Unified Field
In physics, the unified field is understood to be a single field of energy whose characteristics can explain and unify all four existing physical forces, which at present do not appear to operate according to the same principles. It continues to be highly sought after by physicists. A unified field theory aims to reconcile the four fundamental forces (or energy fields) in nature: 1) strong nuclear force (the force responsible for holding quarks together to form neutrons and protons, and holding neutrons and protons together to form nuclei); 2) electromagnetic force (the familiar force that acts on electrically charged particles); 3) weak nuclear force (responsible for radioactivity), and; 4) gravitational force (a long-range force of attraction that acts on all particles with mass). Notable physicists have been pursuing a unified field theory since the early 1800’s and many important discoveries have resulted from their efforts. But they have yet to formulate a consistent theory that combines general relativity and quantum mechanics. In recent years the quest for a unified field has largely focused on string theory and its derivatives, such as M-theory. The Unified Field theory is sometimes confused with the Theory of Everything (TOE) which attempts to explain all four fundamental forces in nature together with the theory of general relativity and the nature of elementary particles that form matter.