Biography

James Prescott Joule (English: James Prescott Joule; December 24, 1818, Salford, Lancashire, England, UK - October 11, 1889, Sale, Cheshire, England, UK) - English physicist who made a significant contribution to the development of thermodynamics. He substantiated the law of conservation of energy through experiments. Established a law defining thermal effect electric current. He calculated the speed of gas molecules and established its dependence on temperature.

He experimentally and theoretically studied the nature of heat and discovered its connection with mechanical work, as a result, almost simultaneously with Mayer, he came to the concept of universal conservation of energy, which, in turn, provided the formulation of the first law of thermodynamics. He worked with Thomson on the absolute temperature scale, described the phenomenon of magnetostriction, and discovered the connection between current flowing through a conductor with a certain resistance and the amount of heat released at the same time (Joule-Lenz law). He made a significant contribution to the technology of physical experiments and improved the designs of many measuring instruments.

The unit of energy measurement, the joule, is named after Joule.

Born into the family of a wealthy brewery owner in Salford near Manchester, he was educated at home, and for several years his teacher in elementary mathematics, the principles of chemistry and physics was Dalton. From 1833 (from the age of 15) he worked at a brewery, and, in parallel with his studies (until the age of 16) and studies in science, until 1854 he participated in the management of the enterprise until it was sold.

He began his first experimental studies already in 1837, having become interested in the possibility of replacing steam engines in a brewery with electric ones. In 1838, on the recommendation of one of his teachers, John Davies, whose close friend was the inventor of the electric motor, Sturgeon, published the first work on electricity in the scientific journal Annals of Electricity, organized the year before by Sturgeon, the work was devoted to the design of an electromagnetic motor . In 1840 he discovered the effect of magnetic saturation during the magnetization of ferromagnets, and during 1840-1845 he experimentally studied electromagnetic phenomena.

Seeking best ways measurements of electric currents, James Joule in 1841 discovered the law named after him, establishing a quadratic relationship between the strength of the current and the amount of heat released by this current in the conductor (in Russian literature it appears as the Joule-Lenz law, since in 1842 this law was independently discovered by the Russian physicist Lenz). The discovery was not appreciated by the Royal Society of London, and the work was published only in the periodical journal of the Manchester Literary and Philosophical Society.

In 1840, Sturgeon moved to Manchester and headed the Royal Victoria Gallery. for the Encouragement of Practical Science) is a commercial exhibition and educational institution, where in 1841 it invites Joule as the first lecturer.

In his works in the early 1840s, he explored the question of the economic feasibility of electromagnetic engines, initially believing that electromagnets could be a source of an unlimited amount of mechanical work, but soon became convinced that, from a practical point of view, steam engines of that time were more efficient, publishing the conclusions in 1841 that The efficiency of an "ideal" electromagnetic motor per pound of zinc (used in batteries) is only 20% of the efficiency of a steam motor per pound of coal burned, which does not hide the disappointment.

In 1842, he discovered and described the phenomenon of magnetostriction, which consists in a change in the size and volume of a body when its state of magnetization changes. In 1843, he formulated and published the final results of his work on the study of heat release in conductors, in particular, he experimentally showed that the heat generated was in no way taken from the environment, which irrevocably refuted the theory of caloric, whose supporters still remained at that time. In the same year I became interested common problem quantitative relationship between various forces leading to the release of heat, and, having come to the conviction of the existence of a definite relationship between work and the amount of heat predicted by Mayer (1842), seeks a numerical relationship between these quantities - the mechanical equivalent of heat. During 1843-1850, he conducted a series of experiments, continuously improving experimental techniques and each time confirming the principle of energy conservation with quantitative results[⇨].

In 1844 the Joule family moved to new home in Whalley Range, where a convenient laboratory was equipped for James. In 1847 he married Amelia Grimes, they soon had a son and daughter, and Amelia Joule died in 1854.

In 1847, he met Thomson, who highly appreciated Joule’s experimental technique, and with whom he subsequently collaborated fruitfully. Thomson’s ideas on issues of molecular kinetic theory were largely formed under the influence of Joule. In their first joint work, Thomson and Joule created a thermodynamic temperature scale.

In 1848, to explain the thermal effects with increasing pressure, he proposed a model of gas as consisting of microscopic elastic balls, the collision of which with the walls of the vessel creates pressure, and estimating the speed of the “elastic balls” of hydrogen at about 1850 m/s. On the recommendation of Clausius, this work was published in the Philosophical Transactions of the Royal Society, and although serious flaws were subsequently revealed in it, it had a significant influence on the development of thermodynamics, in particular, it ideologically echoes the work of Van der Waals in the early 1870s. 1990s on modeling of real gas.

