abdus salam albert einstein alternatives to general relativity an exceptionally simple theory of everything antony garrett lisi bimetric theory boson cern carlo rubbia cartan connection causal dynamical triangulation causal sets classical mechanics classical theories of gravitation classical unified field theories composite gravity conformal gravity dgp model dimensionless physical constant electric current electromagnetic force electromagnetism elementary particle euclidean quantum gravity field theory fifth dimension fringe science general relativity general relativity resources geometrodynamics gluon grand unification theory gravitation graviton heim theory heterotic string higgs mechanism higher-dimensional einstein gravity history of general relativity history of gravitational theory howard georgi induced gravity james clerk maxwell list of string theory topics loop quantum gravity m-theory mssm magnet magnetic field massive gravity mathematics of general relativity mechanical explanations of gravitation michael faraday modified newtonian dynamics neutron nobel prize in physics noncommutative geometry nonsymmetric gravitational theory particle accelerator photon physics planck constant proton proton decay pseudoscience quantum field theory quantum gravity quantum mechanics renormalization scalar-tensor-vector gravity scalar-tensor theory scalar theories of gravitation self-creation cosmology semiclassical gravity simon van der meer spacetime special relativity spontaneous symmetry breaking standard model steven weinberg string theory supergravity superstring theory teleparallelism tensor-vector-scalar gravity tests of general relativity theodor kaluza theoretical physics theory of everything twistor theory w and z bosons yilmaz theory of gravitation