In the NY Times science section, yesterday, an interesting article about how the universe is shaped like a multidimensional torus, or donut. Take a fast spaceship in the direction of the constellation Virgo; you'll emerge into the universe coming in the same direction from behind you.

Yeats, a few decades earlier: "Michael Robartes called the universe a great egg that turns inside-out perpetually without breaking its shell." Yeats also wrote that he considered the cosmos as "a rotating four-dimensional sphere".

Joyce had a similar notion in Finnegans Wake. See Margaret Solomon's study, Eternal Geomater : the sexual universe of Finnegans Wake (So. IL Univ Press, 1969).