The satellite eclipse of Jupiter and the velocity of light(On the measurement of light velocity by O.Rφmer)

Abstract

It is well known that the velocity of light is obtained first by O.Rφmer from the observation of the satellite eclipse of Jupiter. We reexamine his observation and try to find the significance of his scientific work. We find the following points; 1) the observations of satellite eclipse at opposition of Jupiter and its three months later are important, 2) the accurate measurement of the eclipse time is needed in getting the finiteness of the velocity of light.