Commentary Par XXVII 109

For the notion that Dante's universe is four-dimensional, a hypersphere, see Peterson (Pete.1979.1), who believes that Dante's vision of the cosmos looks forward to Einstein's; Osserman (Osse.1995.1), pp. 89-91, suggesting that Peterson overlooks the earlier model proposed by Riemann; Freccero (Frec.1998.1); and Egginton (Eggi.1999.1).  However, the reader probably should temper an enthusiasm for such 'premodern physics' on Dante's part with an awareness of his possible dependence, for his 'ontological, neoplatonic, and theocentric' vision of the rest of the universe, on such models as he found in his precursors.  For instance, see Chiarenza (Chia.1988.1), pp. 232-34, reacting to [Par XXVIII 14-15] with the suggestion that Dante's 'picture' derives from Bonaventure (Itinerarium mentis, V).

For a quick introduction to the properties of the hypersphere, one may visit the following site: http://www.hypersphere.com/hs/abouths.html.