James Clark Maxwell: The Scientist and His Demon. Scientific works of James Maxwell

James Clerk Maxwell (1831-79) - English physicist, creator of classical electrodynamics, one of the founders of statistical physics, organizer and first director (since 1871) of the Cavendish Laboratory, predicted the existence of electromagnetic waves, put forward the idea of ​​​​the electromagnetic nature of light, and established the first statistical law - the law of the distribution of molecules by speed, named after him.

Developing the ideas of Michael Faraday, he created the theory of electrical magnetic field(Maxwell's equations); introduced the concept of displacement current, predicted the existence of electromagnetic waves, and put forward the idea of ​​​​the electromagnetic nature of light. Established a statistical distribution named after him. He studied the viscosity, diffusion and thermal conductivity of gases. Maxwell showed that the rings of Saturn consist of separate bodies. Works on color vision and colorimetry (Maxwell disk), optics (Maxwell effect), elasticity theory (Maxwell's theorem, Maxwell-Cremona diagram), thermodynamics, history of physics, etc.

Family. Years of study

James Maxwell was born on June 13, 1831, in Edinburgh. He was only son Scottish nobleman and lawyer John Clerk, who, having inherited the estate of a relative's wife, née Maxwell, added this name to his surname. After the birth of their son, the family moved to Southern Scotland, to their own estate, Glenlare (“Shelter in the Valley”), where the boy spent his childhood.

In 1841, James's father sent him to a school called Edinburgh Academy. Here, at the age of 15, Maxwell wrote his first scientific article, “On Drawing Ovals.” In 1847 he entered the University of Edinburgh, where he studied for three years, and in 1850 he moved to the University of Cambridge, where he graduated in 1854. By this time, James Maxwell was a first-class mathematician with the superbly developed intuition of a physicist.

Creation of the Cavendish Laboratory. Teaching work

After graduating from university, James Maxwell was left at Cambridge to pedagogical work. In 1856 he received a position as professor at Marischal College at the University of Aberdeen (Scotland). In 1860 he was elected a member of the Royal Society of London. In the same year he moved to London, accepting an offer to take up the post of head of the department of physics at King's College, University of London, where he worked until 1865.

Returning to Cambridge University in 1871, Maxwell organized and headed Britain's first specially equipped laboratory for physical experiments, known as the Cavendish Laboratory (named after the English scientist Henry Cavendish). The formation of this laboratory, which at the turn of the 19th-20th centuries. turned into one of largest centers world science, Maxwell dedicated recent years of your life.

In general, few facts from Maxwell’s life are known. Shy and modest, he sought to live in solitude and did not keep diaries. In 1858 James Maxwell married, but family life, apparently, turned out unsuccessfully, exacerbated his unsociability, and alienated him from his former friends. There is speculation that much of the important material about Maxwell's life was lost in the 1929 fire at his Glenclair home, 50 years after his death. He died of cancer at the age of 48.

Scientific activities

Maxwell's unusually wide sphere of scientific interests covered the theory of electromagnetic phenomena, the kinetic theory of gases, optics, the theory of elasticity and much more. One of his first works was research on the physiology and physics of color vision and colorimetry, begun in 1852. In 1861, James Maxwell first obtained a color image by simultaneously projecting red, green and blue slides onto a screen. This proved the validity of the three-component theory of vision and outlined ways to create color photography. In his works 1857-59, Maxwell theoretically studied the stability of Saturn's rings and showed that Saturn's rings can be stable only if they consist of particles (bodies) that are not connected to each other.

In 1855, D. Maxwell began a series of his main works on electrodynamics. The articles “On Faraday's lines of force” (1855-56), “On physical lines of force” (1861-62), and “Dynamic theory of the electromagnetic field” (1869) were published. The research was completed with the publication of a two-volume monograph, “Treatise on Electricity and Magnetism” (1873).

Creation of the electromagnetic field theory

When James Maxwell began researching electrical and magnetic phenomena in 1855, many of them had already been well studied: in particular, the laws of interaction of stationary electric charges (Coulomb's law) and currents (Ampere's law) had been established; It has been proven that magnetic interactions are interactions of moving electric charges. Most scientists of that time believed that interaction was transmitted instantly, directly through emptiness (the theory of long-range action).