By the end of the 1840s, Joule's work was gaining universal recognition in the scientific community, and in 1850 he was elected a full member of the Royal Society of London.

In his works of 1851, improving his theoretical models for representing heat as the movement of elastic particles, he theoretically calculated the heat capacity of some gases quite accurately. In 1852, he discovered, measured and described in a series of joint works with Thomson the effect of changing gas temperature during adiabatic throttling, known as the Joule-Thomson effect, which later became one of the main methods for obtaining super low temperatures, thereby contributing to the emergence of low temperature physics as a branch of natural science.

In the 1850s, he published a large series of articles on improvement electrical measurements, offering designs of voltmeters, galvanometers, ammeters that provide high measurement accuracy; in general, throughout his scientific practice, Joule paid considerable attention to experimental techniques that allowed him to obtain highly accurate results.

In 1859, he investigated the thermodynamic properties solids, measuring the thermal effect during deformation, and notes non-standard properties of rubber in comparison with other materials.

In the 1860s he was interested in natural phenomena, offering possible explanations for the nature of atmospheric thunderstorms, mirages, and meteorites.

In 1867, Joule, according to the scheme proposed by Thomson, carried out measurements of the standard of the mechanical equivalent of heat for the British Scientific Association, but received results that diverged from the values ​​​​obtained from purely mechanical experiments, however, clarification of the conditions of mechanical experiments confirmed the accuracy of Joule’s measurements and in 1878 the standard of resistance was revised.

On initial stages activities, Joule carried out experiments and carried out research exclusively at his own expense, but after the sale of the brewery in 1854, the financial situation gradually worsened, and he had to use funding from various scientific organizations, and in 1878 a state pension was awarded. Since childhood, he suffered from a spinal disease, and since the early 1870s, due to poor health, he practically did not work. Died in 1889

Mechanical heat equivalent

Beginning in 1843, Joule sought confirmation of the principle of conservation of energy and tried to calculate the mechanical equivalent of heat. In the first experiments, he measures the heating of the liquid in which a solenoid with an iron core is immersed, rotating in the field of an electromagnet, taking measurements in cases of closed and open windings of the electromagnet, then he improves the experiment, eliminating manual rotation and driving the electromagnet with a lowering weight. Based on the measurement results, formulates the following ratio:

The amount of heat that is able to heat 1 pound of water 1 degree Fahrenheit is equal to and can be converted into mechanical force that is able to lift 838 pounds to a vertical height of 1 foot

The results of the experiments were published in 1843 in the article “On the thermal effect of magnetoelectricity and the mechanical significance of heat.” In 1844, he formulated the first version of the law of heat capacity of complex crystalline bodies, known as the Joule-Kopp law (Copp (German: Hermann Kopp) gave the exact formulation and final experimental confirmation in 1864).

Further, in the experiment of 1844, he measures the heat release when forcing a liquid through narrow tubes, in 1845, he measures the heat during compression of a gas, and in the experiment of 1847, he compares the cost of rotating a stirrer in a liquid with the heat generated as a result of friction.

In the works of 1847-1850 it gives an even more accurate mechanical equivalent of heat. He used a metal calorimeter mounted on a wooden bench. Inside the calorimeter there was an axis with blades located on it. On the side walls of the calorimeter there were rows of plates that prevented the movement of water, but did not touch the blades. A thread with two hanging ends was wound around the axis outside the calorimeter, to which weights were attached. The experiments measured the amount of heat generated when the axis rotates due to friction. This amount of heat was compared with the change in the position of the loads and the force acting on them.

Evolution of mechanical equivalent heat values ​​obtained from Joule's experiments (in foot-pounds or foot-pounds per British thermal unit):
838 (4.51 J/cal), 1843;
770 (4.14 J/cal), 1844;
823 (4.43 J/cal), 1845
819 (4.41 J/cal), 1847
772.692 (4.159 J/cal), 1850.

The latest estimate is close to the ultra-precise measurement values ​​​​carried out in the 20th century.

The struggle for priority in the discovery of the law of conservation of energy

From the second half of the 1840s, on the pages of the “Proceedings of the French Academy of Sciences” (French Comptes rendus hebdomadaires des séances de l "Académie des sciences), a heated debate unfolded about the priority in the discovery of the law of conservation of energy for thermodynamic systems between Joule and Mayer, and although Mayer’s publication came out a little earlier, he, being a doctor by profession, was not taken seriously, while Joule was already supported by prominent physicists, in particular, his 1847 report at the British Scientific Association received high marks from those present at the meeting Faraday, Stokes and Thomson. Timiryazev, later reviewing this discussion, noted the consistency of Mayer’s argumentation in the fight against “petty envy of the shop floor scientists" Helmholtz, who published the principle of conservation of energy in 1847, in 1851 drew attention to the work of Mayer, and in 1852 openly recognized his priority.

