Tracks (IMAGE) CNRS Caption From left to right: standard track, consisting of two 84.3-metre straight lines; both types of basket handle-shaped track Credit Amandine Aftalion, Centre d'analyse et de mathématique sociales (CNRS/EHESS) Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.