Many scientific publications and journals in recent times publish articles about achievements in physics and modern scientists, and publications about physicists of the past are rare. We would like to correct this situation and recall one of the outstanding physicists of the last century, James Clerk Maxwell. This is a famous English physicist, the father of classical electrodynamics, statistical physics and many other theories, physical formulas and inventions. Maxwell became the founder and first head of the Cavendish Laboratory.
As you know, Maxwell came from Edinburgh and was born in 1831 into a noble family, which had a relationship with the Scottish surname Clerks of Penicuik. Maxwell's childhood was spent on the Glenlar estate. James' ancestors were politicians, poets, musicians and scientists. Probably, a penchant for the sciences was inherited by him.
James was brought up without a mother (since she died when he was 8 years old) by a father who cared for the boy. The father wanted his son to study natural Sciences. James immediately fell in love with technology and quickly developed practical skills. Little Maxwell took the first lessons at home with perseverance, since he did not like the harsh methods of education used by the teacher. Further training took place in an aristocratic school, where the boy showed great mathematical abilities. Maxwell especially liked geometry.
To many great people, geometry seemed to be an amazing science, and even at the age of 12 he spoke of a geometry textbook as a holy book. Maxwell loved geometry as well as other scientific luminaries, but he had a bad relationship with his schoolmates. They constantly came up with offensive nicknames for him and one of the reasons was his ridiculous clothes. Maxwell's father was considered an eccentric and bought his son clothes that made him smile.
Maxwell already in childhood showed great promise in the field of science. In 1814 he was sent to study at Edinburgh Grammar School, and in 1846 he was awarded a medal for merit in mathematics. His father was proud of his son and was given the opportunity to present one of his son's scientific papers before the board of the Edinburgh Academy of Sciences. This work concerned the mathematical calculations of elliptical figures. Then this work was called "On the drawing of ovals and on ovals with many tricks." It was written in 1846 and published to the masses in 1851.
Maxwell began to study physics intensively after transferring to the University of Edinburgh. Kalland, Forbes and others became his teachers. They immediately saw in James a high intellectual potential and an irresistible desire to study physics. Prior to this period, Maxwell had dealt with certain branches of physics and studied optics (he devoted a lot of time to the polarization of light and Newton's rings). In this he was helped by the famous physicist William Nicol, who at one time invented the prism.
Of course, Maxwell was not alien to other natural sciences, and he Special attention devoted to the study of philosophy, history of science and aesthetics.
In 1850 he entered Cambridge, where Newton had once worked, and in 1854 received his academic degree. After that, his research touched the field of electricity and electrical installations. And in 1855 he was granted membership in the council of Trinity College.
Maxwell's first significant scientific work was On Faraday's Lines of Force, which appeared in 1855. At one time, Boltzmann said about Maxwell's article that this work has a deep meaning and shows how purposefully the young scientist approaches scientific work. Boltzmann believed that Maxwell not only understood the issues of natural science, but also made a special contribution to theoretical physics. Maxwell outlined in his article all the trends in the evolution of physics for the next few decades. Later, Kirchhoff, Mach and. came to the same conclusion.
How was the Cavendish Laboratory formed?
After completing his studies at Cambridge, James Maxwell remained here as a teacher and in 1860 he became a member of the Royal Society of London. At the same time, he moved to London, where he was given a position as head of the physics department at King's College, University of London. He worked in this position for 5 years.
In 1871, Maxwell returned to Cambridge and created the first laboratory in England for research in the field of physics, which was called the Cavendish Laboratory (in honor of Henry Cavendish). The development of the laboratory, which has become a real center scientific research, Maxwell devoted the rest of his life.
Little is known about Maxwell's life, as he kept no notes or diaries. He was a modest and shy person. Maxwell died at the age of 48 from cancer.
What is the scientific legacy of James Maxwell?
Maxwell's scientific activity covered many areas in physics: theory electromagnetic phenomena, kinematic theory of gases, optics, theory of elasticity and others. The first thing that interested James Maxwell was the study and conduct of research in the physiology and physics of color vision.
Maxwell for the first time managed to get a color image, which was obtained due to the simultaneous projection of the red, green and blue range. By this, Maxwell once again proved to the world that the color image of vision is based on a three-component theory. This discovery marked the beginning of the creation of color photographs. In the period from 1857-1859, Maxwell was able to investigate the stability of Saturn's rings. His theory says that the rings of Saturn will be stable only under one condition - the unconnectedness of particles or bodies.
