Imagine winding the hour hand of a clock back from 3 o’clock to noon. Mathematicians have long known how to describe this rotation as a simple multiplication: A number representing the initial ...

It’s 179 years since William Rowan Hamilton really put Ireland on the maths map by inventing quaternions. This is a four-dimensional number system with a highly usual property as the order in which ...

IN this book the author establishes the principles of quaternions by the use of the six operations—addition, subtraction, multiplication, division, reversion, and mean reversion. By the introduction ...