Just a thought for the constancy of the light speed. Since photons are massless and therefore if they do not add the velocity of the moving light source i.e doesn't follow Newtons first law of inertia. It is only the surrounding that moves wrt the observer. The observer and the point light is emitted are always at absolute rest. And therefore the observer would always see the same speed of light irrespective of the motion i.e it is only the surrounding which moves which include the light source. But once the light emit, it emit as if it was emitted from a stationary point in space. That is both observer and the point, when light is emitted are at rest. So my question is, the observer never moves (I can say it is always at absolute rest wrt surrounding) and also since each emitted light is emitted from a stationary point in space. Couldn't this be one reason we always see same speed of light? Thanks.