Discovery

Abstract

Thomas Edison, the prolific inventor, was fond of saying that science requires “5 percent inspiration and 95 percent perspiration. ” The formula still applies today. It takes a great deal of endurance and persistence to produce something new, even under truly favorable conditions. Recently, our team at the Collegè de France was investigating the way a molten plastic flows inside a tube. It is an important problem—for instance, in the process of extrusion of plastic bottles—one that involves poorly understood phenomena. Studying the problem requires measuring speeds in very close proximity to a solid surface (within 500 Å, or 2 millionths of an inch) to determine whether the polymer glides on or sticks to the surface of the tube. This can be done with sophisticated optics. An experiment conducted by applied researchers using optics techniques took 5 years to set up, but it produced beautiful results. It demonstrated that, on carefully prepared surfaces, the polymer sticks under a low-speed regime and glides under a higher-speed regime. By happenstance, the theorists in our group found, almost at the same time, an explanation for the transition between two regimes that agreed perfectly with the results of the experiments.