course homepage(Chemistry World, August 2005 – an RSC publication. 650 words, 3500 characters)
Ask the average chemist to say a word about thermodynamics and that word will probably be ‘Yuk!’. I can relate to that. I believe I only truly understood thermodynamics for a period of seven days in my entire life, but fortunately that golden period coincided with the week of my finals.
But this antipathy is a great pity because thermodynamics is not an optional extra in chemistry. It underpins everything, even showing whether a particular chemical reaction will go or not. Furthermore, after studying the teachings of the Blessed Madonna, and the Divine Britney – kabbalah followers both and therefore convinced that anagrams reveal hidden insights – I have discovered that the letters in ‘thermodynamics’ can be rearranged to yield ‘mad on chemistry’. Could it be a sign?
Fundamental as it is, thermodynamics has its amusing aspects. How many other subjects have a zeroth law, for example? All right, I accept that you can argue that its practitioners must have been pretty dim to get up to law three before realising they had missed one out right at the start and the only way they could remedy the omission was to shoehorn another in before the first law, but no matter.
In fact, the stars of thermodynamics were anything but dim. Rather, they stand among the greats of science as a whole. J Willard Gibbs is just one name that springs to mind. While still in his 30s, Gibbs wrote a series of thermodynamics papers that constituted one of the finest intellectual achievements of science and formed the basis of physical chemistry as we know it.
Sadly, Gibbs didn’t so much hide his light under a bushel as take it out into the back garden and bury it six feet down. He chose to publish this ground-breaking work in the Transactions of the Connecticut Academy, a journal of such mind-numbing obscurity that his fellow US scientists remained largely in ignorance of Gibbs’ contributions.
Only when his work was taken up by Europe several years later did US science wake up to the towering figure in its midst, all unknown. Regrettably, cynics point out that one of Gibbs’ main concepts is impossible, arguing that there is no free energy any more than there is such a thing as a free lunch.
Perhaps most important of all in the wider scheme of things is the fact that, without thermodynamics, science would present us with a world in which time is reversible, which any fule kno is simply not true. Have you tried unboiling an egg recently? Fortunately, entropy, one of the most important planks of thermodynamics, comes to the rescue by generating equations that are time-asymmetric.
Despite all of which, poor old thermodynamics is held in universal ill odour and this surely stems simply from poor teaching of the subject. In my day, the thermodynamics course ended with an offhand mention that there was a statistical explanation for the subject based on probability and the laws of big numbers. In my view, this was where the teaching should have started.
The average chemistry student may have whinnied like a frightened horse at the mention of a hamiltonian operator, and doubtless fervently believed a canonical ensemble was simply a prayer meeting, but he or she would in the end have understood the whole thing so much better than coming at it from a consideration of heat engines. My lecturer should have been made to write out ‘S = k logsigma’ 500 times.
But unfortunate students will assuredly go on having to sit through thermodynamics lectures bored rigid and trying to distract themselves by speculating about Sadi Carnot’s cycle. Is it available with dropped handlebars and derailleur gears? Do the makers do it in red? And which dusty, crusty old museum in downtown France would one have to visit in order to see a surviving road-worthy specimen?
Brian Malpass
Last modified: 1/09/2005