Sym+73

Number 73 Autumn 2020 DALI DIAL I saw this sundial in the rue Saint-Jacques, Paris, in 1993. It was designed by artist Salvador Dali (notice that his surname is an anagram of dial). Its human-like face is a scallop shell, while blue eyes, with eyebrows like flames, are cast in the concrete. The sundial was installed in 1966 at a ceremony with the surrealist himself, who rode up on a lift to the sundial with his pet ocelot to the accompaniment of a brass band. You can see his signature on the bottom right corner of the sundial. The shell face is meant to reference the scallop symbol of the pilgrimage of St. Jacques de Compostela. For a sundial to work, the gnomon (the rod that casts the shadow) should be parallel to the Earth’s axis. This means if extended, it should pass very close to the polestar, Polaris. The Rectangular Peg Conjecture is a variation on the Inscribed Square Problem, or Toeplitz Conjecture. The Inscribed Square Problem was proposed by Otto Toeplitz (shown below) in 1911, who asked whether every continuous simple closed curve in a plane contains an inscribed square. To date, this problem has not been proved, though progress with specific curves has been made. Recently, Joshua Greene and Andrew Lobb have announced a proof of the Rectangular Peg Conjecture, in which the square is replaced by a rectangle. This proof covers the case when the rectangle has to have a specific aspect ratio. Recent News