I always wondered why we see light from stars. If the light travels outward in all directions from a star then you could imagine the light as a growing sphere and the portion we see is a small area on the surface of this sphere. Well if a star is a million light years away this would mean the surface area is about a million million years large. Does this mean there are photons all along the surface of this sphere? If the light are rays coming from the star, wouldn't there be gaps eventually in the rays since they are all pointing outward?