Joule, James Prescott

[person]

English physicist born in Salford (1818-1889). In 1840, Joule published a paper detailing what is now called Joule's Law, which describes the relationship between the current through a resistor and the heat lost from the system. He continued his studies on heat and its relationship to mechanical work, concluding that heat is a form of energy. He developed the theory of conservation of energy, and, subsequently, the First Law of Thermodynamics. The joule, an SI unit of energy, is named after him.