| Line 61: |
Line 61: |
| | precession after the effects of other planets' gravitation action has been compensated for. Those other effects are much larger, and are purely Newtonian in nature. There was another explanation based on Newtonian gravity, involving a slight alteration to the precise inverse-square relation of Newtonian gravity to distance, but it was discarded when it gave very bad results for the Moon's orbit. | | precession after the effects of other planets' gravitation action has been compensated for. Those other effects are much larger, and are purely Newtonian in nature. There was another explanation based on Newtonian gravity, involving a slight alteration to the precise inverse-square relation of Newtonian gravity to distance, but it was discarded when it gave very bad results for the Moon's orbit. |
| | | | |
| − | British Historian Paul Johnson declares the turning point in 20th century to have been when fellow Briton Sir [[Arthur Eddington]], an esteemed English astronomer, ventured out on a boat off Africa in 1919 with a local Army unit to observe the bending of starlight around the sun during a total eclipse. Upon his return to England declared that his observations proven the theory of relativity. In fact recent analysis of Eddington's work revealed that he was biased in selecting his data, and that overall his data were inconclusive about the theory of relativity. The prediction 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>[[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. | + | British Historian Paul Johnson declared the turning point in 20th century to have been when fellow Briton Sir [[Arthur Eddington]], an esteemed English astronomer, ventured out on a boat off Africa in 1919 with a local Army unit to observe the bending of starlight around the sun during a total eclipse. Upon his return to England declared that his observations proven the theory of relativity. In fact recent analysis of Eddington's work revealed that he was biased in selecting his data, and that overall his data were inconclusive about the theory of relativity. The prediction 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>[[Gravitational lensing]]</ref><ref>[http://www.iam.ubc.ca/~newbury/lenses/glgallery.html]</ref> [[Hendrik Lorentz]] had 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> |
| | | | |
| − | The prediction that light is bent by gravity is predicted both by Newtonian physics and relativity, but relativity predicts a larger deflection. | + | The bending of light by gravity is predicted both by Newtonian physics and relativity. Experimental observation agrees with the latter amount (1.75 arcseconds for the Sun), rather approximately for Eddington's measurements, and very accurately for more modern measurements. |
| | | | |
| | 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). |