December 24, 1818, Salford (United Kingdom) - October 11, 1889, Sale (United Kingdom)
As a boy he was educated at home, receiving private lessons in physics and mathematics from John Dalton himself. At the same time, he worked with his father in the family brewery, eventually running it until it was sold in 1854.
Science was his passion and he was fascinated by electricity, so when he was working at the brewery he began to investigate the possibility of replacing the steam engine with an electric motor, which had just been invented at the time. He conducted his research in a room in his father's house, which he used as a laboratory, and it was there that he began to experiment with electricity and magnetism. Joule found that burning a pound of coal in a steam engine produces five times the work of consuming a pound of zinc in a Grove Cell, one of the first electric batteries. Joule's standard unit of work was the ability to lift one pound to a height of one foot, the foot-pound.
Even so, Joule's interest shifted from purely financial about how much work could be extracted from a single source to speculating about energy transformation.
Joule was influenced by the thought of Franz Aepinus and tried to explain the phenomena of electricity and magnetism in terms of atoms surrounded by a ‘calorific ether in a state of vibration’.
However, Dalton encouraged him towards scientific research and he carried out his first experiments in a laboratory near the brewery, training at the same time at the University of Manchester.
He received only two years of education in arithmetic and geometry before Dalton was forced to retire due to a cerebral vascular accident. Even so, Dalton influenced Joule, as did his associates, the chemist William Henry, and the engineers Peter Ewart and Eaton Hodgkinson. He was later educated by John Davis.
In 1838 he contributed his first academic papers on electricity to the Annals of Electricity, founded and edited by Davies' partner William Sturgeon.
In 1840 he discovered the law that would bear his name and tried to impress the Royal Society but was unsuccessful. In the same year, Joule moved to Manchester with Sturgeon and they became the centre of a circle of intellectuals in the city. Both shared the belief that science and theology had to be integrated. During this time, Joule taught at Sturgeon's Royal Victoria Gallery of Practical Science.
In 1843, he published the results of his experiments showing that the heating effect he had quantified in 1841 was due to the generation of heat in the electrical conductor and not to its transmission from another part of the equipment. This was a direct challenge to the caloric theory which held that heat could neither be created nor destroyed and which had dominated the thinking of heat science since Antoine Lavoisier had introduced it in 1783. Lavoisier's prestige and the practical success of the caloric theory of Sadi Carnot's steam engine from 1824 meant that Joule, working outside academia and engineering, had a difficult road to travel.
In 1844, his father moved to Whalley Range and had a laboratory built for his son near the house. Joule maintained a close relationship with the Manchester Literary and Philosophical Society. On 25 January 1842, he became a member, two years later librarian, in 1846 honorary secretary, in 1851 vice-president, and finally in 1860 president.
Joule was to have been president of the British Association in 1872 and 1887, but on both occasions, he was unable to attend because of ill health. From 1872 onwards he became so weak that he led a quiet life until his death in 1889.
As a curiosity, his tombstone bears the inscription ‘772.75’, his culminating measure of the mechanical equivalent of heat (1878), and a quotation from the Gospel of John: ‘While it is the day, I must work the works of him who sent me; but now the night is coming on, when no one can work’ (John 9:4).
Throughout his life, but especially during his later years, he received numerous awards: the Royal Medal (1852), and Copley Medal (1860), he was awarded honoris causa doctor at several universities, the Albert Medal (1880), buildings and monuments in Manchester, a lunar crater is named after him and a French submarine, the international unit of energy, heat and work, the joule, etc.
In addition to discovering the relationship with mechanical work and leading to the theory of energy, he worked with Lord Kelvin to develop the absolute temperature scale, made observations on thermodynamic theory (Joule-Thomson effect), obtained the equivalent mechanical numerical value of heat, contributed to explaining the kinetic theory of gases, established the Joule effect and found a relationship between the electric current passing through a resistance and the heat dissipated, known today as Joule's law, etc.
