Ancient and Modern Physics is a classic science text that deals with the philosophical aspects of physics and includes the following passage: "The Hindu system of physics, on which the metaphysical thought of the East is based, does not in its beginnings differ widely from the latest physics of the West; but it goes so much farther that our physics is soon lost sight of and forgotten. The Hindu conception of the material universe, taken from the Upanishads and some open teaching, will serve for an illustration. They divide physical matter into four kinds--prakriti, ether, prana, and manasa--which they call "planes." These differ only in the rate of vibration, each plane vibrating through one great octave, with gulfs of "lost" octaves between. The highest rate of vibration of prakriti is measured by the thousand, the lowest of the ether by trillions, and the lowest of prana by--never mind; they have, and we have not, the nomenclature."