Thank you for your detailed reply,
but how come people in motion observing a light source see it travel at different speeds to those stationary ?
e.g in Brian Greene's 'The elegant universe' the analogy of people on a train with a light and those at a station , those who were stationary...
Hey, this is my first post of many as I have hundreds of questions!
As speed of light is a constant, does it travel from the eye of the observer ?
e.g is a stationary person observing light travel away at ≈ 3x108m/s
but a person traveling at 1/2 of, c, witnessing it travel 1/2 that speed...