πλησιάζει ὁ ἥλιος - perihelion or mid-summer? (so for πόρρω)

Greek Learning Greek
1

This is a question about the interpretation of an idea in

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)

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.

I personally believe (= suspect) that in forming his images to describe weather, Aristotle is thinking of (using languages and imagery) something along the lines of clothes drying in front of a hearth here in this passgae, where the closer they are to the fire, the quicker they dry and an observer can see ἀναθυμίασις columns of envapoured air rising from them.

Does anyone with an interest in these types of things have some light they could shed on these phrases πλησιάζει ὁ ἥλιος and πόρρω?

2

Doesn’t μετὰ τροπὰς καὶ κυνὸς ἐπιτολήν mean “after the solstice and the rising of Sirius”?

τροπαὶ ἠελίοιο means “solstice”:

http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Dtroph%2F

κυνὸς ἐπιτολήν – usually a mention of the “rising” of a star in antiquity refers to the heliacal rising, i.e., the earliest date after conjunction on which the star becomes visible immediately before dawn. Sirius’ heliacal rising in antiquity was in July or August, I think (it differed from our epoch on account of precession).

3

Those two are easy enough to find in reference works, yes. I’ve mentioned my thoughts on those issues (similar to yours Qimmik) in the other forum. What I hope to find is help with this πλησιάζει ὁ ἥλιος, which is not so clear to me at this stage.

4

They don’t blow either when the sun’s at its closest nor when it’s far off. Without more specification I’d assume this means closest to the earth … Or doesn’t this square with the astronomical indicators?

5

In case it is difficult to view the post in question, here it is quoted in full with the questionable section in red…

6

Closest by declination (seasons - axial tilt) or by orbital eccentricity (the earth’s orbit is a slightly off-centre ellipse)? The other issue is when was the eccentricity of the earth’s orbit discovered - before or after the earth was thought of as orbiting the sun.

7

When it looks bigger.

I don’t see why you take this as implying heliocentrism.

Perhaps it would be worthwhile looking into the state of astronomy in Aristotle’s time.

8

Aside from all the praise he receives, Aristotle is noted for two negative things in the history of science - maintaining a geocentric view of the world, and that heavier objects drop faster than light ones.

The sun is physically (5 million kilometres) closer to the earth on the 3rd of January than it is on the 4th of July each year. But that is not easy to measure in a geocentric world because it involves measuring the diameter of the sun’s disk and triangulation.

To the naked eye, the sun is not going to physically look bigger than it did 6 moths ago, if that could be remembered. In Chinese they say something like 太阳很大 sun-very-big to mean “strong” - usually on the hottest days in summer. It could be something like that here - like proximity to the hearth.

Does anyone know when the concept of perihelion and aphelion was even discovered??

9

Kepler was the first to discover the elliptical shape of the planetary orbits (and that was only because of the more accurate measurements that Tycho achieved with specially built equipment). Even Copernicus conceived of the orbits as concentric circles.

http://en.wikipedia.org/wiki/Nicolaus_Copernicus#mediaviewer/File:Copernican_heliocentrism_theory_diagram.svg

Ancient Greek astronomy had the planets moving on epicycles around circular orbits to account for apparent “retrograde” motion, but this would not have affected the apparent motion of the sun.

10

οὐδεὶς τέλειός ἐστιν. :laughing:

χαῖρε, φίλε Στέφανε ὁ ἑκηβόλος! γράφε ἡμῖν Ἑλληνιστι! θέλομον γὰρ ἀναγιγνώκειν τοὺς λόγους σου τοὺς Ἑλληνικούς! γράφε οὖν ὧδε, παρακαλῶ.

http://discourse.textkit.com/t/topic/12938/1

ἔρρωσο, φίλε!

11

Given his geocentric conception of the “solar” system, you would expect Aristotle to think in terms of the sun’s perigee, not the perihelion. The word περίγειον does indeed occur, but it seems to relate to the moon, not to the sun.

http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Dperi%2Fgeios

I couldn’t find a word for perihelion in LSJ–I would expect this to have been coined by analogy to perigee post-Kepler.

Not much later than Aristotle, Aristarchus, who correctly thought (among other things) that the solar system was heliocentric, was apparently able to measure the apparent diameter of the sun:

http://en.wikipedia.org/wiki/Aristarchus_of_Samos

Aristotle might have had some idea of the tilt of the earth’s axis in relation to the sun–or rather, in the geocentric view, the tilt of the sun’s axis in relation to the earth–from the ecliptic, which doesn’t circle around the celestial equator. Perhaps this gave rise to the idea that the distance to the sun varied throughout the year the northern and southern hemispheres.

12

To me it seems almost certain that when Aristotle talks about the sun being “near” and “far,” he simply means summer and winter. From the northern hemisphere perspective, the sun is “near” (πλησιάζει) in summer (i.e. nearly overhead), and “far away” in the winter (i.e., low on the southern horizon).

So basically, ἑκηβόλος, I think your second paragraph under “Some other understandings…” is the correct one, but there’s no need to get nearly so technical as measuring the precise latitude of cities. Basically you just have to go out under the sky and look! That is, assuming that you’re in roughly the same part of the world as Aristotle was. It’s quite possible that you’re initial southern hemisphere perspective caused you to over-think things.

13

So far as I can imagine it in a geocentric way of looking at thigs, the observable phenomena would be changing “portals” for the sun’s settings (and risings) throughout the year. Presumably that meant (perhaps) equally spaced markers some distance from a known observation point looking to the west (or east).

