A physical theory is a model of physical events. It is judged by the extent to which its predictions agree with empirical observations. The quality of a physical theory is also judged on its ability to make new predictions which can be verified by new observations. A physical theory differs from a mathematical theorem in that while both are based on some form of axioms, judgment of mathematical applicability is not based on agreement with any experimental results.
The equations for an Einstein manifold, used in general relativity to describe the curvature of spacetime
A physical theory involves one or more relationships between various measurable quantities. Archimedes realized that a ship floats by displacing its mass of water, Pythagoras understood the relation between the length of a vibrating string and the musical tone it produces, and how to calculate the length of a rectangle's diagonal. Other examples include entropy as a measure of the uncertainty regarding the positions and motions of unseen particles and the quantum mechanical idea that (action and) energy are not continuously variable.
Sometimes the vision provided by pure mathematical systems can provide clues to how a physical system might be modeled; e.g., the notion, due to Riemann and others, that space itself might be curved.
Theoretical advances may consist in setting aside old, incorrect paradigms (e.g., Burning consists of evolving phlogiston, or Astronomical bodies revolve around the Earth) or may be an alternative model that provides answers that are more accurate or that can be more widely applied.
Physical theories become accepted if they are able to make correct predictions and no (or few) incorrect ones. The theory should have, at least as a secondary objective, a certain economy and elegance (compare to mathematical beauty), a notion sometimes called "Occam's razor" after the 13th-century English philosopher William of Occam (or Ockham), in which the simpler of two theories that describe the same matter just as adequately is preferred. (But conceptual simplicity may mean mathematical complexity.) They are also more likely to be accepted if they connect a wide range of phenomena. Testing the consequences of a theory is part of the scientific method.
Physical theories can be grouped into three categories: mainstream theories, proposed theories and fringe theories.
Other articles related to "physics, theoretical physics, theoretical":
... States, and later as head of the IAEA's reactor physics division, which enabled him to direct senior scientists to working under him ... metallurgy, chemistry and interdisciplinary projects that would differs the physics ... On 20 December, Abdus Salam established the Theoretical Physics Group (TPG) in PAEC when two theoretical physicists working at the International Center for Theoretical Physics (ICTP), were asked ...
... For more details on this topic, see History of physics ... Theoretical physics began at least 2,300 years ago, under the Pre-socratic philosophy, and continued by Plato and Aristotle, whose views held sway for a millennium ... picked up the interactive intertwining of mathematics and physics begun two millennia earlier by Pythagoras ...
... physicist and mathematician who has made contributions in particle physics, statistical mechanics, mathematical physics, theory of unstable systems, classical chaos and quantum chaos ... He then worked at the Department of Theoretical Physics at the University of Geneva, Geneva, Switzerland, until 1966, and became full professor at the Department of Physics, University of Denver, Denver ... He has been Full Professor at the School of Physics, Tel Aviv University since 1972 (Professor Emeritus since 1998), and teaching externally as well at Bar Ilan University from 1990 ...
Famous quotes containing the words physics and/or theoretical:
“We must be physicists in order ... to be creative since so far codes of values and ideals have been constructed in ignorance of physics or even in contradiction to physics.”
—Friedrich Nietzsche (18441900)
“There are theoretical reformers at all times, and all the world over, living on anticipation.”
—Henry David Thoreau (18171862)