UNIVERSITY OF TECHNOLOGY

Named after K.E. Ts I O L K O V S K O G O

Department: General Chemistry, Physics and Chemistry of Composite Materials

ESSAY

Discipline: Concept of Modern Natural Science

Theme:Physical picture of the world

Student: Pavel Dmitrievich Kakorin

Group: 6MEN-1DB-242

Supervisor: A. L. Kachalina

Moscow, 2012

Physical picture of the world

The concept of the physical picture of the world

Knowing the world around, a person creates in his consciousness a certain model of it - a picture of the world. At each stage of its development, humanity has a different idea of the world in which it lives. Therefore, in the history of mankind, there were different pictures of the world: mythological, religious, scientific, etc. In addition, as already noted, each separate science can also form its own picture of the world (physical, chemical, biological, etc.). However, of all the variety of pictures of the world that exist in modern science, the broadest idea is given by the general scientific picture of the world, which describes nature, society and man.

The scientific picture of the world is formed on the basis of the achievements of natural, social and humanitarian sciences, but its foundation, no doubt, is natural science. The importance of natural science in the formation of a scientific picture of the world is so great that often the scientific picture of the world is reduced to natural science, the content of which is made up of pictures of the world of individual natural sciences.

The natural-scientific picture of the world is a systematized and reliable knowledge about nature, historically formed in the course of the development of natural science. This picture of the world includes knowledge obtained from all natural sciences, including their fundamental ideas and theories. At the same time, the history of science testifies that most of the content of natural science is predominantly physical knowledge. It is physics that has been and remains the most developed and systematized natural science. The contribution of other natural sciences to the formation of the scientific picture of the world was much less. Therefore, when the world outlook of European civilization, the New Age arose and the classical natural-scientific picture of the world was formed, it was natural to turn to physics, its concepts and arguments, which largely determined this picture. The degree of development of physics was so great that it was able to create its own physical picture of the world, in contrast to other natural sciences, which only in the XX century. set themselves this task and were able to solve it.

Therefore, starting a conversation about the most important and significant scientific concepts in modern natural science, we will start it with physics and the picture of the world created by this science.

Physics is a science that studies the simplest and at the same time the most general laws of nature, the properties and structure of matter and the laws of its motion. In any phenomenon, physics is looking for something that unites it with all other natural phenomena. Therefore, the concepts and laws of physics are fundamental, i.e. are fundamental to all natural science.

The very word "physics" comes from the Greek - nature. This science arose in antiquity and initially covered the entire body of knowledge about natural phenomena. In other words, then physics was identical to all natural science. Only by the era of Hellenism, with the differentiation of knowledge and research methods, separate natural sciences, including physics, emerged from the general science of nature.

At its core, physics is an experimental science: its laws are based on empirically established facts. This is how it has become since the New Time. But, in addition to experimental physics, they also distinguish between theoretical physics, the purpose of which is to formulate the laws of nature. Experimental and theoretical physics cannot exist without each other.

In accordance with the diversity of the studied physical objects, levels of organization and forms of movement, modern physics is subdivided into a number of disciplines, one way or another related to each other. Depending on the studied physical objects, physics is divided into the physics of elementary particles, the physics of the nucleus, the physics of atoms and molecules, gases and liquids, solids and plasma. According to the criterion of the levels of organization of matter, the physics of the micro-, macro- and megaworld is distinguished. By the nature of the studied processes, phenomena and forms of motion (interaction), mechanical, electromagnetic, quantum and gravitational phenomena, thermal and thermodynamic processes and the corresponding fields of physics are distinguished: mechanics, electrodynamics, quantum physics, the theory of gravity, thermodynamics and statistical physics.

In addition, modern physics contains a small number of fundamental theories covering all branches of physical knowledge. These theories represent a set of the most important knowledge about the nature of physical processes and phenomena, an approximate, but most complete reflection of various forms of motion of matter in nature.

Concept "Physical picture of the world * has been used in natural science for a long time, but only recently it began to be considered not only as a result of the development of physical knowledge, but also as a special independent type of knowledge - the most general theoretical knowledge in physics, a system of concepts, principles and hypotheses that serve as the initial basis for constructing theories. The physical picture of the world, on the one hand, generalizes all previously obtained knowledge about nature, and on the other hand, introduces into physics new philosophical ideas and the concepts, principles and hypotheses caused by them, which did not exist before and which radically change the foundations of physical theoretical knowledge ... In other words, the physical picture of the world is considered as a physical model of nature, which includes fundamental physical and philosophical ideas, physical theories, the most general concepts, principles and methods of cognition, corresponding to a certain historical stage in the development of physics.

The development of physics itself is directly related to the physical picture of the world, since it is a process of formation and change of its various types. The constant development and replacement of some pictures of the world with others, which more adequately reflect the structure and properties of matter, is a process of development of the physical picture of the world itself. The basis for identifying individual types of the physical picture of the world is a qualitative change in fundamental physical ideas, which are the basis for physical theory and our ideas about the structure of matter and the forms of its existence. With a change in the physical picture of the world, a new stage in the development of physics begins with a different system of initial concepts, principles, hypotheses and style of thinking, with different epistemological premises. The transition from one stage to another marks a qualitative leap, a revolution in physics, consisting in the collapse of the old picture of the world and the emergence of a new one.

Within each separate stage, the development of physics proceeds in an evolutionary way, without changing the foundations of the picture of the world. It consists in realizing the possibilities of constructing new theories inherent in a given picture of the world. At the same time, it can evolve, be completed, remaining within the framework of certain specific physical concepts of the world. When the key concepts of the picture of the world change, a revolution occurs in physics. Its result is the emergence of a new physical picture of the world.

The explanation of natural phenomena from the point of view of physics is based on fundamental physical concepts and principles. The most general, fundamental concepts of the physical description of nature include matter, movement, physical interaction, space and time, cause-and-effect relationships, the place and role of man in the world.

The most important of these is the concept of matter. Therefore, revolutions in physics are always associated with a change in ideas about the structure of matter. This happened twice in the history of physics in modern times. In the XIX century. the transition from the established to the 17th century was completed. atomistic, corpuscular concepts of matter to field (continuous). In the XX century. continual representations have been replaced by modern quantum ones. Therefore, we can talk about three successive physical pictures of the world.

The first physical picture of the world in the history of natural science was a mechanical picture of the world, within which they could not find an explanation for electromagnetic phenomena, and therefore it was supplemented by an electromagnetic picture of the world. However, numerous inexplicable physical phenomena discovered at the end of the 19th century showed the limitations of the electromagnetic picture of the world, which led to the emergence of a quantum field picture of the world.

Mechanical picture of the world

The formation of the mechanical picture of the world took place under the influence of metaphysical materialistic ideas about matter and the forms of its existence. It was based on the ideas and laws of mechanics, which in the 17th century. was the most developed branch of physics. In fact, it was mechanics that was the first fundamental physical theory. Ideas, principles and theories of mechanics were a collection of the most essential knowledge about physical laws, most fully reflected the physical processes in nature. In a broad sense, mechanics studies the mechanical movement of material bodies and the interaction that occurs between them. Mechanical motion is understood as a change over time in the relative position of bodies or particles in space. Examples of mechanical movement in nature are the movement of celestial bodies, vibrations of the earth's crust, air and sea currents, etc. The interactions occurring in the process of mechanical movement are those actions of bodies on each other, as a result of which there is a change in the speeds of movement of these bodies in space or their deformation.

