http://arxiv.org/abs/1006.4908 An Explicit Embedding of Gravity and the Standard Model in E8 A. Garrett Lisi 14 pages. For peer review and publication in the "Proceedings of the Conference on Representation Theory and Mathematical Physics." (Submitted on 25 Jun 2010) "The algebraic elements of gravitational and Standard Model gauge fields acting on a generation of fermions may be represented using real matrices. These elements match a subalgebra of spin(11,3) acting on a Majorana-Weyl spinor, consistent with GraviGUT unification. This entire structure embeds in the quaternionic real form of the largest exceptional Lie algebra, E8. These embeddings are presented explicitly and their implications discussed." As I recall there was a conference at Yale last October at which Garrett was invited to present a paper on this topic. I think the Yale 2009 conference was the one referred to here---on Representation Theory and Math Physics. The way it works out, it seems like this "ToE" predicts a whole bunch of new particles which the LHC can find or not find. In effect, it does what theoretical physics is supposed to do, and is what any proposed new unification model is supposed to be---namely predictive and testable. Some of what other particle theorists work on these days is not so explicitly predictive, and does not risk rejection by Nature--it's more along the lines of a mathematical pastime--or a "framework" of math with numerous different possible applications. But I don't think Lisi's is the only testable unification on the table. There is one that Hermann Nicolai presented last year---joint work with Kris Meissner---making, as I recall, explicit predictions which could be ruled out (or confirmed) over the next few years at LHC.