Jamesclerkmaxwell (1831June13 ~187911October 5th), born in Edinburgh, Scotland, is a British physicist and mathematician. Founder of classical electrodynamics and one of the founders of statistical physics. 183/kloc-0 was born in Edinburgh, Scotland on June 3rd,187911died in Cambridge on October 5th.

65438-0847 entered the University of Edinburgh to study mathematics and physics, and graduated from Cambridge University. He spent most of his adult life as a professor in a university and finally taught at Cambridge University. On Electricity and Magnetism, published in 1873, is also considered as the most important physics classic after Newton's Mathematical Principles of Natural Philosophy. Maxwell is generally regarded as one of the most influential physicists in physics. Without electromagnetism, there would be no modern electrician technology and no modern civilization.

Chinese name: james clerk maxwell.

Mbth: JamesClerkMaxwell

Nationality: UK

Place of birth: Edinburgh

Date of birth: 183 1 June 13.

Date of death: 1879 1 1.5.

Occupation: physicist, mathematician

Graduate school: Trinity College, Cambridge University

Belief: atheism

Main achievements: the first professional physics laboratory in Britain was established.

Maxwell equation set up.

Classical electrodynamics was established.

Predicted the existence of electromagnetic waves

The electromagnetic theory of light is put forward.

Masterpieces: General Theory of Electromagnetism and On Electricity and Magnetism.

Schooling career

1846 Maxwell, whose intelligence developed very early, submitted a scientific research paper to the Royal College of Edinburgh. 1847/kloc-graduated from middle school at the age of 0/6 and entered the university of Edinburgh. This is the highest institution of learning in Scotland. He is the youngest student in the class, but his exam results are always among the best. He specializes in mathematics and physics here, showing extraordinary talent. He studies hard, but he doesn't. After studying, he still wrote poems and read extracurricular books endlessly, and accumulated extensive knowledge. At the University of Edinburgh, Maxwell got the basic training necessary to climb the peak of science. Two of them have the deepest influence on him, one is the physicist and mountaineer Forbes, and the other is the professor of logic and metaphysics Hamilton. Forbes is an experimenter. He cultivated Maxwell's strong interest in experimental technology, which is hard for a person engaged in theoretical physics to have. He forced Maxwell to write clearly and passed on his interest in the history of science to Maxwell. Professor Hamilton influenced him with his extensive knowledge and stimulated Maxwell to study basic problems with his excellent and weird critical ability. Under the influence of these talented people, coupled with Maxwell's personal talent and hard work, Maxwell's knowledge is improving day by day, and he completed his four-year studies in three years. In contrast, the cradle of Edinburgh University can no longer satisfy Maxwell's thirst for knowledge. For further study,

1850, with his father's consent, he left Edinburgh to study in Cambridge, where there were many talents. Hertz is a young physicist in Germany. Maxwell's general theory of electromagnetism was published when he was 16 years old. In Germany at that time, people still clung to Newton's traditional concept of physics. Faraday's and Maxwell's theories give a new description of the material world, but they violate the tradition, so they have no place in the heart of Europe such as Germany, and even are regarded as whimsy. At that time, only Boltzmann and Helmholtz supported the study of electromagnetic theory. Hertz later became a student of Helmholtz. Under the influence of his teacher, Hertz made an in-depth study of electromagnetism. After comparing the physical facts, he confirmed that Maxwell's theory was more convincing than the traditional "distance theory". So he decided to prove it with experiments.

1886, Hertz invented a radio loop after repeated experiments, and made a series of experiments with this radio loop. Finally, in 1888, people discovered the electromagnetic wave that people had long suspected. After Hertz's experiment was published, it caused a sensation in the scientific world. The electromagnetic theory initiated by Faraday and summarized by Maxwell won a decisive victory. Maxwell's great last wish has finally come true.

scientific research

1850 transferred to the Department of Mathematics, Trinity College, Cambridge University. 1854 won the Smith Scholarship with the second place and stayed in school for two years after graduation. From 65438 to 0856, he was a professor of natural philosophy at Marisa, Aberdeen, Scotland. 1860 Professor of Natural Philosophy and Astronomy, King's College London. 186 1 was elected as a member of the Royal Society of London. 1in the spring of 865, he resigned from his teaching post and returned to his hometown to systematically summarize his research achievements in electromagnetism, and completed the classic masterpiece on electricity and magnetism in electromagnetic field theory, which was published in 1873.