The most important concepts of mechanics as a fundamental physical theory have become a material point - a body, the shapes and sizes of which are not essential in this problem; absolutely rigid body - a body, the distance between any points of which remains unchanged, and its deformation can be neglected. Both types of material bodies are characterized using the following concepts: mass - a measure of the amount of matter; weight - the force with which the body acts on the support. The mass always remains constant, while the weight can change. These concepts are expressed through the following physical quantities: coordinates, impulses, energy, force.

The basis of the mechanical picture of the world was made up of atomism - a theory that the whole world, including man, considered as a set of a huge number of indivisible material particles - atoms. They moved through space and time in accordance with a few laws of mechanics. Matter is a substance consisting of the smallest, indivisible, absolutely solid moving particles (atoms). This is the corpuscular concept of matter.

The laws of mechanics, which governed both the movement of atoms and the movement of any material bodies, were considered the fundamental laws of the universe. Therefore, the key concept of the mechanical picture of the world was the concept of motion, which was understood as mechanical movement. Bodies have an innate intrinsic property to move evenly and rectilinearly, and deviations from this movement are associated with the action of an external force (inertia) on the body. The only form of movement is mechanical movement, i.e. change in body position in space over time. Any movement can be represented as the sum of spatial displacements. The movement was explained on the basis of Newton's three laws. All states of the mechanical motion of bodies in relation to time are, in principle, the same, since time is considered reversible. The laws of higher forms of motion of matter should be reduced to the laws of its simplest form - mechanical motion.

The mechanical picture of the world reduced all the variety of interactions only to the gravitational one, which meant the presence of forces of attraction between any bodies; the magnitude of these forces was determined by the law of universal gravitation. Therefore, knowing the mass of one body and the force of gravity, it is possible to determine the mass of another body. Gravitational forces are universal, i.e. they act always and between any bodies and impart the same acceleration to any bodies.

Solving the problem of the interaction of bodies, Newton proposed the principle of long-range action. According to this principle, the interaction between bodies occurs instantly at any distance, without material intermediaries, i.e. the intermediate environment does not take part in the transfer of interaction.

The concept of action at a distance is closely related to the understanding of space and time as special environments containing interacting bodies. Newton proposed the concept of absolute space and absolute time. Absolute space was represented by a large “black box”, a universal container of all material bodies in nature. But even if all these bodies suddenly disappeared, absolute space would still remain. Similarly, absolute time was represented in the image of a flowing river. It became the universal duration of all processes in the Universe. Both absolute space and absolute time exist completely independently of matter. Thus, space, time and matter represent three entities independent of each other.

Thus, in accordance with the mechanical picture of the world, the Universe was a well-oiled mechanism operating according to the laws of strict necessity, in which all objects and phenomena are interconnected by rigid cause-and-effect relationships. In such a world, there are no coincidences, she was completely excluded from the picture of the world. The only accident was that the reasons for which we did not yet know. But since the world is rational, and man is endowed with reason, then in the end he can receive complete and comprehensive knowledge of being. This rigid determinism found its expression in the form of dynamic laws.

Life and mind in the mechanical picture of the world did not have any qualitative specificity. A person in this picture of the world was considered as a natural body in a number of other bodies, and therefore remained inexplicable in his "immaterial" qualities. Therefore, the presence of a person in the world did not change anything. If a person once disappeared from the face of the earth, the world would continue to exist as if nothing had happened. In fact, classical natural science did not seek to comprehend man. It was understood that the natural world, in which there is nothing human, could be described objectively, and such a description would be an exact copy of reality. Considering a person as one of the cogs of a well-oiled machine automatically removed him from this picture of the world.

Based on the mechanical picture of the world in the 18th - early 19th centuries. was developed terrestrial, celestial and molecular mechanics. The development of technology proceeded at a rapid pace. This led to the absolutization of the mechanical picture of the world, and it began to be considered as universal.

The development of the mechanical picture of the world was mainly due to the development of mechanics. The success of Newtonian mechanics largely contributed to the absolutization of Newtonian concepts, which was expressed in attempts to reduce the entire variety of natural phenomena to the mechanical form of the motion of matter. This point of view is called mechanistic materialism (mechanism). However, the development of physics showed the inconsistency of such a methodology, since it was impossible to describe thermal, electrical and magnetic phenomena using the laws of mechanics, as well as the movement of atoms and molecules of these physical phenomena. As a result, in the XIX century. in physics there was a crisis, which testified that physics needed a significant change in its views on the world.

Evaluating the mechanical picture of the world as one of the stages in the development of the physical picture of the world, it must be borne in mind that with the development of science, the main provisions of the mechanical picture of the world were not simply discarded. The development of science only revealed the relative nature of the mechanical picture of the world. It was not the mechanical picture of the world itself that turned out to be untenable, but its original philosophical idea - mechanism. In the depths of the mechanical picture of the world, elements of a new - electromagnetic - picture of the world began to take shape.

Electromagnetic picture of the world

Throughout the XIX century. attempts to explain electromagnetic phenomena in the framework of a mechanical picture of the world continued. But this turned out to be impossible: electromagnetic phenomena were too different from mechanical processes. The greatest contribution to the formation of the electromagnetic picture of the world was made by the works of M. Faraday and J. Maxwell. After Maxwell created the theory of the electromagnetic field, it became possible to talk about the appearance electromagnetic picture of the world.

Maxwell developed his theory on the basis of the phenomenon of electromagnetic induction discovered by Faraday. Carrying out experiments with a magnetic needle, trying to explain the nature of electrical and magnetic phenomena, Faraday came to the conclusion that the rotation of the magnetic needle is due not to the electric charges that are in the conductor, but to a special state of the environment that arose at the location of the magnetic needle. This meant that the medium surrounding the conductor plays an active role in the interaction of the current with the magnetic needle. In this regard, he introduced the concept of a field as a set of magnetic lines of force penetrating space and capable of determining and directing (inducing) an electric current. This discovery led Faraday to the idea of the need to replace corpuscular concepts of matter with new, continuous, continuous ones.

Maxwell's theory of the electromagnetic field boils down to the fact that a changing magnetic field creates not only in the surrounding bodies, but also in a vacuum, a vortex electric field, which, in turn, causes the appearance of a magnetic field. So a new reality was introduced into physics - electromagnetic field.

charge, field strength -

electromagnetic.

Only the concepts of matter have radically changed: corpuscular ideas have given way to continuous (field) ones. From now on, the totality of indivisible atoms ceased to be finite, a new reality was introduced - electromagnetic field. Maxwell's theory of the electromagnetic field marked the beginning of a new stage in physics. In accordance with this theory, the world began to appear as a single electrodynamic system, built of electrically charged particles interacting through an electromagnetic field.

The most important concepts of the new theory are: charge, which can be both positive and negative; field strength - the force that would act on a body carrying a unit charge if it were at the point in question.

When electric charges move relative to each other, additional magnetic force appears. Therefore, the total force combining electric and magnetic forces is called electromagnetic. It is believed that electric forces (field) correspond to resting charges, magnetic forces (field) - to moving charges. All the variety of these forces and charges is described by a system of equations of classical electrodynamics, known as Maxwell's equations.

The essence of the equations of classical electrodynamics is reduced to Coulomb's law, which is completely equivalent to Newton's law of universal gravitation, as well as to statements that

that magnetic lines of force are continuous and have no beginning or end; there are no magnetic charges; the electric field is created by an alternating magnetic field; a magnetic field can be created by both an electric current and an alternating electric field.

