For more than a century, physics has been built on two great theories. Einstein's general relativity explains gravity as the ...

String theory attempts to unify all forces and particles in the universe using vibrating strings. It aims to explain the Standard Model of particle physics, which is incomplete. String theory predicts ...

At long last, a unified theory combining gravity with the other fundamental forces—electromagnetism and the strong and weak nuclear forces—is within reach. Bringing gravity into the fold has been the ...