  The Einstein and the de Sitter universe are both spacetimes with two  separate fringes, the infinitely remote past and the infinitely  remote future. Dropping two of its spatial dimensions we imagine  Einstein’s universe as the surface of a straight cylinder of a  certain radius and de Sitter’s universe as a one sheeted hyperboloid. Both surfaces are surfaces of infinite extent in both directions.  Both the Einstein universe and the de Sitter universe spread from the eternal past to the eternal future. However, unlike de Sitter’s  universe, in Einstein’s universe “the metrical relations are  such that the light cone issuing from a world point is folded back  upon itself an infinite number of times. An observer should therefore see infinitely many images of a star, showing him the star in states  between which an eon has elapsed, the time needed by the light to  travel around the sphere of the world.” Weyl (1930) says: 