It does look like I am wrong about the hour, and that spurred me to make sure there are no other anachronisms here. There are a few, and they imply the VMS was written much later than 1420, probably after the
1620s, and no earlier than 1583.
My concession is that it does look like I'm wrong about the hour. The sidereal hour doesn't get defined until 1765, which is just entirely too late, and it's not the equal hour, that's my mistake. If it's in the VMS, it is a surprising anticipation of the idea, which isn't impossible, but I'm not going to cling to that to avoid saying I was wrong. While the approximation between signs and hours was doubtless known to practitioners using clocks, it wasn't exact, is too course to be used the degree, and isn't attested. It would be unreasonable for to simply extend the unit like this to suit my point.
In a similar way, this turns out not to be a small point, and one I missed the significance of even when I first saw your reply several days ago:
(22-04-2026, 10:32 PM)Jorge_Stolfi Wrote: You are not allowed to view links. Register or Login to view.A small point: it seems that up to the 1600s the solar terms were 24 divisions of the year into equal parts. That is, a solar term was 365.25.../24 days. The defintion was changed to be a division of the Ecliptic itself into 24 equal parts in the 1600s. This makes a small difference: because the orbit of the Earth is not circular, during each 1/24 of the year the sun seems to travel sometimes a bit more, sometime less than 1/24 of the Ecliptic. But those variations are small and the two divisions agree year over year. And note that neither definition depends on what was the unit of angle at the time.
If this is the case, and you do appear to be correct, this means that these do not define geometries and could not be used to find objects. If I'm understanding You are not allowed to view links.
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Login to view. correctly, it was not used to actually find the sun, but rather to
model it, and that's the thing it conceptually finds! That essentially precludes the use you imagine here prior to the Jesuits in the 1620s.
Even if the VMS is proof that someone anticipated the Jesuits redefining the solar terms, it is at odds with all the star charts and instruments that were in use prior to adopting Western methods. Per You are not allowed to view links.
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Quote:In specifying RA, the astronomers of China did not employ a single coordinate origin (such as the vernal equinox). Instead, they measured the positions of celestial bodies eastward from a series of twenty-eight unequally spaced local meridians. These meridians were defined by selected determinative stars (juxing), one in each of the lunar lodges; coordinates measured relative to them were termed ruxiudu (degrees within a lodge). The term xiu came to imply both the asterism itself and the zone of RA it covered. As in the case of north polar distance, RA was expressed in du. The equatorial extension of a particular xiu (the angular separation between the standard meridian of that lodge and the adjacent reference meridian of the next xiu to the east) could range from as small as one or two degrees to some thirty-three degrees.
Chinese astronomers did not find objects by counting degrees around a great circle. That is, this is not "Chinese" practice:
(22-04-2026, 10:32 PM)Jorge_Stolfi Wrote: You are not allowed to view links. Register or Login to view.Maybe the labels are star names, and the label of each of those 1-degree arcs is the name of the star that lies on that meridian, or between two meridians.
If you know your history of Chinese missionaries, you might suspect that I deduced 1583 as a lower bound because that is the year Ricci, who won the Ming court over with his knowledge of astronomy, entered the country, but that is coincidental. It is because of this:
(22-04-2026, 03:37 PM)Jorge_Stolfi Wrote: You are not allowed to view links. Register or Login to view.But then for some reason the Author decided to switch to 30-degree diagrams. Maybe he found that he did not have enough vellum for 24 diagrams. Maybe he wanted to make his Zodiac more compatible with the Western ones. Anyway, he told the Scribe to use that format from then on, using three bands of nymphs instead of two. And he had him go back and do Pisces that way -- before Aries, instead of at the end of the section. (Note that the Chinese 24x15 degree thing starts in February.)
(emphasis mine) This is only true after the Gregorian reforms. For most of the middle ages---I did not care to figure out the exact cutoff, but it is going to be well before the 1420s---the procession of the equinoxes had shifted Lichun into January on the Julian calendar. Unless our scribe is in the missionary period, then the start of the solar term cycle would have been approximately January 25th, give or take. This reading is only possible after Inter gravissimus in 1582.
Now, you may not have to maintain that because the reading of the first degree of the Pisces diagram as Lichun leads pretty quickly to nonsense. While not the critical issue, Lichun is in Aquarius, which implies that the start of the year is listed under the wrong sign. Where you really lose me is that this implies the signs are shifted 15 degrees, which becomes absolutely intolerable when we get to Taurus and Aires. Whole diagrams in the VMS have degrees listed under the wrong Western sign if your interpretation is to be sustained. This is especially egregious if they started with Aires---though, in the interest of intellectual honestly, I don't put much weight on that---because that means they started with the whole thing wrong.
To maintain your reading you must (1) use a defintion of solar terms that went into official use in 1645 (2) requiring tools and charts not in use by Chinese practitioners until the handful of decades before then (3) denominated in degrees that only became current around then. This is supported by (4) the Gregorian Calendar to arrive at (5) a reading of the diagram where the scribe put entire diagrams in the wrong sign. Even if you assume away the 1420 carbon dating and judgements of art historians, there is
a lot of European practice in this "Chinese" theory. And that might be explained by placing it in the missionary period, but that assumes the Jesuits, Europeans, had a profound hand in this.
I have answered this question, if briefly.
(22-04-2026, 10:32 PM)Jorge_Stolfi Wrote: You are not allowed to view links. Register or Login to view.Is there a book from that time that does this -- depicts each sign as a circle divided into 30 sectors (rather than mixed 30/31 days) ?
I'll expand, though you are active on other threads where this has come up recently. You are not allowed to view links.
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Login to view. is the standard identification here. The paranatellonta tradition is a way to get an arbitrary sign first, though not in the presentation style we see in the VMS. It associates degrees with labels, and those labels overwhelmingly have etymologies in stars and constellations. Fitting it to the VMS is not unproblematic, as we do not seem to have a direct source for the diagrams in there (presuming, not trivially, such a thing ever existed) and the Voynichese labels are awfully short at face. Those problems, however, are not the same thing as these identifications not existing.
To summarize, I'd like to go through your conception of the problem. On the 24 parts issue, there is no proposed Chinese unit in the relevant period. Solar terms
did not create 24 arcs prior to the redefinition, which was done later under immense
European influence. On the 15|30 issue, the way you read the diagrams has entire diagrams under the wrong sign and relies on the Gregorian Calendar. I maintain that dividing 30 by 2 is not a profound mathematic operation imbued with automatic significance regardless, but your attempts to find some have resulted in anachronism and contradiction. The 360 names issue inherits the problems of the preceding two points---Chinese astronomical practice doesn't support this approach to finding stars and the shifted diagrams renders it unusable even if you assume a thoroughly Western practice---while also ignoring a tradition in Europe with many of the asked-for features.
So my problem, then, is two-fold. The dating issue is obvious and I won't belabor it; most of these concepts are well after the presumed date of the VMS. But accepting that, I think assuming such a thoroughly Westernized set of astronomical definitions to explain a single "Chinese" concept here looks suspiciously like asserting the VMS describes European practice. This is what I mean when I say Europe is "first among equals". As you've tried to read solar terms off this, a whole knot of European ideas got ported in. The simplest explanation is that the origin for all these European ideas in the VMS is...Europe.
