https://phys.org/news/2019-01-story-secret-hollywood-studio-nuclear.html > Yet the story of Lookout Mountain Laboratory was largely unknown—until two University of Illinois professors spent 10 years piecing it together for a new book and website. > The studio's story had not been fully told because it was run largely in secret, as a unit of the U.S. Air Force. Its films and photos were rarely credited and many are lost or were destroyed. No systematic effort was made to preserve its 22-year history, from 1947-69.