BBC: Interested in cowboys and Westerns since he was a child, a French physicist has used mathematical modeling to explain the movement of a spinning lasso. At this week’s March meeting of the American Physical Society, Pierre-Thomas Brun of the École Polytechnique Fédérale de Lausanne in Switzerland discussed his work with elastic threads, examples of which can be seen throughout nature, including DNA chains, yarn, hair, and transatlantic oceanic cables. From his study of cowboy trick roping, Brun has developed a dynamical “string” model to explain the motion of the basic flat-loop trick. Although one of the simplest, it involves a number of physics principles, including circular motion, line tension, and centrifugal force. The event also gave Brun an opportunity to demonstrate his own “cowboy physics” skills.