From 1855, Maxwell paid special attention to work in the field of electrodynamics. There are several scientific works of this period "On Faraday's lines of force", "On physical lines of force", "Treatise on electricity and magnetism" and "Dynamical theory of electro magnetic field».
Maxwell and the theory of the electromagnetic field.
When Maxwell began to study electrical and magnetic phenomena, many of them were already well studied. Was created Coulomb's law, Ampère's law, it was also proved that magnetic interactions are connected by the action of electric charges. Many scientists of that time were supporters of the long-range theory, which states that the interaction occurs instantly and in empty space.
The main role in the theory of short-range action was played by the studies of Michael Faraday (30s of the 19th century). Faraday argued that the nature of the electric charge is based on the surrounding electric field. The field of one charge is connected with the neighboring one in two directions. The currents interact with the help of a magnetic field. Magnetic and electric fields according to Faraday are described by him in the form lines of force, which are elastic lines in a hypothetical medium - in the ether.
Maxwell supported Faraday's theory of the existence of electromagnetic fields, that is, he was a supporter of emerging processes around charge and current.
Maxwell explained Faraday's ideas in a mathematical form, which physics really needed. With the introduction of the field concept, 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 in empty space, electric field with closed lines of force. This phenomenon is called a vortex electric field.
Maxwell's next discovery was that an alternating electric field could generate a magnetic field, much like an ordinary electric current. This theory was called the displacement current hypothesis. In the future, Maxwell expressed the behavior of electromagnetic fields in his equations.
Reference. Maxwell's equations are equations describing electromagnetic phenomena in various media and vacuum space, and also refer 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 electrical and magnetic interactions, which distinguished the theory of short-range interaction and the theory of long-range interaction. Velocity 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 electromagnetic waves.
Molecular-kinetic theory of Maxwell's gases.
Maxwell contributed to the study of molecular kinetic theory (now this science is called statistical mechanics). Maxwell was the first to come up with the idea of the statistical nature of the laws of nature. He created the law of distribution of molecules by speeds, and he also managed to calculate the viscosity of gases in relation to speed indicators and the mean free path of gas molecules. Also, thanks to the work of Maxwell, we have a number of thermodynamic relations.
Reference. The Maxwell distribution is a theory of the velocity distribution of the 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.
Maxwell had many scientific papers that were published: "The Theory of Heat", "Matter and Motion", "Electricity in an Elementary Presentation" and others. Maxwell not only moved science into the period, but was also interested in its history. At one time he managed to publish the works of G. Cavendish, which he supplemented with his comments.
What will the world remember about James Clerk Maxwell?
Maxwell led active work on the study of electromagnetic fields. His theory of their existence did not receive worldwide recognition until a decade after his death.
Maxwell was the first to classify matter and assign its own laws to each, which were not reduced to the laws of Newtonian mechanics.
Many scientists have written about Maxwell. The physicist R. Feynman said about him that Maxwell, who discovered the laws of electrodynamics, looked through the centuries into the future.
Epilogue. James Clerk Maxwell died November 5, 1879 in Cambridge. He was buried in a small Scottish village near his favorite church, which is located not far from his family estate.
James Maxwell (1831-1879).
James Clerk Maxwell was born in Edinburgh on June 13, 1831. Shortly after the birth of the boy, his parents took him to their estate Glenlar. Since that time, the "lair in a narrow gorge" has firmly entered the life of Maxwell. Here his parents lived and died, here he himself lived and was buried for a long time.
When James was eight years old, misfortune came to the house: his mother became seriously ill and soon died. Now the only educator of James was his father, to whom he retained a feeling of tender affection and friendship for the rest of his life. John Maxwell was not only the father and educator of his son, but also his most faithful friend.
Soon the time came when the boy had to start studying. At first, teachers were invited to the house. But the Scottish home teachers were just as rude and ignorant as their English counterparts, described with such sarcasm and hatred by Dickens. Therefore, it was decided to send James to a new school, which bore the loud name of the Edinburgh Academy.
The boy was gradually drawn into school life. He became more interested in the lessons. He especially liked geometry. She remained one of Maxwell's strongest hobbies for the rest of his life. Geometric images and models played a huge role in his scientific work. Started with her scientific way Maxwell.
