Relational theory
Encyclopedia
In physics
and philosophy
, a relational theory is a framework to understand reality
or a physical system in such a way that the positions and other properties
of objects are only meaningful relative to other objects. In a relational spacetime
theory, space
does not exist unless there are objects in it; nor does time
exist without event
s.
The relational view proposes that space is contained in objects and that an object represents within itself relationships to other objects. Space can be defined through the relations among the objects that it contains considering their variations through time.
The alternative spatial theory is an absolute theory
in which the space exists independently of any objects that can be immersed in it.
Someone who has constructed or a relational theory or promotes relational theorising is called a relationist.
The relational point of view was advocated by in physics 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 Relational approach to quantum physics
has been developed, in analogy with Einstein's special relativity
of space and time.
Relationist physicists such as John Baez and Carlo Rovelli
have criticised the leading unified theory of gravity and quantum mechanics
, string theory
, as retaining absolute space. Some prefer a developing theory of gravity, loop quantum gravity
for its 'backgroundlessness'.
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
and philosophy
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
, a relational theory is a framework to understand reality
Reality
In philosophy, reality is the state of things as they actually exist, rather than as they may appear or might be imagined. In a wider definition, reality includes everything that is and has been, whether or not it is observable or comprehensible...
or a physical system in such a way that the positions and other properties
Physical property
A physical property is any property that is measurable whose value describes a physical system's state. The changes in the physical properties of a system can be used to describe its transformations ....
of objects are only meaningful relative to other objects. In a relational spacetime
Spacetime
In physics, spacetime is any mathematical model that combines space and time into a single continuum. Spacetime is usually interpreted with space as being three-dimensional and time playing the role of a fourth dimension that is of a different sort from the spatial dimensions...
theory, space
Space
Space is the boundless, three-dimensional extent in which objects and events occur and have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum...
does not exist unless there are objects in it; nor does time
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
exist without event
Event (philosophy)
In philosophy, events are objects in time or instantiations of properties in objects. However, a definite definition has not been reached, as multiple theories exist concerning events.-Kim’s Property-Exemplification Account of Events:...
s.
The relational view proposes that space is contained in objects and that an object represents within itself relationships to other objects. Space can be defined through the relations among the objects that it contains considering their variations through time.
The alternative spatial theory is an absolute theory
Absolute theory
In physics and philosophy, absolute theory usually refers to a theory based on concepts that exist independently of other concepts and objects. An absolute theory is the opposite of a relational theory....
in which the space exists independently of any objects that can be immersed in it.
Someone who has constructed or a relational theory or promotes relational theorising is called a relationist.
The relational point of view was advocated by in physics by Gottfried von Leibniz, Ernst Mach
Ernst Mach
Ernst Mach was an Austrian physicist and philosopher, noted for his contributions to physics such as the Mach number and the study of shock waves...
(in his Mach's principle
Mach's principle
In theoretical physics, particularly in discussions of gravitation theories, Mach's principle is the name given by Einstein to an imprecise hypothesis often credited to the physicist and philosopher Ernst Mach....
), and it was rejected by Isaac Newton
Isaac Newton
Sir Isaac Newton PRS was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian, who has been "considered by many to be the greatest and most influential scientist who ever lived."...
in his successful description of classical physics
Classical physics
What "classical physics" refers to depends on the context. When discussing special relativity, it refers to the Newtonian physics which preceded relativity, i.e. the branches of physics based on principles developed before the rise of relativity and quantum mechanics...
. Although Albert Einstein
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
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
Brans-Dicke theory
In theoretical physics, the Brans–Dicke theory of gravitation is a theoretical framework to explain gravitation. It is a well-known competitor of Einstein's more popular theory of general relativity...
A Relational approach to quantum physics
Relational approach to quantum physics
The relational approach to quantum physics is an alternative approach to and interpretation of quantum mechanics. It asserts that the physical world can only be studied accurately in terms of relationships between systems, as all experimentally verifiable facts about the world result explicitly...
has been developed, in analogy with Einstein's special relativity
Special relativity
Special relativity is the physical theory of measurement in an inertial frame of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".It generalizes Galileo's...
of space and time.
Relationist physicists such as John Baez and Carlo Rovelli
Carlo Rovelli
Carlo Rovelli is an Italian physicist who has worked in Italy, the USA, and France. His work is mainly in the field of quantum gravity. He is among the founders of the Loop Quantum Gravity theory.-Life and career:...
have criticised the leading unified theory of gravity and quantum mechanics
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
, string theory
String theory
String theory is an active research framework in particle physics that attempts to reconcile quantum mechanics and general relativity. It is a contender for a theory of everything , a manner of describing the known fundamental forces and matter in a mathematically complete system...
, as retaining absolute space. Some prefer a developing theory of gravity, loop quantum gravity
Loop quantum gravity
Loop quantum gravity , also known as loop gravity and quantum geometry, is a proposed quantum theory of spacetime which attempts to reconcile the theories of quantum mechanics and general relativity...
for its 'backgroundlessness'.