187 1 was employed as a newly established professor of experimental physics in Cavendish, Cambridge University, and was responsible for the preparation of the famous Cavendish laboratory.

After the completion of 1874, he served as the first director of this laboratory until 10 died in Cambridge on October 5.

Electromagnetic love

Looking back at the history of electromagnetism, until 1820, physics courses were all based on Newton's physics thoughts. The "forces" of nature-heat, electricity, light, magnetism and chemical action-are gradually attributed to the instantaneous attraction or repulsion between particles of a series of fluids. As we all know, magnetism and static electricity follow the inverse square law similar to the law of universal gravitation. In the 40 years before19th century, there was a trend against this view and in favor of "force correlation". 1820, electromagnetic phenomena discovered by Oster immediately became the first proof of this new trend and an extremely powerful driving force, but people at that time were uncertain and confused about it. The interaction between current and magnet observed by Oster is different from the known phenomenon in two basic points: it is displayed by electrokinetic, and the magnet is positioned transversely to the metal wire without being led by current or pushed away by the metal wire. In the same year, French scientist Ampere summed up Oster's discovery by mathematical method and founded electrodynamics. Since then, Ampere and his followers have tried to reconcile the distance between electromagnetic action and the instantaneous action of existing ideas.

Maxwell's electrical research began at 1854, just a few weeks after he graduated from Cambridge. He read Faraday's experimental research on electricity and was immediately attracted by the novel experiments and ideas in the book. At that time, people had different views and theories about Faraday, and there were many criticisms. The main reason is that the traditional concept of "action from a distance" had a profound influence at that time. On the other hand, Faraday's theory is not rigorous enough. Faraday is a master of experiments. He has something that ordinary people can't do, but he just lacks mathematical skills, so his initial ideas are expressed in an intuitive form. The average physicist abides by Newton's physical theory and feels incredible about Faraday's theory. An astronomer once publicly declared: "Whoever hesitates about the definite action at a distance and the vague concept of force lines is blaspheming Newton!" Among scholars in Cambridge, this difference is also quite obvious. Thomson is also one of the most learned scholars in Cambridge. Maxwell admired him very much, so he wrote to Thomson and asked him about electricity. Thomson is seven years older than Maxwell, and he has given great help to Maxwell's electrical research. Under the guidance of Thomson, Maxwell was inspired and believed that Faraday's new theory had unknown truth. After studying Faraday's works carefully, he felt the valuable value of the line of force thought and saw Faraday's weakness in qualitative expression. So the young scientist who just graduated decided to make up for this with mathematics. 1855, Maxwell published the first paper on electromagnetism, about Faraday's magnetic field lines.

Maxwell is generally regarded as the greatest theoretical physicist from Newton to Einstein. 1879 died at the age of 48. His brilliant career ended early.

From 65438 to 0865, Maxwell resigned as the chairman of the Royal Academy of Sciences and began to devote himself to scientific research, systematically summarizing the research results and writing a monograph on electromagnetism.

Maxwell did not enjoy the honor he deserved, because the significance of his scientific thoughts and methods was not fully reflected until the advent of the scientific revolution in the 20th century. However, he failed to see the scientific revolution happen. 1879165438+1On October 5th, Maxwell died in Cambridge at the age of 48. Einstein was born that year.

Major achievements

Maxwell is mainly engaged in electromagnetic theory, molecular physics, statistical physics, optics, mechanics and elasticity theory. In particular, his electromagnetic field theory, which unifies electricity, magnetism and light, is the most brilliant achievement of the development of physics in the19th century and one of the greatest complexes in the history of science.

He predicted the existence of electromagnetic waves. This theory was predicted and fully verified by experiments. He erected a monument to physics. Radio technology for the benefit of mankind is developed on the basis of electromagnetic field theory. Maxwell began to study electromagnetism around 1855. After studying Faraday's new theory and thought about electromagnetism, he firmly believes that Faraday's new theory contains truth. So he held the desire to "provide the foundation of mathematical methods" for Faraday's theory and determined to express Faraday's genius thought in clear and accurate mathematical form.