Maxwell graduated from the academy in one of the first graduations. At parting with the beloved school, he composed the anthem of the Edinburgh Academy, which was sung in unison and with enthusiasm by its pupils. Now the doors of the University of Edinburgh were flung open before him.
As a student, Maxwell carried out serious research on the theory of elasticity, which was highly appreciated by specialists. And now he was faced with the question of the prospect of his further studies at Cambridge.
Founded in 1284, St. Peter's (Peterhouse), and the most famous is the College of St. Trinity College (Trinity College), founded in 1546. The glory of this college was created by his famous pupil Isaac Newton. Peterhouse and Trinity College were successively the Cambridge sojourn of the young Maxwell. After a short stay at Peterhouse, Maxwell transferred to Trinity College.
The volume of Maxwell's knowledge, the power of his intellect and independence of thought allowed him to achieve a high place in his release. He took second place.
The young bachelor was left at Trinity College as a teacher. But he was concerned about scientific problems. In addition to his old fascination with geometry and the problem of colors, which he began to study as early as 1852, Maxwell became interested in electricity.
On February 20, 1854, Maxwell informs Thomson of his intention to "attack electricity". The result of the "attack" was the essay "On Faraday's Lines of Force" - the first of Maxwell's three main works devoted to the study of the electromagnetic field. The word "field" first appeared in that same letter to Thomson, but neither in this nor in a later work on lines of force. Maxwell does not use it. This concept reappears only in 1864 in the work "Dynamical Theory of the Electromagnetic Field".
In the autumn of 1856 Maxwell took up the post of professor of natural philosophy at Marischal College, Aberdeen. The Department of Natural Philosophy, i.e. the Department of Physics in Aberdeen, did not exist before Maxwell, and the young professor had to organize an educational and scientific work in physics.
The stay in Aberdeen was marked important event and in Maxwell's personal life: he married the daughter of the head of Marischal College, Daniel Dewar, Katherine Mary Dewar. This event took place in 1858. From that time until the end of their lives, the Maxwells went through their life path hand in hand.
In 1857-1859, the scientist carried out his calculations of the movement of Saturn's rings. He showed that the liquid ring during rotation will be destroyed by the waves arising in it and will break into separate satellites. Maxwell considered the motion of a finite number of such satellites. The most difficult mathematical research brought him the Adams Prize and fame as a first-class mathematician. The prized essay was published in 1859 by the University of Cambridge.
From the study of the rings of Saturn, it was quite natural to move on to the consideration of the motions of gas molecules. The Aberdeen period of Maxwell's life ended with his speech at the meeting of the British Association in 1859 with a report "On the dynamical theory of gases". This document marked the beginning of Maxwell's many years of fruitful research in the field of the kinetic theory of gases and statistical physics.
Since the department where Maxwell worked was closed, the scientist had to look for new job. In 1860, Maxwell was elected professor of natural philosophy at King's College London.
The London period was marked by the publication of a large article "Explanations to the Dynamic Theory of Gases", which was published in the leading English physics journal, the Philosophical Journal, in 1860. With this article, Maxwell made a huge contribution to a new branch of theoretical physics - statistical physics. The founders of statistical physics in its classical form are Maxwell, Boltzmann and Gibbs.
The Maxwells spent the summer of 1860 at the Glenlar family estate before the start of the autumn semester in London. However, Maxwell failed to rest and gain strength. He fell ill with smallpox in a severe form. The doctors feared for his life. But the extraordinary courage and patience of Catherine, who was devoted to him, who did everything to get out her sick husband, helped them to defeat terrible disease. Such a difficult test began his life in London. During this period of his life, Maxwell published a large article on colors, as well as the work "Explanations to the dynamic theory of gases." But the main work of his life was devoted to the theory of electricity.
He publishes two main works on the electromagnetic field theory he created: "On Physical Lines of Force" (1861-1862) and "Dynamical Theory of the Electromagnetic Field" (1864-1865). For ten years, Maxwell has grown into a prominent scientist, the creator of the fundamental theory of electromagnetic phenomena, which, along with mechanics, thermodynamics and statistical physics, has become one of the foundations of classical theoretical physics.
