Tag: thermodynamics

William Thomson

Posted on by Dan
William Thomson, 1st Baron Kelvin
William Thomson, 1st Baron Kelvin

William Thomson (1824 – 1907) was a Scottish physicist known for early work in thermodynamics and for establishing the Kelvin temperature scale.  In 1892 he was ennobled Baron Kelvin for his work on thermodynamics and is also known as Lord Kelvin – the name from which the Kelvin temperature scale is given in his honor.

William Thomson was born in Belfast and attended Cambridge University where he took an interest in mathematics and physics.  After he graduated he found himself working as a professor at the University of Glasgow where he would stay for the next 50 years.  His early work was in thermodynamics but he his real genius was in that he was able to synthesis a variety of sub-disciplines in physics such as heat, mechanics, electricity, and magnetism.

Thomson is most known for his work in thermodynamics, in particular for his proposal of an absolute temperature scale which is named Kelvin in his honor.  The Kelvin scale uses the same scale as the Celsius but sets the value of 0 at the point at which there is no movement in molecules and hence no heat.  This value is approximately -273.   Thomson also helped to develop the second law of thermodynamics which states the heat moves from hotter to colder objects, or stated another way that entropy always increases. He surmised that if entropy always increased that there would come a point where no work could be done and there would be total uniformity throughout the universe.  This he called the heat death of the universe.

Throughout his life Thomson was active in all area’s of science.  He was a friend and colleague to James Clerk Maxwell and some of his idea’s help Maxwell to formulate his electromagnetic theories.  He was interested in geology and evolution, but he ultimately sided against Darwin’s Theory on Evolution by Natural Selection on the basis that he thought the Earth was no hospitable to life long enough to allow evolution to run its course.  In this he was later proved to be wrong.  Lord Kelvin lived a long and successful 83 years of life and is buried at Westminster Abbey.

Benjamin Thompson

Posted on by Dan
Benjamin Thompson portrait
Benjamin Thompson

Benjamin Thompson (1753 – 1814) was an American born physicist who made many contributions to our understanding of the nature of heat.  His work helped lay the foundations to the modern theories of thermodynamics.

Benjamin Thompson was born to a farming family in Massachusetts two decades before the American Revolution began.  His life prospects increased when he married a rich widow at age nineteen.  Soon the American Revolution began and he sided with the British, serving as a spy.  In 1776 he moved to England and continued to work for the British government.  He was elected a fellow member of the Royal Society in 1779 for his scientific work on the force of gunpowder.  He soon moved on to Bavaria where he worked as a military commander and in 1791 he was made a count, taking the name of Count Rumford. He returned to London in 1798 and a year later helped to found the Royal Institution of Great Britain.

While working in the military he naturally became interested in the effects of heat on the equipment, especially cannons.  The leading theory of the day was the caloric theory in that heat was a type of fluid that flowed from one substance to another.  While watching the process of boring cannons he noticed that the heat generated in the process was substantial and almost limitless.  He correctly concluded that heat was not a fluid and that it was the motion of the borer creating friction with the cannon that generated the heat.  His knowledge about heat made him a capable inventor and he made improvements to chimneys, fireplaces, stoves, and furnaces.

Count Rumford, as he came to be called, never returned to the United States and in 1804 he married the widow of the French chemist Antonie Lavoisier.  He stayed the rest of his life in Paris continuing his scientific work until he died in 1814.