Newtonian physics with but a single change can unify all of physics. This single change involves a redefinition of the speed of gravity. Four hundred years ago Kepler published his Third Law which has a fundamental flaw in that it assumes the central mass is unresponsive to the gravity of the orbiting mass. This can only be assumed if the speed of gravity is infinite. By changing the speed of gravity to a finite speed both Dark Matter and Dark Energy are predicted in the amounts observed.
The Unification of Physics
Newton's Law of gravity was derived from Kepler's Third Law. Therefore, Newton's Law also has the inheritanly assumption that gravity travels infinitely fast.