A decisive turn to the theory of short-range action was made by Michael Faraday in the 30s. 19th century According to Faraday's ideas, an electric charge creates an electric field in the surrounding space. The field of one charge acts on another, and vice versa. The interaction of currents is carried out through a magnetic field. Faraday described the distribution of electric and magnetic fields in space using lines of force, which, in his view, resemble ordinary elastic lines in a hypothetical medium - the world ether.

Maxwell fully accepted Faraday's ideas about the existence of an electromagnetic field, that is, about the reality of processes in space near charges and currents. He believed that the body cannot act where it does not exist.

The first thing D.K. did Maxwell - gave Faraday's ideas a strict mathematical form, so necessary in physics. It turned out that with the introduction of the concept of field, the laws of Coulomb and Ampere began to be expressed most fully, deeply and elegantly. In the phenomenon electromagnetic induction Maxwell saw a new property of fields: an alternating magnetic field generates in empty space an electric field with closed lines of force (the so-called vortex electric field).

The next and final step in the discovery of the basic properties of the electromagnetic field was taken by Maxwell without any reliance on experiment. He made a brilliant guess that an alternating electric field generates a magnetic field, just like a normal one. electric current(displacement current hypothesis). By 1869, all the basic laws of the behavior of the electromagnetic field were established and formulated in the form of a system of four equations, called Maxwell's equations.

Maxwell's equations are the basic equations of classical macroscopic electrodynamics, describing electromagnetic phenomena in arbitrary media and in vacuum. Maxwell's equations were obtained by J.C. Maxwell in the 60s. 19th century as a result of generalization of the laws of electrical and magnetic phenomena found from experience.

A fundamental conclusion followed from Maxwell's equations: the finite speed of propagation of electromagnetic interactions. This is the main thing that distinguishes the theory of short-range action from the theory of long-range action. The speed turned out to be equal speed light in vacuum: 300,000 km/s. From this Maxwell concluded that light is a form of electromagnetic waves.

Works on the molecular kinetic theory of gases

The role of James Maxwell in the development and establishment of molecular kinetic theory is extremely important ( modern name- statistical mechanics). Maxwell was the first to make a statement about the statistical nature of the laws of nature. In 1866 he discovered the first statistical law - the law of the distribution of molecules by speed (Maxwell distribution). In addition, he calculated the viscosity of gases depending on the speeds and mean free path of molecules, and derived a number of thermodynamic relations.

Maxwell's distribution is the velocity distribution of molecules of a system in a state of thermodynamic equilibrium (provided that the translational motion of molecules is described by the laws of classical mechanics). Established by J.C. Maxwell in 1859.

Maxwell was a brilliant popularizer of science. He wrote a number of articles for the Encyclopedia Britannica and popular books: “The Theory of Heat” (1870), “Matter and Motion” (1873), “Electricity in Elementary Exposition” (1881), which were translated into Russian; gave lectures and reports at physical topics for a wide audience. Maxwell also showed great interest in the history of science. In 1879 he published the works of G. Cavendish on electricity, providing them with extensive comments.

Evaluation of Maxwell's work

The scientist's works were not appreciated by his contemporaries. Ideas about the existence of an electromagnetic field seemed arbitrary and unfruitful. Only after Heinrich Hertz experimentally proved the existence of electromagnetic waves predicted by Maxwell in 1886-89 did his theory gain universal acceptance. This happened ten years after Maxwell's death.

After experimental confirmation of the reality of the electromagnetic field, a fundamental scientific discovery was made: there are various types matter, and each of them has its own laws that cannot be reduced to Newton’s laws of mechanics. However, Maxwell himself was hardly clearly aware of this and at first tried to build mechanical models of electromagnetic phenomena.

