Thomson, Lord Kelvin, William (1824-1907)

Scottish physicist

William Thomson, known to history as Lord Kelvin, was granted the first scientific peerage by Queen Victoria in 1892 for his unique consulting work that made possible the installation of the transatlantic cable linking the telegraph systems of America and England. The peerage was created especially for him, taking the name from the Kelvin River near Glasgow, Scotland. Thus, when Thomson's proposal for an absolute scale measuring heat was widely accepted, it was given the name Kelvin.

Thomson was a child prodigy who grew up in the environment of academia and became a professor at a young age. Thomson was enthusiastic and dramatic in his teaching style. Known as an expert on the dynamics of heat, he was also noted for having a wide range of interests in the sciences, particularly electricity and magnetism . As a science and technology authority, Thomson was willing to take on the unpopular side of a controversy. This characteristic almost ruined his career when he attempted to establish the age of Earth, accepting the least popular premise concerning the origins of the planet. However, his gamble in supporting James Prescott Joule rewarded Thomson with a lifelong friendship and a proficient research collaboration.

Thomson was born in Belfast, Northern Ireland, in 1807. While he was still young, the family moved to Glasgow where his father received a position as a mathematics professor. His mother died when he was six years old, and young William became accustomed to attending his father's lectures. After attending his father's classes for many years, Thomson surprised many by actively participating. By age ten, he was ready for college. He was able to keep up with his much older classmates and he even surpassed them by writing his first scholarly treatise at the age of fourteen. Many were impressed with this work and a respected professor, representing Thomson, presented it in lecture to the Royal Society of Edinburgh. Thomson and his professors decided he should not present the paper himself because his young age would have undermined the respect his paper deserved.

After enrolling in Peterhouse College at age seventeen, Thomson achieved honors in a difficult mathematics program by age 21. Although his father had hoped that William would follow him into mathematics, Thomson was strongly interested in natural philosophy (as science was called in his time). He was very much interested in Fourier and other newly emerging theories of heat, having already achieved valuable experience at Regnault's Laboratory in Paris. Thus, when offered a position as professor of natural philosophy at the University of Glasgow in 1846, Thomson accepted. He remained a professor at Glasgow for the next fifty-eight years.

Thomson's first achievement as a professor was an attempt to establish the age of Earth based on mathematical models representing the difference in temperature between Earth and the Sun . This research was almost a fiasco, upsetting well-respected geologists of the day. Although Thompson's basic geological premise was faulty, his proficient models and accurate calculations were impressive. More importantly, the principles of thermodynamics he employed were well thought out. Fortunately, because many paid attention to the strengths of his study, Thomson advanced his expertise on the properties and dynamics of heat.

At Glasgow, Thomson's students were fascinated with his youthfulness and his energetic lecturing style. He built his own laboratory for his students by converting an old wine cellar belonging to a more established member of the faculty.

In 1847, at a conference of the British association, Thomson listened as Joule presented findings on the effects of heat on gases. Joule's presentation was not convincing to most of the assembled scientists and he would have been ignored if Thomson had not come to his defense. Thomson not only supported Joule in this conference, but also agreed to collaborate with him on new research. From this work came the Joule-Thomson effect of heat conservation, presented in a paper in 1851. This concept—that gas allowed to expand in a vacuum will reduce its heat—became the foundation of an early refrigeration industry.

While studying the effects of heat on gases, Thomson recognized that the linear relationship between the heat and mass in gases was awkwardly graphed using the traditional Celsius Scale. In 1848, he proposed an absolute scale using the same range as the Celsius scale but with zero set at the point where there is virtually no movement among the molecules (−273.18°C). This can be considered the point of absolutely no heat. In 1851, Thomson further elaborated how this new scale would illustrate the principles of thermodynamics more clearly in experiments. Scientists in other fields also recognized how the absolute (later called Kelvin) scale could be very useful.

Thomson admitted that he learned much from Joule. However, for many years he tried to resolve the theoretical differences between the dynamic theories of heat that Joule was relying on and the principles he found to be true in the theories of Sadi Carnot. In his dissertation of 1851, he thoroughly presented the strengths of Carnot's theories reconciled to the dynamic theory. From this paper, the second law of thermodynamics was established. This law stated that heat transferred from hotter matter to colder matter has to release mechanical work. Furthermore, heat taken from colder matter to hotter matter requires the input of mechanical work. However, the second law of thermodynamics was not fully credited to Thomson because it was contemporaneously developed (separate from Thomson's work) by other researchers.

Thomson also excelled in other areas of science. His improvements in the conductivity of cable and in galvanometers were patented inventions without which the practicality of the transatlantic cable would not have been possible. Among Thomson's many honors, he was elected president of the Royal Society and held the post from 1890 to 1894. He continued to invent and study in his later life. After a short period of retirement from the university, he returned as a graduate student. Although Thomson maintained a sharp mind until his death, he was adamant against the changes in old paradigms that new discoveries brought at the end of the nineteenth century. For example, Thomson once remarked that air travel other than ballooning would be a scientific impossibility. Thomson died in 1907 and was buried in Westminster Abbey, leaving no children to inherit his title.

See also Physics; Temperature and temperature scales

Kelvin, Lord See THOMSON, WILLIAM.