Mathematician and physicist John Baez declares himself fascinated by exceptions in mathematics. This interest has led him to study the octonions, and, through them, to find out more about the origins of complex numbers and quaternions. In the second of two articles, he talks about the characters of the different dimensions, beauty and utility in mathematics, and just why he likes dimension 8 so much.
This charming book is in its second edition (the first was published in 1994). It is about integers, with a short section for each number between 1 and 200, and a line for each between 201 and 999. There are "boxes" for interesting facts and definitions, such as "perfect number", and a few "large numbers" also make the cut, including 1729, the subject of a famous anecdote about Hardy and Ramanujan, and 101000, the googol.
Most of us have heard of "stealth" - a technology used by the military to disguise craft from enemy radar. But nature's stealth fighters are not so well known - creatures that use motion camouflaging to approach their prey undetected. Lewis Dartnell looks at the vector mathematics behind the phenomenon.
Many people find no beauty and pleasure in maths - but, as Lewis Dartnell explains, our brains have evolved to take pleasure in rhythm, structure and pattern. Since these topics are fundamentally mathematical, it should be no surprise that mathematical methods can illuminate our aesthetic sense.