tension, increased breathing and increased blood pressure. Orange evokes a feeling of well-being and cheerfulness, while yellow lifts the mood and stimulates the nervous system and vision. Green is calming, useful during insomnia, fatigue, and improves the overall tone of the body. The color violet has a relaxing effect on the psyche. Blue calms the nervous system and keeps muscles toned.
A small retreat
Why, when considering what radiation is in physics, do we talk mostly about EMR? The fact is that this is precisely what is meant in most cases when the topic is addressed. The same corpuscular radiation and wave motion of the medium is an order of magnitude smaller in scale and known. Very often, when they talk about types of radiation, they mean exclusively those into which EMR is divided, which is fundamentally wrong. After all, when talking about what radiation is in physics, attention should be paid to all aspects. But at the same time, emphasis is placed on the most important points.
About radiation sources
We continue to consider electromagnetic radiation. We know that it represents waves that arise when an electric or magnetic field is disturbed. This process is interpreted by modern physics from the point of view of the theory of wave-particle duality. Thus, it is recognized that the minimum portion of EMR is a quantum. But at the same time, it is believed that it also has frequency-wave properties, on which the main characteristics depend. To improve the ability to classify sources, different emission spectra of EMR frequencies are distinguished. So this:
- Hard radiation (ionized);
- Optical (visible to the eye);
- Thermal (aka infrared);
- Radio frequency.
Some of them have already been considered. Each radiation spectrum has its own unique characteristics.
Nature of the sources
Depending on their origin, electromagnetic waves can arise in two cases:
- When there is a disturbance of artificial origin.
- Registration of radiation coming from a natural source.
What can you say about the first ones? Artificial sources most often represent a side effect that occurs as a result of the operation of various electrical devices and mechanisms. Radiation of natural origin generates the Earth’s magnetic field, electrical processes in the planet’s atmosphere, and nuclear fusion in the depths of the sun. The degree of electromagnetic field strength depends on the power level of the source. Conventionally, the radiation that is recorded is divided into low-level and high-level. The first ones include:
- Almost all devices equipped with a CRT display (such as a computer).
- Various household appliances, from climate control systems to irons;
- Engineering systems that provide electricity supply to various objects. Examples include power cables, sockets, and electricity meters.
High-level electromagnetic radiation is produced by:
- Power lines.
- All electric transport and its infrastructure.
- Radio and television towers, as well as mobile and mobile communication stations.
- Elevators and other lifting equipment using electromechanical power plants.
- Network voltage conversion devices (waves emanating from a distribution substation or transformer).
Separately, there is special equipment that is used in medicine and emits hard radiation. Examples include MRI, X-ray machines and the like.
The influence of electromagnetic radiation on humans
In the course of numerous studies, scientists have come to the sad conclusion that long-term exposure to EMR contributes to a real explosion of diseases. However, many disorders occur at the genetic level. Therefore, protection against electromagnetic radiation is relevant. This is due to the fact that EMR has a high level of biological activity. In this case, the result of the influence depends on:
- The nature of the radiation.
- Duration and intensity of influence.
Specific moments of influence
It all depends on the localization. Absorption of radiation can be local or general. An example of the second case is the effect that power lines have. An example of local exposure is the electromagnetic waves emitted by a digital watch or mobile phone. Thermal effects should also be mentioned. Due to the vibration of molecules, the field energy is converted into heat. Microwave emitters operate on this principle and are used to heat various substances. It should be noted that when influencing a person, the thermal effect is always negative, and even harmful. It should be noted that we are constantly exposed to radiation. At work, at home, moving around the city. Over time, the negative effect only intensifies. Therefore, protection against electromagnetic radiation is becoming increasingly important.
How can you protect yourself?
Initially, you need to know what you are dealing with. A special device for measuring radiation will help with this. It will allow you to assess the security situation. In production, absorbent screens are used for protection. But, alas, they are not designed for use at home. To get started, here are three tips you can follow:
- You should stay at a safe distance from devices. For power lines, television and radio towers, this is at least 25 meters. With CRT monitors and televisions, thirty centimeters is enough. Electronic watches should be no closer than 5 cm. And it is not recommended to bring radios and cell phones closer than 2.5 centimeters. You can select a location using a special device - a flux meter. The permissible dose of radiation recorded by it should not exceed 0.2 µT.
- Try to reduce the time you have to be exposed to radiation.
- You should always turn off electrical appliances when not in use. After all, even when inactive, they continue to emit EMR.
