William Thomson, 1st Baron Kelvin

Born in Belfast in 1824, Thomson spent 53 years as professor of Natural Philosophy at the University of Glasgow, where his mathematical analysis of electricity helped shape the first and second laws of thermodynamics and pulled physics together as a coherent discipline. He calculated absolute zero at roughly −273.15 degrees Celsius, a boundary the universe itself enforces. But Thomson also had a parallel career as a telegraph engineer: his work on the transatlantic cable earned him a knighthood in 1866, serious money, and public celebrity. He served as president of the Royal Society, became the first scientist elevated to the House of Lords in 1892, and refused every offer to leave Glasgow. He stayed until retirement in 1899, then joined Kodak's British board and became Chancellor of the University of Glasgow in 1904. He died in 1907 at Netherhall, the mansion he'd built in Largs - his smoking-pipe now rests in the Hunterian Museum.