Maxwell's equations are written in terms of field theory, which makes it possible to uniformly describe stationary and non-stationary electromagnetic phenomena, to relate spatial and temporal changes in electric and magnetic fields. These equations have solutions that describe electromagnetic waves traveling at the speed of light. From them it is possible to obtain solutions for the totality of all waves that can propagate in any direction in space.

Thus, new physical and philosophical views on matter, space, time and forces were put forward, which in many respects changed the previous mechanical picture of the world. Of course, it cannot be said that these changes were cardinal, since they were carried out within the framework of classical science. Therefore, the new electromagnetic picture of the world can be considered intermediate, combining both new ideas and old mechanistic ideas about the world.

Only the concepts of matter have radically changed: corpuscular ideas have given way to continuous (field) ones. From now on, the totality of indivisible atoms ceased to be finite

the divisibility limit of matter. As such, we took a single absolutely continuous infinite field with power point centers - electric charges and wave motions in it. According to the electromagnetic picture of the world, matter exists in two forms - matter and field. They are strictly separated, and their transformation into each other is impossible. The main of them is the field, which means that the main property of matter is continuity as opposed to discreteness. The electromagnetic field propagates in the form of transverse electromagnetic waves at the speed of light, constantly capturing new areas of space. The filling of space with an electromagnetic field cannot be described on the basis of Newton's laws, since mechanics does not understand this mechanism. In electromagnetism, a change in one entity (magnetic field) leads to the appearance of another entity (electric field). Both of these entities together form an electromagnetic field. In mechanics, one material phenomenon does not depend on the change of another, and together they do not create a single entity.

The concept of movement has also expanded. It began to be understood not only as a simple mechanical movement, but also as the propagation of vibrations in the field. Accordingly, the laws of Newtonian mechanics gave way to their dominant place to the laws of Maxwell's electrodynamics.

The new picture of the world required a new solution to the problem of physical interaction. Newton's principle of long-range action was replaced by the Faraday principle of short-range action, which asserted that any interactions are transmitted by a field from point to point continuously and with a finite speed.

The concept of absolute space and absolute time of Newton did not fit the new field concepts of matter, since the fields do not have clearly defined boundaries and overlap each other. In addition, fields are absolutely continuous matter, so there is simply no empty space. Likewise, time should be inextricably linked with the processes taking place in the field. It was clear that space and time cannot be regarded as independent entities, independent of matter. But the inertia of thinking and the force of habit were so great that for a long time scientists preferred to believe in the existence of absolute space and absolute time.

Initially, in understanding space and time, the electromagnetic picture of the world proceeded from the belief that absolute empty space is filled with world ether. Scientists tried to connect the absolute frame of reference with the stationary ether. At the same time, to explain many material phenomena, the ether had to ascribe unusual properties, often contradicting each other. However, the creation of a special theory of relativity forced scientists to abandon the idea of ether, since this theory proceeded from the relativity of length, time and mass, i.e. from their dependence on the frame of reference. Therefore, only by the beginning of the XX century. the absolute concept of space and time has given way to the relational (relative) concept of space and time, according to which space, time and matter exist only together, are completely dependent on each other. In this case, space and time are the properties of material bodies.

The electromagnetic picture of the world has made a real revolution in physics. It was based on the ideas of the continuity of matter, the material electric field, the continuity of matter and motion, the connection of space and time both with each other and with moving matter. The new understanding of the essence of matter has put scientists in front of the need to revise and re-evaluate these fundamental qualities of matter.

The laws of electrodynamics, like the laws of classical mechanics, still unambiguously predetermined the events they described, so they tried to exclude chance from the physical picture of the world. However, in the middle of the XIX century. for the first time a fundamental physical theory of a new type appeared, which was based on the theory of probability. It was the kinetic theory of gases, or statistical mechanics. Randomness and probability finally found their place in physics and were reflected in the form of so-called statistical laws. True, while physicists did not give up hope of finding clear unambiguous laws, similar to Newton's laws, behind the probabilistic characteristics, and considered the newly created theory an intermediate version, a temporary measure. Nevertheless, progress was evident: the concept of probability entered the electromagnetic picture of the world.

The idea of the place and role of man in the Universe did not change in the electromagnetic picture of the world. His appearance was considered only a whim of nature. These views were further strengthened after the emergence of the Darwinian theory of evolution. Ideas about the qualitative specifics of life and mind made their way in the scientific worldview with great difficulty.

The electromagnetic picture of the world explained a wide range of physical phenomena that were incomprehensible from the point of view of the previous mechanical picture of the world. However, its further development showed that it has a limited character. The main problem was that the continual understanding of matter did not agree with the experimental facts confirming the discreteness of its many properties - charge, radiation, action. The problem of the relationship between the field and the charge also remained unsolved; it was not possible to explain the stability of atoms and their spectra, the radiation of an absolutely black body. All this testified to the relative nature of the electromagnetic picture of the world and the need to replace it with a new physical picture of the world. Therefore, it was replaced by a new - quantum-field - picture of the world, which combines the discreteness of the mechanical picture of the world and the continuity of the electromagnetic picture of the world.

Section 1. Mechanical scientific picture of the world …………………… ..3-5

Section 2. Electromagnetic scientific picture of the world .. ……………… .6-8

Section 3 Quantum-relativistic scientific picture of the world ………… ..9-10

Conclusions ……………………………………………………………… 11-13

Literature ………………………………………………………… .... 14

Section 1 . Mechanical scientific picture of the world.

In the history of science, scientific pictures of the world did not remain unchanged, but replaced each other, thus, we can talk about the evolution of scientific pictures of the world. The evolution of physical pictures of the world seems to be the most obvious: natural-philosophical - up to the 16-17th centuries, mechanistic - until the second half of the 19th century, thermodynamic (within the framework of mechanistic theory) in the 19th century, relativistic and quantum-mechanical in the 20th century.

The mechanical picture of the world was formed under the influence of materialistic ideas about matter and the forms of its existence. The fundamental ideas of this picture of the World are classical atomism, dating back to Democritus and the so-called mechanism. The very formation of the mechanical picture is rightly associated with the name of Galileo Galilei, who was the first to use the experimental method for the study of nature, together with measurements of the investigated quantities and subsequent mathematical processing of the results. This method was fundamentally different from the previously existing natural philosophical method, in which a priori (

The laws of planetary motion discovered by Johannes Kepler, in turn, testified that there is no fundamental difference between the motions of earthly and celestial bodies (as Aristotle believed), since they all obey certain natural laws.

The core of the mechanical picture of the world is Newtonian mechanics (classical mechanics). Formation of classical mechanics and the mechanical picture of the world based on it took place in 2 directions:

1) generalization of the previously obtained results and, first of all, the laws of free fall of bodies discovered by Galileo, as well as the laws of planetary motion formulated by Kepler;

2) creation of methods for the quantitative analysis of mechanical movement in general.

In the first half of the 19th century. along with theoretical mechanics, applied (technical) mechanics is also distinguished, which has achieved great success in solving applied problems. All this led to the idea of the omnipotence of mechanics and to the desire to create a theory of heat and electricity based on mechanical concepts. This idea was most clearly expressed in 1847 by the physicist Hermann Helmholtz in his report “On the conservation of force”: “The final task of the physical sciences is to

natural phenomena to be reduced to invariable attractive and repulsive forces, the magnitude of which depends on the distance "

In any physical theory there are quite a few concepts, but among them there are basic ones, in which the specificity of this theory, its basis, ideological essence is manifested. These concepts include the so-called fundamental concepts, namely:

Matter,

Traffic,

Space,

Interaction.

Each of these concepts cannot exist without the four others.

The most important principles of the mechanical picture of the world are:

The principle of relativity,

The principle of action at a distance,

The principle of causality.

