R. Mirman writes "String theory has been proven with mathematical rigor to be wrong. It has long been known that physics (a universe)would be impossible in any dimension but 3+1. Also there is a quantum theory of gravity, the only possible one since it is required by geometry: GR. The description of the books showing this is at impunv.blogspot.com. For the dimension see
Our Almost Impossible Universe:
Why the laws of nature make the existence of humans extraordinarily unlikely
and for the derivation of GR from geometry (the Poincare group) and quantum gravity see Massless Representations of the Poincare Group electromagnetism, gravitation, quantum mechanics, geometry
The proofs are rigorous and verified by others."