Biographies of great people. Absolute zero Lord Kelvin Lord Kelvin biography

THOMSON (Kelvin) William (Thomson William, Baron Kelvin) (26.VI.1824 - 17.XII.1907)– English physicist, one of the founders of thermodynamics, member of the Royal Society of London (1851), president in 1890-95. In 1892 he received the title of Lord Kelvin. R. in Belfast. Graduated from Cambridge University (1845). In 1846 - 99 - professor at the University of Glasgow (in 1846 he organized one of the first physics laboratories), from 1904 - president.
The works relate to thermodynamics, hydrodynamics, electromagnetism, elasticity, heat, mathematics, and technology. In 1851 he formulated (independently from R. Clausius) second law of thermodynamics: “in nature a process is impossible, the only result of which would be mechanical work, accomplished by cooling the thermal reservoir.” According to this formulation of the second law of thermodynamics (according to Thomson), the impossibility was proven perpetual motion machine of the second kind. Introduced the concept of internal energy (1851). However, based on the open law of thermodynamics and applying it to the Universe as a whole, he came (1852) to the erroneous conclusion about the inevitability of the “thermal death of the Universe” (the hypothesis of the thermal death of the Universe). The illegality of this approach and the fallacy of the hypothesis was proved by L. Boltzmann .
Widely used the thermodynamic method to explain various physical phenomena.
In 1848 he introduced the concept of absolute temperature and the absolute temperature scale named after him (Kelvin scale).
He showed how the boiling point of a liquid, depending on pressure, is related to the heat of vaporization, the volume of the liquid and the steam formed from it, and established in 1870 that the elasticity of saturated vapor depends on the shape of the surface of the liquid.
Together with J. Joulem established in 1853 - 54 the change in gas temperature during its slow stationary adiabatic flow through a porous partition (Joule - Thomson effect). Using this effect is one of the main methods of obtaining low temperatures.
In 1856 he discovered the third thermodynamic effect (Thomson effect): if there is a temperature difference along a conductor through which an electric current flows, then, in addition to Joule heat, in the volume of the conductor, depending on the direction of the current, some more heat is released or absorbed (Thomson heat) . Constructed a thermodynamic theory of thermoelectric phenomena.

He worked fruitfully in the field of studying electrical and magnetic phenomena, in particular, studied the magnetic properties of crystals.
Discovered in 1851 a change in the specific electrical conductivity of ferromagnets when they are magnetized (Thomson effect).
He designed a number of highly sensitive electrometers and galvanometers, a universal compass and other instruments.
Gave a calculation electrical vibrations in a circuit, having derived in 1853 a formula for the dependence of the period of natural oscillations in a circuit on its capacitance and inductance (Thomson’s formula). Established (1856) the change in the resistance of metals in a magnetic field perpendicular to the current.
Thomson's theoretical research on electromagnetism and a number of his technical inventions significantly contributed to the practical implementation of telegraph communications, in particular via the transatlantic cable, in the laying of which he took an active part.
His research on thermal conductivity is known, which he tried to use to calculate the age of the Earth, studied the problem of the Earth's rotation around its axis, and came to the conclusion that sea tides influence this rotation.
Put forward (1902) a hypothesis about the structure of atoms, carried out calculations of the sizes of molecules, etc.
Member of many academies of sciences and scientific societies, in particular the St. Petersburg Academy of Sciences (1896).

Literature:

1. V. Lebedinsky. William Thomson Lord Kelvin – Leningrad, 1924
2. M. McCartney. William Thomson, Lord Kelvin, King of Victorian Physics / Physics. September 1st.
3. Physics is getting warm. Lord Kelvin. Classical thermodynamics. – M.: De Agostini, 2015 (Science. The greatest theories: issue 31)

100 famous scientists Sklyarenko Valentina Markovna

THOMSON WILLIAM, BARON KELVIN (1824 - 1907)

THOMSON WILLIAM, BARON KELVIN

(1824 – 1907)

On June 26, 1824, William Thomson was born in the Irish city of Belfast - one of greatest physicists in the history of science, a person who stood for his scientific achievements was awarded the title of lord (which, it must be said, did not happen often). His ancestors were ordinary Irish farmers. True, James Thomson, William's father, graduated from the University of Glasgow and was a fairly famous mathematician, teaching at the Royal Academic Institute of Belfast. In 1817 he married Margaret Gardner. Their marriage was large (four boys and two girls). The eldest son, James, and William were raised in their father's house, while the younger boys were raised by their older sisters. It is not surprising that Thomson Sr. took care of a decent education for his sons. At first he more attention devoted to James, but it soon became clear that the poor health of his eldest son would not allow him to receive good education, and the father focused on raising William.