Galileo's principle of relativity. Galileo's principle of relativity asserts that all inertial reference frames (IFRs) from the point of view of mechanics are completely equal (equivalent). The transition from one IFR to another is carried out on the basis of Galileo transformations

The principle of action at a distance. In the mechanical picture of the world, it was accepted that the interaction is transmitted instantly, and the intermediate medium does not take part in the transmission of the interaction. This position was called the principle of long-range action.

The principle of causality. As already mentioned, in the mechanical picture of the world, all the variety of natural phenomena to the mechanical form of the movement of matter (mechanistic materialism, mechanicism). On the other hand, it is known that there are no causeless phenomena, that it is always possible (in principle) to single out the cause and effect. Cause and effect are interrelated and affect each other. The effect of one cause can lead to another effect. This idea was developed by the mathematician Laplace, stating the following: “Every existing phenomenon is connected with the previous one on the basis of the obvious principle that it cannot arise without a generating cause. The opposite opinion is an illusion of the mind. " those. Laplace believed that all connections between phenomena are based on unambiguous laws. This doctrine of the conditioning of one phenomenon by another, of their unambiguous regular connection, entered physics as the so-called Laplace determinism (determinism - predetermination).

Section 2. Electromagnetic picture of the world.

The greatest contribution to the formation of this view of the world was made by the works of M. Faraday and D. Maxwell. After the creation of the theory of the electromagnetic field by the latter on the basis of the phenomenon of electromagnetic induction discovered by Faraday, it became possible to speak of the emergence of an electromagnetic picture of the world.

Maxwell's theory of the electromagnetic field marked the beginning of a new stage in physics. In accordance with it, the world began to appear as a single electrodynamic system, built of electrically charged particles interacting through an electromagnetic field.

The most important concepts of the new theory are: charge, which can be both positive and negative; field strength - the force that would act on a body carrying a unit charge if it were at the point in question.

When electric charges move relative to each other, additional magnetic force appears. Therefore, the total force combining electric (resting charges) and magnetic (moving charges) forces is called electromagnetic. The whole variety of these forces and charges is described by the system of equations of classical electrodynamics. These are known as Maxwell's equations. This is Sh. Coulomb's law, which is completely equivalent to Newton's law of universal gravitation; magnetic lines of force are continuous and have no beginning or end, magnetic charges do not exist; the electric field is created by an alternating magnetic field; a magnetic field can be created by both an electric current and an alternating electric field.

Thus, new physical and philosophical views on matter, space, time and forces were put forward, which in many respects changed the previous mechanical picture of the world. But it cannot be said that these changes were cardinal, since they were carried out within the framework of classical science. Therefore, the new electromagnetic picture of the world can be considered intermediate, combining both new ideas and old mechanistic ideas about the world.

The electromagnetic picture of the world required a new solution to the problem of physical interaction. Newton's principle of long-range action was replaced by the Faraday principle of short-range action, which asserted that any interactions are transmitted by a field from point to point, continuously and with a finite speed.

They still tried to exclude chance from the physical picture of the world. But in the middle of the XIX century. for the first time a fundamental physical theory of a new type appeared, which was based on the theory of probability. It was the kinetic theory of gases, or statistical mechanics. Randomness and probability finally found their place in physics and were reflected in the form of so-called statistical laws. True, while physicists did not give up hope of finding clear unambiguous laws, similar to Newton's laws, behind the probabilistic characteristics, and considered the newly created theory an intermediate version, a temporary measure. Nevertheless, progress was evident: the concept of probability entered the electromagnetic picture of the world.

The idea of the place and role of man in the Universe did not change in the electromagnetic picture of the world. His appearance was considered only a whim of nature.

The electromagnetic picture of the world explained a wide range of physical phenomena that were incomprehensible from the point of view of the previous mechanical view of the world. However, its further development showed that it has a relative character. Therefore, it was replaced by a new - quantum field - picture of the world, which combines the discreteness of the mechanical picture of the world and the continuity of the electromagnetic picture of the world.

Section 3. Quantum-field picture of the world... The modern quantum field picture of the world is based on a new physical theory - quantum mechanics, which describes the state and motion of microparticles (elementary particles, atoms, molecules, atomic nuclei) and their systems, as well as the relationship of quantities characterizing particles and systems with physical quantities, directly measurable by experience. The laws of quantum mechanics form the foundation for studying the structure of matter. They make it possible to elucidate the structure of atoms, establish the nature of chemical bonds, explain the periodic table of elements, and study the properties of elementary particles.

In accordance with the quantum field picture of the world, any micro-object, possessing wave and corpuscular properties, does not have a definite trajectory of motion and cannot have definite coordinates and velocity (momentum). In quantum mechanics, in contrast to classical physics, the behavior of each microparticle obeys nondynamic, but statistical laws.

The general picture of reality in the quantum field picture of the world is, as it were, two-dimensional: on the one hand, it includes the characteristics of the object under study, and on the other, the observation conditions on which the certainty of these characteristics depends. This means that the picture of reality in modern physics is not only a picture of an object, but also a picture of the process of its cognition.

Gone are the notions of the immutability of matter, of the possibility of reaching the final limit of its divisibility.

The concept of motion is radically changing, which becomes only a special case of fundamental physical interactions, of which four types are known: gravitational, electromagnetic, strong and weak.

The specificity of quantum field concepts of regularity and causality is that they always appear in a probabilistic form, in the form of so-called statistical laws that contribute to a deeper level of knowledge of natural laws. Thus, it turned out that the world is based on chance, probability.

Also, the new picture of the world for the first time included an observer, on whose presence the obtained research results depended. Moreover, the so-called anthropic principle was formulated, which claims that our world is what it is, only thanks to the existence of man. From now on, the appearance of man is considered a natural result of the evolution of the Universe.

Conclusions.

Each of the considered pictures of the world interprets concepts; matter space and time in different ways.

According to mechanical picture of the world Is a substance consisting of the smallest, further indivisible, absolutely solid moving particles - atoms, i.e. discrete (discrete - “discontinuous”), or, in other words, corpuscular concepts of matter were adopted in the MCM. That is why the most important concepts in mechanics were the concepts of a material point and an absolutely rigid body (a material point is a body whose dimensions can be neglected under the conditions of a given problem, an absolutely rigid body is a system of material points, the distance between which always remains unchanged).

Space. Recall that Aristotle denied the existence of empty space, linking space, time and motion. Atomists 18-19 centuries on the contrary, they recognized the atoms and the empty space in which the atoms move. Newton, however, considered two types of space:

· The relative, with which people get to know by measuring the spatial relationship between bodies;

· The absolute, which by its very essence is irrelevant to anything and external and remains always the same and motionless; those. absolute space is an empty container of bodies, it is not associated with time, and its properties do not depend on the presence or absence of material objects in it. Space in Newtonian mechanics is

Subsequently, A. Einstein, analyzing the concepts of absolute space and absolute time, wrote: “If matter disappeared, then only space and time would remain (a kind of stage on which physical phenomena are played out)”. In this case, space and time do not contain any special "marks" from which one could count down and answer the questions "Where?" and when?" Therefore, to study material objects in them, it is necessary to introduce a reference system (coordinate system and clock). A frame of reference rigidly connected with absolute space is called inertial. Space in Newtonian mechanics is:

Three-dimensional (the position of any point can be described by three coordinates),

Continuous,

Endless

Isotropic (properties of space do not depend on direction).

Spatial relationships in MCM are described by Euclidean geometry.

