I have made the claim - confusedly, now I believe - on the B-Greek forum that πλησιάζει ὁ ἥλιος refers to the perihelion (3rd of January) and that πόρρω refers to the aphelion (4th of July) in terms of this discussion of Aristotle's about the timing of Meltemi/Etesian winds that blow in summer. Because I come from the southern hemisphere, I had remembered that the the perihelion occurs in summer, but of course the seasons are reversed in the different hemispheres, and in Greece it occurs in winter. The winds and other astronomical features which Aristotle mentions all occur in summer (Northern hemisphere summer)Aristotle, Meteorology, Book 2, § 5. wrote:Οἱ δ' ἐτησίαι πνέουσι μετὰ τροπὰς καὶ κυνὸς ἐπιτολήν, καὶ οὔτε τηνικαῦτα ὅτε μάλιστα πλησιάζει ὁ ἥλιος, [362a] οὔτε ὅτε πόρρω· καὶ τὰς μὲν ἡμέρας πνέουσι, τὰς δὲ νύκτας παύονται. Αἴτιον δ' ὅτι πλησίον μὲν ὢν φθάνει ξηραίνων πρὶν γενέσθαι τὴν ἀναθυμίασιν·
The major issue is that the eccentricity of the earth's orbit around the sun is only about 5 million kilometers or 3%, and that is a calculation that is much easier to make in a heliocentric conceptualisation than in a geocentric understanding of astronomy because the apparent size of the sun's disk is also varying due to the inclination of the earth and change in season's too, so even if the sun's could be accurately measured (angular distance of 32′ 42′′ at perihelion and 31′ 36′′ at aphelion) - given that Mediterranean winters are wet (i.e. cloudy and the sun's disk can't be seen) the apparent intensity of the sun in a cloudless summer sky.
Some other understandings that I could imagine are:
- Near and far with reference to either horizon, i.e "at dawn" or "at dusk" (or vice versa) when the sun "appears" bigger and by false perspective appears closer and further is further from that point (but actually near the western horizon it also appears bigger and apparently closer), and so is referring to the time of day the wind blows as καὶ τὰς μὲν ἡμέρας πνέουσι, τὰς δὲ νύκτας παύονται does.
- Since Athens at 37°58′N (and more so Pella at 40°48′N) is north of the Tropic of Cancer (~23°27′ N) the sun would never be directly overhead (at its zenith), so it would only "draw near" to an overhead position and then get further away again as as the sun appeared in a more southerly declination, ie the sun would never pass overhead and return again as it would in the topics (cf. subsolar points). In other words it is a reference to an angular measurement getting near to the gravitational perpendicular (it easy and safe enough to measure the angle of the sun from the azimuthal, by fixing a pole in the ground which is straight according to a pumb-bob and then measuring the shadow when the sun is at the point it appears highest in the sky - as it passes the meridian (dead south) - on any given day - solar noon) and then, if needed, use trigonometry to calculate the angle. Near (πλησίον) and far (πόρρω), then are another way of referring to the summer and winter solstices,by measuring them at noon, hence it is similar to the μετὰ τροπὰς (which was measured at dusk - presumably when the sun's disk could be looked at without causing permanent damage to the eye, especially when only looking at the mid-point of the sun's disk - the very last part of the sun to sink below the horizon) that was mentioned earlier. Assuming that the knowledge of astronomy was adapted to the Greek situation from astronomy that had been developed in desert regions (Egypt) where the sun is visible every day, morning, evening, and the stars every night and where the sun does appear perpendicularly overhead at noon some days, this would be an indirect way of saying that the sun does not actually reach the point that we (they) knew happened in countries further to the south, but only drew near to it.
Does anyone with an interest in these types of things have some light they could shed on these phrases πλησιάζει ὁ ἥλιος and πόρρω?