In 1832, Thomson senior received a position as professor of mathematics in Glasgow, and the family left Belfast. In 1834, William entered the University of Glasgow, where disciplines were taught for capable children high school. John Nicol, a famous Scottish astronomer and popularizer of science, who worked at the university since 1839, played a major role in shaping the young man’s scientific interests. He followed the advanced achievements of science and tried to introduce them to his students. One of these innovations was the method of Fourier series, to the application of which in physical research Thomson, while still a student, devoted several works. In particular, he applied the method of Fourier series to the study of the patterns of heat propagation in various media and showed the analogy between the propagation of heat and electric current.

In 1841, William's father got him a job at Cambridge. The young man studied successfully; in 1845 he received a diploma as a second runner and won the Smith Prize. It must be said that William Thomson was a well-rounded young man, he went in for sports, even was a member of the Cambridge rowing team and, together with his comrades, defeated Oxford students in the famous race, held since 1829. Thomson was also well versed in music and literature. But to all these hobbies he preferred science, and here his interests were also varied.

In 1845, William Thomson made one of the first attempts to mathematically interpret Faraday's ideas about short-range action. This year he received a special scholarship, thanks to which he was able to go to Paris, where he worked for some time in the laboratory of the famous physicist Henri Victor Ragno. In France, William was mainly involved in electrostatics and published a number of works, in which, in particular, he outlined the electrical method receiving an image. This method subsequently became very useful tool in many electrostatic studies.

In 1846, Thomson received an invitation to head the department theoretical physics in Glasgow. Even then, the 23-year-old scientist gained a certain authority and fame in scientific circles. This is evidenced by his participation in the annual meeting of the British Association for the Advancement of Science in 1847, during which William heard Joule's report on the theories of heat transfer. This topic interested him very much and he seriously took up thermodynamics. Already in 1848, Thomson proposed his famous thermodynamic temperature scale (Kelvin scale). It differs from other temperature scales in that absolute zero temperature is taken as the reference point. Thus, this scale does not depend on the properties of the thermometric substance (the substance used in the device measuring temperature).

In 1851, William, almost simultaneously with and independently of Rudolf Clausius, formulated the second law of thermodynamics. As formulated by Thomson, this law sounded like this: “A process is impossible in nature, the only result of which would be mechanical work performed by cooling the heat reservoir.” From here the English scientist made far-reaching conclusions: since mechanical energy can completely turn into heat, but a complete reverse transformation is impossible - in the end, all the energy will turn into heat, and therefore mechanical movements will stop. This conclusion became known as the “heat death of the universe” idea. It should be said that now the hypothesis of the thermal death of the Universe is considered erroneous, but in any case it greatly contributed to the development of thermodynamics.

William Thomson continued to explore electrical phenomena. In the same 1851, he made another discovery: he discovered that when ferromagnets are magnetized, their electrical resistance. This phenomenon is called the Thomson effect in ferromagnets (we will talk about the thermoelectric Thomson effect below). With his work, William attracted the attention of an ever-widening circle of colleagues. The year 1851 was marked by another significant event - Thomson was elected a member of the Royal Society of London.

In 1852, the scientist married Margaret Crum, with whom he had been in love since childhood. He was happy, but the happiness, unfortunately, did not last long. Already during the honeymoon, Margaret's health deteriorated sharply. The next 17 years of Thomson’s life were overshadowed by constant worries about his wife’s health, and almost all free time the scientist devoted himself to caring for her.

