The Quantum Astrologer's Handbook

This very strange book is entertaining at times, frustrating at other times, even infuriating here and there. I found it hard to put down even as I was very conscious of its problems.

I think the author expected this kind of reaction from someone like me. The “author’s note” at the end begins like this:

In case you were in any doubt, this is not an academic work. It is not something to be referenced, or consulted as if it were scholarly research. (p. 243)

No doubt!

At the center of the book are two topics, which somehow are linked together in the author’s mind. The first is the “interpretation” of quantum mechanics. The second is the life and work of Girolamo Cardano. The links between those subjects are, I think, two. First, Brooks puts Cardano at the beginning of the history of complex numbers and probability theory, both of which play a central role in quantum mechanics. (He is mostly wrong about this: while Cardano does mention complex numbers and even does some computations with them, it was Raphael Bombelli that really showed how complex numbers could be used to obtain real results; Cardano’s work on probability had no perceptible influence on later developments.) Second, Cardano was a dedicated astrologer, and Brooks wants to hint at the idea that our current understanding of basic physics may seem as absurd, to our descendants, as the early modern fascination with astrology seems to us. Well, it certainly might.

The book centers on a sequence of conversations between Brooks and Cardano. The author imagines himself at the site of Cardano’s imprisonment by the Inquisition. There, he and Cardano talk about quantum mechanics. (Of course, the real Cardano would not understand a word of this; the explanations are really aimed at the reader.) They also talk, to some extent, about Cardano’s life and misfortunes (there were many).

On the quantum mechanics side, Brooks’s repeated theme is that he “does not understand” quantum physics — indeed, that no one does. What he means is that he finds the mathematical model unsatisfying, and he wants to dig below it to discover “what is really going on.” In that, he is similar (a comparison he himself makes) to Leibniz and others who objected to Newton’s theory of gravity on the grounds that there was no mechanism by which the Sun would exert a force on the Earth. Leibniz claimed that the assertion of mysterious forces acting at a distance was not physics. Similarly, Brooks feels that quantum mechanics, while correctly predicting what happens, does not explain how it is that such things can happen.

My reaction to all this was, perhaps, a sign that I am a mathematician, not a physicist. It seems to me that mathematical models of how things work are all we can have. The question of “how can that be” strikes me as metaphysical rather than physical.

Putting on my historian’s hat, I see other problems. Brooks says many things about Cardano, but he provides no notes, so we are left to wonder whether what he says is true. He makes this dilemma worse by noting, halfway through the book, that Alan Wykes’s Doctor Cardano, Physician Extraordinary is wrong about a rather crucial point. How do we know Brooks is right?

Well, maybe that is the wrong question. Brooks has fallen in love with Cardano and his story. He tends to take Cardano’s word about things. (Cardano wrote an autobiography, The Book of my Life.) While he has read scholarly accounts of Cardano and his life, he is more interested in telling a dramatic story and giving us a glimpse of the Cardano of his imagination.

The result is certainly a great read. The present-tense narration and Brooks’s sense of drama make the narrative intense and dreamlike. It is occasionally overdone, but overall it is effective. Anyone who has not had to deal with the “meaning of quantum mechanics” will learn a lot here, as will anyone who has not read much about Cardano.

A final protest much be registered, however. Cardano is consistently referred to as “Jerome” Cardano. No other character has their name anglicized: Chiara does not become “Claire”, Lucia does not become “Lucy”, Nicolo (Tartaglia) does not become “Nicholas” or (God help us) “Nick”. The only exception I can recall is Scipione del Ferro, who is Latinized into “Scipio Ferreus”. So why can’t Cardano be Girolamo? Every single reference to “Jerome” annoyed me.

Nevertheless: this is an interesting book. If you are interested in Cardano or in quantum mechanics, you should consider reading it.

Fernando Q. Gouvêa is Carter Professor of Mathematics at Colby College. Despite the suggestion of a well-known author, he refuses to be known as “Ferdinand Gubbins”.