About the silent killer
And we will conclude the article with an important, although rather poorly known in wide circles, topic - radiation. Throughout his life, development and existence, man was irradiated by natural background. Natural radiation can be roughly divided into external and internal exposure. The first includes cosmic radiation, solar radiation, the influence of the earth's crust and air. Even the building materials from which houses and structures are created generate a certain background.
Radiation has a significant penetrating force, so stopping it is problematic. So, in order to completely isolate the rays, you need to hide behind a lead wall 80 centimeters thick. Internal radiation occurs when natural radioactive substances enter the body along with food, air, and water. Radon, thoron, uranium, thorium, rubidium, and radium can be found in the bowels of the earth. All of them are absorbed by plants, can be in water - and when eaten, they enter our body.
Radiation, in its most general form, can be imagined as the emergence and propagation of waves, leading to field disturbance. The propagation of energy is expressed in the form of electromagnetic, ionizing, gravitational and Hawking radiation. Electromagnetic waves are disturbances of the electromagnetic field. They are radio wave, infrared (thermal radiation), terahertz, ultraviolet, x-ray and visible (optical). An electromagnetic wave has the property of propagating in any medium. The characteristics of electromagnetic radiation are frequency, polarization and length. The science of quantum electrodynamics studies the nature of electromagnetic radiation most professionally and deeply. It made it possible to confirm a number of theories that are widely used in various fields of knowledge. Features of electromagnetic waves: mutual perpendicularity of three vectors - wave, and electric field and magnetic field strength; the waves are transverse, and the tension vectors in them oscillate perpendicular to the direction of its propagation.
Thermal radiation arises due to the internal energy of the body itself. Thermal radiation is radiation of a continuous spectrum, the maximum of which corresponds to body temperature. If radiation and matter are thermodynamic, the radiation is equilibrium. This is described by Planck's law. But in practice, thermodynamic equilibrium is not observed. Thus, a hotter body tends to cool down, and a colder body, on the contrary, tends to heat up. This interaction is defined in Kirchhoff's law. Thus, bodies have absorptive capacity and reflective capacity. Ionizing radiation is microparticles and fields that have the ability to ionize matter. This includes: X-rays and radioactive radiation with alpha, beta and gamma rays. In this case, X-ray radiation and gamma rays are short-wavelength. And beta and alpha particles are streams of particles. There are natural and artificial sources of ionization. In nature, these are: the decay of radionuclides, rays of space, thermonuclear reaction in the Sun. Artificial ones are: radiation from an X-ray machine, nuclear reactors and artificial radionuclides. In everyday life, special sensors and dosimeters of radioactive radiation are used. The well-known Geiger Counter is capable of correctly identifying only gamma rays. In science, scintillators are used, which perfectly separate rays by energy.
Gravitational radiation is considered to be radiation in which the space-time field is disturbed at the speed of light. In general relativity, gravitational radiation is caused by Einstein's equations. What is characteristic is that gravity is inherent in any matter that moves at an accelerated rate. But a gravitational wave can only be given a greater amplitude by emitting a large mass. Typically, gravitational waves are very weak. A device capable of registering them is a detector. Hawking radiation is more of a hypothetical possibility of particles being emitted by a black hole. Quantum physics studies these processes. According to this theory, a black hole only absorbs matter up to a certain point. When taking into account quantum moments, it turns out that it is capable of emitting elementary particles.
Today we’ll talk about what radiation is in physics. Let's talk about the nature of electronic transitions and give an electromagnetic scale.
Deity and atom
The structure of matter became a subject of interest to scientists more than two thousand years ago. Ancient Greek philosophers asked questions about how air differs from fire, and earth from water, why marble is white and coal is black. They created complex systems of interdependent components, refuted or supported each other. And the most incomprehensible phenomena, for example, a lightning strike or sunrise, were attributed to the action of the gods.
Once, after observing the steps of the temple for many years, one scientist noticed: each foot that stands on a stone carries away a tiny particle of matter. Over time, the marble changed shape and sagged in the middle. The name of this scientist is Leucippus, and he called the smallest particles atoms, indivisible. This began the path to studying what radiation is in physics.
Easter and light
Then dark times came and science was abandoned. All who tried to study the forces of nature were dubbed witches and sorcerers. But, oddly enough, it was religion that gave impetus to the further development of science. The study of what radiation is in physics began with astronomy.
The time for celebrating Easter was calculated differently each time in those days. The complex system of relationships between the vernal equinox, the 26-day lunar cycle and the 7-day week prevented the compilation of date tables for the celebration of Easter for more than a couple of years. But the church had to plan everything in advance. Therefore, Pope Leo X ordered the compilation of more accurate tables. This required careful observation of the movements of the Moon, stars and Sun. And in the end, Nicolaus Copernicus realized: the Earth is not flat and not the center of the universe. A planet is a ball that revolves around the Sun. And the Moon is a sphere in Earth's orbit. Of course, one might ask, “What does all this have to do with what radiation is in physics?” Let's reveal it now.
