In many respects, the science of materials has only fully utilized two of its three fundamental tools - the variables of temperature and chemical composition. Pressure, the third fundamental variable altering materials, is in many ways the most remarkable, as it spans some 60 orders of magnitude in the universe. High-pressure science has experienced tremendous growth, particularly in the last few years. With recent developments in static and dynamic compression techniques, extreme pressure and temperature conditions can now be produced and carefully controlled over a wide range. Moreover, a ne.