The next round of the struggle for priority occurred in the 1860s, when the law received universal recognition in the scientific community. Tyndall in 1862, in a public lecture, shows Mayer's priority, and Clausius takes his point of view. Tait, known for his pro-British patriotic views, in a series of publications insists on the priority of Joule, not recognizing the physical content of Mayer’s work of 1842; Clausius opposes him, and the philosopher Dühring, while belittling the importance of the works of Joule and Helmholtz, actively insists on the priority of Mayer, which in many ways served as the final recognition of Mayer's priority.

Recognition and memory

In 1850 he was elected a member of the Royal Society of London. In 1852, he was awarded the first Royal Medal for his work on the quantitative equivalent of heat. In 1860 he was elected honorary president of the Manchester Literary and Philosophical Society.

Received the scientific degrees of Doctor of Laws from Trinity College Dublin (1857), Doctor of Laws civil law(English DCL) Oxford University a (1860), Doctor of Laws (LL.D.) from the University of Edinburgh (1871).

In 1866, Joule was awarded the Copley Medal, and in 1880, the Albert Medal. In 1878, the government awarded him a lifetime pension of £215.

In 1872 and 1877, he was twice elected president of the British Association for the Advancement of Science.

At the Second International Congress of Electricians, held in 1889 - the year of Joule's death, a unified unit of measurement of work, energy, amount of heat was named after him, for which the transition coefficient between mechanical work and heat (mechanical equivalent of heat) was not required, which became one of the derived units SI with own name.

In Manchester Town Hall there is a monument to Joule by sculptor Alfred Gilbert, opposite the monument to Dalton.

In 1970, the International Astronomical Union named the James Joule crater on back side Moons.

James Prescott Joule($1818$ - $1889$) - English physicist who made a significant contribution to the development of thermodynamics.

Biography

Note 1

He was the son of Benjamin Joule, owner of a relatively large brewery.
James Joule received his initial education from private tutors, mainly due to his poor health. He had problems with his spine, but over time his condition improved, but throughout his life the scientist remained hunched over, this affected his character and contributed to his shyness.

With $1834, he studied with John Dalton in Manchester at the Literary and Philosophical Society. Like Dalton, Joule was a strong proponent of atomic theory, while many scientists during this period were still skeptical about it.

In later years, James Joule studied under John Davis and became interested in electricity; he and his brother experimented with electrocuting each other and the family's servants.

Note 2

Scientific achievements

Electricity

Note 3

Science was initially a hobby for Joule, but even while working at the brewery he began to explore the possibilities of replacing boilers with the newly invented electric motor.

Driven in part by a desire to assess the economic impact of such a substitution, he focuses on measurements that can be used to determine which energy source is more efficient. Thus, in $1841, he discovered Joule's law, in which the heat generated by the direct action of any galvanic current is proportional to the square of the current multiplied by the resistance of the conductor. (The derived unit of energy or work, the Joule, was named after him). Joule concluded that burning a pound of coal would be more economical than wasting precious pounds of zinc for an electric battery.

Joule tries to present the results before the Royal Society, but they mistook him for a provincial amateur.

In $1843, Joule calculated the amount of mechanical work required to produce an equivalent amount of heat. This quantity was called the “mechanical equivalent of heat.” Again he presented a report on his findings, this time to the British Association for the Advancement of Science. Again the response was unenthusiastic. Several leading journals also refused to publish papers on Joule's work.

Joule's work on the relationship between heat, electricity, and mechanical work was largely ignored until 1847. Only William Thomson recognized that Joule's work fit into a unifying pattern that was already beginning to emerge in physics, and he enthusiastically endorsed Joule's work.

In 1849, Joule read his paper entitled "On the Mechanical Equivalent of Heat" at the Royal Society, with Faraday as his sponsor. IN next year The Royal Society published Joule's paper.

James Prescott Joule(eng. James Prescott Joule; December 24, 1818, Salford, Lancashire, England, UK - October 11, 1889, Sale, Cheshire, England, UK) - English physicist who made a significant contribution to the development of thermodynamics. He substantiated the law of conservation of energy through experiments. Established a law determining the thermal effect of electric current. He calculated the speed of movement of gas molecules and established its dependence on temperature.

