Aristarchus of Samos, the ancient Copernicus ; a history of Greek astronomy to Aristarchus, together with Aristarchus's Treatise on the sizes and distances of the sun and moon
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Aristarchus of Samos, the ancient Copernicus ; a history of Greek astronomy to Aristarchus, together with Aristarchus's Treatise on the sizes and distances of the sun and moon : a new Greek text with translation and notes. 448 Pages.
ancienne, pp. 283–94. Tannery prefers the title restored by Letronne, Didascalie celeste de Leptine. The document, written in Egypt between the years 193 and 165 B.C., seems to have been a student’s note-book, written perhaps during or after a course of lectures. 26 Simplicius, loc. cit., p. 495. 25. 27 Simplicius, loc. cit., p. 496. 23. 28 Simplicius, loc. cit., pp. 496. 23–497. 5. 29 Schiaparelli’s geometrical propositions are too long to be quoted here, but the whole thing can be worked
which it revolves passes through the centre of the earth; the zones are therefore incompatible with the Pythagorean system, according to which the earth moves round the central fire. Hultsch admits, however, that this argument does not hold if the hypothesis of the central fire was not thought of by any one before Philolaus; and there is no evidence that it was. As soon as Pythagoras had satisfied himself that the universe and the earth were concentric spheres, the centre of both being the centre
sun and of the moon are due to their being thrust back by the air. The moon’s turnings are frequent because it cannot get the better of the cold.’34 Again : ‘We do not feel the warmth of the stars because they are at a great distance from the earth; besides which they are not as hot as the sun because they occupy a colder region. The moon is below the sun and nearer to us.’35 ‘The stars were originally carried round (laterally) like a dome, the pole which is always visible being vertically
proceeds, and in fact swings gradually (completing an oscillation in a year) between two extreme positions inclined to the mean position at an angle equal to the obliquity of the ecliptic. But it is very unlikely that Empedocles, with his elementary Gotions of astronomy, worked out his theory in this way. It would appear that Empedocles’ theory of the sun gave a lead to the later Pythagoreans, for we shall find Philolaus saying that ‘there are in a manner two suns . . . unless [in Aëtius’s
compounded of the daily rotation and the special movement along the zodiac. For such a composite movement would take place in a direction and with a velocity continually altering and it would follow that, if at a given instant the harmonical proportions of the velocities and the distances held good, these proportions would not hold good for the next instant. Accordingly it was necessary to assign to each heavenly body one single simple and uniform movement, and this could not be realized except