eldavojohn writes "PhysOrg is covering an interesting year-old paper that proposes an alternative six-dimensional theory of space and time. George Sparling's proposition, based on Einstein's general relativity and Elie Cartan's triality, is a twistor space (which I've only read of in Roger Penrose's latest work). The gist is that space-time is modeled not by four dimensions but by six, and that the extra two dimensions are time-like. Sparling is hoping that tests from the Large Hadron Collider will help prove his theory. The paper is heavy but the PhysOrg article summarizes it nicely."