Issue 14

March 2001

How likely is it that you will catch a disease? Why do some diseases become epidemics? How closely are maths and magic linked? And what is the maths behind radioactive decay? This issue has the answers.

C. J. Budd and C. J. Sangwin show us how to create mazes, and explain why mazes and networks have much in common. In fact the study of mazes and labyrinths takes us into the dark territory of murder, suicide, adultery, passion, intrigue, religion and conquest...

Over the past one hundred years, mathematics has been used to understand and predict the spread of diseases, relating important public-health questions to basic infection parameters. Matthew Keeling describes some of the mathematical developments that have improved our understanding and predictive ability.
Until you understand the basics of functions and algebra, the thought that a number can be predicted is a surprising one. And of course `magic' and `being surprised' are often the same thing. Rob Eastaway shows us how mathemagicians trade off the fact that you can usually predict precisely the outcome of doing something in mathematics, but only if you know the secret beforehand.
Arguably, the exponential function crops up more than any other when using mathematics to describe the physical world. In the second of two articles on physical phenomena which obey exponential laws, Ian Garbett discusses radioactive decay.
Adam Smith is often thought of as the father of modern economics. In his book "An Inquiry into the Nature and Causes of the Wealth of Nations" Smith decribed the "invisible hand" mechanism by which he felt economic society operated. Modern game theory has much to add to Smith's description.

Chomp is a simple two-dimensional game, played as follows.
Cookies are set out on a rectangular grid. The bottom left cookie is poisoned.
Two players take it in turn to "chomp" - that is, to eat one of the remaining cookies, plus all the cookies above and to the right of that cookie.

Actuaries use mathematics to model the real world, finding business solutions to the perennial problems thrown up by life's uncertainties. Kathy Byrne tells Plus about life as Actuarial Director of an Insurance Company.
The 3 3 8 8 puzzle
"The Language of Mathematics" is a book that sets itself an ambitious task - to sum up all of mathematics. Clearly, the author does not intend to do this without omissions - mathematics is far too large a subject for that - rather, he hopes that the reader will come away with an understanding of what maths is and what mathematicians do and why.
In this book, Martin Gardner, best known for his columns on recreational maths in Scientific American and the many books collecting this material, surveys a wide range of mathematical magic. Many of the tricks described require little or no dexterity and nothing except readily available props, such as cards or dice, and so are suitable for the beginner.
This is the story of Sarah Flannery, who at age 16 won the titles of 1999 Irish Young Scientist of the Year and European Young Scientist of the Year for her innovative work on cryptography. Written by Sarah with her father David, who taught her mathematics from a young age and encouraged her mathematical flights, the book is an engaging mix of mathematical exposition - always clear and rigorous but never dull - and first-person descriptions of the storm that erupted when the world media latched onto her story. Easily written in a friendly style, you could imagine that this is the adventure of someone you know.
"Math Chat" began as a live phone-in TV show in the USA, spawned a newspaper column and a website, and now it has produced a book. The whole project was the brainchild of Williams' College mathematician Frank Morgan and has both stimulated interest in maths across a broad range of the community and led to the formation of highly successful undergraduate research groups in mathematics.