History of Astronomy |
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Page 108
... measured spectroscopically the velocity of the earth to and from a star by observations taken six months apart . Thence he obtained an accurate value of the sun's distance.1 But the remarkably erratic minor planet , Eros , discovered by ...
... measured spectroscopically the velocity of the earth to and from a star by observations taken six months apart . Thence he obtained an accurate value of the sun's distance.1 But the remarkably erratic minor planet , Eros , discovered by ...
Page 117
... measured , we can calculate the rate of approach or recession in miles per second . In 1868 Huggins ' succeeded in thus measuring . the velocities of stars in the direction of the line of sight . In 1873 Vogel ' compared the spectra of ...
... measured , we can calculate the rate of approach or recession in miles per second . In 1868 Huggins ' succeeded in thus measuring . the velocities of stars in the direction of the line of sight . In 1873 Vogel ' compared the spectra of ...
Page 136
... measured the heights of lunar moun- tains by their shadows , and found four of them over 20,000 feet above the surrounding plains . Langrenus1 was the first to do serious work on selenography , and named the lunar features after eminent ...
... measured the heights of lunar moun- tains by their shadows , and found four of them over 20,000 feet above the surrounding plains . Langrenus1 was the first to do serious work on selenography , and named the lunar features after eminent ...
Page 138
... a star by atmospheric refrac- tion at occultation has been surely recorded . The moon seems to be dead . The distance of the moon from the earth is just The base now the subject of re - measurement . 138 History of Astronomy.
... a star by atmospheric refrac- tion at occultation has been surely recorded . The moon seems to be dead . The distance of the moon from the earth is just The base now the subject of re - measurement . 138 History of Astronomy.
Page 139
George Forbes. The base now the subject of re - measurement . line is from Greenwich to Cape of Good Hope , and the new ... measured . The Inferior Planets . When the telescope was invented , the phases of Venus attracted much attention ...
George Forbes. The base now the subject of re - measurement . line is from Greenwich to Cape of Good Hope , and the new ... measured . The Inferior Planets . When the telescope was invented , the phases of Venus attracted much attention ...
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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.