Posthuman Blues

Gravity doughnut promises time machine

"He says that according to Einstein's theories, space can be twisted enough to create a local gravity field that looks like a doughnut of some arbitrary size. The gravitational field lines circle around the outside of this doughnut, so that space and time are both tightly curved back on themselves. Crucially, this does away with the need for any hypothetical exotic matter."

Homer Simpson: "Mmmm . . . A donut of arbitrary size . . ."