Chemiotics: Unrequired reading

Mar 27, 2019
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Posted on behalf of Retread

If you look back at your notes on thermodynamics, you are likely to find a blizzard of partial derivatives, state functions and total differentials. As an organic chemist, I had an intuitive understanding of the thermodynamics I needed at the molecular level (actually it’s pretty simple), but the math and the big ideas were not friends. Should you be in the same boat and wish to get the big picture, have a look at “Four Laws that Drive the Universe” by Peter Atkins. It’s 124 small pages, written extremely well and bounces back and forth between the macroscopic and the microscopic illuminating each by the other. If there is a derivative to be found, I missed it.

The book may produce in you physics envy (with apologies to Freud). On p. 45 you will find a discussion of Noether’s theorem, which states that under all the conservation laws of physics lies a symmetry. The first law (conservation of energy) is really about the symmetry of time flow — e.g., “time flows steadily, it does not bunch up and run faster then spread out and run slowly.” Chemistry just doesn’t have statements of such majesty (or strangeness).

If you liked Atkins you’ll love “Boltzmann’s Atom” by David Lindley. It concerns Boltzmann’s trials and tribulations as he developed statistical mechanics. As a neurologist I doubt that they drove him to suicide at 62 (he sounds pretty loosely wrapped throughout his life). Boltzmann’s big opponent was Ernst Mach, who didn’t see the need for atoms as an explanatory device. Mach’s view was that physics should establish laws tying observable phenomena together — e.g., the ideal gas law etc, etc… Postulating something you couldn’t see to explain something you could, was not considered science (by Mach and his followers). Pretty strange to our way of thinking today, but these were the events of just over 100 years ago.

However, vestiges of Mach’s thinking linger on in the Copenhagen interpretation of quantum mechanics. As junior chemistry majors in the 50s we had to read “The Logic of Modern Physics” written by P. W. Bridgeman in 1927. It was our introduction to quantum mechanics (as none of us had the math to tackle it). All you could hope to predict by a theory were ‘numbers on a dial’. Going deeper, by hoping for a trajectory explaining things was a no no (the nodes in atomic and molecular orbitals pretty much rule out trajectories don’t they?). The book drove us nuts at the time, as chemistry back then was firmly on the macroscopic side of the quantum mechanical divide.

Gibbs and Maxwell make their appearance in Lindley’s book, as does the culture and politics of Austria-Hungary before WWI, so there is some breathing room for the reader. One of the founders of physical chemistry, Wilhelm Ostwald, also appears. He doesn’t come off too well — he was enamored of something called energetics, which to Boltzmann (and to Lindley who is a physicist) meant that he really didn’t understand physics very well.

Atoms were finally accepted after Einstein’s work on Brownian motion in 1905 (also described). Parenthetically, there was a similar controversy ending about the same time, as to whether the brain was made of cells, and whether individual neurons existed, or whether the whole brain was a big gemish of nuclei and fibers.


Stu Cantrill

Chief Editor, Nature Chemistry, Springer Nature

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