On the basis of predecessors' achievements, he made a systematic and comprehensive study of electromagnetic phenomena, and with his profound mathematical attainments and rich imagination, he successively published three theoretical papers on electromagnetic fields: On Faraday's magnetic field lines (from 1855 to1856); The line of force in physics (186 1 to1862); Electromagnetic field dynamics theory (1864 65438+February 8). Summarizing predecessors' and own work comprehensively, the electromagnetic field theory is expressed in a concise, symmetrical and perfect mathematical form, and after finishing and rewriting by later generations, it becomes Maxwell equations as the main foundation of classical electrodynamics. Accordingly, he predicted the existence of electromagnetic waves in 1865, which can only be shear waves, and deduced that the propagation speed of electromagnetic waves is equal to the speed of light. At the same time, he came to the conclusion that light is a form of electromagnetic wave and revealed the relationship between light phenomenon and electromagnetic phenomena. 1888 German physicist Hertz verified the existence of electromagnetic waves through experiments.

Maxwell published his scientific masterpiece Electromagnetic Theory in 1873. The electromagnetic field theory is systematically, comprehensively and perfectly expounded. This theory has become one of the important pillars of classical physics. Maxwell also made important contributions to thermodynamics and statistical physics. He is one of the founders of gas dynamics theory. 1859, he obtained Maxwell's velocity distribution law for the first time by using statistical laws, thus finding a more accurate method to calculate the statistical average from microscopic quantities. In 1866, he gave a new method to deduce the molecular distribution function by velocity, which was based on the forward and backward collision analysis. He introduced the concept of relaxation time, developed the general transport theory and applied it to gas diffusion, heat conduction and internal friction. The term "statistical mechanics" was introduced in 1867. Maxwell is a master who uses mathematical tools to analyze physical problems and accurately express scientific ideas. He attaches great importance to experiments. The Cavendish laboratory established by him, under the leadership of him and several subsequent directors, has developed into one of the world-famous academic centers.

Maxwell equations

Research background

He is famous for listing four-element equations that express the basic laws of electromagnetism. Many years before Maxwell, people have conducted extensive research on the two fields of electricity and magnetism, and people all know that they are closely related. Various electromagnetic laws applicable to specific occasions have been discovered, but there was no complete and unified theory before Maxwell. Maxwell can accurately describe the characteristics of electromagnetic field and its interaction (but it is very complicated) by listing short four-element equations. In this way, he summed up the chaotic phenomenon into a unified and complete theory. Maxwell equation has been widely used in theory and applied science for a century.

superiority

The greatest advantage of Maxwell's equation lies in its universality and can be applied to any situation. Before this, all electromagnetic laws can be derived from Maxwell's equation, and many unknowns that could not be solved before can also be found out from the process of equation derivation.

The most important of these new achievements was drawn by Maxwell himself. According to his equation, the existence of periodic oscillation of electromagnetic field can be proved. This kind of oscillation is called electromagnetic wave. Once it is emitted, it will spread outward through space. According to the equation, Maxwell can show that the speed of electromagnetic wave is close to 300,000 kilometers (65,438+086,000 miles)/second, and Maxwell realizes that this is the same as the measured speed of light. From this, he came to the correct conclusion that light itself is composed of electromagnetic waves.

Therefore, Maxwell's equation is not only the basic law of electromagnetism, but also the basic law of optics. In fact, all previously known optical laws can be derived from the equation, and many previously undiscovered facts and relationships can also be derived from the equation. On this basis, Maxwell thinks that light is an electromagnetic wave with a certain frequency. This is another great progress in understanding the nature of light. It is in this sense that Maxwell unified optics and electromagnetism, which is one of the greatest syntheses in the history of science in the19th century.

