Abstract

The principle of relativity, that there is no preferred state of uniform motion, has recently come into conflict with certain cosmological observations. In an attempt to overcome this difficulty, an alternative formulation is explored in which this principle is replaced by the principle of universal time, while retaining the invariance of the speed of light. These two postulates lead to a well-defined world model in which one inertial frame has a preferred status. But the invariance properties of the laws of physics are unaffected, and the model may be regarded as a modified form of special relativity which is in accordance with the new cosmological evidence