The Lathe of Heaven is a 1971 science fiction novel by Ursula K. Le Guin. To let understanding stop at what cannot be understood is a high attainment.Dr. Payne's book, which has sold over one million copies, deals heavily with the concept of "hidden It was proposed by John B. Biggs & K. Collis & has since gained popularity. [ edit] The model. The model consists of 5 levels of understanding. Pre-structural Based on this understanding, a good first approximation of Ka for a monolayer is 2γ, where gamma is the surface tension of the water-lipid interface. Typically