Time. Newton considered two types of time, similar to space: relative and absolute. People cognize relative time in the process of measurements, and absolute (true, mathematical time) in itself and in its essence, without any relation to anything external, flows uniformly and is otherwise called duration. Thus, Newton's time, similar to space, is an empty container of events that does not depend on anything. Time flows in one direction - from the past to the future.

In turn, in quantum field picture of the world the ideas about the relativity of space and time, their dependence on matter are finally approved. They cease to be independent of each other and, according to the theory of relativity, merge in a single four-dimensional space-time that does not exist outside of material bodies.

V electromagnetic picture of the world the concept of matter has changed dramatically.

They are strictly separated, and their transformation into each other is impossible. The main of them is the field, which means that the main property of matter is continuity as opposed to discreteness.

Literature.

1) Sadokhin A.P. Concepts of modern natural science: a tutorial. M .: Omega-L, 2008. -239 p.

2) Lipovko P.O. Concepts of modern natural science. Textbook for universities. Rostov n / a: Phoenix, 2004 .-- 512 p.

The technical revolution. Quantum -relativistic scientific painting the world became ... mechanical determinism, absolutely excluding the element of randomness from paintings the world ...

Modern scientific painting the world (2)

Abstract >> Biology

... mechanical painting the world which changed relativistic painting the world... The first step towards building a new scientific physical paintings the world.... Originally quantum mechanics was created ... the theory of the weak and electromagnetic interactions. Undertaken ...

The subject of philosophy. Religious, scientific and philosophical paintings the world

Abstract >> Philosophy

... Scientific painting the world based on experience, evidence. She is constantly changing. Philosophical painting the world, as well as scientific... simple mechanical displacement ..., is divided electromagnetic and weak ... classic, relativistic and quantum mechanics). ...

Scientific revolution (2)

Abstract >> Biology

Complemented the mechanistic picture the world electromagnetic... Electrical and ... paintings realities not reducible to mechanical picture the world; the object is understood in accordance with scientific ... relativistic and quantum theories in physics, the formation of genetics, quantum ...

The electromagnetic picture of the world is based on the whole not only on the doctrine of electromagnetism, but also on achievements in other areas of natural science, such as the discovery of the electron, the creation of a nuclear model of the atom, the creation of the periodic table of elements by D.I. Mendeleev and many others / The electromagnetic concept also includes some ideas of the theory of relativity and quantum mechanics.

The main features of the electromagnetic picture of the world can be briefly defined as follows:

Matter exists in two forms - in the form of matter and in the form of a field (the gravitational and electromagnetic fields are known). These types of matter are strictly separated. Transformations of a field into a substance, substances in a field are impossible;

Electromagnetic interaction determines the absolute majority of natural phenomena (except for those related to gravitation) - respectively electrical and magnetic, as well as optical, chemical, thermal and mechanical. So, for example, an atomic nucleus is assumed to consist of protons and so-called doublets - neutral compounds of a proton and an electron, which reduces all forces acting in a substance to electromagnetic;

An electron and a proton are released as elementary constituents of matter. The stability of these particles explains the stability of matter and the universe as a whole. The photon is the quantum of the electromagnetic field. The idea of wave-corpuscular dualism is being developed, "linking" wave and corpuscular (quantum) properties;

The predominance of unambiguous causal relationships; probabilistic patterns are not recognized as fundamental; they refer only to collectives of particles (for example, molecules), and each of the particles individually obeys the laws of Newtonian mechanics.

The electromagnetic picture of the world represented a significant step forward in understanding the world. Many of its provisions and details are included in the modern natural science concept of the universe.

Literature for chapter 2

1. Borovoy A, A. et al. The laws of electromagnetism. - Moscow: Nauka, 1970.

2. Boutiques E. N. Optics. - M .: Nauka, 1987.

Z. De Groote S, Satthorp L., Electrodynamics. - M .: Nauka, 1982.

4. Kaganov MI, Tsukernik VM The nature of magnetism. - M .: Nauka, 1982.

5. Kalashnikov S. G. Electricity. - M .: Nauka, 1977.

6. Kartsev VL Adventures of great equations. - M .: Knowledge, 1986.

7. Landsberg GS Optics. - M .: Nauka, 1976.

8. Matveev AN Electrodynamics and the theory of relativity. - M .: Higher school, 1964.

9. Tatur TA Fundamentals of the theory of the electromagnetic field. - M .: Higher school, 1989.

10. Tamm IE Fundamentals of the theory of electricity. - M .: Nauka, 1976.

11. Filonovich SR The fate of the classical law. - M .; Science, 1990.

Questions and tasks for chapter 2

1. Get acquainted with the recommended literature with the main discoveries in the field of electromagnetism and optics in the XYII-XX centuries, with the biographies and scientific achievements of outstanding scientists: A. Ampere, G. Hertz, H. Huygens, G. Lorentz, J. Maxwell, G. Kirchhoff, Sch. Coulomb, G. Ohm, M. Faraday, O. Fresnel, H. Oersted.

2. Review electrical and magnetic topics in high school textbooks and other literature.

3. In writing in your workbook, formulate the concepts of electric charge, electromagnetic field, electric field strength, magnetic induction, current strength and density, volumetric charge density.

4. Explain what is the essence of the inseparability of magnetic and electric fields. Is it fair in this connection to consider the electric field separately?

5. Formulate Coulomb's law Calculate the strength of the Coulomb interaction between a proton and an electron in a hydrogen atom. Compare the value of this force with the force of gravitational attraction of these particles. How can you test Coulomb's law experimentally without measuring charges?

6. Think of how a magnetic field can separate positively and negatively charged particles moving together.

7. Consider, following Faraday, possible experiments to detect electromagnetic induction. Try to reproduce one of the experiences.

8. Generalize Faraday's law of electromagnetic induction; write down your reasoning.

9. What is the physical meaning of Lenz's rule? What will happen if the law of electromagnetic induction is replaced by "+"?

10. What is the asymmetry of electric and magnetic fields?

11. Give arguments proving that light is electromagnetic waves.

12. Get the formulas connecting the characteristics of an electromagnetic wave - frequency v and wavelength λ , period T, wavenumber k.

13. Try to determine the type of polarization of the waves carrying the television signal, knowing that the location of the vibrators of the receiving television antennas is related to the polarization of the electromagnetic waves emitted by the transmitting antennas.

14. Try to understand the "design" of Nature, which determined the range of visible light for human vision. What picture would we see in the range, for example, microwave? In the X-ray range?

15. Why do natural sources always emit incoherent light waves?

16. What should a diffraction grating look like for VHF radio waves?

17. What are the limitations of the electromagnetic picture of the world?

18. It is known that classical electrodynamics was created as a generalization of numerous natural phenomena, experiments and theoretical premises. Try to go the opposite way and, based on the general laws of electromagnetism, explain some specific electromagnetic phenomenon (for example, the occurrence of lightning, the action of an electric current on a magnetic needle, etc.)

Send your good work in the knowledge base is simple. Use the form below

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

Posted on http://www.allbest.ru/

MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION

NABEREZHNOCHELNINSKY INSTITUTE (BRANCH) OF THE FEDERAL STATE AUTONOMOUS EDUCATIONAL INSTITUTION OF HIGHER PROFESSIONAL EDUCATION

"KAZAN (Volga Region) FEDERAL UNIVERSITY"

Department: "Finance and Accounting"

abstract

on the topic: "Electromagnetic picture of the world"

on discipline: "Concepts of modern natural science"

Naberezhnye Chelny, 2016.

