Customer Reviews

Inventing Temperature: Measurement and Scientific Progress (Oxford Studies in Philosophy of Science)

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Several years ago, the science fiction author Isaac Asimov wrote a short story set in the far future. He depicted a time so advanced that the simplest arithmetic was done by computers, and forgotten by humans. And so it goes here, in Chang's book. He has done us a service by revisiting solved problems that have been solved for so long that their basic importance is no longer appreciated by practising scientists.

Consider your typical undergraduate textbooks that discuss heat and temperature. Very little mention is given about the bootstrapping problem. Without modern instrumentation, how do you define a temperature scale that is consistently reproducible? One might wonder why it took scientists of an earlier age so long to strive over such a simple problem. Were they stupid back then?

Not so. Chang shows that the problem is divided into two closely related parts. One experimental and one conceptual. The former relates to the search for fixed points, like the freezing and boiling points of water. Not as straightforward as it might first seem. And no, it was not the dependence of these on the atmospheric pressure. That was quickly discovered and accomodated. But other phenomenon like the supercooling of liquid water, which can push it below the normal freezing point, were harder to understand.

It turned out that the key conceptual problem is just as serious, if not more so. One runs into a circular pattern of logic. One way out is to follow Euclid's approach by starting with a small set of axioms that everyone accepts, and build from them. Anyway, the core of Chang's book is how this problem was tackled and solved. It took some of the most prominent scientists of the 18th and 19th centuries to tie this down. And that is the merit of this book. Chang helps us appreciate one of the foundations of our science.

Inventing Temperature tells the long and intriguing history of thermometry, the science of the measurement of temperature. First, thermometers had to be invented, followed by methods to calibrate them. But to calibrate a thermometer at least one reproducible phenomenon that always took place at the same temperature was needed. But how would one know that something, say the boiling of water, always took place at the same temperature if one didn't have a calibrated thermometer? This circularity was behind most of the hurdles the pioneering thermometrists had to overcome. Finally, temperature scales, a multitude of them, were devised--almost one by each independent thermometer maker.

I learned quite a bit from this book. Among the more interesting episodes were a series of experiments by Marc-Auguste Pictet in the late 18th century that demonstrated quite puzzlingly that cold, like heat, could be reflected from a mirror and Charles Darwin's grandfather potter Josiah Wedgwood's almost contemporaneous invention of a pyrometer to measure very high temperatures--it used small pieces of clay, the amount of shrinkage of which at a given temperature were supposed to have been reproducible.

I wish Chang's prose were a bit more straight and readable and the contents of the book a bit more uniform. The first 4 of the 6 chapters have 2 parts each: a historical narrative followed by an analysis that dwells into philosophical issues that I thought were boring and not always relevant. I confess I skipped most of the analyses.

Chang ends his book with a chapter on "complementary science", his provocative research program that intends, by utilizing the historical and philosophical aspects of a particular scientific area, physics, in his case, to "generate scientific knowledge in places where science itself fails to do so."