Science Forums 2

[CraigD]

Originally Posted by HydrogenBond

I am not sure what it is called, but I think Einstein said if one was to travel into space one would eventually return to where they began in sort of a loop. Does this mean that the universe will loop, returning by default?

Though I can’t recall a specific mention of Einstein of the idea that space “loops back” on itself (rather like the “space” in video games like Asteroids), it sounds like something he’d say. Einstein liked thinking about geometry, and relating it to the physical universe.

The best discussion of this idea I’ve read was “Is Space Finite” (600 KB PDF) by Jean-Pierre Luminet, Glenn D. Starkman, and Jeffrey R. Weeks, which appeared in the 4/1999 issue of Scientific American. Though very speculative, this article does IMHO an excellent job of presenting the idea’s many complicated (if you’ll pardon the pun) twists and turns, and notes that of myriad hypothetical “wraparound universes”, many are falsifiable via special analysis of telescope data, and names several teams with plans, as of the 4/1999, to conduct such surveys.

In summary, I’d describe the “wraparound universe” as a unlikely, but very interesting hypothesis, well worth study and contemplation regardless of its truth or falsehood.

Care should be taken not to confuse the “wraparound universe” idea with the “cyclic universe” idea. Although both draw from the same theories and observations, they describe completely different hypothetically observable phenomena.