The Language of Mathematics: The Stories Behind the Symbols

This stimulating if technical inquiry from Rojas (Konrad Zuse’s Early Computers), a mathematics professor at the University of Nevada, Reno, investigates the origins of mathematical symbols. He explains that most “calculations were made with fractions of base 60” until 10th-century Damascus mathematician Abu’l-Hasan Ahmad ibn Ibrahim al-Uqlidisi invented decimal notation, only for his work to soon after fade into oblivion; English physicist John Napier would have to independently propose the decimal point seven centuries later for it to catch on. Elsewhere, Rojas discusses how ancient Mayans devised the concept of zero more than 2,000 years ago, how 17th-century French philosopher René Descartes established “x” as standard notation for an unknown variable, and how the addition symbol emerged in 15th-century Germany owing to its resemblance to et, the Latin word for “and.” Rojas provides plenty of fascinating background on mathematical history, noting that equations were written out in words until third-century Greek mathematician Diophantus started incorporating symbols. Unfortunately, discussions of more advanced notations will be difficult for lay readers to follow (“It is ironic that [19th-century Irish mathematician William Rowan] Hamilton gave vector analysis ammunition with the nabla symbol since for years he had promoted the calculus of quaternions as an alternative to vector calculus”). Rewarding if challenging, this is worth checking out. (Jan.)