Suppose the sun suddenly disappears, would the earth immediately change course or will it take 8 minutes for the earth to notice that the sun’s gravitational pull is no longer there?

Answer

It takes about 8 minutes before the earth “notices” that there is no more gravitational pull. This is one of the consequences of general relativity. In this theory (developed by Albert Einstein) gravity is considered to be a consequence of the curvature of space-time. This theory also shows that gravity propagates at the speed of light. Since the sun is about 8 light minutes (= time it takes light to travel the distance earth-sun) away from us, it also takes 8 minutes before the earth feels that the sun has disappeared. At the same time, the earth also sees the sunlight disappear.