§1.8#18 ὅπως δὲ καὶ διὰ τίνʼ αἰτίαν γίγνεται καὶ τὶ ἐστι τὸ γάλα, λέγωμεν ἢδη.
8 Let us now speak of how and for what cause the Milky Way arises, and what it is.
προδιέλθωμεν δὲ καὶ περὶ τούτου τὰ παρὰ τῶν ἄλλων εἰρημένα πρῶτον.
But let us first run through what has been said by others on this subject as well.
τῶν μὲν οὖν καλουμένων Πυθαγορείων φασί τινες ὁδὸν εἶναι ταύτην οἱ μὲν τῶν ἐκπεσόντων τινὸς ἀστέρων, κατὰ τὴν λεγομένην ἐπὶ Φαέθοντος φθοράν, οἱ δὲ τὸν ἥλιον τοῦτον τὸν κύκλον φέρεσθαί ποτέ φασιν· οἷον οὖν διακεκαῦσθαι τὸν τόπον τοῦτον ἤ τι τοιοῦτον ἄλλο πεπονθέναι πάθος ὑπὸ τῆς φορᾶς αὐτῶν.
Some of those called Pythagoreans say that this is a path, some of them saying it is of one of the stars that fell out of their course, in accordance with the so-called ruin in the time of Phaethon, while others say that the sun once was carried along this circle; as if, therefore, this place had been scorched or had suffered some other such affection by their motion.
ἄτοπον δὲ τὸ μὴ συννοεῖν ὅτι εἴπερ τοῦτʼ ἦν τὸ αἴτιον, ἔδει καὶ τὸν τῶν ζῳδίων κύκλον οὕτως ἔχειν, καὶ μᾶλλον ἢ τὸν τοῦ γάλακτος· ἀπαντα γὰρ ἐν αὐτῷ φέρεται τὰ πλανώμενα καὶ οὐχ ὁ ἥλιος μόνος.
But it is absurd not to notice that if this were the cause, the circle of the zodiac ought also to be in this state, and even more so than that of the Milky Way; for all the planets are carried in it, and not the sun alone.
δῆλος δʼ ἡμῖν ἅπας ὁ κύκλος· αἰεὶ γὰρ αὐτοῦ φανερὸν ἡμικύκλιον τῆς νυκτός.
And the whole circle is clear to us; for a semicircle of it is always visible during the night.
ἀλλὰ πεπονθὼς οὐδὲν φαίνεται τοιοῦτον, πλὴν εἴ τι συνάπτει μόριον αὐτοῦ πρὸς τὸν τοῦ γάλακτος κύκλον.
Yet it appears to have suffered no such thing, except if some part of it joins with the circle of the Milky Way.
οἱ δὲ περὶ Ἀναξαγόραν καὶ Δημόκριτον φῶς εἶναι τὸ γάλα λέγουσιν ἄστρων τινῶν· τὸν γὰρ ἥλιον ὑπὸ τὴν γῆν φερόμενον οὐχ ὁρᾶν ἕνια τῶν ἄστρων.
But those around Anaxagoras and Democritus say that the Milky Way is the light of certain stars; for they say that when the sun is carried under the earth, it does not see some of the stars.
ὅσα μὲν οὖν περιορᾶται ὑπʼ αὐτοῦ, τούτων μὲν οὐ φαίνεσθαι τὸ φῶς (κωλύεσθαι γὰρ ὑπὸ τῶν τοῦ ἡλίου ἀκτίνων)· ὅσοις δʼ ἀντιφράττει ἡ γῇ ὥστε μὴ ὁρᾶσθαι ὑπὸ τοῦ ἡλίου, τὸ τούτων οἰκεῖον φῶς εἶναί φασι τὸ γάλα.
Those, therefore, which are seen around by it, of these the light does not appear (for it is prevented by the rays of the sun); but those for which the earth blocks so that they are not seen by the sun, their own proper light is, they say, the Milky Way.
φανερὸν δʼ ὅτι καὶ τοῦτʼ ἀδύνατον· τὸ μὲν γὰρ γάλα ἀεὶ τὸ αὐτὸ ἐν τοῖς αὐτοῖς ἐστιν ἄστροις (φαίνεται γὰρ μέγιστος ὢν κύκλος), ὑπὸ δὲ τοῦ ἡλίου ἀεὶ ἕτερα τὰ οὐχ ὁρώμενα διὰ τὸ μὴ ἐν ταὐτῷ μένειν τόπῳ.
But it is manifest that this too is impossible; for the Milky Way is always the same among the same stars (for it appears to be a greatest circle), while those not seen by the sun are always different because the sun does not remain in the same place.
ἔδει οὖν μεθισταμένου τοῦ ἡλίου μεθίστασθαι καὶ τὸ γάλα· νῦν δὲ οὐ φαίνεται τοῦτο γιγνόμενον.
Therefore, as the sun moves, the Milky Way ought also to move; but now this does not appear to happen.
