The history of polymer science and technology is amazingly short, but so is that of modern physics and chemistry. The idea that heat flows from a high to a low energy reservoir was introduced by Carnot in 1824. This led to formulation of the second law of thermodynamics by Joule and Kelvin in the 1850s. The concept of entropy was introduced by Clausius in 1865, who in 1879 wrote, ‘Die Energie der Welt ist Konstant. Die Entropie der Welt strebt einem Maximum zu.’