Visible light is not the only electromagnetic radiation. Maxwell's equation shows that other electromagnetic waves with different wavelengths and frequencies from visible light may also exist. These theoretical conclusions were later proved by heinrich hertz's public demonstration. Hertz not only produced but also tested the invisible waves predicted by Maxwell. A few years later, Gaglielmo Marconi proved that these invisible waves could be used for radio communication, and radio came out. Today we also use invisible light for TV communication. X-rays, gamma rays, infrared rays and ultraviolet rays are other examples of electromagnetic radiation. All these rays can be studied by Maxwell's equation.

meaning

Maxwell's main contribution is to establish Maxwell's equations, establish classical electrodynamics, predict the existence of electromagnetic waves and put forward the electromagnetic theory of light. Maxwell is a master of electromagnetic theory. He was born in 183 1 year when Faraday, the founder of electromagnetic theory, put forward the electromagnetic induction theorem. Later, he forged an unforgettable friendship with Faraday and built a scientific system of electromagnetic theory together with * * *. In the history of physics, Newton's classical mechanics opened the door to the mechanical age, while Maxwell's electromagnetic theory laid the cornerstone for the electrical age.

Astronomy and thermodynamics

Although Maxwell is famous mainly for his great contributions to electromagnetism and optics, he also made important contributions to many other disciplines, including astronomy and thermodynamics. One of his special interests is gas kinematics. Maxwell realized that not all gas molecules move at the same speed. Some molecules move very slowly, some molecules move very fast, and some molecules move very fast. Maxwell derived a formula to find the percentage of molecules in a known gas moving at a certain speed. This formula is called Maxwell distribution, which is one of the most widely used scientific formulas and plays an important role in many branches of physics.

mechanics

Maxwell's contributions to mechanics are as follows: 1853, which popularized the method of measuring stress with polarized light; 1864 puts forward the graphic method of truss internal force in joint mechanics, points out that truss shape and internal force diagram are a pair of reciprocal diagrams, and puts forward the unit load method to solve the displacement of statically indeterminate truss. 1868 puts forward the model of viscoelastic materials (Maxwell model) and introduces the concept of relaxation time. In the same year, in On Regulator, the motion stability of automatic governor and clock mechanism of steam engine was analyzed. In 1870, the stress function in elasticity proposed by G.R. Airy is extended from two dimensions to three dimensions, and it is pointed out that it should satisfy the biharmonic equation. 1873 gives the stress field caused by gravity and repulsion in a charged system.

Cavendish laboratory

Another important work of Maxwell was to establish the first physics laboratory of Cambridge University-the famous Cavendish laboratory. This laboratory has had an extremely important influence on the development of experimental physics, and many famous scientists have worked in this laboratory. Cavendish laboratory is even known as "the cradle of Nobel Prize winners in physics". As the first director of the laboratory, Maxwell elaborated the future teaching policy and research spirit of the laboratory in his inaugural speech of 187 1, which was an important speech in the history of science. Maxwell's work route is theoretical physics, but he clearly knows that the era of experimental dominance is not over yet. He criticized the traditional British "chalk" physics at that time and called for strengthening the research of experimental physics and its role in university education, which laid the spirit of experimental science for later generations.

Theoretical analysis of Saturn's rings

As early as 1787, Laplace counted Saturn's rings as solids. At that time, he had determined that Saturn's ring, as a uniform rigid ring, would not collapse because of two conditions. One is that its running speed balances centrifugal force and Saturn's gravity, and the other is that.

The ratio of ring density to Saturn density exceeds the critical value of 0.8, so that the attraction between the inner and outer layers of the ring exceeds the difference between centrifugal force and attraction at different radii. He has this inference because the motion of the uniform ring is unstable in dynamics, and any small displacement that destroys the balance will cause the motion of the ring to be destroyed, causing the halo to fall on Saturn. Laplace speculated that Saturn's ring is a solid ring with irregular mass distribution.

By 1855, the theory still stayed here, and during this period, people observed a new Saturn dark ring, further separation, and the slow change of the overall scale of the ring system since it was discovered 200 years ago. Therefore, some scientists put forward a hypothesis to explain the dynamic stability of Saturn's rings. The hypothesis is that Saturn's rings are composed of solid fluids and a large number of substances that are not dense with each other. Maxwell discussed according to this hypothesis. Starting with the theory of solid rings left by Laplace, he first determined the stability conditions of rings with arbitrary shapes. Maxwell listed the equations of motion according to the potential caused by Saturn's central ring, obtained two restrictions on the first derivative of the potential when it was moving at a uniform speed, and then obtained three conditions about the second derivative of the stable motion from Taylor expansion. Maxwell transformed these results into conditions about the first three coefficients of Fourier series of mass distribution. So he proved that almost all conceivable rings are unstable unless there is a wonderful special case. This special situation means that the mass carried by the uniform ring at a certain point is between 4.43 times and 4.67 times of the remaining mass. However, in this special case, the solid ring will collapse under uneven gravity, so the theoretical assumption of the solid ring cannot be established.

