Reviewed by Ian Lipke

When offered this book to review I came close to rejecting it. That I struggle when dealing with mathematical concepts is beyond debate. But I could not resist the title. A mathematics of life I could comprehend, but of death?

Yates grabbed me when he stated that understanding the number systems around us would give an insight into the history and culture of our species. If there’s any explanation of the social behaviours (and misbehaviours) of our current and next generations, I couldn’t wait to hear it. The strange and unfamiliar systems of our ancestors fascinated me. I was thrilled to read in Yates something that I had learned in childhood but had forgotten viz that the Yuki people of California did not count on their fingers but rather on the spaces between (Yates, 179). They counted in base eight. Yates then led me on to a bizarre practice I did not know – “The Oksapmin people of Papua New Guinea use a system based on the number 27: starting with the thumb on one hand (1), travelling up and down the arms, taking in the nose (14) and finishing with the little finger on the other hand” (27). I was hooked!

Yates quickly eased my worries about mathematics. It is simply a practical tool whose job is to make sense of our complex world. At its most fundamental, mathematics is about patterns (xiv). Every time I look at some aspect of my world, e.g. a tree, my mind is seeing patterns which combine into mathematical models by which I make sense of the rules that govern the world around us (xv).

Yates takes the position that the best models are stories and analogies. “The key to exemplifying the influence of the unseen undercurrent of maths is to demonstrate its effects on people’s lives” (xv). The seven chapters that follow explore the true stories of life-changing events in which “the application (or misapplication) of mathematics has played a critical role” (xv).

Yates’s
first chapter is called ‘Thinking Exponentially’. I remembered something about
the letter ‘e’ that made curves grow faster than normal and my blood ran cold.
A textbook with exponential and logarithmic series proceeding to a limit…oh, my
God, not again! The chapter’s subtitle “Exploring the Awesome Power and
Sobering Limits of Exponential Behaviour” made my heart skip…and not from
passion. I read on, and true to form, Yates gave me an anecdote, a true story,
which told the story of pyramid selling, then of *strep. f* in milk, and a tale he repeats farther on in the book
about the familiar sweet, M-and-Ms. The chapter discusses the bombing of
Hiroshima and the Chernobyl disaster. This was mathematics applied to my world
and I loved it! The man discusses the population explosion and a section with a
provocative title ‘Time flies when you’re getting old’.

The chapter ends with:

*This genomics revolution has the potential to
lend unprecedented insight into our own health traits, but only…if the
mathematics that underpins modern medicine is able to keep pace (39)*

and I understood all that I had read, including the mathematics.

The other six chapters are variously named ‘Why maths makes medicine matter’, ‘Investigating the role of mathematics in the law’, ‘Debunking media statistics’, ‘The evolution of our number systems and how they let us down’, ‘Relentless Optimisation’, and ‘Containing disease is in our own hands’.

I was particularly intrigued by the subject matter of the chapter that claims number systems have let us down. Attempting to subtract the digits of MMXV from the digits of MMXIX from right to left soon alerted me to the Roman citizen’s need for a positional or place value number system. Or try writing a book on mathematics in the year MDCCCLXXXVIII. Yates had my support when he pointed out the benefits of a binary system such as we use in our computers, and I appreciated his deft humour in introducing the old mathematical joke ‘There are only 10 types of people: those who understand binary and those who don’t’. [10 represents the number 2 in binary]. A joke introduced after many chapters of hard labouring is the pressure relief valve one requires.

Looking back through the book, (and incidentally glorying in the fact that I had read, and enjoyed, and understood a book about mathematics), I can support Yates’s view that mathematics underpins all that we do. We need maths to communicate and navigate, to buy and sell with methods commensurate with the demands of modern society. How we work and relax and how we administer the law are influenced by mathematics. It is humbling to observe how sophisticated mathematical algorithms allow us to find solutions in a matter of seconds to problems in formerly almost unimaginable tasks.

Mathematics of life and death? Any mathematician knows that’s the story of growth and decay. Where’s the problem?

(2019)

By Kit Yates

Quercus/ Hachette UK

ISBN: 978-1-78747- 541-0

$29.99; 352pp