I once read about a theory that combined the two main forces, electromagnetic-nuclear force with gravity. This theory was based in the existance of a 4rth spacial dimension. The author described a unic 4rth dimensional gravity, and said that the projection of this force field into a 3dimensional Universe was divided into what we call gravity and electromagnetic-nuclear force fields.
Does anybody know anything more about this theory?
If so, can you lead me to any kind of bibliography about it?
Thanks,
Martin.