in 1904-05 henri poincaré discovered a graphical tool for visualizing different types of polarized light (known as poincaré sphere). the poincaré homology sphere, also called poincaré dodecahedral space, is a particular example of a homology sphere. being a spherical 3-manifold, it is the only homology 3-sphere, besides the 3-sphere itself, with a finite fundamental group. while it is not known the extent to which such discoveries influenced metzinger's representation of the radiating sun in "coucher de soleil no. 1", his interest and prowess in mathematics is well documented.