Before reading this book, I had not realised what an affect Sir William Thomson (Lord Kelvin) had had on my world today as an electrical engineer.
I had not realised what an affect Sir William Thomson (Lord Kelvin) had had on my world today as an electrical engineer. I had always associated him with work in graduating temperature (because of the units) erroneously as it turns out. I knew he was considered one of the greats (he was buried next to Newton after all), but I could not say why. Coincidentally, while I was reading Degrees Kelvin by David Lindley (published by Joseph Henry Press, 2004) his named popped up in the comments of one of Max Maxfield’s blogs.
Thomson was one of those guys that we love to hate: brilliant, good looking, gregarious, personable, and excelled at sports. He was born into an academic family and was destined for great things at an early age. He attended Cambridge University to much acclaim and academic success and then returned to take up an academic post in Glasgow in 1846. At that point very little was known of heat and energy, light, electricity and magnetism. In fact according to the book, physics as we know it (it was known as Natural Philosophy) was not codified until the 1860s by Thomson and Peter Tait in their multi-volume book that covered the discoveries and developments that had taken place in the two decades.
Apparently Thomson was much taken and completely absorbed Fourier’s analysis of heat flow. He then started creating the mathematics around the first law of thermodynamics and was right in the thick of things in propounding the law of conservation of energy. Much of the book is taken up with who was the first to come up with what concept, but there are many names that pop up in this field as it further moved to the second law of thermodynamics and conceptualising entropy. Carnot, Clausius, Stokes and Joule are all his contemporaries and were all in contact through journals and correspondence (actually Carnot was a little before). If that was all, it would have been enough to establish his name in the halls of fame. But wait, there’s more...
Michael Faraday had come up with the concept of magnetic fields, but he was unable to express it in scientific terms for two reasons. Firstly he did not have the mathematical skills and secondly he did not have the vocabulary to describe it. Actually, that’s not fair- nobody had the vocabulary. Reading some if the correspondence, even with the stilted Victorian prose, you can’t help but note how they were struggling to match phenomena with words. Terms like ether, flux and vortex are bandied around as they tried to firstly describe and then quantify their observations as they evolved. Faraday regarded Thomson as the only person who managed to understand his concepts and express them mathematically.
Thomson had an immensely practical side to him and managed to apply theory into practice, being one of the first to take scientific principles and translate them into practical applications. If you don’t think that sounds like engineering, consider this. He was involved in the establishment of the undersea cable from Europe to North America and the elsewhere right from the get-go including the problems of insulation and cable weight in addition to transmission issues. The Morse signals were impaired as a result of the resistance and leakage of the cables and Thomson developed a galvanometer that sensitive enough to enable the signals to be read reliably (Edison was trained on one). As a later development he tried and largely succeeded to get a pen output to provide a permanent record of the transmission. He came up with a technique of charging the ink to get it out the nozzle which is the same technique used in ink-jet printers today. Even if this was not enough to convince you of the nascence of engineering, Sir William learned about the patenting process and patented all his products establishing himself as an incredibly wealthy man. The wealth probably had more to do with his elevation to the aristocracy than his science.
At the time there was no method of measuring electric current. In fact they didn’t even know what to call it. There were arguments on how to measure resistance including concepts from Wheatstone and Siemens. Because of its derivation from the concept of work done developed by Joule, resistance was initially measured in kilometres per second! Thomson was deeply involved in the development of the standards and even developed the first calibrated galvanometer to aid in the measurement of resistance. The names of the electrical units approximating the ones we use today appear to have been apportioned by chauvinistic considerations at a meeting in 1881 that included luminaries like Helmholtz, a close friend of Thomson. People involved with electricity including Thomson were inevitably called “electricians” which morphed into “telegraph engineers” before becoming “electrical engineer” in the 1880s.
Despite all this, like all of us he also had some flaws. There were contradictions for a start. He loved the Scottish landscape, but had no qualms converting Niagara Falls in a giant power generation scheme so that no water flowed over the falls. He was a great friend of Westinghouse despite his (Thomson`s) preference of DC over AC . He refused to accept the Theory of Evolution because according to his calculations based on the loss of heat from the earth, the earth could be no more than 100 million years old. Notwithstanding this he chose to defer to a religious defence when discussing evolution. He could not accept Maxwell’s explanation of electromagnetic radiation because he could not understand how it could pass through a vacuum. He always wanted a mechanical model to explain the phenomenon despite the fact that Maxwell`s treatise seemed to match Faraday’s original concepts. Even after Heaviside transformed Maxwell’s equations into the elegant form that we use today, he could not accept it. He did not believe that an element could change into another element even with the evidence of radium. He was limited by the concepts of his time and background and at the end of his life his approach of mechanical modelling of everything no longer could explain the new science. This is a point also made by Bill Bryson in his “A Short History of Nearly Everything” about how Michael Faraday’s deep religious beliefs hampered his understanding of electro-magnetism.
Thomson’s brilliance was the ability to combine different peoples’ work and theories to create an explanation that everyone else had missed (according to the book). In the process though, he made these approaches his own and did not always appear to acknowledge their source or in fact recognise that they were not his own.
The book has several tedious bits. Apparently Thomson enjoyed a good argument and employed a Peter Tait as his bulldog in the journals. The book spends an inordinate amount of time on these discussions for my taste, especially on the arguments as to who came up with a particular concept. It also delves too deeply into his early years at Cambridge. Nevertheless the book manages to imbue all these great people with aspects of their humanity and makes it a worthwhile read. It also shows us how great ideas do not often develop as a single flash of genius but are based on ideas that came before. Despite chauvinistic claims there are smart people everywhere and they worked together either collaboratively or competitively to create the world we have today.
Aubrey Kagan is a professional engineer with a BSEE from the
Technion-Israel Institute of Technology and an MBA from the University of the
Witwatersrand. Aubrey is engineering manager at Emphatec, a Toronto-based design
house of industrial control interfaces and switch-mode power supplies. In
addition to writing several articles for
Circuit Cellar and having ideas
Electronic Design, Aubrey wrote
Excel by Example: A Microsoft Excel Cookbook for Electronics