James Prescott Joule

James Prescott Joule

James Prescott Joule was an English physicist who studied the nature of heat and established its relationship to mechanical work. He therefore laid the foundation for the theory of conservation of energy, which later influenced the First Law of Thermodynamics. He also formulated the Joule’s laws which deal with the transfer of energy.

Early Life and Education:

Born in Salford, Lancashire on December 24, 1818, James Prescott Joule’s father was a rich brewer. Joule was mostly homeschooled. He studied arithmetic and geometry under John Dalton at the Manchester Literary and Philosophical Society. He was later taught by famous scientist and lecturer, John Davies.

Contributions and Achievements:

James Prescott Joule analyzed the nature of heat, and established its relationship to mechanical energy. His efforts had a profound influence on the theory of conversation of energy (the First Law of Thermodynamics). He collaborated with Lord Kelvin on the formulation of the absolute scale of temperature, and carried out extensive research on magnetostriction; a property of ferromagnetic materials that makes them modify their shapes when exposed to a magnetic field.

Joule was the first scientist to identify this property in 1842 during an experiment with a sample of nickel. He established the relationship between the flow of current through a resistance and the heat dissipated, which was later termed as Joule’s law. He is also credited with the first-ever calculation the velocity of a gas molecule. The derived unit of energy or work, the Joule, is named after him.

Joule was elected to the Royal Society of London and was given a Copley award. He also served as the president of the British Association for the Advancement of Science.

Later Life and Death:

James Prescott Joule died on October 11, 1889 in Sale, Greater Manchester, England. He was 70 years old.