The New York Times has a fascinating article about this artist.
It is difficult to say much more about the piece without descending into gibberish. This is one of the first things you notice when you spend time around Turrell. Though he is uncommonly eloquent on a host of subjects, from Riemannian geometry to vortex dynamics, he has developed a dense and impenetrable vocabulary to describe his work. Nearly everyone who speaks and writes about Turrell uses the same infernal jargon. It can be grating to endure a cocktail party filled with people talking about the “thingness of light” and the “alpha state” of mind — at least until you’ve seen enough Turrell to realize that, without those terms, it would be nearly impossible to discuss his work. It is simply too far removed from the language of reality, or for that matter, from reality itself.
Turrell's work sounds fascinating. He uses light to creates immersive environments that destroy, diffuse and de-fuses one's ordinary sense of space so that the light itself assumes a numinous presence.