These images don't really give the real feeling of being before a work by Turrell (who is one of many great contemporary artists that I haven't had a chance to discuss yet). I saw one of his works at the Whitney in NYC. It looked like a colored wall, but you could put your hand through it, and then it was all light and presence. It was quite a (non-sectarian) spiritual experience. He is now working on a crater in the southwest: Roden Crater.
I saw one of his pieces (rooms) at the Indianapolis Museum of Art in the early 90's(?).
I stood before the "painting" for a long while trying to understand the unusual, luminous quality it had. One of the museum security told me that this was the only painting in the museum we were allowed to touch. Even standing with a foot of the work I couldn't tell that it wasn't a painting at all.
Of course, as I leaned in to touch the piece my hand past the point where it should have come in contact with mass. It was momentarily disorienting.