In the introduction Asimov talks about the necessity and burden of specialization. Writing and selling science essays is a nice way to generalize about science even in this modern age.

A characteristic of his essays that I enjoy is the way a single essay may use facts that we should know as guides to his main discussion. For example, in "Now Hear This!" which is mostly about echo-location, he makes an illuminating excursion into the history of the understanding of the physics of light.

The essays:

Part I: Biology
That's about the Size of It (October 1961)
An simple essay about the relative sizes of animals with a scale of the logs of their mass at the end. A helpful reminder that the blue whale is still the biggest animal ever. A discussion of shrews, which being so small must eat constantly to survive, and are consequently very aggressive as well as small. The thesis of the essay was almost meaningless, just that humans are not really as comparatively small as they like to think of themselves wrt. other members of the animal kingdom, or that they have done some of that conquering with their brawn not their brain. The way he limits his comparison among existing and extinct animals does not make much sense in relation to his thesis. It's the chart and the asides about the individual animals (a full-grown elephant is about the size of a new-born blue whale), which makes this essay enjoyable.

Part II: Chemistry
The Element of Perfection (November 1960)
About helium, the noblest of the noble gases. Helium is so named because it was first identified by its spectral signature in the light from the sun; it was only later discovered on Earth. These essays have a nice excursion through the analysis of air.

Part III: Physics
Now Hear This (December 1960)
About echolocation in dolphins and bats, about the possibility of speech in dolphins, and about the wave nature of light.

Part IV: Astronomy
Superficially Speaking (February 1962)
About the colonization of other planets and about the possibility of hollowing out asteroids. Seems flaky now.

4/6/22