After almost 20 years, math problem falls

        <p><a href="http://www.physorg.com/news/2011-07-years-math-problem-falls.html%22%3EAfter almost 20 years, math problem falls</a></p>
        <p>Mathematicians and engineers are often concerned with finding the minimum value of a particular mathematical function. That minimum could represent the optimal trade-off between competing criteria — between the surface area, weight and wind resistance of a car’s body design, for instance. In control theory, a minimum might represent a stable state of an electromechanical system, like an airplane in flight or a bipedal robot trying to keep itself balanced. There, the goal of a control algorithm might be to continuously steer the system back toward the minimum.</p>