I want to know that if we are standing on the earth's equator facing west and throw a beam of light at some distance, say 100 km towards west. then would the eastward rotation of earth around its axis would decrease the actual distance for light to travel.? because as the photons emitted from the light source started moving towards the target, in the mean time earth rotates towards east along its axis. So does the photons emitted from the source have to move less distance when they reaches the target which is 100 km away ?. i think as the photons have 0 mass so gravity have no effect on them and they will actually have to cover less distance than the actual distance.