Search Loci: Convergence:
I am coming more and more to the conviction that the necessity of our geometry cannot be demonstrated, at least neither by, nor for, the human intellect ... geometry should be ranked, not with arithmetic, which is purely aprioristic, but with mechanics.
Quoted in J. Koenderink, Solid Shape, Cambridge Mass.: MIT Press, 1990.
Kepler's Epitome of Astronomy
Johannes Kepler's (1571-1630) most influential work in introducing the heliocentric theory to a broad audience was his Epitome Astronomia Copernicanae [Epitome of Copernican Astronomy], published in the years 1618-1621. This work comprises three volumes and contains seven books: Volume I contains three books, Volume II contains Book Four, and Volume III contains the remaining three books. Here is the title page from Volume I of the 1635 edition. The first three books are devoted to the “Doctrine of the Sphere.”
Pages 278 and 279 of Kepler’s Epitome. The diagram on page 279 illustrates the rotation of the Earth about the Sun. Note the text above the diagram telling the reader, “Solis S immobile”—the Sun does not move.