Rays of light

I honestly don't know what to think about these kind of magnificient sights. They look absolutely beautiful and a little mysterious too but it makes me think that if the rays of light are so visible what makes them so? I mean if the air is totally clear these rays wouldn't be visible. What makes them visible as far as I know are the small particles in the air. I wonder if those particles are pollution or water vapour. Most likely both.

Anyhow in my opinion it isn't too good a thing that you can see the air more and more ofthen these days. But as they say "even the darkest cloud has a silver lining". Even if the reason for these rays of lights being so visible is pollution at least it makes nice lightshows from time to time.