He experimentally and theoretically studied the nature of heat and discovered its connection with mechanical work, as a result, almost simultaneously with Mayer, he came to the concept of universal conservation of energy, which, in turn, provided the formulation of the first law of thermodynamics. He worked with Thomson on the absolute temperature scale, described the phenomenon of magnetostriction, and discovered the connection between current flowing through a conductor with a certain resistance and the amount of heat released at the same time (Joule-Lenz law). He made a significant contribution to the technology of physical experiments and improved the designs of many measuring instruments.

The unit of energy measurement, the joule, is named after Joule.

Biography

Born into the family of a wealthy brewery owner in Salford near Manchester, he was educated at home, and for several years his teacher in elementary mathematics, the principles of chemistry and physics was Dalton. From 1833 (from the age of 15) he worked at a brewery, and, in parallel with his studies (until the age of 16) and studies in science, until 1854 he participated in the management of the enterprise until it was sold.

He began his first experimental studies already in 1837, having become interested in the possibility of replacing steam engines in a brewery with electric ones. In 1838, on the recommendation of one of his teachers, John Davies, whose close friend was the inventor of the electric motor, Sturgeon, published the first work on electricity in the scientific journal Annals of Electricity, organized the year before by Sturgeon, the work was devoted to the design of an electromagnetic motor . In 1840 he discovered the effect of magnetic saturation during the magnetization of ferromagnets, and during 1840-1845 he experimentally studied electromagnetic phenomena.

Looking for better ways to measure electric currents, James Joule in 1841 discovered the law named after him, establishing a quadratic relationship between the strength of the current and the amount of heat released by this current in the conductor (in Russian literature it appears as the Joule-Lenz law, since in 1842 this law was independent was discovered by the Russian physicist Lenz). The discovery was not appreciated by the Royal Society of London, and the work was published only in the periodical journal of the Manchester Literary and Philosophical Society.

In 1840, Sturgeon moved to Manchester and headed the Royal Victoria Gallery for the Encouragement of Practical Science, a commercial exhibition and educational institution, where in 1841 he invited Joule as the first lecturer.

In his works in the early 1840s, he explored the question of the economic feasibility of electromagnetic engines, initially believing that electromagnets could be a source of an unlimited amount of mechanical work, but soon became convinced that, from a practical point of view, steam engines of that time were more efficient, publishing the conclusions in 1841 that The efficiency of an "ideal" electromagnetic motor per pound of zinc (used in batteries) is only 20% of the efficiency of a steam motor per pound of coal burned, which does not hide the disappointment.

In 1842, he discovered and described the phenomenon of magnetostriction, which consists in a change in the size and volume of a body when its state of magnetization changes. In 1843, he formulated and published the final results of his work on the study of heat release in conductors, in particular, he experimentally showed that the heat generated was in no way taken from the environment, which irrevocably refuted the theory of caloric, whose supporters still remained at that time. In the same year, he became interested in the general problem of the quantitative relationship between various forces leading to the release of heat, and, having come to the conviction of the existence of a certain relationship between work and the amount of heat predicted by Mayer (1842), he looked for a numerical relationship between these quantities - the mechanical equivalent of heat. During 1843-1850, he conducted a series of experiments, continuously improving experimental techniques and each time confirming the principle of energy conservation with quantitative results.

James Joule short biography English physicist are presented in this article.

Joule James Prescott short biography

James Prescott Joule was born on December 24, 1818 in the family of a wealthy brewery owner. The family's good financial situation allowed James to be educated at home until the age of 15. He received excellent knowledge in the fields of physics, mathematics and chemistry, and feeling a further attraction to the sciences, James Joule wanted to continue his education. But fate decreed otherwise - due to his father’s illness, he and his older brother managed the family brewery for some time.

The current circumstances did not prevent James from pursuing science. At home, he organizes a physics laboratory and begins to carry out his experiments. During the first work on electric motors, the scientist discovered the following - power electric machines directly proportional to voltage and current output.

For 7 years, starting in 1847, the scientist conducted a series of experiments to study the effect of heat on electric current, passing through the conductor. The result of his work was the discovery of the proportional relationship between the amount of heat released in the conductor and the resistance of this material and the square of the current that passes through it.

Joule's discovery made him a famous scientist. He was offered a joint job by W. Thomson. They, working in tandem, became, in fact, the progenitors of all refrigeration units and refrigerators. Joule discovered that expansion of a gas without performing any work leads to a significant decrease in its temperature. This effect was named after scientists - it is called the Joule-Thomson effect.

