Black-Body Theory and the Quantum Discontinuity, 1894-1912

I knew Thomas Kuhn's work well before reading this book. My radical friends and I threw around the work 'paradigm' freely to suggest that the neoclassical economics we were studying at Harvard was just one of many equally plausible alternative frameworks.When I got to the Institute for Advanced Study in Princeton, 1977, my office was right across the hall from Kuhn's, and we spent many hours talking about science, the history of science, and related themes. Kuhn gave me a draft of Black-Body Theory... to read and comment on, but I did not know enough history of the period to have anything useful to say.I did learn from Kuhn that he was very dissatisfied with the way in which his earlier book, Structure of Scientific Revolutions, was being transformed into an anti-science post-modern diatribe by many academics. He taught me that there is nothing post-modern whatever about his theory of scientific change. I never forgot the lesson.This book reveals the art of a true historian of science craftsman. The scientific content is very simple. Planck did not discover the quantum, but he discover and measure Planck's constant h brilliantly. Planck followed Boltzmann's statistical mechanics argument, in which phase space is divided up into very small cells of size epsilon, where epsilon is sufficiently large that each cell can contain many particles. Boltzmann then analyzing the resulting multinomial distribution, assuming all occupancy combinations are equally probable. It turned out for Boltzmann that the size of epsilon did not much matter (you could not take zero-limit, though). When Planck did the same thing with h rather than epsilon, he found that he could fit the observed shape of the black-body radiation curve, and fit it almost perfectly for the now well-known value of h. However, Planck believe the radiation was still continuous (a la Maxwell), and h was a property of what he called 'resonators'; i.e., the radiating dipoles that he used in the proof./ Only after Einstein, in 1910 or so, did Planck recognize the quantum nature of light.So who cares? We should care. Kuhn's work supports the idea that science progresses from-what-we-know to what-we-know-next. This is in contrast with the Whig interpretation of science, which is the inevitable march from darkness to light, from confusion to clarity, from error to truth. Of course, there is nothing wrong with teaching physics by recounting its past successes, but that is not in fact how the dynamic of knowledge works.Kuhn makes the interesting point in the Afterward to the book that even the innovators often rewrite the past to make the dynamics more "logical' and 'transparent.' Kuhn says: "...quite usually, scientists will strenuously resist recognizing that their discoveries were the product of beliefs and theories incompatible with those to which the discoveries themselves gave rise." (p.366).Insights such as this abound in this rich work.

Good book.

I found the story of how the quantum actually entered physics to be somewhat different than the logical pathway presented briefly as an introduction to most popular accounts of physics. That said, I found the story to be written in a style that is a bit stiff and also repetitive. A more well organized account could have cut the length of the book by 25%.I recommend this book as the only one I've run across that gives a full account of the development in Planck's time. I also am very impressed with the depth to which the author penetrated the chaotic jumble of publications from a time when there were so many alternate hypotheses on how to explain the appearance of the quantum. The author possessed not only documentary skills, but also a depth of physics knowledge. The only reason I can't give it a higher rating is this: The book feels to me like it needed to be sent back to the author by the editor for a re-write--not to correct errors but to streamline the prose and make it read more smoothly--before going to press.

This is a good book for a physicist or physical chemist wanting to know more about how Max Planck developed his theory of Blackbody radiation, and more about physics and physical chemistry at the beginning of the 20th century. The book dispels some of the myths surrounding Planck’s work – that his law came about from a mere curve-fitting exercise and that he recognized that it implied a quantization of the radiation of the Blackbody. Kuhn shows how Planck developed his law from applying Boltzmann statistics and that when he presented it he did not see his law as requiring energy quantization. It was not until much later, after Einstein pointed out the necessity for quantization, that Planck came around to this idea, and then it was not until 1909 at the earliest.While I like the book, I feel that it also had several significant negative features. Kuhn writes in a somewhat ponderous style overly wordy style and the book requires familiarity with thermodynamics and statistical mechanics. Kuhn was trained as a physicist and this book contains a great many equations and their derivations, and thus this book would be a very poor choice for the casual reader. The book delves quite deeply into Planck’s physics and therefore requires a strong physics or physical chemistry background and a reader not so equipped will likely find this book extremely difficult going.

Everything you need to get through Boltzmann and co.

Anyone who has learned quantum mechanics has been told, in a general way, what Planck did and how it fits into the history of quantum physics. Kuhn shows that Planck thought about his goals and his results very differently than do textbook writers today.Warning! This is a very tough read:- You will not get much out of this book unless you are able and willing to follow detailed arguments in thermodynamics and statistical physics, in fairly gory mathematical detail. Quantum history-lite this isn't!- You will also not get much out of this book unless you are willing to relax about the "right" way of thinking about thermodynamics and quantum theory. However YOU may think about it, Planck thought about it differently -- and Kuhn attempts to follow his thought, zigging & zagging as he did. If you're not willing to follow along closely and attentively for the ride, you will miss the story.The payoff from reading this book is a more vivid understanding and appreciation for how very very differently we think about physics than the way it physicists saw it 100 years ago.