During the same period of his life, Maxwell began work on electrical measurements. He was especially interested in rational system electrical units, since the electromagnetic theory of light he created was based only on the coincidence of the ratio of electrostatic and electromagnetic units of electricity with the speed of light. It is quite natural that he became one of the active members of the "Commission of Units" of the British Association. In addition, Maxwell deeply understood the close connection between science and technology, the importance of this union both for the progress of science and for technical progress. Therefore, from the sixties until the end of his life, he tirelessly worked in the field of electrical measurements.
The stressful London life had taken a toll on the health of Maxwell and his wife, and they decided to live on their family estate of Glenlar. This decision became inevitable after Maxwell's serious illness at the end of his summer vacation in 1865, which he spent as usual at his estate. Maxwell left the service in London and lived in Glenlare for five years (from 1866 to 1871), occasionally traveling to Cambridge for examinations, and only in 1867, on the advice of doctors, he traveled to Italy. Being engaged in economic affairs in Glenlar, Maxwell did not leave scientific studies. He worked hard on the main work of his life, "A Treatise on Electricity and Magnetism", wrote the book "Theory of Heat", important work about regulators, a number of articles on the kinetic theory of gases, participated in meetings of the British Association. creative life Maxwell in the countryside continued as intensely as in the university city.
In 1871, Maxwell published The Theory of Heat in London. This textbook has been very popular. The scientist wrote that the purpose of his book "The Theory of Heat" was to present the doctrine of heat "in the sequence in which it developed."
Shortly after the publication of The Theory of Heat, Maxwell received an offer to take the newly organized chair of experimental physics at Cambridge. He agreed and on 8 March 1871 was appointed Cavendish Professor at the University of Cambridge.
In 1873, the Treatise on Electricity and Magnetism (in two volumes) and the book Matter and Motion were published.
"Matter and Motion" is a small book devoted to the presentation of the fundamentals of mechanics.
"Treatise on Electricity and Magnetism" - the main work of Maxwell and the pinnacle of his scientific work. In it, he summed up the results of many years of work on electromagnetism, which began as early as the beginning of 1854. The preface to the "Treatise" is dated February 1, 1873. Nineteen years Maxwell worked on his fundamental work!
Maxwell reviewed the entire amount of knowledge on electricity and magnetism of his time, starting with the basic facts of electrostatics and ending with the electromagnetic theory of light he created. He summed up the struggle between the theories of long-range and short-range action, which began during Newton's lifetime, devoting the last chapter of his book to consideration of theories of action at a distance. Maxwell did not openly speak out against the theories of electricity that existed before him; he presented the Faraday concept as equal to the mainstream theories, but the whole spirit of his book, his approach to the analysis of electromagnetic phenomena, was so new and unusual that contemporaries refused to understand the book.
In the famous preface to the Treatise, Maxwell characterizes the purpose of his work as follows: to describe the most important of electromagnetic phenomena, to show how they can be measured, and "to trace the mathematical relationships between the measured quantities." He indicates that he will try "as far as possible to shed light on the connection between the mathematical form of this theory and general dynamics, in order to be prepared to a certain extent for the definition of those dynamic laws, among which we should look for illustrations or explanations of electromagnetic phenomena."
Maxwell considers the laws of mechanics to be the basic laws of nature. It is no coincidence that, therefore, as a fundamental prerequisite to his basic equations of electromagnetic theory, he sets out the basic provisions of dynamics. But at the same time, Maxwell understands that the theory of electromagnetic phenomena is a qualitatively new theory, not reducible to mechanics, although mechanics facilitates penetration into this new field of natural phenomena.
Maxwell's main conclusions boil down to the following: an alternating magnetic field excited by a changing current creates an electric field in the surrounding space, which in turn excites a magnetic field, etc. Changing electric and magnetic fields, mutually generating each other, form a single alternating electromagnetic field is an electromagnetic wave.
He derived equations showing that the magnetic field created by a current source propagates from it with constant speed. Having arisen, the electromagnetic field propagates in space at the speed of light of 300,000 km/s, occupying a larger and larger volume. D. Maxwell argued that the waves of light are of the same nature as the waves that arise around a wire in which there is a variable electricity. They differ from each other only in length. Very short wavelengths is visible light.
