The Clock Paradox in Relativity

I have been following with great interest the discussions on the above topic which have been published in several journals. On reading a recent letter to Nature by Professor Herbert Dingle (1957) in reply to a previous letter by Sir Charles Darwin (1957), I noticed that it is feasible to perform astronomical observations which could provide an experimental basis for choosing between the two points of view. In fact, these observations may have already been made.