Physics is perhaps the most fundamental of the sciences. It involves the study of the nature of basic things, such as motion, forces, energy, matter, heat, sound, light, and the atom. Physics reduces our knowledge of the world around us to a more orderly and satisfying form. It is successfully applied to solving problems of practical importance to society. Modern technology depends heavily upon physics, and technological progress follows advances in physics and the other basic sciences. The interest of physicists extends from the vast world of stars and galaxies to the minute world of atoms and elementary particles. Physicists did the pioneering work in the discovery and development of electrical and nuclear power, communication systems, solid state devices and integrated circuits, computers, jet propulsion, and interplanetary space navigation. They continue to search for more discoveries that will benefit society.