In 1874, he begins a major historical work: the study of the scientific heritage of the eighteenth-century scientist Henry Cavendish and prepares it for publication. After Maxwell's research, it became clear that long before Faraday, Cavendish discovered the influence of a dielectric on the magnitude of the electric capacitance, and 15 years before Coulomb discovered the law of electrical interactions.
Cavendish's works on electricity, describing experiments, took up a large volume, published in 1879 under the title "Papers on Electricity of the Honorable Henry Cavendish." This was Maxwell's last book published during his lifetime. On November 5, 1879, he died in Cambridge.
(1831-1879) English physicist, creator of the electromagnetic field theory
James Clerk Maxwell was born in 1831 into a wealthy noble family that belonged to the noble and old Scottish family of Clerks. His father, John Clerk, who adopted the surname Maxwell, was a lawyer. He showed great interest to natural science, was a man with versatile cultural interests, a traveler, inventor and scientist. James spent his childhood in Glenlar, a picturesque corner located a few miles from the Irish Sea.
James was very fond of reworking things, improving their design, crafting, drawing, knitting and embroidering. His natural curiosity and propensity for solitary contemplation were fully understood by his family, and especially by his father. James carried his friendship with his father throughout his life, and, as an adult, he will say that the greatest success in life is to have kind and wise parents. The boy lost his mother early: in 1839 she died without undergoing a major operation.
In 1841, at the age of 10, James entered the Edinburgh Academy - secondary educational institution type of classical gymnasium. Until the fifth grade, he studied without much interest, he was sick a lot. In the fifth grade, the boy became interested in geometry, began to make models of geometric bodies and come up with his own methods for solving problems. In 1846, when he was not even 15 years old, he wrote his first scientific work - "On the drawing of ovals and on ovals with many tricks", which was subsequently published in the proceedings of the Royal Society of Edinburgh. This youthful work opens a two-volume collection of Maxwell's scientific articles.
In 1847, without finishing grammar school, he entered the University of Edinburgh. By this time, James became interested in experiments in optics, chemistry, magnetism, and did a lot of physics and mathematics. In 1850, he delivered a report to the members of the Royal Society "On the Equilibrium of Elastic Bodies", in which he proved a well-known theorem called "Maxwell's theorem".
In 1850, James transferred to the University of Cambridge, to the famous Trinity College, where Isaac Newton had once studied. An important role in shaping the scientific worldview young man played his communication with the scientists of the college, primarily with George Stokes and William Thomson (Kelvin). A painstaking study of Michael Faraday's work on electricity paved the way for his own further research.
In 1854, Maxwell graduated from the University of Cambridge, receiving a second award - the Smith Prize, awarded for winning the most difficult mathematical exam. He lost the first award to Raus, the future famous mechanic and mathematician. Immediately after graduation, he began teaching at Trinity College. Maxwell lectures on hydraulics and optics, and does research on color theory. In 1855, he sent a report "Experiments in Color" to the Royal Society of Edinburgh, developing a theory of color vision. As contemporaries testified, James Maxwell was not a brilliant teacher, but he treated his pedagogical duties very conscientiously. His true passion was scientific research.
By this time, he had awakened interest in the problems of electricity and magnetism, and in 1855-1856 he completed his first work in this area - "On Faraday's lines of force." It already outlines the main features of his future great work. Since 1855, the scientist has been a member of the Royal Society of Edinburgh.
In 1856, Professor J. Maxwell went to work at the Department of Natural Philosophy at the University of Aberdeen in Scotland, where he remained until 1860. In 1857 he sent his paper on electromagnetism to Michael Faraday, which touched him very much. Faraday was amazed at the strength of the young scientist's talent. During this period, Maxwell, in parallel with the problems of electromagnetism, was solving scientific problems in other areas. He takes part in the Cambridge University competition on the stability of the rings of Saturn, and submits to the competition the work "On the stability of the rings of Saturn", in which he shows that the rings are not solid or liquid, but are a swarm of meteorites. This work has been called one of the great applications of mathematics, and the scientist received an honorary Adams Prize.
James Maxwell is one of the creators of the kinetic theory of gases. In 1859, he established a statistical law for the distribution of gas molecules in a state of thermal equilibrium over velocities, which was called the Maxwell distribution.
From 1860 to 1865 Maxwell was professor of physics at King's College, University of London. Here he first met his idol - Michael Faraday, who was already old and sick.
