This topic may have been covered but I am not sure how to search for it, what phrase would I use? So my apologies if I am going over old ground. I am have great difficulty with light and its nature. Recalling some very basic physics, light behaves as both a particle and a wave. true or recanted ? If light is a wave what makes it take on a particle status? Does the wave 'collapse' to a particle? Consider a far distant star. The light from it has travelled many trillions of kilometres. Why is it that the person next to me can see the same star as me. Surely as the light expands from the star large gaps must appear so that if a light particle hits my eye, my friends eye is missed. Draw a circle and then draw lines from it radiating out, the further from the circle the greater the distance between the lines. Now try to draw enough lines so that there is no space between the lines Now extend these lines a few trillion K's. without creating spaces. Can any one please explain this?