Probably there is no person who does not know the name James Joel. The discoveries of this physicist are used all over the world. What path did the scientist take? What discoveries did he make?
The life of an outstanding physicist
James Joule was born on December 24, 1818. The biography of the future physicist begins in the English town of Salford, in the family of a successful brewery owner. The boy's education took place at home, for some time he was taught physics and chemistry by John D alton. Thanks to him, the English physicist fell in love with science.
Joule did not have good he alth, he spent a lot of time at home, conducting physical experiments and experiments. Already at the age of 15, due to the illness of his father, he had to manage the brewery with his brother. Working at his father's factory did not give him the opportunity to go to university, so James Joule devoted himself entirely to his home laboratory.
From 1838 to 1847, the physicist actively studied electricity and made his first scientific progress. In the Annals of Electricity, he published an article on electricity, and in 1841 discovered a new physical law, which now bears his name.
In 1847, Joule entered into his first and only marriage to Amelia Grimes. Soon they haveAlice Amelia and Benjamin Arthur are born. In 1854, his wife and son died. Joule himself dies in 1889 in England, in the city of Sale.
Throughout his life, he published about 97 papers in physics, some of them written jointly with other scientists: Lyon, Thomson, etc. For outstanding scientific achievements and discovered laws of physics, he was awarded several medals and received a lifetime pension from the UK government in the amount of about 200 pounds.
First works and experiments
While observing the steam engines in his father's brewery, James Joule decided to replace them with electric ones for efficiency. In 1838, he published an article in a scientific journal in which he describes the device of an electromagnetic engine he invented. In 1840, new electric motors appeared at the brewery, and the physicist continued to study electric current and heat release. Later it turned out that steam engines were much more efficient.
During the experiments, Joule creates thermometers that can measure temperature with an accuracy of 1/200 degrees. This allows him to delve deeper into the study of the thermal effect of the current. In 1840, thanks to further observations, the physicist discovers the effect of magnetic saturation. In the same year, he sent to the Royal Scientific Society the work "On the formation of heat by means of electric current." The article was not rated. Only the Manchester Literary and Philosophical Journal agreed to publish it.
Joule-Lenz Law
Unrecognized by the London Scientific Society, the article later turned out to be one of the mainscientist's achievements. In the article, James Joule talked about the relationship between current strength and the amount of heat released. He argued that the amount of heat that is released in the conductor is directly proportional to the resistance of the conductor, the square of the force and the time of passage of the current.
At that time, a similar theory was developed by Emilius Lenz. The fact that the conductivity of a metal conductor depends on temperature was discovered by a Russian physicist back in 1832. To accurately determine the temperature in the conductor, the scientist invented a special vessel into which alcohol was poured. The wire through which the current was passed was lowered into the vessel. Next, it was tracked how long the alcohol would heat up. Joule James Prescott used a similar method, but used water as the liquid.
The results of many years of research Lenz published only in 1843, but in his writings there were more accurate scientific justifications than that of Joule, whose work at first did not even want to be printed. Given the primacy of Joule and the exact calculations of Emil Lenz, it was decided to name the law after both. Over time, the Joule-Lenz law laid the foundation for thermodynamics.
Magnetostriction
In parallel with the properties of electric current, James Joule studies magnetic phenomena. In 1842, he notices that iron changes in size under the influence of magnetic waves. If metal rods are placed in a magnetic field, their length will become slightly longer.
The scientific community doubted the existence of any discovery here. The change in the size of the rods wasso insignificant that the human eye could not catch it. But the physicist developed a special technique with which he obtained visual evidence.
Later it turned out that other metals also have this effect, and the phenomenon itself was called magnetostriction. Now, many applications have been found for the discovery of the Joule. For example, magnetostrictive metals serve as the material of a waveguide for measuring the water level in tanks. This phenomenon is also used to make tags in anti-theft systems.
Gas experiments
In the 40s, James Joule actively studied the properties of gas, namely the phenomena associated with its expansion and contraction. He conducted an experiment with the expansion of a rarefied gas, while proving that its internal energy does not depend on volume. Only the temperature of the gas matters.
In 1848, Joule measured the speed of gas molecules for the first time in the history of physics. This experience was an early work on the kinetic theory of gases, giving impetus to further research in this area. Joule's work was later continued by the Scot James Maxwell.
For a significant scientific contribution in honor of the English physicist, the unit for measuring work, the amount of heat and energy, the Joule, was named.
Joule and Thomson
William Thomson had a huge impact on Joule's activities and his recognition in the scientific world. The scientists met in 1847 when Joule presented a report on measurements of the mechanical equivalent of heat to the British Association of Scientists.
Before Thomson Joule was not taken seriously in scientific circles. Who knows, maybe we would not have known the laws of physics he discovered if William Thomas had not explained their importance to the “snobs” of the British community.
Together, physicists studied the properties of gases, discovering that gas is cooled during adiabatic throttling. That is, the temperature of the gas (or liquid) decreases during passage through the orifice (isolated valve). The phenomenon is called the Joule-Thomson effect. Now this phenomenon is used to obtain low temperatures.
Scientists also worked on the thermodynamic scale, named after the title of Lord Kelvin, which belonged to William Thomson.
James Joule confession
Fame and recognition still overtook the English physicist. In the 50s of the 19th century, he became a member of the Royal Society of London and was awarded the Royal Medal. In 1866 he received the Copley medal and later the Albert medal.
Several times Joule became the President of the British Scientific Association. He was awarded Doctor of Laws degrees from Dublin College, Edinburgh and Oxford Universities.
There is a statue in his honor at City Hall in Manchester and a memorial in Westminster Abbey. There is a James Joule crater on the far side of the Moon.
Conclusion
The famous scientist, whose name is given to the laws of physics and units of measurement, might not have been recognized. Thanks to hisperseverance and work, he did not stop before numerous failures. In the end, he proved the right to his place under the sun, or at least on a lunar crater.