The election of J. Maxwell in 1861 as a member of the Royal Society in London was a recognition of the importance of his scientific works, among which two important articles on electromagnetism should be noted: "On Physical Lines of Force" (1861-1862) and "Dynamical Theory of the Electromagnetic Field" (1864-1862). 1865). AT latest work the theory of the electromagnetic field is presented, which he formulated in the form of a system of several equations - Maxwell's equations, expressing all the basic laws of electromagnetic phenomena. It also gives an idea of light as electromagnetic waves.
1 The theory of the electromagnetic field is the greatest scientific achievement of James Maxwell, it marked the beginning of a new stage in physics. Most scientists highly appreciated the theory of Maxwell, who became one of the world's leading physicists.
In 1865 he had an accident while riding. Transferring serious disease, he left the department at the University of London and moved to his native Glenlar, to his estate, where for six years (until 1871) he continued research on the theory of electromagnetism and heat. The results of his work were published in 1871 in The Theory of Heat.
In 1871, at the expense of a descendant of the famous English scientist of the 18th century, Henry Cavendish - the Duke of Cavendish - the Department of Experimental Physics was established at the University of Cambridge, the first professor of which was Maxwell. Along with the chair, he also took over the laboratory, the construction of which had just begun under his supervision and guidance. It was the future famous Cavendish Laboratory - a scientific and research center, which later became famous throughout the world. On June 16, 1874, the inauguration of the Cavendish Laboratory took place, which Maxwell headed until the end of his life. Subsequently, it was headed by J. Rayleigh, D. D. Gomson, E. Rutherford, W. Bragg.
James Maxwell was an excellent head of the laboratory and had unquestioned authority among the staff. He was distinguished by great simplicity, gentleness and sincerity in dealing with people, he was always principled and active, appreciated and loved humor.
In Cavendish, Maxwell did a great deal of scientific and pedagogical work. In 1873, his "Treatise on Electricity and Magnetism" was published, summing up his research in this area and becoming the pinnacle of his scientific work. He devoted eight years to the Treatise, and devoted the last five years of his life to processing and publishing the unpublished works of Henry Cavendish, after whom the laboratory was named. Maxwell published two large volumes of Cavendish's works with his comments in 1879.
He never showed selfishness and resentment, did not strive for fame, and always calmly accepted criticism addressed to him. His companions have always been self-control and endurance. Even when he fell seriously ill and experienced excruciating pain, he remained balanced and calm. The scientist courageously met the doctor's words that he had no more than a month to live.
James Clerk Maxwell died on November 5, 1879 of cancer at the age of forty-eight. The doctor who treated him writes in his memoirs that James courageously endured the disease. He experienced incredible pain, but none of those around him even knew about it. Until his death, he thought clearly and clearly, perfectly aware of his imminent death and maintaining complete calm.
MAXWELL (Maxwell) James Clerk ( Clerk) (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. 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, put forward the idea of the electromagnetic nature of light. Established a statistical distribution named after him. Investigated the viscosity, diffusion and thermal conductivity of gases. He showed that the rings of Saturn are composed of separate bodies. Proceedings on color vision and colorimetry (Maxwell's disk), optics (Maxwell's effect), theory of elasticity (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 century - 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 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 family name. After the birth of their son, the family moved to South Scotland, to their own estate Glenlar ("Shelter in the valley"), where the boy spent his childhood. In 1841, his father sent James to a school called Edinburgh Academy. Here, at the age of 15, Maxwell wrote his first scientific article "On the Drawing of Ovals". In 1847 he entered the University of Edinburgh, where he studied for three years, and in 1850 moved to the University of Cambridge, from which he graduated in 1854. By this time, Maxwell was a first-class mathematician with excellent developed intuition physics.
Creation of the Cavendish Laboratory. Teaching work
After graduation, Maxwell was left in Cambridge for teaching work. In 1856 he received a professorship at Marishall 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 the post of head of the department of physics at King's College, London University, where he worked until 1865.
Returning to the University of Cambridge in 1871, Maxwell organized and headed the UK's first specially equipped laboratory for physical experiments, known as the Cavendish Laboratory (after the English scientist G. Cavendish). The formation of this laboratory, which at the turn of the 19-20 centuries. turned into one of the largest centers of world science, Maxwell devoted last years own life.
