Mathematics and Astronomy

Abstract

Thanks to Einstein, we are aware that motion is relative. One can choose any heavenly body one likes as a fixed frame of reference for studying the motion of other heavenly bodies. One can say that the earth goes around the sun or one can say that the sun goes around the earth. From a mathematical point of view, it is best to take as a fixed frame of reference neither the earth nor the sun, but the centre of mass of the solar system — because this choice makes the mathematics of solar system motion simpler. Prom Einstein’s point of view, then, it seems silly that Galileo Galilei (1564–1642) and the Inquisition fought over whether the earth goes around the sun or vice versa.