The American physicist Richard Feynman said excellently about Maxwell’s role in the development of science: “In the history of mankind (if you look at it, say, ten thousand years later), the most significant event of the 19th century will undoubtedly be Maxwell’s discovery of the laws of electrodynamics. Against the backdrop of this important scientific discovery civil war in America in the same decade will look like a provincial incident.”

James Maxwell has passed away 5 November 1879, Cambridge. He is buried not in the tomb of the great men of England - Westminster Abbey - but in a modest grave next to his beloved church in a Scottish village, not far from the family estate.

Javascript is disabled in your browser.
To perform calculations, you must enable ActiveX controls!

James Clark Maxwell lived only 48 years, but his contribution to mathematics, physics and mechanics is difficult to overestimate. Albert Einstein himself stated that he owed his theory of relativity to Maxwell's equations for the electromagnetic field.

There is a house in India Street in Edinburgh with a plaque on the wall:
"James Clarke Maxwell
Naturalist
Born here June 13, 1831."

The future great scientist belonged to an old noble family and spent most of his childhood on his father's estate, Middleby, located in southern Scotland. He grew up curious and active child, and even then his relatives noted that his favorite questions were: “How to do this?” and "How does this happen?"

When James turned ten, by family decision, he entered the Edinburgh Academy, where he studied diligently, although without showing any special talents. However, being carried away by geometry, Maxwell invented new way drawing ovals. The content of his work on the geometry of oval curves was outlined in the Transactions of the Royal Society of Edinburgh for 1846. The author was only fourteen years old at the time. At sixteen, Maxwell went to the University of Edinburgh, choosing physics and mathematics as his main subjects. In addition, he became interested in the problems of philosophy and took courses in logic and metaphysics.

The already mentioned “Proceedings of the Royal Society of Edinburgh” published two more works by a talented student - on rolling curves and on elastic properties solids. The last topic was important for structural mechanics.

After studying in Edinburgh, nineteen-year-old Maxwell moved to Cambridge University, first to St. Peter's College, then to the more prestigious Trinity College. The study of mathematics there was carried out at a deeper level, and the requirements for students were noticeably higher than in Edinburgh. Despite this, Maxwell managed to achieve second place in the public three-stage exam in mathematics for a bachelor's degree.

At Cambridge, Maxwell interacted a lot with different people, joined the club of the apostles, which consisted of 12 members united by their breadth and originality of thinking. He participated in the activities of the Workers' College, created for education ordinary people, gave lectures there.

In the fall of 1855, when Maxwell completed his studies, he was accepted into the College of the Holy Trinity and invited to remain as a teacher. A little later, he joined the Royal Society of Edinburgh, the national scientific association of Scotland. In 1856, Maxwell left Cambridge for a professorship at Marischal College in the Scottish city of Aberdeen.

Having become friends with the college's principal, the Reverend Daniel Dewar, Maxwell met his daughter Catherine Mary. They announced their engagement in the late winter of 1858 and were married in June. According to the memoirs of biographer and friend of the scientist Lewis Campbell, their marriage turned out to be an example of incredible devotion. It is known that Katherine helped her husband in laboratory research.

Overall, the Aberdeen period was very fruitful in Maxwell's life. While still at Cambridge, he began researching the structure of the rings of Saturn, and in 1859 his monograph was published, where he proved that they are solid bodies revolving around the planet. At the same time, the scientist wrote an article “Explanations on the dynamic theory of gases,” in which he derived a function reflecting the distribution of gas molecules depending on their speed, later called the Maxwell distribution. This was one of the first examples of statistical laws that describe the behavior not of one object or single particle, but the behavior of many objects or particles. The “Maxwell’s demon”, a thought experiment in which some intelligent, incorporeal being separates gas molecules by speed, which the researcher later invented, demonstrated the statistical nature of the second law of thermodynamics.

In 1860, several colleges were merged into the University of Aberdeen and some departments were abolished. Young Professor Maxwell was also laid off. But he did not remain unemployed for long; almost immediately he was invited to teach at King's College London, where he stayed for the next five years.

