The whole space issue.

I have trouble wrapping my mind around the concept of space and where it could end, since it doesn't end, it seemed impossible to me when I would think about it sometimes. I guess it isn't so hard to understand once you get passed the concept of distance. Since it is really just a relative point of view based on sight or comprehension.

Anyways, I realized that essentially everything is only reactions. Given this, I have come to the understanding that the area of nothingness out there is only a concept of something that isn't real, and the only thing that counts as "space" should be considered the medium through which light travels since light occupies this space.

This breaks down though, when I think about the fact that there could be two area's of light that haven't reached each other, in other words there is distance between the two lights.

Anyway I was just wondering what other people have to explain this vague concept of distance in terms of the universe and its expansiveness.