Posted: Sep 04, 2010 6:01 pm
by Severian
The trouble with String Theory is that it doesn't really say anything about nature that we don't already know. It can produce gauge theories, and GR from within itself, which is great, but it doesn't tell us anything about these gauge theories. It makes no predictions about, for example, the Standard Model. It doesn't tell us what the particle masses are, or what representations they come in, or even which gauge groups we should have.

And you don't need String Theory to have Exceptional groups. You can fit all the SM particles (including the Higgs, but excluding the gauge boons of course, which stay in the adjoint) into the fundamental representation of E6 for example.