In 1852–1856, Thomson actively collaborated with Joule, although the scientists communicated mainly through correspondence. In 1853–1854, they jointly conducted a series of experiments and discovered the effect of changing the temperature of a gas during its adiabatic expansion. The Joule–Thomson effect can be positive (the gas is cooled) and negative (the gas is heated). In addition to scientific interest, this phenomenon also has practical application: it is used to obtain very low temperatures.

Finally, in 1855, the scientist combined two areas of his scientific interests and began to study thermoelectric processes. He developed a thermodynamic theory of thermoelectric phenomena. Many such phenomena were already known, some were discovered by Thomson himself. One of them is called the Thomson thermoelectric effect. It is as follows: if there is a temperature difference along the conductor through which an electric current flows, then in addition to the heating process explained by the Joule-Lenz law, additional heat absorption or release occurs (depending on the direction of the current). The most amazing thing is that Thomson did not experimentally carry out this discovery, but predicted it based on his theory. And this at a time when scientists did not yet have even more or less correct ideas about the nature of electric current! Thomson also involved students in the study of thermoelectric phenomena. Thanks to this initiative, the first teaching and research laboratory at the University of Glasgow was created.

The English scientist was very interested practical application achievements of contemporary science. In 1854, he received an offer to take part in a project to lay a transatlantic telegraph cable. Thomson devoted a lot of time and effort to this work; from 1856, he served on the board of directors of the Atlantic Telegraph Company and participated, mainly during the holidays, in cable-laying expeditions. But Thomson provided the greatest assistance to the implementation of the project with his scientific research. He studied the patterns of propagation of electrical impulses through wires, electric currents in oscillatory circuit, developed the theory of electromagnetic oscillations and, in particular, derived one of the basic formulas of electrical and radio engineering, named after him (Thomson’s formula determines the dependence of the oscillation period of a circuit on the capacitance of its capacitor and the inductance of the coil).

Of course, during the expeditions, such a versatile and enthusiastic person as Thomson could not help but become interested in issues of navigation. He also found application for his inventive and scientific talents in this area: he improved the designs of the compass and lot, conducted research on the theory of waves and the theory of tides, etc. In general, the inventive activity of William Thomson deserves special attention. He designed and improved a number of physical instruments: a mirror galvanometer, square and absolute electrometers, and was the author of several applied inventions. For example, he patented an undulator with a siphon supply of ink, one type of telegraph key, and even water tap own design.

For their participation in laying the transatlantic telegraph cable on November 10, 1866, William Thomson and other project leaders were given the title of Lords. This activity took a lot of effort and time, and for a long time the scientist had to limit himself to only those studies that could be carried out without being distracted from it. But this work fascinated Thomson, and he passionately fell in love with the sea. Since 1869, William Thomson took part in laying the French Atlantic cable.

Margaret died on June 17, 1870. After this, the scientist decided to change his life, devote more time to rest, he even bought a schooner, on which he took walks with friends and colleagues. In the summer of 1873, Thomson led another cable-laying expedition. Due to damage to the cable, the crew was forced to make a 16-day stop in Madeira, where the scientist became friends with Charles Blandy's family, especially Fanny, one of his daughters, whom he married the following summer.

In addition to scientific, teaching and engineering activities, William Thomson performed many honorary duties. Three times (1873–1878, 1886–1890, 1895–1907) he was elected president of the Royal Society of Edinburgh, and from 1890 to 1895 he headed the Royal Society of London. In 1884 he traveled to the USA, where he gave a series of lectures. In 1892, for his scientific merits, the scientist received the title of first Baron Kelvin (this name was taken from the name of the river flowing through the territory of the University of Glasgow). Unfortunately, William became not only the first, but also the last Baron Kelvin - his second marriage, like his first, turned out to be childless. In 1899, Kelvin left his chair in Glasgow, although he did not stop studying science. IN next year he gave a lecture on the crisis of the dynamic theory of light and heat. Later, the scientist was interested in new discoveries: X-rays, radioactivity, etc. Lord William Kelvin died on December 17, 1907. The scientist was buried in Westminster Abbey, next to the grave of Isaac Newton.