The German mathematician Adam Ries (1492-1559) was the author of the most successful textbook of commercial arithmetic of his day. The book, published in 1552, earned such a high reputation that the German phrase nach Adam Ries is used to this day to indicate a correct calculation.

Underlying our vast global telecommunications networks are codes: formal schemes for representing information in machine-readable and transmissible formats. Kona Macphee examines the prefix property, one of the important features of a good code.

Robert Hunt concludes our Origins of Proof series by asking what a proof really is, and how we know that we've actually found one. One for the philosophers to ponder...

Kevin Jones investigates the links between music and mathematics, throwing in limericks, Fibonacci and Scott Joplin along the way. Plus is proud to present an extended version of his winning entry for the THES/OUP 1999 Science Writing Prize.

Is the Universe finite, with an edge, or infinite, with no edges? Or is it even stranger: finite but with no edges? It sounds far-fetched but the mathematical theory of topology makes it possible, and nobody yet knows the truth. Janna Levin tells us more.

Eugen Jost is a Swiss artist whose work is strongly influenced by mathematics. He sent us this Postcard from Italy, telling us about his work and the important roles that nature and numbers play in it.