Some remarks on clock rates in special relativity

In part I a simple gedanken experiment is discussed that clearly develops a connection between the rates of accelerated clocks in special relativity theory and the rates of clocks at different points in a uniform gravitational field in any theory which incorporates the equivalence principle, such as general relativity theory. In part II it is shown that the time dilation effect observed when the rate of a moving clock is compared with that of a clock at rest can be derived by observing the Doppler shift, not only of light waves emitted by the moving clock, but of any periodic wave, e.g., sound.