I have 2 questions: 1. Since space is expanding, shouldn't the distance between the earth and the sun be getting greater? And shouldn't that affect the orbit of the earth (greater distance between the earth and sun ->> less gravitational attraction)? 2. Is it possible that the speed of light could have been faster at one point. For example I was looking at the following: t = t0(1-(v^2/c^2))^(1/2) (I think this is correct) I understand why this formula (and the others like it for mass and distance) would imply that no object could travel faster than the speed of light (can't take square root of a negative)...but that doesn't seem to limit what c can be. If c were greater that doesn't cause any problems in the formula. Are there other reasons for saying that the speed of light has always been a constant speed? Thanks.