Currently, much of the software that we would like to run fast on multi-core processors is written in C — a language in which expressing concurrency is difficult and error prone. Unfortunately, moving such programs to a new language is very difficult, since the programmers only know C, the tools only know C, and developers are unkeen to trust their projects to a language that might not be suppo...

Introduction: The impact history of the solar system remains controversial. Early investigation of lunar samples, returned by Apollo astronauts, led to the 'Late Heavy Bombardment' (LHB) concept [1,2] which hypothesized a sharp increase in bolide flux centered around ~3.9 Ga. Evidence for this cataclysm was first derived from whole-rock U-Pb and Rb-Sr ages [2] but subsequently more on 40 Ar-39 ...