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434 bytes added ,  01:07, October 20, 2008
fixed some of the gravitational lensing stuff. Feel free to clean up, the sentence structure needs work. However, it does need to have the bit about photons with mass in it.
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::''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>
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The prediction that light is bent by gravity is predicted both by Newtonian physics and relativity, but relativity predicts a larger deflection.
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The bending of light can be predicted in Newtonian physics if one posits that photons have mass.  Given a particle of light with a small but non-zero mass, the bending of a light ray can be calculated.  However, since photons have momentum but not mass this method of determining lensing is based on faulty premises.<ref>[http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/photon_mass.html]</ref>  General relativity predicts deflection without resorting to massive photons, although the lensing predicted by each method differs.
    
Special relativity is the limiting case of general relativity where all gravitational fields are weak.  Alternatively, special relativity is the limiting case of general relativity when all reference frames are inertial (non-accelerating and without gravity).
 
Special relativity is the limiting case of general relativity where all gravitational fields are weak.  Alternatively, special relativity is the limiting case of general relativity when all reference frames are inertial (non-accelerating and without gravity).
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The [[perihelion]] of Mercury's [[orbit]] [[precession|precesses]] at a measurable rate, but even after after accounting for gravitational perturbations caused all other planets in the [[solar system]], Newton's theory (assuming a precise inverse-square relationship for distance) predicts a rate of precession that differs from the measured rate by approximately 43 [[arcsecond]]s per century.  General relativity was developed in part to provide an estimate for this rate of precession that better matches observations.<ref>http://physics.ucr.edu/~wudka/Physics7/Notes_www/node98.html#SECTION032121000000000000000</ref> <ref> http://www.alberteinstein.info/gallery/pdf/CP6Doc30_English_pp146-200.pdf</ref> <ref> http://farside.ph.utexas.edu/teaching/336k/lectures/node117.html</ref>
 
The [[perihelion]] of Mercury's [[orbit]] [[precession|precesses]] at a measurable rate, but even after after accounting for gravitational perturbations caused all other planets in the [[solar system]], Newton's theory (assuming a precise inverse-square relationship for distance) predicts a rate of precession that differs from the measured rate by approximately 43 [[arcsecond]]s per century.  General relativity was developed in part to provide an estimate for this rate of precession that better matches observations.<ref>http://physics.ucr.edu/~wudka/Physics7/Notes_www/node98.html#SECTION032121000000000000000</ref> <ref> http://www.alberteinstein.info/gallery/pdf/CP6Doc30_English_pp146-200.pdf</ref> <ref> http://farside.ph.utexas.edu/teaching/336k/lectures/node117.html</ref>
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General relativity predicts twice as much bending in light as it passes near massive objects than Newton's theory predicts,<ref>http://www.mathpages.com/rr/s6-03/6-03.htm</ref> a phenomenon known as [[gravitational lens|gravitational lensing]]. A large number of instances of gravitational lensing have been observed, and it is now a standard astronomical tool.<ref> http://imagine.gsfc.nasa.gov/docs/features/news/grav_lens.html</ref> <ref> http://astro.berkeley.edu/~jcohn/lens.html</ref> <ref> http://www.iam.ubc.ca/~newbury/lenses/glgallery.html</ref>
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General relativity predicts twice as much bending in light as it passes near massive objects than a modified version of Newton's theory with massive photons predicts,<ref>http://www.mathpages.com/rr/s6-03/6-03.htm</ref> a phenomenon known as [[gravitational lens|gravitational lensing]]. A large number of instances of gravitational lensing have been observed, and it is now a standard astronomical tool.<ref> http://imagine.gsfc.nasa.gov/docs/features/news/grav_lens.html</ref> <ref> http://astro.berkeley.edu/~jcohn/lens.html</ref> <ref> http://www.iam.ubc.ca/~newbury/lenses/glgallery.html</ref>
    
== Ostensible Paradoxes ==
 
== Ostensible Paradoxes ==
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