Verification of Einstein's Special Theory of Relativity using

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					         Verification of Einstein’s Special Theory of Relativity
                 using Transverse Doppler Effect
                A Critical Review of Ives-Stilwell Experiment of 1938

                   Chai Haoqiang, Du Long, Hoang Phuc Hung and Wang Yibin
       UNL2201, University Scholars Programme, National University of Singapore, Singapore

     Doppler Effect is a very well-known physical phenomenon. Discovered by Austrian physicist

Christian Doppler in 1842, it describes the change of frequency of a wave for an observer

moving relative to the source of the wave. Doppler Effect had been confirmed by numerous

experiments under Classical physics, but was once again put under scrutiny of the Special

Theory of Relativity (SR) when Einstein published his seminal paper On the Electrodynamics of

Moving Bodies in 1905. In this paper, Einstein predicted the existence of the “Transverse

Doppler Effect” (TDE), which would emerge under Lorentz Transformation, of the classical

formula for Doppler Effect (Einstein 1905). In 1938, Herbert E. Ives and G. R. Stilwell conducted a

groundbreaking experiment to verify this prediction, and the positive results obtained were

considered as the first direct and quantitative confirmation for the time dilation factor of the SR.

     This paper presents a critical commentary on the Ives-Stilwell experiment. The original

experiment is reviewed and analysed in three main areas, namely the theory, the experimental

setup and the empirical results. Several possible sources of error are discussed, including optical

dissymmetry and possible Doppler shift in the central reference line. This is followed by a review

of subsequent studies on this experiment, including experiments adopting the principle of this

experiment and also experiments using different principles.
     Although Ives-Stilwell Experiment was aimed to prove the validity of the Lorentz

transformation, it indirectly provided strong confirmation for the time-dilation factor of SR. This

experiment was certainly not perfect. There are several sources of errors, and the level of

accuracy of the experimental results is indeed rather low compared to the modern standard.

However, Ives and Stilwell experiment inspired a series of experiments using the same principle

but with much higher accuracy. These experiments all successfully demonstrated the excellent

predictability of the SR.

     It was also noted that the current experiments mainly focus on the high frequency region

of the electromagnetic wave spectrum, and TDE in the low frequency waves such as microwaves

are seldom studied. Also, there are many other experimental setups different from the Ives-

Stilwell type experiments but can be used to verify the same TDE. However, they also lack

sufficient investigation. More experiments done in these areas will definitely contribute to a

more thorough verification of SR.

Main references:

     Ives, H E, and G R Stilwell. "An Experimental Study of the Rate of a Moving Atomic Clock."

Journal of the Optical Society of America, 1938: 215-226.

     —. "An experimental study of the rate of a moving atomic clock. II." Journal of the Optical

Society of America, 1941: 369-374.

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Tags: Doppler, Effect
Description: Doppler effect is to commemorate the Doppler, Christian Johann named, who in 1842 first proposed the theory. The main contents are: the object wavelength radiation light source and the observer because of the relative motion of change. Source of waves in motion in front of the wave is compressed, the wavelength becomes shorter, the frequency becomes higher (blue shift blue shift); when the campaign behind the wave source, it will have the opposite effect. Wavelength becomes longer, the frequency becomes lower (red shift red shift). The higher the speed of wave source, the greater the effect produced. According to light red (blue) the degree of shift can be calculated wave source follow the direction of the velocity observations.