E8 Lie Group

This is a difficult subject for non mathematicians but, IMHO, it is a worthwhile reading.

For well over two decades now String Theory has been the preeminent model for physics beyond the Standard Model. Indeed, String Theory is often touted among physicists as the ultimate Theory of Everything. The basic premise of String Theory is that the most fundamental building blocks of the Universe are not atoms, or even elementary particles like electrons, muons, and quarks, but rather exotic string-like objects living in a 26-dimensional space. The great appeal of String Theory to modern physicists is two-fold. First of all, it very deftly circumvents two theoretical obstructions that had long thwarted the unification of Einstein's theory of General Relativity with the quantum field theory of elementary particle physics (viz., the lack of renormalizability and the occurrence of quantization anomalies). The second is its apparent uniqueness: once one adopts the basic principles of string theory, it can be argued that we live in the universe we live in because it is the only one that is possible.