That same year, at a meeting of the British Association, the scientist read a report on his developments concerning color perception, for which he later received the Rumford Medal from the Royal Society of London. Proving the correctness of his own theory of color, Maxwell presented to the public a new product that captured their imagination - color photography. No one could get it before him.

In 1861, Maxwell was appointed to the Standards Committee, created to define the main electrical units.

In addition, Maxwell did not give up research on the elasticity of solids and was awarded the Keith Prize of the Royal Society of Edinburgh for the results obtained.

While working at King's College London, Maxwell completed his theory of the electromagnetic field. The very idea of ​​the field was proposed by the famous physicist Michael Faraday, but his knowledge was not enough to present his discovery in the language of formulas. The mathematical description of electromagnetic fields became the main scientific problem for Maxwell. Based on the method of analogies, thanks to which the similarities between electrical interaction and heat transfer in a solid body, the scientist transferred the research data on heat to electricity and was the first to be able to mathematically substantiate the transfer electrical action in the environment.

The year 1873 was marked by the publication of “Treatise on Electricity and Magnetism,” whose significance is comparable to that of Newton’s “Mathematical Principles of Philosophy.” Using equations, Maxwell described electromagnetic phenomena and concluded that there are electromagnetic waves, that they propagate at the speed of light and light itself is of an electromagnetic nature.

The Treatise was published when Maxwell had already been head of the physics laboratory at Cambridge University for two years (since 1871), whose creation meant recognition in the scientific community of the enormous importance of the experimental approach to research.

No less significant task Maxwell saw the popularization of science. To do this, he wrote articles for the Encyclopedia Britannica, a work where he tried to in simple language explain the basic concepts of matter, motion, electricity, atoms and molecules.

In 1879, Maxwell's health deteriorated greatly. He knew that he was seriously ill and his diagnosis was cancer. Realizing that he was doomed, he bravely endured the pain and calmly met death, which occurred on November 5, 1879.

Although Maxwell’s works received a worthy assessment during the scientist’s lifetime, their real significance became clear only years later, when in the twentieth century the concept of a field was firmly established in scientific use, and Albert Einstein stated that Maxwell’s equations for the electromagnetic field preceded his theory of relativity.

The memory of the scientist is immortalized in the names of one of the buildings of the University of Edinburgh, the main building and concert hall of the University of Salford, and the James Clerk Maxwell Center of the Edinburgh Academy. In Aberdeen and Cambridge you can find streets named after him. Westminster Abbey has a memorial plaque dedicated to Maxwell, and visitors to the University of Aberdeen Art Gallery can see a bust of the scientist. In 2008, a bronze monument to Maxwell was erected in Edinburgh.

Many organizations and awards are also associated with Maxwell's name. The physics laboratory he headed established a scholarship for the most talented graduate students. The British Institute of Physics awards the Maxwell Medal and Prize to young physicists who have made significant contributions to science. The University of London has a Maxwell Professorship and a Maxwell Student Society. Created in 1977, the Maxwell Foundation organizes conferences in physics and mathematics.

Along with the recognition, Maxwell was named the most famous Scottish scientist in a 2006 poll, all of which indicates that great role, which he played in the history of science.

"... a great turning point occurred, which is forever associated with the names of Faraday, Maxwell, Hertz. The lion's share in this revolution belongs to Maxwell... After Maxwell, physical reality was conceived in the form of continuous fields that cannot be explained mechanically... This change in the concept of reality is the most deep and fruitful of those that physics has experienced since the time of Newton."

Einstein

Aphorisms and quotes by James Maxwell.
"When a phenomenon can be described as special case some general principle applicable to other phenomena, then they say that this phenomenon has been explained"

“...For the development of science, it is required in any given era not only that people think in general, but that they concentrate their thoughts on that part of the vast field of science that is in given time requires development"

“Of all the hypotheses... choose the one that does not interfere with further thinking about the things being studied”

“In order to lead quite correctly scientific work through systematic experimentation and precise demonstration, the art of strategy is required."

“...The history of science is not limited to listing successful research. It should tell us about unsuccessful studies and explain why some of the most capable people could not find the key of knowledge, and how the reputation of others gave only greater support to the errors into which they fell.”