Oval and beam
Later, Kepler supplemented the Copernican system by establishing that the planets move in oval orbits, and this movement is uneven. But it was precisely that first step that instilled in humanity an interest in astronomy. And there it was not far from the questions: “What is a star?”, “Why do people see its rays?” and “How does one luminary differ from another?” But first you will have to move from huge objects to the smallest. And then we come to radiation, a concept in physics.
Atom and raisin
At the end of the nineteenth century, sufficient knowledge had accumulated about the smallest chemical units of matter - atoms. They were known to be electrically neutral, but to contain both positively and negatively charged elements.
Many assumptions have been made: that positive charges are distributed in a negative field, like raisins in a bun, and that an atom is a drop of dissimilarly charged liquid parts. But Rutherford's experience clarified everything. He proved that at the center of the atom there is a positive heavy nucleus, and around it there are light negative electrons. And the configuration of the shells is different for each atom. This is where the peculiarities of radiation in the physics of electronic transitions lie.
Boron and orbit
When scientists found out that the light negative parts of the atom are electrons, another question arose - why they do not fall onto the nucleus. After all, according to Maxwell’s theory, any moving charge radiates, and therefore loses energy. But atoms existed as long as the universe, and were not going to annihilate. Bohr came to the rescue. He postulated that electrons are in certain stationary orbits around the atomic nucleus, and can only be in them. The transition of an electron between orbits is carried out by a jerk with the absorption or emission of energy. This energy could be, for example, a quantum of light. In essence, we have now outlined the definition of radiation in particle physics.
Hydrogen and photography
Initially, photography technology was invented as a commercial project. People wanted to remain for centuries, but not everyone could afford to order a portrait from an artist. And photographs were cheap and did not require such a large investment. Then the art of glass and silver nitrate put military affairs into its service. And then science began to take advantage of photosensitive materials.
Spectra were photographed first. It has long been known that hot hydrogen emits specific lines. The distance between them obeyed a certain law. But the spectrum of helium was more complex: it contained the same set of lines as hydrogen, and one more. The second series no longer obeyed the law derived for the first series. Here Bohr's theory came to the rescue.
It turned out that there is only one electron in a hydrogen atom, and it can move from all higher excited orbits to one lower one. This was the first series of lines. Heavier atoms are more complex.
Lens, grating, spectrum
This marked the beginning of the use of radiation in physics. Spectral analysis is one of the most powerful and reliable ways to determine the composition, quantity and structure of a substance.
- The electron emission spectrum will tell you what is contained in the object and what the percentage of a particular component is. This method is used in absolutely all areas of science: from biology and medicine to quantum physics.
- The absorption spectrum will tell you which ions and in which positions are present in the lattice of the solid.
- The rotational spectrum will demonstrate how far apart the molecules are inside the atom, how many and what kind of bonds each element has.
And the ranges of application of electromagnetic radiation are countless:
- radio waves explore the structure of very distant objects and the interior of planets;
- thermal radiation will tell about the energy of processes;
- visible light will tell you in which directions the brightest stars lie;
- ultraviolet rays will make it clear that high-energy interactions are occurring;
- The X-ray spectrum itself allows people to study the structure of matter (including the human body), and the presence of these rays in cosmic objects will notify scientists that there is a neutron star, a supernova explosion or a black hole at the focus of the telescope.
Pure black body
But there is a special section that studies what thermal radiation is in physics. Unlike atomic light, thermal emission of light has a continuous spectrum. And the best model object for calculations is an absolutely black body. This is an object that “catches” all the light falling on it, but does not release it back. Oddly enough, a completely black body emits radiation, and the maximum wavelength will depend on the temperature of the model. In classical physics, thermal radiation gave rise to a paradox. It turned out that any heated thing should radiate more and more energy until, in the ultraviolet range, its energy would destroy the universe.
Max Planck was able to resolve the paradox. He introduced a new quantity, quantum, into the radiation formula. Without giving it any special physical meaning, he discovered a whole world. Now quantization of quantities is the basis of modern science. Scientists realized that fields and phenomena consist of indivisible elements, quanta. This led to deeper studies of matter. For example, the modern world belongs to semiconductors. Previously, everything was simple: metal conducts current, other substances are dielectrics. And substances such as silicon and germanium (semiconductors) behave incomprehensibly in relation to electricity. To learn how to control their properties, it was necessary to create an entire theory and calculate all the possibilities of p-n junctions.