Little is known about Maxwell's life. Shy, modest, he strove to live in solitude; did not keep diaries. Maxwell married in 1858, but family life, apparently, it turned out unsuccessfully, exacerbated his unsociableness, alienated him from his former friends. There is an assumption that many important materials about the life of Maxwell were lost during the fire of 1929 in his Glenlar house, 50 years after his death. He died of cancer at the age of 48.
Scientific activity
Maxwell's unusually wide scope 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 projecting red, green, and blue transparencies onto a screen simultaneously. This proved the validity of the three-component theory of vision and outlined ways to create a color photograph. In the works of 1857-59, Maxwell theoretically investigated the stability of the rings of Saturn and showed that the rings of Saturn can be stable only if they consist of unrelated particles (bodies).
In 1855 Maxwell began a cycle of his main works on electrodynamics. The articles "On Faraday Field Lines" (1855-56), "On Physical Field Lines" (1861-62), and "Dynamical Theory of the Electromagnetic Field" (1869) were published. The research was completed with the publication of the 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 (Ampère's law) were established; it has been proved that magnetic interactions are interactions of moving electric charges. Most scientists of that time believed that the interaction is transmitted instantly, directly through the void (long-range theory).
A decisive turn towards the theory of short-range action was made by M. Faraday in the 1930s. 19th century According to Faraday, 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 by means of a magnetic field. The distribution of electric and magnetic fields in space was described by Faraday with the help of 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 function where it does not exist.
The first thing Maxwell did was to give Faraday's ideas a strict mathematical form so necessary in physics. It turned out that with the introduction of the concept of a field, the laws of Coulomb and Ampere began to be expressed most fully, deeply and gracefully. 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 last, 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, like an ordinary electric current (hypothesis of the displacement current). By 1869, all the basic laws governing the behavior of the electromagnetic field had been established and formulated as a system of four equations, called Maxwell's equations.
A fundamental conclusion followed from Maxwell's equations: the finiteness of the propagation velocity 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
The role of Maxwell in the development and development of the molecular-kinetic theory (the modern name is statistical mechanics) is extremely great. 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 velocities (Maxwell distribution). In addition, he calculated the values of the viscosity of gases depending on the velocities 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 Encyclopædia Britannica and popular books: "The Theory of Heat" (1870), "Matter and Motion" (1873), "Electricity in Elementary Presentation" (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.
Appreciation of Maxwell's work
The works of the scientist were not appreciated by his contemporaries. Ideas about the existence of an electromagnetic field seemed arbitrary and unproductive. Only after G. Hertz in 1886-89 experimentally proved the existence of electromagnetic waves predicted by Maxwell, his theory received universal recognition. It 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 kinds matter, and each of them has its own laws, not reducible to the laws of Newtonian mechanics. However, Maxwell himself was hardly clearly aware of this and at first he tried to build mechanical models of electromagnetic phenomena.
The American physicist R. Feynman said excellently about the role of Maxwell in the development of science: “In the history of mankind (if you look at it, say, in ten thousand years), the most significant event of the 19th century will undoubtedly be the discovery by Maxwell of the laws of electrodynamics. Against the background of this important scientific discovery Civil War in America in the same decade will look like a provincial incident.
Maxwell is buried not in the tomb of the great people of England - Westminster Abbey - but in a modest grave next to his favorite church in a Scottish village, not far from the family estate.
MAXWELL, James Clerk
The English physicist James Clerk Maxwell was born in Edinburgh to a Scottish nobleman from the noble family of Clerks. He studied first at Edinburgh (1847-1850), then at Cambridge (1850-1854) universities. In 1855, Maxwell became a member of the board of Trinity College, in 1856-1860. was a professor at Marishall College, Aberdeen University, from 1860 he headed the Department of Physics and Astronomy at King's College, University of London. In 1865, in connection with a serious illness, Maxwell resigned from the chair and settled in his family estate of Glenlar near Edinburgh. There he continued to study science, wrote several essays on physics and mathematics. In 1871 he took the chair of experimental physics at the University of Cambridge. Maxwell organized a research laboratory, which opened on June 16, 1874 and was named Cavendish - in honor of Henry Cavendish.
