Lord Kelvin

William Thomson, 1st Baron Kelvin (26 June 1824 - 17 December 1907)

Among many things, Lord Kelvin is associated with the creation of the First and Second Laws of Thermodynamics and the temperature scale of Kelvin.

His work on the Laws of Thermodynamics began after hearing another attempt made by James Prescott Joule to discredit the highly popular caloric theory associated with heat. Unlike many of the attendees, Kelvin was intrigued enough to listen to Joule's work, even though he himself was skeptical. Kelvin still believed the Carnot–Clapeyron caloric theory, however, he began to doubt it after experiments he performed himself. The caloric theory did not yield an "absolute temperature scale", only an "operational definition of temperature". Over time, Kelvin began to believe the theory that Joule was discussing, however, he believed that it was possible to find a compromise between Carnot and Joule's theories. This pondering lead to his formulation of the Second Law of Thermodynamics. Soon a partnership between Joule and Thomson lead to publications, Joule's work being accepted, and the kinetic theory.

During his doubts of the Carnot-Clapeyron theory, his want for an absolute temperature scale had him thinking. He thought that a certain point could be reached where no further heat could be transferred, later to become 'absolute zero', which had been speculated by Guillaume Amontons in 1702. He was later able to determine the correct temperatures of absolute zero: as approximately −273.15 degree Celsius or −459.67 degree Fahrenheit.

References https://en.wikipedia.org/wiki/William_Thomson%2C_1st_Baron_Kelvin