Theory of Original Gravity Revisited: Unified Field Theory,Starting out from the Quantum Formulation to the Manifold Geometry

This paper assumes an acquaintance with a new concept of time and gravity to provide the unified field theory. A new mathematical attempt intended to formalise the gravity current (J^A) and the speed of gravity signal (V_g) have been shown. The present author starts out from the“Theory of Original Gravity” [1] and presents to the unified field theory in a simple manner.This paper includes the formulations of quantum mechanics, pseudo-Riemannian manifold, four-gradient operator and Lorentz-invariant interval as a notable mathematical tools. All of the ideas and matters presented in this paper are mainly based on quantum theory and manifold geometry.