James Turrell, views on light

“I’m interested in having a light that inhabits space, so that you feel light to be physically present. I mean, light is a substance that is, in fact, a thing, but we don’t attribute thing-ness to it. We use light to illuminate other things, something we read, sculpture, paintings. And it gladly does this. But the most interesting thing to find is that light is aware that we are looking at it, so that it behaves differently when we are watching it and when we’re not, which imbues it with consciousness. Often people say that they want to touch some of the work I do. Well, that feeling is actually coming from the fact that the eyes are touching, the eyes are feeling. And this happens because the eyes are quite sensitive only in low light, for which we were made. We’re actually made for this light of Plato’s cave, the light of twilight.” 
[x]