1. Electromagnetic picture of the world

2. Development of the field concept of describing the properties of matter

3. Concepts of long-range and short-range action

4. Discreteness and continuity of matter

5. The essence of Maxwell's electromagnetic theory

6. The main features of EHCM

1. Electromagnetic picture of the world

In the 19th century, the natural sciences have accumulated a huge amount of empirical material that needs to be rethought and generalized. Many scientific facts obtained as a result of research did not quite fit into the established mechanical ideas about the world around us. In the second half of the 19th century, on the basis of research in the field of electromagnetism, a new physical picture of the world was formed - the electromagnetic picture of the world (EMCM).

In its formation, the research carried out by the outstanding scientists M. Faraday and J. Maxwell and G. Hertz played a decisive role.

M. Faraday, rejecting the concept of long-range action (carrier of interaction), introduces the concept of a physical field, which plays a significant role in the further development of science and technology (radio communication, television, etc.). J. Maxwell develops the theory of the electromagnetic field, and G. Hertz experimentally discovers electromagnetic waves.

In EMCM, the whole world is filled with electromagnetic ether, which can be in various states. Physical fields were interpreted as states of the ether. Ether is a medium for the propagation of electromagnetic waves and, in particular, light.

Matter is considered to be continuous. All laws of nature are reduced to the equations of J. Maxwell, describing continuous substance: nature does not make leaps. Matter consists of electrically charged particles interacting with each other through fields.

All known mechanical, electrical, magnetic, chemical, thermal, optical phenomena are explained on the basis of electromagnetic interactions.

Attempts are being made to reduce the mechanical description of phenomena to a description based on the theory of the electromagnetic field. The interpretation of phenomena based on electromagnetism seems elegant and complete. The whole variety of natural phenomena is reduced to several mathematically rigorous, albeit very complex, relationships.

The concept of ether (as a carrier of light and electromagnetic waves) is slowly evolving - up to a complete rejection in the end from the very concept of ether.

Scientists' ideas about space and time are changing. The first works of A. Einstein on the theory of relativity appear. Scientific works give rise to new views on the nature of gravitation, different from those that developed in the mechanical picture of the world.

The universe, as it were, takes on completely new features. Scientists are discovering the "scattering" of galaxies. EMCM expands, refines and deepens. Scientists are building more and more new models of the atom, trying to find out which of them is still closest to the truth.

The most beautiful and accurate was the planetary model of the atom, created by E. Rutherford. But it was she who became the starting point when completely new views on the structure of the world around us appeared.

Already at the end of the XIX, beginning of the XX century, the experimental data obtained in the study of the micro- and megaworld sharply diverged from the predictions of existing natural-scientific theories, demanded the development of new, more accurate and adequate essence of many mysterious phenomena.

Despite this, the electromagnetic picture of the world has given us a lot, without which we cannot imagine modern life: methods of obtaining and using electrical energy, for example, electric lighting and heating, modern electromagnetic communications (radio, telephone, television). Without radio communication, for example, the existence of modern states, the functioning of transport and production is no longer possible, even everyday communication of people is unthinkable.

2. Development of the field concept of describing the properties of matter

electromagnetic discreteness continuity matter

In the classical view, as noted above, two types of matter are distinguished: matter and field. The first of them includes atoms, molecules and all bodies built from them, the structure and shape of which are very diverse. A field is a special form of matter (sometimes it is called a physical field). By now, several types of fields are known: electromagnetic and gravitational fields, the field of nuclear forces, as well as wave (quantum) fields corresponding to various elementary particles.

Let us restrict ourselves to considering the electromagnetic field. It was for the description of electromagnetic phenomena that the outstanding English self-taught physicist Michael Faraday (1791-1867) in the 30s of the XIX century. first introduced the concept of a field.

The science of the properties and laws of behavior of a special type of matter - the electromagnetic field, through which the interaction between electrically charged bodies is carried out, is called electrodynamics.

Among the four types of fundamental interactions - gravitational, electromagnetic, strong and weak - electromagnetic interaction takes first place in the breadth and variety of manifestations. In everyday life and in technology, we most often encounter various types of electromagnetic interactions: the forces of elasticity, friction, the strength of our muscles and the muscles of various animals, etc.

Electromagnetic interaction allows us to see the diverse objects and bodies around us, since light is one of the forms of the electromagnetic field. Life itself is inconceivable without the forces of an electromagnetic nature. Living beings and even man, as the flights of astronauts show, are capable of being in a state of weightlessness for a long time, when the forces of gravity do not noticeably manifest themselves. But if for a moment the action of electromagnetic forces ceased, then life would immediately disappear. The structure of the atomic shell, the cohesion of atoms into molecules (chemical bond) and the formation of bodies of various shapes from matter are determined exclusively by electromagnetic interaction.

The creation of the electromagnetic field theory was led by a long chain of random discoveries and systematic painstaking research, starting with the discovery of the ability of amber, rubbed on silk, to attract light objects and ending with the idea of the generation of a magnetic field by an alternating electric field, proposed by the great English scientist James Clerk Maxwell.

Only after Maxwell created the electromagnetic field theory, in the second half of the 19th century, widespread practical use of electromagnetic phenomena began. The invention of the radio by the Russian physicist and electromechanic A.S. Popov (1859-1906) - one of the first important applications of the principles of a new, electromagnetic, theory. With the development of electromagnetic field theory, for the first time, scientific research preceded technical applications. If the steam engine was built long before the creation of the theory of thermal processes, then it was possible to design an electric motor or a radio receiver only after the discovery and study of the laws of electrodynamics.

Numerous practical applications of electromagnetic phenomena undoubtedly contributed to a significant transformation of the sphere of human activity and the development of civilization.

3. Long-range and short-range concepts

The affirmation of the concept of a field was largely facilitated by the desire to understand the long-range nature of electric and gravitational forces. Immediately after I. Newton's discovery of the law of universal gravitation, and then, about a hundred years later, and the Coulomb's law, which describes the interaction of charged bodies, questions of a more philosophical content arose: why physical bodies with mass act on each other at distances, even on huge ones, through empty space, and why do charged bodies interact even through an electrically neutral medium? Before the introduction of the concept of a field, there were no satisfactory answers to these questions.

For a long time it was believed that the interaction between bodies can be carried out directly through empty space, which does not take part in this process. The transfer of interaction occurs instantly. This assumption is the essence of the concept of action at a distance. I. Newton himself considered such interaction of bodies to be incredible and even impossible.

The founder of the concept of long-range action is the French mathematician, physicist and philosopher Rene Descartes. Many scholars adhered to this concept until the end of the 19th century.

Experimental studies of electromagnetic phenomena have shown the inconsistency of the concept of long-range action with physical experience. In addition, this concept is in contradiction with the postulate of the special theory of relativity, according to which the speed of transmission of interactions of bodies is limited and should not exceed the speed of light in a vacuum.

It was proved that the interaction of electrically charged bodies is not instantaneous and the movement of one charged particle leads to a change in the forces acting on other particles, not at the same moment, but only after a finite time. Each electrically charged particle creates an electromagnetic field that acts on other charged particles, that is, the interaction is transmitted through an “intermediary” - the electromagnetic field. The speed of propagation of an electromagnetic field is equal to the speed of light in a void - about 300,000 km / s. This is the essence of the new concept - the concept of short-range interaction, which applies not only to the electromagnetic, but also to other types of interactions. According to the concept of short-range interaction, the interaction between bodies is carried out by means of certain fields (for example, gravitation - by means of a gravitational field), continuously distributed in space.

