The Sun, the Stars and the UniverseLongmans, Green and Company, 1928 - 291 páginas |
Términos y frases comunes
absolute magnitude absorption accurately angle angular apparent magnitude appear astronomical astronomical unit atmosphere atoms average axis bright stars calcium calculated celestial sphere centre Cepheid chapter chromosphere comet component constellation curve dark deduced density described diameter direction discovery distance double star dwarf earth eclipse electrons energy example faint Figure galactic system giant gravitation hydrogen images ionised Jupiter Kepler's known later light light-years lines luminosity Mars measured meteors method miles per second Milky million minor planets moon moving nebula Neptune number of stars observations Observatory orbit parallax parsecs particles particular period photographic plate photosphere planetary position pressure prominent proper motion radial velocity radiation ratio relative result revolving right ascension rotation satellites Saturn seen Sirius solar spectrum solar system spectra spectral class spectral type spectroscopic binary star's stellar sun-spot sun's mass surface telescope temperature terrestrial theory tion Uranus violet visible visual visual magnitude wave-length
Pasajes populares
Página 143 - The Ram, the Bull, the heavenly Twins, And next the Crab, the Lion, shines. The Virgin, and the Scales ; The Scorpion, Archer, and Sea-goat, The Man that holds the -water-pot, And Fish with glitt'ring tails.
Página 35 - Newton generalized the law of attraction into a statement that every particle of matter in the universe attracts every other particle with a force which varies directly as the product of their masses and inversely as the square of the distance between them; and he thence deduced the law of attraction for spherical shells of constant density.
Página 66 - I have said, he spent to satisfy himself; six more years to satisfy, and still thirteen more to convince, mankind. For thirty years never has the Sun exhibited his disc above the horizon of Dessau without being confronted by Schwabe's imperturbable telescope, and that appears to have happened, on an average, about 300 days a year.
Página 39 - Formed a design in the beginning of this week, of investigating, as soon as possible after taking my degree, the irregularities in the motion of Uranus, which are yet unaccounted for; in order to find whether they may be attributed to the action of an undiscovered planet beyond it; and if possible thence to determine the elements of its orbit, etc. approximately, which would probably lead to its discovery.
Página 40 - We see it as Columbus saw America from the shores of Spain. Its movements have been felt trembling along the farreaching line of our analysis with a certainty hardly inferior to ocular demonstration.
Página 66 - ... groups. This is, I believe, an instance of devoted persistence ( if the word were not equivocal, I should say, pertinacity) unsurpassed in the annals of astronomy. The energy of one man has revealed a phenomenon that had eluded even the suspicion of astronomers for 200 years.
Página 31 - Aristotle's writings from end to end many times, and I can assure you that I have nowhere found in them anything similar to what you mention. Go, my son, and tranquillize yourself: be assured that what you take for spots in the sun are the faults of your glasses, or of your eyes.
Página 29 - The line joining the planet to the sun sweeps out equal areas in equal times.
Página 39 - Adams had entered in his journal: "Formed a design in the beginning of this week of investigating, as soon as possible after taking my degree, the irregularities in the motion of Uranus ... in order to find out whether they may be attributed to the action of an undiscovered planet beyond it...
Página 67 - ... the sun. An eclipse of the sun is caused by the interposition of the moon between the earth and sun, and therefore it must happen when the moon is in conjunction with the sun, or at the new moon.