optics

Maxwell started the color mixing experiment in Forbes Lab in Edinburgh as early as 1849. At that time, there were many color scholars in Edinburgh, besides Forbes, Wilson and Brewster, there were also some doctors and scientists who were interested in eyes. The main purpose of the experiment is to observe the colors produced by several color sectors on a rapidly rotating disk. Maxwell and Forbes first made an experiment to make the combination of red, yellow and blue produce gray. Their experiment failed, mainly because the mixture of blue and yellow does not produce green as usual, but produces a reddish color when neither of them is dominant, and this mixture with red cannot produce any gray.

Character works

marry

1856 On April 30th, james clerk maxwell was appointed as Professor of Natural Philosophy at Marichar College in Aberdeen. In Aberdeen, Maxwell met KatherineMaryDewar, the daughter of the president of Mashal College. Catherine is seven years older than Maxwell, beautiful, slightly taller than him, clear and frank.

1858 February18, he wrote to Jenny Menstruation to inform her of her engagement, saying, Dear Menstruation, this letter is to tell you that I am going to have a wife. I don't write all her qualities completely, which I think is inappropriate; But what I want to tell you is that we need each other more closely than any couple I have ever met. Don't worry;

She doesn't study math; But there are many other things besides math, and she doesn't want to win with math. Now you know who she is. She is Catherine Marie Dewar (so far). I heard Uncle Robert talk (indirectly) about her father, the Dean. Her mother is a lady of high society, quiet and rigorous, but she always treats everything with a tolerant attitude. This is the case. I have settled things with her, and everything is going well. These are all guaranteed, and you will know. Maxwell expressed his feelings for Catherine in his poem:

You and I will be together forever.

In the vibrant spring tide,

My god has.

Across such a vast world?

I want to spend my whole life.

Introduce this vibrant spring tide,

Really will achieve three selves.

Crossing the vastness of this world

In this poem, Maxwell sincerely expressed his love. 1858 On July 4th, Maxwell and KatherineMaryDewar (later changed to Clark Maxwell's surname, that is, changed to Maxwell's surname, named Catherine Clark Maxwell. When they got married, she was 34 years old-she was already a Victorian spinster. ) officially married, and the wedding was held in Aberdeen.

Personality assessment

193 1 year, Einstein commented on Maxwell's achievements at the centennial birthday commemorative meeting, "it is the most profound and fruitful work in physics since Newton.

Maxwell's achievements in electromagnetism are called "the second great unification of physics" after isaac newton. Maxwell is generally regarded as the most influential19th century physicist in the 20th century. His contribution to basic natural science is second only to that of isaac newton.

In the history of science, it is said that Newton unified the motion law of heaven and earth, which was the first big synthesis, and Maxwell unified electricity and light, which was the second big synthesis, so it should be as famous as Newton.

General Theory of Electromagnetism is a classic work of electromagnetic theory, which can be compared with Newton's mathematical principles (mechanics) and Darwin's origin of species (biology). From Ampere, Oster, Faraday, Thomson and Maxwell, after several generations of unremitting efforts, a magnificent building of electromagnetic theory was finally established. The publication of this book, of course, became a major event in physics, when Maxwell was only 42 years old and had returned to Cambridge as a professor of experimental physics. People have known him for a long time through his insightful papers. His friends, students and scientific people have been waiting for his book for a long time, scrambling to buy it in bookstores around the world in order to get a quick look, so the first edition of this book was quickly snapped up.

Personality influence

On June 7, 2006, NASA announced that it was testing a small hybrid aircraft with unique wings and 14 motors. NASA named it X-57, also known as Maxwell. Maxwell's name comes from JamsClerkMaxwell, a Scottish physicist in the19th century.