A New Theory of GravitationWhittaker & Company, 1844 - 50 pages |
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Common terms and phrases
action of gravity analogical method Analogical Velocities appear ascertained attraction of mag calculation centri centrifugal and centripetal centripetal forces circular orbit computation constant velocity cube cube-roots Daily Velocity demonstrated difference duplicate proportion earth's distance earth's gravitation earth's orbit equal forces equality of ratios equator following table force of gra force of gravitation forces E B heavy bodies Hence Herschell hypothesis Kepler's Analogy known quan lites of Jupiter magnetic attraction mean velocities miles per diem moving forces Newton Newton's analogy Newton's theory North Pole observations obvious orbit round periodic phenomena planets are inversely Pole primary planets proposition quadrantial method Quadrantial Velocities respective centrifugal forces retain the moon revolution right line round the earth SATELLITES Saturn shown sixteen solar system South Pole square-roots stant velocity sun's gravitating force supposing supposition tances term THEORY OF GRAVITATION tion vitating force
Popular passages
Page 50 - In experimental philosophy, propositions collected from the phenomena by induction are to be deemed, notwithstanding contrary hypotheses, either exactly, or very nearly, true; till other phenomena occur, by which they may be rendered either more accurate, or liable to exception.
Page 3 - ... diminution, he considered with himself that, if the moon be retained in her orbit by the force of gravity, no doubt the primary planets are carried round the sun by the like power. And, by comparing the periods of the several planets with their distances from the sun, he found...
Page 8 - ... the existence of the principle which he discovered, but the development of its consequences and its advantages, has been the work of the successors of this great geometer.
Page 3 - ... comparing the periods of the several planets with their distances from the sun, he found, that if any power like gravity held them in their courses, its strength must decrease in the duplicate proportion of the increase of distance. This he concluded by supposing them to move in perfect circles, concentric to the sun, from which the orbits of the greatest part of them do not much differ. Supposing, therefore, the force of gravity, when extended to the moon...
Page 5 - Picart having not longbefore, viz. in 1679, measured a degree of the earth with sufficient accuracy, by using his measures, that planet appeared to be retained in her orbit by the sole power of gravity; and, consequently, that this power decreases in the duplicate ratio of the distance ; as he had formerly conjectured. Upon this principle he found the line described by a falling body to be an ellipsis, having one focus in the centre of the earth.
Page 4 - This he concluded by supposing them to move in perfect circles concentrical to the sun, from which the orbits of the greatest part of them do not much differ. Supposing therefore the power of gravity, when extended to the moon, to decrease in the same manner, he computed whether that force would be sufficient to keep the moon in her orbit.
Page 7 - Newton has well established the existence of the principle he had the merit of discovering ; but the development of its consequences and advantages has been the work of the successors of this great mathematician. The imperfection of the infinitesimal calculus when first discovered, did not allow him completely to resolve the difficult problems which the theory of the universe offers ; and he was oftentimes forced to give mere hints, which were [always uncertain till confirmed by rigorous analysis.
Page 9 - This, also, is in conformity with the result of the theory of attraction following the law of the inverse square of the distance. I suppose there is no science in the world in which such important laws have been first discovered independently from observation only, and which have afterwards been shewn...
Page 3 - ... the sun by the like power. And, by comparing the periods of the several planets with their distances from the sun, he found that if any power like gravity held them in their courses, its strength must decrease in the duplicate proportion of the increase of distance. This...