History of Astronomy |
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Page 23
... mean motion . [ Halley , in 1693 , com- pared this value with his own measurements , and so discovered the acceleration of the moon's mean motion . This was conclusively estab- lished , but could not be explained by the Newtonian theory ...
... mean motion . [ Halley , in 1693 , com- pared this value with his own measurements , and so discovered the acceleration of the moon's mean motion . This was conclusively estab- lished , but could not be explained by the Newtonian theory ...
Page 63
... mean motion , and indicated the retardation of Saturn's mean motion . Horrocks ' investigations , so far as they could be collected , were published posthumously in 1672 , and seldom , if ever , has a man who lived only twenty - two ...
... mean motion , and indicated the retardation of Saturn's mean motion . Horrocks ' investigations , so far as they could be collected , were published posthumously in 1672 , and seldom , if ever , has a man who lived only twenty - two ...
Page 72
... Mean monthly motion of Apses ...... Mean annual motion of nodes Newton . 0 / 1 Modern Tables . O III 3.4.0 19.21.22,50 1.31.28 19.18.1,23 Mean value of " variation " .. 36.10 35.47 Annual equation .... 11.51 II . 14 Inequality of mean ...
... Mean monthly motion of Apses ...... Mean annual motion of nodes Newton . 0 / 1 Modern Tables . O III 3.4.0 19.21.22,50 1.31.28 19.18.1,23 Mean value of " variation " .. 36.10 35.47 Annual equation .... 11.51 II . 14 Inequality of mean ...
Page 76
George Forbes. He was the first to detect the acceleration of the moon's mean motion . Hipparchus , having compared his own observations with those of more ancient astronomers , supplied an accurate value of the moon's mean motion in his ...
George Forbes. He was the first to detect the acceleration of the moon's mean motion . Hipparchus , having compared his own observations with those of more ancient astronomers , supplied an accurate value of the moon's mean motion in his ...
Page 77
... mean motion in- creased . Laplace computed the amount at 10 " in one century , agreeing with observation . ( Later on Adams showed that Laplace's calcu- lation was wrong , and that the value he found was too large ; so , part of the ...
... mean motion in- creased . Laplace computed the amount at 10 " in one century , agreeing with observation . ( Later on Adams showed that Laplace's calcu- lation was wrong , and that the value he found was too large ; so , part of the ...
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accurate Airy ancient astron Astronomer Royal astronomical units bright calculations Cape catalogue centre century Chaldæans Chinese comet Copernicus diameter discovered discovery earth Egyptian epicycles equatorial error excentric explain fact fixed stars Galileo Greenwich Halley heavenly bodies heavens heliometer Hipparchus History of Astronomy instruments JOHANNES KEPLER John Herschel Jupiter Jupiter's Kepler Laplace Lick Observatory light line of apses line of sight lunar Mars mathematical mean distance mean motion measured ment Mercury meteor miles a second moon moon's nebulæ Newton observations Observatory orbit parallax period photographic physical planet planetary pole position predicted proper motion proved Ptolemy R. S. Phil records refractor retrograde retrograde motion revolving round ring rotation satellites Saturn seems showing Sir William Herschel Sirius solar eclipse solar system spectra spectroscope spectrum sphere spots stellar sun-spot supposed tables telescope theory tion Trans Tycho Brahe universal gravitation Uranus velocity Venus Verrier
Popular passages
Page 67 - that every particle of matter in the universe attracts every other particle, with a force whose direction is that of the line joining the two, and whose magnitude is directly as the product of their masses, and inversely as the square of their distances from each other.
Page 26 - So he sate and cunningly guided the craft with the helm, nor did sleep fall upon his eyelids, as he viewed the Pleiads and Bootes, that setteth late, and the Bear, which they likewise call the Wain, which turneth ever in one place, and keepeth watch upon Orion, and alone hath no part, in the baths of Ocean. This star, Calypso, the fair goddess, bade him to keep ever on the left as he traversed the deep.
Page 53 - The third, viz. that the squares of the periodic times are proportional to the cubes of the mean distances...
Page 79 - Wherefore if according to what we have already said it should return again about the year 1758, candid posterity will not refuse to acknowledge that this was first discovered by an Englishman.
Page 122 - ... They have not been regarded as so successful as his geometrical analysis of the observed phenomena. It is only just to add that he himself did not attach equal weight to them ; for in answer to objections urged by Lalande to his theory that the spots are depressions, Wilson wrote thus in 1783 : — ' Whether their first production and subsequent numberless changes depend upon the eructation of elastic vapours from below, or upon eddies or whirlpools commencing at the surface, or upon the dissolving...
Page 51 - He then said boldly that it was impossible that so good an observer as Tycho could be wrong by eight minutes* and added, " out of these eight minutes we will construct a new theory that will explain the motions of all the planets.