Changes

However, "even though General Relativity has passed many tests, most physicists don’t believe it is ultimately correct because it conflicts with [[quantum mechanics]]." [http://newsdesk.org/2010/08/conservapedia-calls-theory-of-relativity-a-liberal-conspiracy/]

However, "even though General Relativity has passed many tests, most physicists don’t believe it is ultimately correct because it conflicts with [[quantum mechanics]]." [http://newsdesk.org/2010/08/conservapedia-calls-theory-of-relativity-a-liberal-conspiracy/]

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 20th 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.

''Main article:'' [[Gravitational lensing]]

''Main article:'' [[Gravitational lensing]]

General relativity predicts that the path of light will be distorted when it passes near a massive object.  In 1919, Sir [[Arthur Eddington]], an esteemed English astronomer, used this to test general relativity by observing the bending of starlight around the sun during a total [[solar eclipse]].<ref>Paul Johnson, British historian</ref>. (A smaller degree of bending could also be consistent with Newton's theory, if one hypothesized light to consist of particles.  However, that [[particle theory of light]] had gone out of favor previously.)  Eddington detected a bending of light, but his range of error overlapped both Einstein's and Newton's predictions.  Upon his return to England, Eddington declared that his observations proven the theory of relativity.  His experiment was later confirmed by more rigorous experiments, such as those performed by the [[Hubble Space Telescope]] <ref>[http://www.spaceimages.com/gravlen.html Hubble Gravitational Lens Photo]</ref><ref> [http://csep10.phys.utk.edu/astr162/lect/galaxies/lensing.html Gravitational Lensing] </ref><ref>[http://www.iam.ubc.ca/~newbury/lenses/glgallery.html]</ref>. Lorentz has this to say on the discrepancies between the empirical eclipse data and Einstein's predictions.

General relativity predicts that the path of light will be distorted when it passes near a massive object.  In 1919, Sir [[Arthur Eddington]], an esteemed English astronomer, used this to test general relativity by observing the bending of starlight around the sun during a total [[solar eclipse]].<ref>Paul Johnson, British historian</ref>  (A smaller degree of bending could also be consistent with Newton's theory, if one hypothesized light to consist of particles.  However, that [[particle theory of light]] had gone out of favor previously.)  Eddington detected a bending of light, but his range of error overlapped both Einstein's and Newton's predictions.  Upon his return to England, Eddington declared that his observations proven the theory of relativity.  His experiment was later confirmed by more rigorous experiments, such as those performed by the [[Hubble Space Telescope]].<ref>[http://www.spaceimages.com/gravlen.html Hubble Gravitational Lens Photo]</ref><ref>[http://csep10.phys.utk.edu/astr162/lect/galaxies/lensing.html Gravitational Lensing]</ref><ref>[http://www.iam.ubc.ca/~newbury/lenses/glgallery.html]</ref>  Lorentz has this to say on the discrepancies between the empirical eclipse data and Einstein's predictions.

::''It indeed seems that the discrepancies may be ascribed to faults in observations, which supposition is supported by the fact that the observations at Prince's Island, which, it is true, did not turn out quite as well as those mentioned above, gave the result, of 1.64, somewhat lower than Einstein's figure.''<ref>Lorentz, H.A. [http://ia331314.us.archive.org/2/items/theeinsteintheor11335gut/11335-h/11335-h.htm The Einstein Theory of Relativity]</ref>

::''It indeed seems that the discrepancies may be ascribed to faults in observations, which supposition is supported by the fact that the observations at Prince's Island, which, it is true, did not turn out quite as well as those mentioned above, gave the result, of 1.64, somewhat lower than Einstein's figure.''<ref>Lorentz, H.A. [http://ia331314.us.archive.org/2/items/theeinsteintheor11335gut/11335-h/11335-h.htm The Einstein Theory of Relativity]</ref>

{{Relativity}}

{{Relativity}}

==External Links==

==External links==

*Einstein, Albert (1916), [http://www.alberteinstein.info/gallery/pdf/CP6Doc30_English_pp146-200.pdf "The Foundation of the General Theory of Relativity"] (PDF), Annalen der Physik 49

*Einstein, Albert (1916), [http://www.alberteinstein.info/gallery/pdf/CP6Doc30_English_pp146-200.pdf "The Foundation of the General Theory of Relativity"] (PDF), Annalen der Physik 49

*[http://www.rareuniverse.org/general_science/general_relativity.html A simple explanation of General Relativity]

*[http://www.rareuniverse.org/general_science/general_relativity.html A simple explanation of General Relativity]