Astronomical clock designed and made in Norway by Rasmus Sornes between 1958 and 1964. It computes sidereal time, apparent solar time, mean solar time, Gregorian date (taking the leap rule fully into account), solar and lunar eclipses, precession, and the positions of all planets. (Courtesy of The Time Museum, Rockford, IL.)
Appendix BLisp Implementation
It has been often said that a person does not really understand something until he teaches it to someone else. Actually a person does not really understand something until he can teach it to a computer, i.e., express it as an algorithm.
—Donald E. Knuth: “Computer Science and its Relation ...