(English) James Prescott Joule, MFA: December 24, 1818 – October 11, 1889) was an English physicist and brewer.
Joule studied the nature of heat and determined the amount of heat released during mechanical work. This led him to the discovery of the law of conservation of energy and, finally, to the formulation of the first law of thermodynamics. Together with Lord Kelvin, he worked on the development of the absolute temperature scale. He also determines the amount of heat released when current passes through a conductor (Joule-Lenz law). Investigated magnetostriction.
The unit of measurement of energy, the Joule, used in international system SI.
Born in Salfordy near Manchester on December 24, 1818. By the age of 15, Joule was raised in the family of his father, a wealthy brewer, and was educated at home. For several years he was taught mathematics, physics, and the principles of chemistry by the famous physicist and chemist John Dalton, under whose influence Joule began experimental research at the age of 19. It was Dalton who instilled in Joule a love of science and a passion for collecting and understanding the numerical data on which scientific theories and laws. Unfortunately, Joule's mathematical training was weak, which in the future greatly hampered his research and may have prevented him from making even more significant discoveries.
In 1838, his article describing an electromagnetic motor appeared in the journal Annals of Electricity; in 1840, he discovered the effect of magnetic saturation, and in 1842, the phenomenon of magnetostriction.
Joule had no profession and no work other than helping to manage his father's factory. Until 1854, when factory was finally sold, see also concrete plant, Joule worked on it and in fits and starts, at night, did his experiments. After 1854, Joule had both the time and the means to build in own home physical laboratory and devote himself entirely to experimental physics. Later, Joule had financial difficulties and turned to Queen Victoria for financial assistance to continue his research.
Joule's research device for studying heat, 1845 during 1837-1847 Joule devoted all his free time to various experiments on the transformation various forms energy - mechanical, electrical, chemical - in thermal energy. He developed thermometers that measured temperature with an accuracy of one to two hundred degrees, which allowed him to carry out measurements with the best accuracy for that time. Influenced by Faraday's work, Joule turned to the study of the thermal effects of current, which resulted in the discovery of a law now called Joule's law. According to this law, the amount of heat released in a current-carrying conductor is proportional to the resistance of the conductor and the square of the current.
In 1843 Joule began new problem: proof of the existence of a quantitative relationship between “forces” of different natures leading to the release of heat. His first experiments consisted of measuring the amount of heat released in a vessel of water, in which a rotating electromagnet was lowered under the influence of a load, and the vessel itself was placed in a magnetic field. In these experiments, he first determined the mechanical equivalent of heat (4.5 J / cal in modern units), and in subsequent years he studied thermal effects when forcing liquid through narrow holes (1844), compressing gas (1845), etc. All these experiments led Joule to the discovery of the law of conservation of energy. Subsequently, a unit of measurement of all types of energy - mechanical, thermal, electrical, radiation and others - was named after him.
In June 1847, Joule presented a paper at a meeting of the British Association of Scientists in which he reported precise measurements of the mechanical equivalent of heat. The report became a turning point in his career. In 1850 Joule was elected a member of the Royal Society of London. He became one of the most authoritative scientists of his time, the owner of many titles and awards. The Queen elevated him to knighthood.
In 1847, Joule met W. Thomson and together with him studied the behavior of gases under various conditions. The result of this collaboration was the discovery of the cooling effect of gas during its slow adiabatic flow through a porous partition (Joule–Thomson effect). This effect is used to liquefy gases. In addition, Joule constructed a thermodynamic temperature scale, calculated the heat capacity of some gases, calculated the speed of gas molecules and established its dependence on temperature.
In 1854, Joule sold the plant, which was left to him from his father, and devoted himself entirely to science. Working tirelessly in the same field, before his death Joule published 97 scientific works, of which about 20 were done in collaboration with W. Thomson and L. Plefer; most of them concern the application mechanical theory heat to the theory of gases, molecular physics and acoustics and belong to classical works in physics.
Statue of Joule in Manchester City Council Joule was a Fellow of the Royal Society of London, honorary titles of Honoris causa from Trinity College Dublin (1857), Oxford University (1861), Doctor of Hc from Edinburgh (1871) and Leiden (1875) Universities; in 1878, the government assigned him a lifelong pension of 200 pounds.
Joule's works are collected in "Scientific papers by JP Joule" (2 vols., London, 1884-87) and translated in 1872 by Sprengel into German.
Among the awards and honors that the scientist was awarded are the gold medal of the Royal Society (1852), the Copley medal (1866), and the Albert medal (1880). In 1872 and 1877 Joule was elected president of the British Association for the Diffusion of Scientific Knowledge.
Joule died in Sale on October 11, 1889.