4. Discreteness and continuity of matter

What is a physical field? Is it possible to represent it visually with the help of simple images that are accessible to our understanding? How does it compare with the concept of particles of matter?

The simplest idea of a field is given by a continuous medium, for example, water filling a certain area of space (or, in general, all space). This medium can have at different points, for example, different density or temperature, and move in different ways. It is a specific physical property of the environment, which is different at different points and available for measurement, that physically determines the field. In this regard, a distinction is made between a temperature field, a velocity field, a force field, etc.

Philosophically, the division of the world into bodies and particles, on the one hand, and a continuous medium, field and empty space, on the other, corresponds to the selection of two extreme properties of the world - its discreteness and continuity.

Discreteness (or discontinuity) means “granularity”, the final divisibility of the spatio-temporal structure and state of an object or object, its properties and forms of movement (leaps), while continuity expresses the unity, integrity and indivisibility of an object, the very fact of its stable existence. For a continuous, there are no divisible boundaries.

In mathematics, these philosophical categories correspond to a discrete set of natural numbers and a continuous set (continuum) of real numbers. For an accurate spatio-temporal description of the properties of a continuous medium (and field), a special section of mathematics was developed.

Discrete and continuous properties of the world within the framework of classical physics initially appear as opposed to each other, separate and independent from each other, although as a whole they complement the general idea of the world. And only the development of the field concept, mainly for describing electromagnetic phenomena, made it possible to understand their dialectical unity. In modern quantum theory, this unity of opposites of discrete and continuous has found a deeper physical and mathematical foundation in the concept of wave-particle dualism.

After the advent of quantum field theory, the concept of interaction has changed significantly. According to this theory, any field is not continuous, but has a discrete structure. For example, electromagnetic interaction in quantum field theory is the result of the exchange of particles by photons - quanta of the electromagnetic field, that is, photons are the carriers of this field. Similarly, other types of interaction arise as a result of the exchange of particles by quanta of the corresponding fields. For example, gravitons are supposed to take part in the gravitational interaction (their existence has not yet been experimentally confirmed).

According to the field concept, the particles participating in the interaction create a special state at each point of the space surrounding them - a field of forces, which manifests itself in a force effect on others, particles placed at any point in this space. Initially, a mechanical interpretation of the field was put forward as elastic stresses of a hypothetical "ether" medium. The theory of relativity, rejecting "ether" as a special elastic medium, at the same time gave a fundamental meaning to the concept of a field as a primary physical reality.

In modern quantum physics, a new possible type of matter - physical vacuum - can claim the role of "ether". The first ideas about it were given by one of the founders of quantum field theory, the English physicist P. Dirac (the so-called "Dirac sea"). Although we do not directly see the vacuum (it is transparent to electromagnetic radiation and does not offer any resistance to the movement of material particles and bodies), it can nevertheless manifest itself when the same particles or electromagnetic waves (gamma quanta) with sufficient energy interact with it. If this energy exceeds twice the rest energy of, for example, an electron, then a gamma quantum in the presence of one more particle (atomic nucleus) can disappear by itself and generate an electron-positron pair, as if "torn out" from the vacuum. There is also other evidence in favor of the physical vacuum.

In the history of physics over the past 300 years, at least four different concepts of "ether" have been proposed: Newton's absolute space, Huygens' luminiferous ether, Einstein's gravitational ether, and Dirac's physical vacuum. Only the future will show how justified the intuition of physicists about the existence of a special environment in nature - a physical vacuum.

5. The essence of Maxwell's electromagnetic theory

In the 60s of the XIX century. English physicist Maxwell developed Faraday's theory of the electromagnetic field and created the theory of the electromagnetic field. This was the first field theory. It deals only with electric and magnetic fields and very successfully explains many electromagnetic phenomena. It is useful to recall some of the main ideas behind this theory and the conclusions that follow from it.

It follows from Faraday's law that any change in the magnetic flux coupled to the circuit leads to the emergence of an electromotive force (EMF) of induction, as a result of which an induction current appears. Consequently, the occurrence of an EMF of electromagnetic induction is also possible in a stationary circuit located in an alternating magnetic field. However, the EMF in any circuit occurs only when external forces act on the current carriers in it, i.e., forces of non-electrostatic origin. Therefore, the question naturally arises about the nature of external forces in this case. Experience shows that such external forces are not associated with either thermal or chemical processes in the circuit; their occurrence also cannot be explained by the Lorentz forces, since they do not act on stationary charges. Maxwell hypothesized that any alternating magnetic field excites an electric field in the surrounding space, which is the cause of the induction current in the circuit. According to Maxwell's concept, the contour in which the EMF appears plays a secondary role, being a kind of only "device" that detects this field. The electric field excited by a magnetic field, like the magnetic field itself, is vortex.

According to Maxwell, if any alternating magnetic field excites a vortex electric field in space, then the opposite phenomenon should exist: any change in the electric field should cause a vortex magnetic field to appear in the surrounding space. To establish quantitative relationships between the changing electric field and the magnetic field caused by it, Maxwell introduced into consideration the so-called displacement current, which has the ability to create a magnetic field in the surrounding space. The displacement current in a vacuum is not associated with the movement of charges, but is caused only by the change in the electric field in time and at the same time excites a magnetic field - this is Maxwell's fundamentally new statement.

It follows from Maxwell's equations that the sources of the electric field can be either electric charges or magnetic fields changing in time, and magnetic fields can be excited either by moving electric charges (electric currents) or alternating electric fields. Maxwell's equations are not symmetric with respect to electric and magnetic fields. This is due to the fact that there are electric charges in nature, but there are no magnetic charges.

In the stationary case, when the electric and magnetic fields do not change in time, the sources of the electric field are only electric charges, and the sources of the magnetic field are only conduction currents. In this case, the electric and magnetic fields are independent of each other, which makes it possible to study separately constant electric and magnetic fields.

Maxwell's equations are the most general equations for electric and magnetic fields in media at rest. In electromagnetism, they play the same role as Newton's laws in mechanics. It follows from Maxwell's equations that the alternating magnetic field is always associated with the electric field generated by it, and the alternating electric field with the magnetic field generated by it, that is, the electric and magnetic fields are inextricably interconnected and form a single electromagnetic field.

Only Einstein's principle of relativity is applicable to the electromagnetic field, since the fact of propagation of electromagnetic waves in vacuum in all reference frames with the same speed is not compatible with Galileo's principle of relativity.

6. The main features of EHCM

The main initial idea of EMCM is natural science materialism, and its core is the theory of the electromagnetic field. EMCM was based on the following ideas:

Continuity of matter (continuity),

The materiality of the electromagnetic field,

Inseparability of matter and motion,

· The connection of space and time both with each other and with moving matter.

Matter and motion. Matter exists in two forms: matter and field. They are strictly separated and their transformation into each other is impossible. The main is the field, which means that the main property of matter is continuity (continuity) as opposed to discreteness.

Space and time. In the original EMCM, the absolute and empty space (as in the MCM) was filled with the world ether. The electromagnetic field was presented as vibrations of the ether. They tried to connect the absolute frame of reference, the simplest, the best, with the motionless ether. The creation of the SRT led to the abandonment of the ether.

From the postulates of SRT (special theory of relativity), the relativity of length, time and mass followed, i.e. their dependence on the frame of reference. From the Lorentz transformations, derived for the transition from one IFR (inertial frame of reference (IFR) - a frame of reference in which all free bodies move rectilinearly and uniformly, or at rest) to another, it followed that space and time are interconnected and form a single four-dimensional world (space-time continuum of Minkowski), being its projections. The properties of the space-time continuum (metric of the World, its geometry) are determined by the distribution and motion of matter.

