Nine Zulu Queens Ruled China

I mentioned the other day when I finished reading Death by Black Hole that I was going to read Isaac Asimov’s essay collection, The Secret of the Universe next. I have since changed my mind. This morning, I started a book that I bought back in October and have been wanting to read for some time, but just haven’t gotten around to it yet: Unknown Quantity: A Real and Imagined History of Algebra by John Derbyshire. I enjoy books on mathematical subjects and have read several. I started this one this morning on the train into work and so far, I’m not disappointed.

Incidentally, the title of this blog entry, “Nine Zulu Queens Ruled China” is a non-sense mnemonic for the nested number sets used in number theory: N represents the natural numbers, Z represents the integers, Q represents the rational numbers, R represents real numbers, and C represents complex numbers (which include imaginary numbers).