Rho calculus

One important thread in computer science is the study of extensions of the lambda calculus. The lambda calculus is a model of computation that uses rewrite rules based on a simple notion of a function. The rho calculus extends the lambda calculus to allow more general rewrite rules based on pattern matching. For a survey, see the paper Matching Power or the web site The Rho-Calculus Home Page.

Via Lambda the Ultimate.

Doubly Special Relativity

Physicists are developing an alternative to special relativity, called Doubly Special Relativity. (When the Wikipedia article for this first appeared, people were so sure that the name had to be a joke that the article was nominated for deletion.) Doubly special relativity, which currently is somewhere in between an idea and an actual full-fledged theory, depends on two parameters, the speed of light and the Planck mass (this puts the two in “doubly”). For an introduction, see Introduction to Doubly Special Relativity by Jerzy Kowalski-Glikman.