An event that occurs with a certain particle is characterized by the place where it happened (i.e., the set of values x, y, z), and the time when it happened. ("What where When?"). In an imaginary four-dimensional space, along the axes of which spatial coordinates x, y, z and time t are plotted, an event can be depicted as a point. A point representing an event in 4-dimensional space is called a world point. Over time, the world point corresponding to a given particle moves in 4-dimensional space, describing a certain line, which is called the world line.

Interaction. During the formation and development of EMCM, physics knew two interactions - gravitational and electromagnetic. Within the framework of this picture of the World, both of these interactions were explained proceeding from their concept of "field". This meant that both interactions are transmitted using an intermediate environment, i.e. fields with a speed equal to the speed of light. Thus, the principle of long-range action of the MCM was replaced by the principle of short-range action. Within the framework of the EMCM, A. Einstein made an attempt to develop a unified theory of gravitational and electromagnetic interactions. After the creation of general relativity (general theory of relativity), the scientist until the end of his life worked on the creation of a unified field theory - a work beyond the strength of one person. (Today, a field theory has been created that includes three interactions: electromagnetic, strong and weak. The inclusion of gravitational interaction in it is still a problem).

The main principles of EMCM are Einstein's principle of relativity, short-range action, constancy and limit of the speed of light, equivalence of inert and gravitational masses, causality. (There was no new understanding of causality in comparison with MCM. The main ones were the cause-effect relationships and the dynamic laws expressing them.) Establishing the relationship between mass and energy (E = mc2) was of great importance. Mass has become not only a measure of inertia and gravity, but also a measure of energy content. As a result, two conservation laws - mass and energy - were combined into one general law of conservation of mass and energy.

Further development of physics showed that EMCM has a limited character. The main difficulty here was that the continual understanding of matter did not agree with the experimental facts confirming the discreteness of many of its properties - charge, radiation, action. It was not possible to explain the relationship between the field and the charge, the stability of atoms, their spectra, the phenomenon of the photoelectric effect, the radiation of an absolutely black body. All this testified to the relative nature of the EHRM and the need to replace it with a new picture of the world.

Soon, the EMCM was replaced by a new one - the quantum-field picture of the World, which combined the discreteness of the MCM and the continuity of the EMCM.

Posted on Allbest.ru

...

Quantum-relativistic picture of the world

The prerequisites for its creation were: the discovery of the photoelectric effect, radioactivity and the microcosm (the world of elementary particles). Photoelectric effect - the emission of electrons by a substance under the influence of electromagnetic radiation (discovered by Hertz in 1887). From Maxwell's point of view, this phenomenon could not be explained, since according to his theory, the electron must accumulate the output energy (otherwise spend time on this), but experiment has shown that this does not happen. It became clear that other theories were needed. Max Planck proposed a quantum hypothesis that light is emitted not continuously, but in portions (quanta). Based on this hypothesis, Einstein created the quantum theory of light - light is a flux of quanta, photons, with the help of which the photoeffect was explained - a photon is emitted and absorbed as a whole, an electron borrows the energy of a photon, so the photoeffect occurs instantly. At the end of the 19th century, thanks to a happy accident, the discovery of radioactivity took place - a phenomenon that proves the complex composition of the atomic nucleus. Recall that X-rays were first obtained in collisions of fast electrons with the glass wall of a discharge tube. At the same time, the luminescence of the tube walls was observed. Becquerel for a long time studied a related phenomenon - the luminescence of substances previously irradiated with sunlight. Such substances include, in particular, uranium salts, with which Becquerel experimented. And so he had a question: do not X-rays appear along with visible light after the irradiation of uranium salts? Becquerel wrapped the photographic plate in thick black paper, placed grains of uranium salt on top and exposed it to bright sunlight. After the development, the plate turned black in the areas where the salt lay. Consequently, uranium created some kind of radiation, which, like X-rays, penetrates opaque bodies and acts on a photographic plate. Becquerel thought that this radiation arises from the influence of sunlight. But one day, in February 1896, he failed to carry out another experiment due to cloudy weather. Becquerel put the plate into a drawer, placing a copper cross covered with uranium salt on top of it. Having developed the plate, just in case, two days later, he discovered on it a blackening in the form of a distinct shadow of a cross. This meant that uranium salts spontaneously, without the influence of external factors, create some kind of radiation. Intensive research began. After the discovery of radioactive elements, research began on the physical nature of their radiation. In addition to Becquerel and the Curies, he did it. Rutherford. The classical experiment that made it possible to detect the complex composition of radioactive radiation was as follows. The radium preparation was placed at the bottom of a narrow channel in a piece of lead. A photographic plate was placed opposite the channel. The radiation emerging from the channel was acted upon by a strong magnetic field perpendicular to the beam. The entire setup was housed in a vacuum. In the absence of a magnetic field on the photographic plate after development, one dark spot was detected, exactly opposite the channel. In a magnetic field, the beam split into three beams. Two components of the primary flow deviated in opposite directions. This indicated the presence of electric charges of opposite signs in these radiations. In this case, the negative component of the radiation was deflected by the magnetic field, much more than the positive one. The third component was not deflected by the magnetic field. A positively charged component is called alpha rays, a negatively charged one - beta rays and a neutral one - gamma rays. These three types of radiation are very different from each other in their penetrating ability, i.e. by how intensively they are absorbed by various substances. Alpha rays have the least penetrating power. A layer of paper with a thickness of about 0.1 mm is already opaque for them. If you cover the hole in the lead plate with a piece of paper, then a spot corresponding to alpha radiation will not be found on the photographic plate. Beta rays are absorbed much less when passing through the substance. The aluminum plate completely detains them only with a thickness of a few millimeters. Gamma rays have the greatest penetrating power. In terms of their properties, gamma rays are very much like X-rays, but only their penetrating power is much greater than that of X-rays. This suggests that gamma rays are electromagnetic waves. From the very beginning, alpha and beta rays were considered as streams of charged particles. The easiest way was to experiment with beta rays. And, since they are strongly deflected in both a magnetic and an electric field. When studying the deflection of beta particles in electric and magnetic fields, it was found that they are nothing more than electrons moving at speeds very close to the speed of light. It turned out to be more difficult to find out the nature of alpha particles, since they are weakly deflected by magnetic and electric fields. Finally, Rutherford managed to solve this problem. He measured the ratio of the charge q of a particle to its mass m from the deflection in a magnetic field. It turned out to be about half that of a proton - the nucleus of a hydrogen atom. The charge of a proton is equal to the elementary one, and its mass is very close to the atomic mass unit. Consequently, an alpha particle has a mass equal to two atomic mass units for one elementary charge. Consequently, there are four atomic mass units for two elementary charges. The same charge and the same relative atomic mass has the helium nucleus. From this it follows that the alpha particle is the nucleus of the helium atom (or, accordingly, its time-ion of the helium atom). Not content with the result achieved, Rutherford then proved by direct experiments that helium is formed during radioactive alpha decay. Collecting alpha particles inside a special reservoir for several days, Rutherford, using spectral analysis, made sure that helium was accumulating in the vessel (each alpha particle captured two electrons and turned into a helium atom).

What's new in the electromagnetic picture of the world. General characteristics of the electromagnetic picture of the world. on the topic: "Electromagnetic picture of the world"

Modern scientific painting the world (2)

The subject of philosophy. Religious, scientific and philosophical paintings the world

Scientific revolution (2)

Send your good work in the knowledge base is simple. Use the form below

Similar documents

Quantum-relativistic picture of the world