Abstract
Formulation of a single theory that connects and explains all aspects of the universe is one of the unsolved problems in physics. Though the mass-energy equivalence tends to connect mass and energy through a constant which is the square of the velocity of light, it fails to bring about an element that underlies both mass and energy. A theory of everything lies in the definition of this underlying element. This paper is a hypothesis wherein I have called this underlying element matter. I have defined matter from the perspective of an observer observing from outside the realm of matter, making mass and energy, the constituents of matter, an observed phenomenon. The hypothesis reveals that it is the same energy that shows up in the form of electromagnetic radiation under certain conditions and is stored in the form of potential and experienced as gravity in another.