Relational theory

…:"This article is about relational theory in physics and philosophy. There is a separate article about the relational model (database) and Relational Philosophy as a category of Philosophical anthropology"

In physics and philosophy, a relational theory is a framework to understand reality or a physical system in such a way that the position and other properties of the objects are only meaningful relative to other objects. In a relational theory, space does not exist unless there are objects in it.The relational view proposes that space is contained in objects and that an object represents within it self relationships to other objects. Space can be defined through the relations among the objects that it contains considering their variations through time. The alternative is an absolute theory in which the space exists independently of any objects that can be immersed in it.

The relational point of view was advocated by Gottfried von Leibniz, Ernst Mach (in his Mach's principle), and it was rejected by Isaac Newton in his successful description of classical physics. Although Albert Einstein was impressed by Mach's principle, he did not fully incorporate it into his theory of general relativity. Several attempts have been made to formulate a full Machian theory, but most physicists think that none have so far succeeded. For example, see Brans-Dicke theory.

A developing theory of gravity, loop quantum gravity, is revisiting the relational view.