“The thrill of unexpected discovery”

That, according to Isaac Asimov in his Introduction to this highly thought-provoking book, “cannot help but stir the blood.” And stir the blood he does, as the reader is taken on an intriguing journey through basic scientific questions dealing with the Earth (How high is up?), to the physicist’s real land (it’s called “Mu”), and, ultimately, to the most baffling speculation of all—the size of the entire universe! But whatever the immediate subject at hand, Dr. Asimov is always brilliant in his lucid expositions of the most current scientific theories. He has given us “a book to stretch the mind and the imagination…glimpses of the vast domain of the sciences.” Choice

For some reason, this F&SF essay collection isn’t one which I sticks in my memory very much, although several of the individual essays are among my favorites.

Let’s start with the last five essays, about astronomy. “Time and Tide” is itself interesting and was the inspiration for Larry Niven’s Hugo-winning story “Neutron Star,” of which I am also very fond. It also mentions Asimov’s next book, The Moon, and Asimov’s problems in trying to figure out how to tell third-graders why there are two tides a day—when, in fact, he doesn’t make that explanation in The Moon.

Among the astronomic essays is also “Harmony in Heaven,” which talks about Kepler’s Third Law and includes lots of fun equations which can be used to play around with in one’s own explorations of heavenly phenomena. “The Proton-Reckoner” presents a discussion of how Asimov and Archimedes are intellectual brothers because of their fondness for calculating things like just how many protons would fit into the Universe, and I must confess to sharing their interest.

Finally, the astronomic essays include the embarassing “Squ-u-u-ush!” The essay talks about densities and starts with osmium, working its way up to neutron stars. At the end, Asimov speculates about the possibility of “super-neutron stars,” so dense that their escape velocity surpasses the speed of light, in which case, Asimov asserts, neither electromagnetic radiation, nor gravitons, nor anything would be able to get out—and in that case, it wouldn’t interact with anything gravitationally or in any other way.

He means, of course, black holes and gets spectacularly wrong the extent of their gravitational interaction with the rest of the Universe—but it’s an innocent mistake, and one is glad to forgive him.

I have other favorite essays here. “Oh, East is West and West is East—,” “Water, Water, Everywhere—” and “Up and Down the Earth” on geography, “Exclamation Point!” on factorials and e (even if he persists in calling “n!” “factorial n” instead of “n factorial”), “To Tell a Chemist” on furry little burrowing mammals (or is it breakwaters?), and the trio of “The Certainty of Uncertainty,” “Behind the Teacher’s Back,” and the delightfully named “The Land of Mu” on subatomic physics.

Definitely one of the best collections in the series, even if I can never remember it.