To encounter a work by American artist James Turrell is to enter another world-a realm where eye and mind meet. The artist engages us, the viewers, in order to make us witnesses of his focus on nature through scientific means. By making us watch and contemplate for extended periods, Turrell also makes us part of his artistic practice. Included in this publication is an interview with James Turrell by Michael Govan, Director of the Los Angeles County Museum of Art, an essay by EC Krupp, astronomer and Director of the Griffin Observatory, Los Angeles, as well as discussions on Turrell's works.