"Any great man is one of a kind. In the historical procession of scientists, each of them has his own specific task and his own specific place»

“The real hearth of science is not volumes of scientific works, but the living mind of a person, and in order to advance science, it is necessary to direct human thought into a scientific direction. It can be done in various ways: by announcing some discovery, by defending a paradoxical idea, or by inventing a scientific phrase, or by setting forth a system of doctrine.”

Maxwell and the theory of the electromagnetic field.
Maxwell studied electrical and magnetic phenomena when many of them were already well understood. Coulomb's law and Ampere's law were created, and it was also proven that magnetic interactions are related to the action of electric charges. Many scientists of that time were proponents of the theory of long-range action, which states that interaction occurs instantaneously and in empty space.

The main role in the theory of short-range action was played by the research of Michael Faraday (30s of the 19th century). Faraday argued that the nature of electric charge was based on the surrounding electric field. The field of one charge is connected to the neighboring one in two directions. Currents interact using a magnetic field. Magnetic and electric fields according to Faraday, they are described by him in the form of lines of force, which are elastic lines in a hypothetical medium - in the ether.

Maxwell explained Faraday's ideas in mathematical form, something that physics really needed. With the introduction of the concept of field, the laws of Coulomb and Ampere became more convincing and deeply meaningful. In the concept of electromagnetic induction, Maxwell was able to consider the properties of the field itself. Under the influence of an alternating magnetic field, an electric field with closed lines of force is generated in empty space. This phenomenon is called a vortex electric field.
Maxwell showed that an alternating electric field can generate a magnetic field, similar to an ordinary electric current. This theory was called the displacement current hypothesis. Subsequently, Maxwell expressed the behavior of electromagnetic fields in his equations.

Reference. Maxwell's equations are equations that describe electromagnetic phenomena in different environments and vacuum space, and also relate to classical macroscopic electrodynamics. This is a logical conclusion drawn from experiments based on the laws of electrical and magnetic phenomena.
The main conclusion of Maxwell's equations is the finiteness of the propagation of electric and magnetic interactions, which distinguished between the theory of short-range action and the theory of long-range action. Speed ​​characteristics approached the speed of light 300,000 km/s. This gave Maxwell reason to argue that light is a phenomenon associated with the action of electromagnetic waves.

Molecular kinetic theory of Maxwell's gases.

Maxwell contributed to the study of molecular kinetic theory (today it is called statistical mechanics). He was the first to come up with the idea of ​​the statistical nature of the laws of nature. Maxwellcreated a law for the distribution of molecules by speed, and he also managed to calculate the viscosity of gases in relation to speed indicators and the free path of gas molecules. Thanks to Maxwell's work, we have a number of thermodynamic relations.

Reference. Maxwell's distribution is a theory of the velocity distribution of molecules of a system under conditions of thermodynamic equilibrium. Thermodynamic equilibrium is a condition for the translational motion of molecules described by the laws of classical dynamics.
Scientific worksMaxwell: “Theory of Heat”, “Matter and Motion”, “Electricity in Elementary Presentation”. He was also interested in the history of science. At one time he managed to publish the works of Cavendish, whichMaxwellI added my comments.
Maxwell was actively working on the study of electromagnetic fields. His theory about their existence received worldwide recognition only a decade after his death.

Maxwell was the first to classify matter and assign each its own laws, which were not reducible to Newton's laws of mechanics.

Many scientists have written about it. Physicist Feynman said about Maxwellwho discovered the laws of electrodynamicsMaxwell, looked through the centuries into the future.

MAXWELL (Maxwell) James Clerk ( Clerk) (1831-79), English physicist, creator of classical electrodynamics, one of the founders of statistical physics, organizer and first director (from 1871) of the Cavendish Laboratory. Developing the ideas of M. Faraday, he created the theory of the electromagnetic field (Maxwell's equations); introduced the concept of displacement current, predicted the existence of electromagnetic waves, and put forward the idea of ​​​​the electromagnetic nature of light. Established a statistical distribution named after him. He studied the viscosity, diffusion and thermal conductivity of gases. Showed that the rings of Saturn consist of individual bodies. Works on color vision and colorimetry (Maxwell disk), optics (Maxwell effect), elasticity theory (Maxwell's theorem, Maxwell-Cremona diagram), thermodynamics, history of physics, etc.

