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''See [[Counterexamples to Relativity]]''.

''See [[Counterexamples to Relativity]]''.

<br>''See [[Theory of Relativity]]'' for a more "general" description of relativity.''

<br>''See [[Theory of relativity]]'' for a more "general" description of relativity.''

The '''General Theory of Relativity''' is an extension of [[Special theory of relativity|special relativity]], dealing with curved coordinate systems, accelerating frames of reference, curvilinear motion, and curvature of spacetime itself.  It could be said that general relativity is to special relativity as vector calculus is to vector algebra.  General relativity is best known for its formulation of gravity as a fictitious force arising from the curvature of spacetime.  In fact, "general relativity" and "Einstein's formulation of gravity" are nearly synonymous in many people's minds.

The '''General Theory of Relativity''' is an extension of [[Special theory of relativity|special relativity]], dealing with curved coordinate systems, accelerating frames of reference, curvilinear motion, and curvature of spacetime itself.  It could be said that general relativity is to special relativity as vector calculus is to vector algebra.  General relativity is best known for its formulation of gravity as a fictitious force arising from the curvature of spacetime.  In fact, "general relativity" and "Einstein's formulation of gravity" are nearly synonymous in many people's minds.

General relativity, like [[quantum mechanics]] (the other of the two theories comprising "modern physics") both have reputations for being notoriously complicated and difficult to understand.  In fact, in the early decades of the 20^th century, general relativity had a sort of cult status in this regard.  General relativity and quantum mechanics are both advanced college-level and postgraduate level topics.  Hence this article can't possibly give a comprehensive explanation of general relativity at the expert level.  But we will attempt to give a rough outline, for lay people, of the general relativistic formulation of gravity.

General relativity, like [[quantum mechanics]] (the other of the two theories comprising "modern physics") both have reputations for being notoriously complicated and difficult to understand.  In fact, in the early decades of the 20^th century, general relativity had a sort of cult status in this regard.  General relativity and quantum mechanics are both advanced college-level and postgraduate level topics.  Hence this article can't possibly give a comprehensive explanation of general relativity at the expert level.  But we will attempt to give a rough outline, for lay people, of the general relativistic formulation of gravity.

In the [[weak field approximation]], where velocities of moving objects are low and gravitational fields are not very severe, the theory of general relativity is said to ''reduce to'' the law of universal gravitation. That is to say, under those circumstances the equations of general relativity are mathematically equivalent to the equations of Newtonian gravitation.

In the weak field approximation, where velocities of moving objects are low and gravitational fields are not very severe, the theory of general relativity is said to ''reduce to'' the law of universal gravitation. That is to say, under those circumstances the equations of general relativity are mathematically equivalent to the equations of Newtonian gravitation.

Modern science does not say that Newtonian (classical) gravity is wrong.  It is obviously very very nearly correct.  In the weak field approximation, such as one finds in our solar system, the differences between general relativity and Newtonian gravity are miniscule.  It takes very sensitive tests to show the difference.  The history of those tests is a fascinating subject, and will be covered near the end of this article.  But in all tests conducted so far, where there are discrepancies between the predictions of general relativity and Newtonian gravity (or other competing theories for that matter), experimental results have shown general relativity to be a better description.

Modern science does not say that Newtonian (classical) gravity is wrong.  It is obviously very very nearly correct.  In the weak field approximation, such as one finds in our solar system, the differences between general relativity and Newtonian gravity are miniscule.  It takes very sensitive tests to show the difference.  The history of those tests is a fascinating subject, and will be covered near the end of this article.  But in all tests conducted so far, where there are discrepancies between the predictions of general relativity and Newtonian gravity (or other competing theories for that matter), experimental results have shown general relativity to be a better description.