Postprint version. Published in Hyperfine Interactions, Volume 151-152, Issue 1-4, December 1, 2003, pages 191-193.
The definitive version is available at https://doi.org/10.1023/B:HYPE.0000020410.24629.ad.
This paper is an ode to my friend Hendrik. We collaborated on hyperfine interactions from 1962 to 1984, when he was colleague and friend. Since then I have been working on the Physics of Societal Issues (Springer Verlag, 2003). The paper below models energy use in buildings, which could save considerable energy with well-designed buildings.