Maxwell completed his first scientific work while still at school, inventing a simple way to draw oval shapes. This work was reported at a meeting of the Royal Society and even published in its Proceedings. As a member of the Council of Trinity College, he experimented on color theory, acting as a successor to Jung's theory and Helmholtz's theory of the three primary colors. In experiments on mixing colors, Maxwell used a special top, the disk of which was divided into sectors, colored in different colors(Maxwell disk). When the spinning top rotated quickly, the colors merged: if the disk was painted over in the way the colors of the spectrum are located, it seemed white; if one half of it was painted red and the other half yellow, it appeared orange; mixing blue and yellow gave the impression of green. In 1860, Maxwell was awarded the Rumfoord Medal for his work on color perception and optics.
In 1857, the University of Cambridge announced a competition for best job on the stability of Saturn's rings. These formations were discovered by Galileo at the beginning of the 17th century. and represented an amazing mystery of nature: the planet seemed to be surrounded by three continuous concentric rings, consisting of a substance of an unknown nature. Laplace proved that they cannot be solid. After spending mathematical analysis, Maxwell was convinced that they could not be liquid either, and came to the conclusion that such a structure could be stable only if it consisted of a swarm of unrelated meteorites. The stability of the rings is ensured by their attraction to Saturn and the mutual motion of the planet and meteorites. For this work, Maxwell received the J. Adams Prize.
One of Maxwell's first works was his kinetic theory of gases. In 1859, the scientist made a report at a meeting of the British Association, in which he gave the distribution of molecules by velocities (Maxwellian distribution). Maxwell developed the ideas of his predecessor in developing the kinetic theory of gases, Rudolf Clausius, who introduced the concept of "mean mean free path". Maxwell proceeded from the idea of a gas as an ensemble of perfectly elastic balls moving randomly in a closed space. Balls (molecules) can be divided into groups according to their velocities, while in the stationary state the number of molecules in each group remains constant, although they can leave the groups and enter them. From such a consideration it followed that “particles are distributed according to velocities according to the same law as the observation errors are distributed in the theory of the least squares method, i.e. according to Gaussian statistics. As part of his theory, Maxwell explained Avogadro's law, diffusion, heat conduction, internal friction (transfer theory). In 1867 he showed the statistical nature of the second law of thermodynamics.
In 1831, the year Maxwell was born, Michael Faraday performed the classic experiments that led him to the discovery of electromagnetic induction. Maxwell began to study electricity and magnetism about 20 years later, when there were two views on the nature of electric and magnetic effects. Scientists such as A. M. Ampere and F. Neumann adhered to the concept of long-range action, considering electromagnetic forces as an analogue of the gravitational attraction between two masses. Faraday was an adherent of the idea of lines of force that connect positive and negative electric charges or north and south poles magnet. The lines of force fill the entire surrounding space (the field, in Faraday's terminology) and determine the electrical and magnetic interactions. Following Faraday, Maxwell developed a hydrodynamic model of lines of force and expressed the then known relations of electrodynamics in a mathematical language corresponding to Faraday's mechanical models. The main results of this study are reflected in the work "Faraday's lines of force" (1857). In 1860–1865 Maxwell created the theory of the electromagnetic field, which he formulated as a system of equations (Maxwell's equations) describing the basic laws of electromagnetic phenomena: the 1st equation expressed Faraday's electromagnetic induction; 2nd - magnetoelectric induction, discovered by Maxwell and based on the concepts of displacement currents; 3rd - the law of conservation of the amount of electricity; 4th - the vortex nature of the magnetic field.
Continuing to develop these ideas, Maxwell came to the conclusion that any changes in the electric and magnetic fields should cause changes in the lines of force penetrating the surrounding space, i.e. there must be impulses (or waves) propagating in the medium. The speed of propagation of these waves (electromagnetic disturbance) depends on the dielectric and magnetic permeability of the medium and is equal to the ratio of the electromagnetic unit to the electrostatic unit. According to Maxwell and other researchers, this ratio is 3·10 10 cm/s, which is close to the speed of light measured seven years earlier by the French physicist A. Fizeau. In October 1861, Maxwell informed Faraday of his discovery that light is an electromagnetic disturbance propagating in a non-conductive medium, i.e. kind of electromagnetic waves. This final stage of research is outlined in Maxwell's work "The Dynamic Theory of the Electromagnetic Field" (1864), and his work on electrodynamics was summed up in the famous "Treatise on Electricity and Magnetism" (1873).