MAXWELL (Maxwell) James Clerk (June 13, 1831, Edinburgh, - November 5, 1879, Cambridge), English physicist, creator of classical electrodynamics, one of the founders of statistical physics, founder of one of the world's largest scientific centers late 19th - early 20th centuries - Cavendish Laboratory; created the theory of the electromagnetic field, predicted the existence of electromagnetic waves, put forward the idea of ​​​​the electromagnetic nature of light, established the first statistical law - the law of the distribution of molecules by speed, named after him.

Family. Years of study

Maxwell was the only son of the Scottish nobleman and lawyer John Clerk, who, having inherited the estate of a relative's wife, née Maxwell, added this name to his surname. After the birth of their son, the family moved to Southern Scotland, to their own estate Glenlair (“Shelter in the Valley”), where the boy spent his childhood. In 1841, James's father sent him to a school called Edinburgh Academy. Here, at the age of 15, Maxwell wrote his first scientific article, “On Drawing Ovals.” In 1847 he entered the University of Edinburgh, where he studied for three years, and in 1850 he moved to the University of Cambridge, where he graduated in 1854. By this time, Maxwell was a first-class mathematician with the superbly developed intuition of a physicist.

Creation of the Cavendish Laboratory. Teaching work

After graduating from the university, Maxwell was left in Cambridge for teaching work. In 1856 he received a position as professor at Marischal College at the University of Aberdeen (Scotland). In 1860 he was elected a member of the Royal Society of London. In the same year he moved to London, accepting an offer to take up the post of head of the department of physics at King's College, University of London, where he worked until 1865.

Returning to the University of Cambridge in 1871, Maxwell organized and headed the first specially equipped laboratory in Great Britain for physical experiments, known as the Cavendish Laboratory (named after the English scientist G. Cavendish). The formation of this laboratory, which at the turn of the 19th-20th centuries. turned into one of the largest centers of world science, Maxwell devoted the last years of his life.

Few facts from Maxwell's life are known. Shy, modest, he sought to live alone; I didn’t keep diaries. In 1858, Maxwell married, but his family life, apparently, was unsuccessful, aggravated his unsociability, and alienated him from his former friends. There is speculation that much of the important material about Maxwell's life was lost in the 1929 fire at his Glenclair home, 50 years after his death. He died of cancer at the age of 48.

Scientific activities

Maxwell's unusually wide sphere of scientific interests covered the theory of electromagnetic phenomena, the kinetic theory of gases, optics, the theory of elasticity and much more. One of his first works was research on the physiology and physics of color vision and colorimetry, begun in 1852. In 1861, Maxwell first obtained a color image by simultaneously projecting red, green and blue slides onto a screen. This proved the validity of the three-component theory of vision and outlined ways to create color photography. In his works 1857-59, Maxwell theoretically studied the stability of Saturn's rings and showed that Saturn's rings can be stable only if they consist of particles (bodies) that are not connected to each other.

In 1855, Maxwell began a series of his main works on electrodynamics. The articles “On Faraday's lines of force” (1855-56), “On physical lines of force” (1861-62), and “Dynamic theory of the electromagnetic field” (1869) were published. The research was completed with the publication of a two-volume monograph, “Treatise on Electricity and Magnetism” (1873).

Creation of the electromagnetic field theory

When Maxwell began researching electrical and magnetic phenomena in 1855, many of them had already been well studied: in particular, the laws of interaction of stationary electric charges (Coulomb's law) and currents (Ampere's law) had been established; It has been proven that magnetic interactions are interactions of moving electric charges. Most scientists of that time believed that interaction was transmitted instantly, directly through emptiness (the theory of long-range action).

