Polytropy

Here is an annotated transcription of a 1981 manuscript by Charles Greenleaf Bell (1916–2010) called “The Axiomatic Drama of Classical Physics.” A theme is what Heraclitus observed, as in fragment B49a of Diels, LXXXI of Bywater, and D65a of Laks and Most:

We step and we do not step into the same rivers,
we are and we are not.

ποταμοῖς τοῖς αὐτοῖς ἐμβαίνομέν τε καὶ οὐκ ἐμβαίνομεν,
εἶμέν τε καὶ οὐκ εἶμεν.

Bell reviews the mathematics, and the thought behind it, of

1. free fall,
2. the pendulum,
3. the Carnot heat engine.

In a postlude called “The Uses of Paradox,” Bell notes:

Forty-five years ago I decided that when reason drives a sheer impasse into an activity which in fact goes on, we have to think of the polar cleavage as both real and unreal.

I like that reference to “an activity which in fact goes on.” In youth it may be hard to recognize that there are activities that go on. We do things then, but that they will get anywhere may be no more than a dream. In any case, Bell himself goes on:

… that is a job as huge and demanding as Aristotle’s, and for me at 70, just begun.

“Look,” my friends say, “Bell’s been doing the same thing since he was 25. About that time he had a vision of Paradox as paradise, and he’s been stuck there ever since.”

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