In the 19th century, scientists were researching what was the lowest temperature possible. The Kelvin scale uses the same units as the Celcius scale, but it starts at ABSOLUTE ZERO, the temperature at which everything including air freezes solid. Absolute zero is O K, which is - 273°C degrees Celsius.
Lord Kelvin - BiographySir William Thomson, Baron Kelvin of Largs, Lord Kelvin of Scotland (1824 - 1907) studied at Cambridge University, was a champion rower, and later became a Professor of Natural Philosophy at the University of Glasgow. Among his other achievements was the 1852 discovery of the "Joule-Thomson Effect" of gases and his work on the first transatlantic telegraph cable (for which he was knighted), and his inventing of the mirror galvanometer used in cable signaling, the siphon recorder, the mechanical tide predictor, an improved ship's compass.