A decisive turn to the theory of short-range action was made by M. Faraday in the 30s. 19th century According to Faraday's ideas, an electric charge creates an electric field in the surrounding space. The field of one charge acts on another, and vice versa. The interaction of currents is carried out through a magnetic field. Faraday described the distribution of electric and magnetic fields in space using lines of force, which, in his view, resemble ordinary elastic lines in a hypothetical medium - the world ether.

Maxwell fully accepted Faraday's ideas about the existence of an electromagnetic field, that is, about the reality of processes in space near charges and currents. He believed that the body cannot act where it does not exist.

The first thing Maxwell did was to give Faraday's ideas a rigorous mathematical form, so necessary in physics. It turned out that with the introduction of the concept of field, the laws of Coulomb and Ampere began to be expressed most fully, deeply and elegantly. In the phenomenon of electromagnetic induction, Maxwell saw a new property of fields: an alternating magnetic field generates in empty space an electric field with closed lines of force (the so-called vortex electric field).

The next and final step in the discovery of the basic properties of the electromagnetic field was taken by Maxwell without any reliance on experiment. He made a brilliant guess that an alternating electric field generates a magnetic field, just like an ordinary electric current (displacement current hypothesis). By 1869, all the basic laws of the behavior of the electromagnetic field were established and formulated in the form of a system of four equations, called Maxwell's equations.

A fundamental conclusion followed from Maxwell's equations: the finite speed of propagation of electromagnetic interactions. This is the main thing that distinguishes the theory of short-range action from the theory of long-range action. The speed turned out to be equal to the speed of light in vacuum: 300,000 km/s. From this Maxwell concluded that light is a form of electromagnetic waves.

Works on the molecular kinetic theory of gases

Maxwell's role in the development and establishment of molecular kinetic theory (the modern name is statistical mechanics) is extremely important. Maxwell was the first to make a statement about the statistical nature of the laws of nature. In 1866 he discovered the first statistical law - the law of the distribution of molecules by speed (Maxwell distribution). In addition, he calculated the viscosity of gases depending on the speeds and mean free path of molecules, and derived a number of thermodynamic relations.

Maxwell was a brilliant popularizer of science. He wrote a number of articles for the Encyclopedia Britannica and popular books: “The Theory of Heat” (1870), “Matter and Motion” (1873), “Electricity in Elementary Exposition” (1881), which were translated into Russian; gave lectures and reports on physical topics for a wide audience. Maxwell also showed great interest in the history of science. In 1879 he published the works of G. Cavendish on electricity, providing them with extensive comments.

Evaluation of Maxwell's work

The scientist's works were not appreciated by his contemporaries. Ideas about the existence of an electromagnetic field seemed arbitrary and unfruitful. Only after G. Hertz in 1886-89 experimentally proved the existence of electromagnetic waves predicted by Maxwell, his theory received universal recognition. This happened ten years after Maxwell's death.

After experimental confirmation of the reality of the electromagnetic field, a fundamental scientific discovery was made: there are different types of matter, and each of them has its own laws, which are not reducible to Newton’s laws of mechanics. However, Maxwell himself was hardly clearly aware of this and at first tried to build mechanical models of electromagnetic phenomena.

The American physicist R. Feynman excellently spoke about Maxwell’s role in the development of science: “In the history of mankind (if you look at it, say, ten thousand years later), the most significant event of the 19th century will undoubtedly be Maxwell’s discovery of the laws of electrodynamics. Against the background of this important scientific opening, the American Civil War in the same decade will look like a provincial incident."

Maxwell is buried not in the tomb of the great men of England - Westminster Abbey - but in a modest grave next to his beloved church in a Scottish village, not far from the family estate.

Creator of classical electrodynamics, one of the founders of statistical physics.

Maxwell James Clerk (13.6.1831, Edinburgh, - 5.11.1879, Cambridge), English physicist, creator of classical electrodynamics, one of the founders of statistical physics. Member of the Royal Society of London (1860). The son of a Scottish nobleman from a noble family of Clerks. He studied at Edinburgh (1847-50) and Cambridge (1850-54) universities. Professor at Marischal College, Aberdeen (1856-60), then at the University of London (1860-65). From 1871 he became a professor at the University of Cambridge, where M. founded the first specially equipped physical laboratory in Great Britain - the Cavendish Laboratory, of which he was director from 1871.