That, then, would be Aristotle expressing it in layman’s terms. (Just as “42” was the simple answer that not even Deep-Thought (in my case Over-Thought) could explain, so just as they needed some real experience in the world to understand the meaning of life, the universe and everything, you’re suggesting that I also need to step outside and simply look at the sun :laughing: :laughing: ).

Τriantafyllides gives a Latin etymology for the Modern Greek περιήλιο, rather than explaining it as simply analogous, though the mechanical construction of the word was probably by analogy.

14

χαῖρε Mark. Well, you and I both know that I could have composed this thread in Greek, but that might impede the discussion that did follow it (in English), rather than foster it. It was a point that is technical and difficult to understand even in English. (And at present my office computer can’t type Greek).

Discussing the Bible has its place in life, but I prefer discussing my day to day life in Greek, as you have noticed by the quantity of extra-biblical vocabulary that I bring into my discussions on the other forum.

While I am improving my technical vocabulary, I still need to keep a hold of my basic vocabulary and more importantly my fluency. I hope that relating to my daily life in Greek will improve or at least let me retain my very basic ability in the language. Any suggestions?

I dream of making U-tubes about my life in Nanchang like you did about your city (we have hamburgers here too). I’m working on on building up the words for that, which is going well. However, unlike you, I always mumble along in Greek rather than enunciating clearly, and don’t have that star-like visage :sunglasses: in front of the camera that you do :cry: .

15

I have corrected that detail of my post on B-Greek and acknowledged some of the contributions made to this discussion here (which indirectly contribute to the discussion there).

16

Great discussion everyone! And, I don’t want to belabor it, but I think we can still get an even clearer picture of what Aristotle was describing:

Aristotle probably didn’t think he was “expressing it in layman’s terms.” He was using normal terminology based on his mental picture of the universe. The thing to remember is, ancient people always thought about seasons in terms of the sun’s yearly passage around the ecliptic, through the signs of the zodiac. This was not something abstract; you could observe it in the sky every night if you wanted to. So for instance, if I go out tonight (in mid-northern latitudes), I will see that the sun is setting due west. When it gets dark enough, I will see Libra low in the southwest; Scorpius to its left; and Sagittarius due south. From night to night, all these signs will gradually shift toward the right (as I’m facing south): a month from now, Libra will be gone, Scorpius low in the southwest, Sagittarius and Capricornus due south. So it’s plain to see that the sun is moving through the signs; a month from now, I will know that it’s in Libra; in December it will have reached Sagittarius. I’ll be able to confirm this in the daytime: at noon in December, the sun will be low in the south, in the exact same position where Sagittarius is now.

Ancient people could also plainly see that ecliptic is at an angle relative to the celestial equator. Some of the signs come high overhead (at mid-northern latitudes); others sweep far away toward the south - toward mysterious unknown lands. Because it’s important to remember that for ancient Greeks, the “Southern Hemisphere” was just a hypothetical construct, like hyperspace or dark matter are for us today; no Greek, as far as we know, had ever been there. You couldn’t get past the burning sands of Libya; some Phoenicians had sailed down the Red Sea coast, but eventually reached savage tribes, jungles, and more impassible deserts.

So when Aristotle talks about the sun being near, he’s thinking about its passage up through Taurus and Gemini into Cancer, where (in his time) it had its τροπή, or turning point, before heading back south. From his perspective, those signs were “near.” Sagittarius and Capricornus were far away, over hypothetical “antipodes” or lands that no one could ever visit; there would be no point in describing the seasons from their vantage point, any more than we would bother talking about the Earth’s current position in the sky as seen from Mars.

One last point: in a discussion like this, even the terms “geocentric” and “heliocentric” can be a little bit misleading. When we use those terms, both of them conjure up an image like we see in textbooks: the earth as a round ball, with the sun in somewhere nearby - all as viewed from some external vantage point. But for ancient people, there was no external vantage point. They saw the universe as they actually saw it, from the earth, looking up at the sky. A scholar like Aristotle could, I’m sure, abstract himself and picture the model from some other vantage point if he really wanted to. But normally, when he talked and wrote about it, he would have seen it from the perspective of everyday life.

17

Damoetas is surely right–Arisotle thought of the sun as “closer” when its daily journey through the sky was highest as it moved along the ecliptic, since that’s when the sun was hottest, and as “further” in winter when it sank lower into the southern sky. What still puzzles me is that apparently the Etesian winds blow from May to September, which would include the summer solstice, according to this:

http://en.wikipedia.org/wiki/Etesian

18

One person’s “belabouring” is another person’s exhaustive inquiry.

A passage that follow the one that started this discussion goes on to say:

Which states clearly that the winds were northerly.

Here are some weather data (and pertinent for this discussion some wind data) for Athens:

That duration of the “warm season” more-or-less corresponds to Aristotle’s description of the winds.

Wind speed and direction are both given in (averaged) detail at the bottom of that same page. From July to September the wind direction is NE or N - those dates with the wind in those directions are more or less the same period too.

Those are a little different from the data given for Skyros (an island NE of Athens) where there is not the same sharp rise in wind speed that we saw on the graph for Athens during the “warm period”. The weather data for Thessalonica (a city founded a relatively short distance from Pella, the Ancient Macedonian capital where Aristotle was for a while as tutor), there is no particularly distinct wind from the North at that time, though the dates of strong wind in that area match those noted in the Wiki article you mentioned.

In short, it seems that the weather pattern described in Aristotle here matches only the local situation in Athens, while the Wiki article is covering / talking about a much broader phenomenon in the Aegean Basin.