πρὸς δὲ τούτοις, εἰ καθάπερ δείκνυται νῦν ἐν τοῖς περὶ ἀστρολογίαν θεωρήμασιν, τὸ τοῦ ἡλίου μέγεθος μεῖζόν ἐστιν ἢ τὸ τῆς γύης καὶ τὸ διάστημα πολλαπλασίως μεῖζον τὸ τῶν ἄστρων πρὸς τὴν γῆν ἢ τὸ τοῦ ἡλίου, καθάπερ τὸ τοῦ ἡλίου πρὸς τὴν γῆν ἢ τὸ τῆς σελήνης, οὐκ ἂν πόρρω που τῆς γῆς ὁ κῶνος ὁ ἀπὸ τοῦ ἡλίου συμβάλλοι τὰς ἀκτῖνας, οὐδʼ ἂν ἡ σκιὰ πρὸς τοῖς ἄστροις εἴη τῆς γῆς, ἡ καλουμένη νύξ· ἀλλʼ ἀνάγκη πάντα τὸν ἥλιον τὰ ἄστρα περιορᾶν, καὶ μηδενὶ τὴν γῆν ἀντιφράττειν αὐτῶν.
In addition to these things, if, as is now shown in the theorems concerning astronomy, the size of the sun is greater than that of the earth, and the distance of the stars from the earth is many times greater than that of the sun, just as that of the sun is to the earth or that of the moon, then the cone from the sun would not join its rays far from the earth, nor would the shadow of the earth be near the stars, which is called night; but the sun must necessarily see around all the stars, and the earth block none of them.
ἔτι δʼ ἐστὶν τρίτη τις ὑπόληψις περὶ αὐτοῦ· λέγουσιν γάρ τινες ἀνάκλασιν εἶναι τὸ γάλα τῆς ἡμετέρας ὄψεως πρὸς τὸν ἥλιον, ὥσπερ καὶ τὸν ἀστέρα τὸν κομήτην.
And again, there is a certain third opinion about it; for some say that the Milky Way is a reflection of our sight to the sun, just as the comet star is.
ἀδύνατον δὲ καὶ τοῦτο εἰ μὲν γὰρ τό τε ὁρῶν ἠρεμοίη καὶ τὸ ἔνοπτρον καὶ τὸ ὁρώμενον ἄπαν, ἐν τῷ αὐτῷ σημείῳ τοῦ ἐνόπτρου τὸ αὐτὸ φαίνοιτʼ ἂν μέρος τῆς ἐμφάσεως· εἰ δὲ κινοῖτο τὸ ἔνοπτρον καὶ τὸ ὁρώμενον ἐν τῷ αὐτῷ μὲν ἀποστήματι πρὸς τὸ ὁρῶν καὶ ἠρεμοῦν, πρὸς ἄλληλα δὲ μήτε ἰσοταχῶς μηδʼ ἐν τῷ αὐτῷ ἀεὶ διαστήματι, ἀδύνατον τὴν αὐτὴν ἔμφασιν ἐπὶ τοῦ αὐτοῦ εἶναι μέρους τοῦ ἐνόπτρου.
But this also is impossible; for if the seer, the mirror, and the whole seen object were at rest, the same part of the reflection would appear in the same point of the mirror; but if the mirror and the seen object were moved at the same distance in relation to the seer which is at rest, but in relation to each other neither with equal speed nor always at the same distance, it is impossible for the same reflection to be upon the same part of the mirror.
τὰ δʼ ἐν τῷ τοῦ γάλακτος κύκλῳ φερδμενα ἄστρα κινεῖται καὶ ὁ ἥλιος πρὸς ὃν ἡ ἀνάκλασις, μενόντων ἡμῶν, καὶ ὁμοίως καὶ ἴσον πρὸς ἡμᾶς ἀπέχοντα, αὐτῶν δʼ οὐκ ἴσον· ὁτὲ μὲν γὰρ μέσων νυκτῶν ὁ δελφὶς ἐπιτέλλει, ὁτὲ δὲ ἔωθεν, τὰ δὲ μόρια τοῦ γάλακτος τὰ αὐτὰ μένει ἐν ἑκάστῳ.
But the stars carried in the circle of the Milky Way move, and the sun to which the reflection occurs, while we remain at rest, and similarly and equally distant in relation to us, but not equally in relation to themselves; for sometimes at midnight the Dolphin rises, and sometimes at dawn, but the parts of the Milky Way remain the same in each.
καίτοι οὐκ ἔδει, εἰ ἦν ἔμφασις, ἀλλὰ μὴ ἐν αὐτοῖς τι ἦν τοῦτο τὸ πάθος τοῖς τόποις.
And yet it ought not to be so, if it were a reflection, and if this affection were not something in those places themselves.
ἔτι δὲ νύκτωρ ἐν ὕδατι καὶ τοῖς τοιούτοις ἐνόπτροις τὸ μὲν γάλα ἐμφαί νεται θεωροῦσι, τὸ δὲ τὴν ὄψιν ἀνακλᾶσθαι πρὸς τὸν ἥλιον πῶς δυνατόν;
And again, at night, in water and such mirrors, the Milky Way appears to those observing, but how is it possible for the sight to be reflected to the sun?
ὅτι μὲν οὖν οὔτε ὁδὸς τῶν πλανήτων οὐδενὸς οὔτε φῶς ἐστι τῶν μὴ ὁρωμένων ἄστρων οὔτʼ ἀνάκλασις, ἐκ τούτων φανερόν.
That, therefore, it is neither a path of any of the planets, nor the light of unseen stars, nor a reflection, is manifest from these things.
σχεδὸν δὲ ταῦτʼ ἐστὶν μόνον τὰ μέχρι τοῦ νῦν παραδεδομένα παρὰ τῶν ἄλλων.
And these are pretty much the only things handed down by others up to the present.