Misner space is an abstract mathematical spacetime,[1] first described by Charles W. Misner.[2] It is also known as the Lorentzian orbifold . It is a simplified, two-dimensional version of the Taub–NUT spacetime. It contains a non-curvature singularity and is an important counterexample to various hypotheses in general relativity.
Michio Kaku develops the following analogy for understanding the concept: "Misner space is an idealized space in which a room, for example, becomes the entire universe. For example, every point on the left wall of the room is identical to the corresponding point on the right wall, such that if you were to walk toward the left wall you will walk through the wall and appear frm the right wall. This suggests that the left and right wall are joined, in some sense, as in a cylinder. The opposite walls are thus all identified with each other, and the ceiling is likewise identified with the floor. Misner space is often studied because it has the same topology as a wormhole but is much simpler to handle mathematically. If the walls move, then time travel might be possible within the Misner universe."[3]