Pumpernickel an old Bavarian term for "hard", either referring to the process used to grind the grain into flour, or the density of the final bread product. According to "Langenscheidts Taschen Wörterbücher" (1956), it refers to a form of "pumping work". The philologist Johann Christoph Adelung states that the word has an origin in the Germanic vernacular where was a New High German synonym for being flatulent, and was a form of the name Nicholas, commonly associated with a goblin or devil (e.g. "Old Nick", a familiar name for Satan), or more generally for a malevolent spirit or demon. Hence, "pumpernickel"
What Is Mathematics? What Is Mathematics? What Is Mathematics? is a mathematics book written by Richard Courant and Herbert Robbins, published in England by Oxford University Press. It is an introduction to mathematics, intended both for the mathematics student and for the general public. First published in 1941, it discusses number theory, geometry, topology and calculus. A second edition was published in 1996 with an additional chapter on recent progress in mathematics, written by Ian Stewart. The book was based on Courant's course material. Although Robbins assisted in writing a large part of the book, he had to fight for authorship. Nevertheless, Courant