- Bibliography
- Early years
- Studies
- Contributions to science
- Joule's Law
- Joule-Thomson effect
- First Law of Thermodynamics
- Recognitions
- References
James Prescott Joule (1818-1889) was a British physicist best known for his research in electricity and thermodynamics. His studies in the field of magnetism led him to discover its relationship with mechanical work and led him to the theory of energy. The international unit of energy, heat and work, known as the joule or July, is named after him.
Today he is recognized as one of the most remarkable physicists of his time, due to his pioneering research in thermodynamics. However it was not always so. Joule had to fight for most of his youth to be taken seriously by the scientific community. Despite the quality of his work, he found it difficult to attract funding and publish in reputable magazines.
He was a shy and humble young man, that is why he needed the support of stronger personalities to help him make himself valued within the scientific community. In 1847 he collaborated with William Thomson, later known as Lord Kelvin, who, although six years younger than him, never had a problem with self-promotion.
Bibliography
James Prescott Joule was born in 1818 in Salford, near Manchester; and passed away in Sale in 1889. He grew up in a wealthy family that owned a beer factory, which he managed to manage.
He did not attend school due to health problems, but received classes in his own home until he was 15 years old, at which age he had to start working at the distillery.
John Dalton, the famous British chemist, was his professor of mathematics and physics, and who encouraged him to carry out his scientific research. Additionally, Dalton was a member of the Royal London Society for the Advancement of Natural Science and knew many of the leading scientists of the time.
He impressed young Joule to such an extent that, while developing his own views on energy transformation, he was adamant in the print media, even when almost all other scientists disagreed with him.
Early years
James Joule had some health problems during his childhood. A weakness in the spine caused a slight deformity. For this reason, he did not attend school and received private classes at home, which he combined with his work at his father's distillery.
By not interacting with other children at school, he was shy when he was in company. In fact, the lack of a stronger personality may be behind its lack of recognition in the scientific community.
For this reason, he needed the support of other scientists who possessed the gifts that he lacked. However, it was not until 1847 that William Thomson came into his life. Until then Joule struggled to publish articles of great scientific importance, but with little or no impact.
Studies
From 1834 to 1837, James and his older brother Benjamin received private lessons in their own home. His professor of physics and mathematics was the British chemist John Dalton, who encouraged him towards scientific research.
At first, he carried out his experiments in the laboratory that he had installed in the basement of his house, while he continued his studies at the University of Manchester.
At first, he studied aspects related to magnetism during electric currents, and thanks to this he invented the electric motor. He also conducted research in the field of electricity and thermodynamics.
At age 20, he managed to replace the steam engine at his father's brewery with an electric one with the idea of increasing efficiency and saving the company money. While conducting his research on the heat released from an electrical circuit, he formulated what is now known as Joule's law.
Contributions to science
Joule's work is the story of a constant struggle against a critical scientific establishment that was unwilling to accept the evidence until it was impossible to ignore it.
His scientific research culminated in 1850. In that year he published an article in which he presented measurements of the mechanical equivalent of heat, for which he used his famous paddle wheel apparatus.
Joule's Law
While investigating the heat that is given off in electrical circuits, he exposed the well-known Joule's law. When an electric current flows through a conductor, there is an increase in temperature. This law allows us to calculate the heat that is generated when electric current flows through a resistance.
Joule-Thomson effect
In 1852 Joule and William Thomson discovered that when a gas is allowed to expand without doing any external work, the temperature of the gas decreases. This phenomenon, which was called the Joule-Thomson effect, was the basis for refrigeration and air conditioners.
First Law of Thermodynamics
James Joule played a pivotal role in studies of how to conserve energy, or first law of thermodynamics, as a universal principle of physics. It is based on Joule's conclusion that heat and energy are equivalent.
Recognitions
The scientific world of the early 19th century was complicated. Science degrees were not awarded in Britain and there were no professional scientific qualifications. Only a small minority of those who published scientific articles had a paid job in science.
Joule himself conducted most of his experiments in the basement of his home as a private individual and worked with the few resources at his disposal.
However, in 1866 the Royal Society awarded him its highest recognition, the Copley medal. In addition, he was elected president of the British Association for the Advancement of Science in 1872 and in 1887.
In his honor, the unit of the International System used to measure energy, work and heat is called a joule.
References
- Esq, JPJ (1843). XXXII. on the calorific effects of magneto-electricity, and on the mechanical value of heat. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 23 (152), 263-276.
- James joule - MagLab. Retrieved Jul 8, 2019, from nationalmaglab.org
- James joule, william thomson and the concept of a perfect gas. (2010). Notes and Records of the Royal Society, 64 (1), 43-57.
- Sarton, G., Mayer, JR, Joule, JP, & Carnot, S. (1929). The discovery of the law of conservation of energy. Isis, 13 (1), 18-44.
- Young, J. (2015). Heat, work and subtle fluids: A commentary on joule (1850) 'On the mechanical equivalent of heat'. Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences, 373 (2039) doi: 10.1098 / rsta.2014.0348