26th June 1824

Inventor and physicist Lord Kelvin is born

William Thomson was the University of Glasgow’s sixth Professor of Natural Philosophy, but today we remember him more for one of his innovations than for the role he occupied at the time. After all, natural philosophy is, in effect, just another way of saying physics or nature.

Among other things, Thomson was interested in the study of thermodynamics, for which it was important to establish an immutable scale against which various aspects, including temperature, could be measured. This scale turned out to be the Kelvin scale, which defines absolute zero to be -273.15 degrees Celsius. Absolute zero is the point at which more or less everything – down to the level of molecules – becomes frozen and stops moving.

Although Thomson didn’t invent the concept of absolute himself, he was the one who established its equivalence to Celsius and Fahrenheit, thereby making it useable. The units that make up the scale are thus known as kelvins (just as the units that make up Celsius and Fahrenheit are known as degrees), since Thomson himself was later ennobled as Baron Kelvin of Largs in the County of Ayr in 1892.

Lord Kelvin’s innovations

Beyond his work into thermodynamics, Thomson was president of the Royal Society of Edinburgh three times over, and helped improve early designs for a transatlantic cable so that it could carry more data. He worked on a device to predict tides, advised on the construction of Niagara Falls power station, and attempted to calculate the age of planet Earth, making a significant underestimate when compared to current calculations.

Thomson spent more than 50 years at the University of Glasgow and became the university’s chancellor in his retirement. He died in 1907 at his home in Largs after catching a cold. By then he was so respected that shops closed as a mark of respect, and he was taken to London by train for burial at Westminster Abbey.