I am not able to understand light although I guess I am not the only one since It is such an abstract subject. When light with its own duality wave-particle goes through the air, does it experiment any collision against it? Because air must have particles, atoms... should not there be a collision, a elastic or inelastic one? Or this does not happen because It is a wave? Imagine a strong wind It is travelling at huge speed, I believe this wind does change the direction of sound, I do not know about the speed, What about light will it be affected by the strong wind if not why not? Wind is an example but it could be any other force if I push an object this object moves if I could throw my arm at huge speed into light will this affect its direction, intuitively the answer looks no but I want to know the reason. Another way to ask this question in a more elegant way would be: What forces do act upon light? I heard gravity do acts on it, bending it, black holes... maybe some electromagnetic forces as light It is an electromagnetic wave could but I think I read this is not the case, do we know any other force outside gravity that affect light? I am enthusiastic to read your responses.