Das Relativittsptinzip

Abstract

IT is almost impossible nowadays to glance through a journal containing original papers in physics without coming across something relating to the Principle of Relativity. This principle is an extension of that Newtonian relativity which enables us to treat machines on a moving earth as if they were at rest. The new extension covers the phenomena of optics, heat, and electromagnetism. It is sometimes called the electromagnetic principle of relativity, but as it contains also a mechanical principle it has now become usual to term it simply the Principle of Relativity. It asserts that physical phenomena generally do not depend upon rectilinear uniform translation through space; that, for instance, the optical isotropy of space is not affected by motion through it; that the velocity of light is the same in all directions and independent of displacement; and that it is therefore impossible to discover, say, the earth's motion of translation by any optical, electrical, or mechanical device. In fact, it is based upon the negative result of the Michelson-Morley experiment, and all other attempts to discover “æther-drift.” Das Relativittsptinzip. By Dr. M. Laue. Pp. x + 208. (Braunschweig: F. Vieweg und Sohn, 1911.) Price 6.50 marks.