M.'s scientific activities cover problems of electromagnetism, kinetic theory of gases, optics, elasticity theory, and much more. M. completed his first work, “On Drawing Ovals and Ovals with Many Tricks,” when he was not yet 15 years old (1846, published in 1851). Some of his first research was work on the physiology and physics of color vision and colorimetry (1852-72, see Color measurements). In 1861, M. was the first to demonstrate a color image obtained from the simultaneous projection of red, green, and blue slides onto a screen, thereby proving the validity of the three-component theory of color vision and at the same time outlining ways to create color photography. He created one of the first instruments for the quantitative measurement of color, which was called the disk of M. In 1857-59, M. carried out a theoretical study of the stability of the rings of Saturn and showed that the rings of Saturn can be stable only if they consist of unconnected solid particles.

In research on electricity and magnetism (articles “On Faradian lines of force”, 1855-56; “On physical lines of force”, 1861-62; “Dynamic theory of the electromagnetic field”, 1864; two-volume fundamental “Treatise on Electricity and Magnetism”, 1873 ) M. mathematically developed the views of M. Faraday on the role of the intermediate medium in electrical and magnetic interactions. He tried (following Faraday) to interpret this medium as an all-pervasive world ether, but these attempts were not successful. Further development physics showed that the carrier of electromagnetic interactions is the electromagnetic field, the theory of which (in classical physics) M. created. In this theory, M. summarized all the facts of macroscopic electrodynamics known at that time and for the first time introduced the idea of ​​a displacement current generating a magnetic field like an ordinary current (conduction current moving electric charges). M. expressed the laws of the electromagnetic field in the form of a system of 4 partial differential equations (see Maxwell's equations). The general and comprehensive nature of these equations was manifested in the fact that their analysis made it possible to predict many previously unknown phenomena and patterns. Thus, it followed from them the existence of electromagnetic waves, which were later experimentally discovered by G. Hertz. Studying these equations, M. came to the conclusion about the electromagnetic nature of light (1865) and showed that the speed of any other electromagnetic waves in a vacuum is equal to the speed of light. He measured (with greater accuracy than W. Weber and F. Kohlrausch in 1856) the ratio of the electrostatic unit of charge to the electromagnetic one and confirmed its equality to the speed of light. It followed from M.'s theory that electromagnetic waves produce pressure. Light pressure was experimentally established in 1899 by P. N. Lebedev.

The theory of electromagnetism of M. received full experimental confirmation and became generally accepted classical basis modern physics. The role of this theory was clearly described by A. Einstein: “... here a great turning point occurred, which is forever associated with the names of Faraday, Maxwell, Hertz. The lion's share in this revolution belongs to Maxwell... After Maxwell, physical reality was conceived in the form of continuous fields that cannot be explained mechanically... This change in the concept of reality is the most profound and fruitful of those that physics has experienced since the time of Newton" (Collected Scientific Works, Vol. 4, M., 1967, p. 138).

In research on the molecular kinetic theory of gases (articles “Explanations on the dynamic theory of gases,” 1860, and “Dynamic theory of gases,” 1866), M. was the first to solve the statistical problem of the distribution of molecules ideal gas by speed (see Maxwell distribution). M. calculated the dependence of gas viscosity on the speed and free path of molecules (1860), calculating absolute value the latter, derived a number of important relations of thermodynamics (1860). Experimentally measured the viscosity coefficient of dry air (1866). In 1873-74 M. discovered the phenomenon of double refraction in a flow (M. effect).

M. was a major popularizer. He wrote a number of articles for the Encyclopedia Britannica, popular books [such as “The Theory of Heat” (1870), “Matter and Motion” (1873), “Electricity in Elementary Exposition” (1881), translated into Russian]. An important contribution to the history of physics is M.’s publication of manuscripts of G. Cavendish’s works on electricity (1879) with extensive comments by M.