Would this magnitude be appropriate for Polaris?

(12-09-2017, 09:18 PM)Helmut Winkler Wrote: You are not allowed to view links. Register or Login to view.... a French transl. of al Sufi is online, You are not allowed to view links. Register or Login to view. and there seem to  be medieval Latin translations of al Sufi

There ia an interesting site, You are not allowed to view links. Register or Login to view. pagina.htm, including Forschungsbibliothek Gotha Pergamenthandschrift M II 141, the Latin text seems similar to the clm-text. Is it Ptolemaios?

I hope there is someone who knows more about these things than I do

The French translation has a table right in the beginning, showing the comparison between magnitudes in Ptolemy and in Al Sufi's catalogue, which is exactly what I was looking for at the time. The differences are minimal. Thanks! That was very helpful.

In general, the site: You are not allowed to view links. Register or Login to view.  is a *great* resource.
The link given by Helmust was corrupted by the presence of a space character: You are not allowed to view links. Register or Login to view.  .

W.r.t. the MS in Gotha, this seems one a several very similar copies of a translation from Greek of Ptolemaios' work, with modifications by Al Sufi.
(This is based on what the web site says).

Another thought. The star map I generated had a rotation of about 35 degrees (I didn't measure it accurately). The rotation of the stars is 1 degree every 71.6 years, so 35 degrees would put it at about 490BC. Ptolemy in AD150 would have a rotation of 26 degrees. 1420 would make it 8 degrees. This assumes the Voynich manuscript and the modern map are lined up along the same principals. Any angular shift could also be explained by differences between the date within the year the maps are made.

Andy

(27-09-2017, 12:27 PM)Andrew Harrington Wrote: You are not allowed to view links. Register or Login to view.Another thought. The star map I generated had a rotation of about 35 degrees (I didn't measure it accurately). The rotation of the stars is 1 degree every 71.6 years, so 35 degrees would put it at about 490BC. Ptolemy in AD150 would have a rotation of 26 degrees. 1420 would make it 8 degrees. This assumes the Voynich manuscript and the modern map are lined up along the same principals. Any angular shift could also be explained by differences between the date within the year the maps are made.

Andy

I wonder if the symbols that look like numbers or a date in the bottom figure of 68r1 might have any bearing.

It's hard to tell what the first two characters are, they are small and filled in (it looks a bit like EVA-ol but could also be 04) followed by 9° 9.


Some time back, I looked up eclipse dates in the 15th century and I think there was one on Sept. 9th, but it was later in the century, not earlier, and the numbers (assuming they are numbers) don't necessarily have to be a date (or the record of an eclipse).

The symbol for degrees (descending from the abbreviation g° = grado/grade) had been in use for some time.

The last word is certainly weird. A bit like someone wrote it at the wrong angle. This is not at all like the words in all the other pictures.

Another thought about the faces at the bottom of 68r1 and the top of 68r2. The crescent shape looks a bit like an equator line on a star map that you get from the tilt of the Earth.

Andy

In these discussions, it is important to remember that the manuscript's manufacture is dated 1405-1438.  

So, to start at the beginning - the first astronomer to classify stars in terms of magnitude was Hipparchus, not Claudius Ptolemy.

Without returning to the primary sources, here's a nice brief modern summary:
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So, in theory at least, stars' being ordered in terms of magnitude -  and that magnitude expressed by number of points for a star - is a practice we might attribute to no later than the last decades of the second century BC., since Hipparchus' dates are c.190-120 BC.

This doesn't mean that Hipparchus was the first person ever to depict stars that way: just the earliest mathematical astronomer to employ the scheme of classification by relative magnitude. 

It is also worth mentioning that the Arabic star-names weren't the first, nor the only names given stars.  Nor were the Romans'.  There is no guarantee at all that these two vocabularies - best known in the Latin world - are those which inform the labels on the Voynich star-maps.

On the brighter side, such a way of depicting sun and moon is attested (as I've shown) in fourteenth and fifteenth-century works produced by chart-makers of the western Mediterranean.  

For more details on that last point, it's probably easiest to give a link to the second in a series of posts  that I published in March last year because there the explanation comes with  comparative material, bibliog. references, cross-reference to other folios and so forth:

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Marco Ponzi did some good work a while ago on the Catalan sphere. I expect that's still visible at Stephen Bax' site where, again, efforts were made to attach the 'Arab' star names consistently to the Voynich labels.

 but to get back to the idea of depicting magnitudes by numbers of points.  

It is important in discussing this to keep three things in mind:

1. the difference between apparent and absolute magnitude.
2. the state of knowledge in wherever-it-was the Vms' images were first enunciated at the time they were first enunciated - quite a big question-mark when the last two remain unknown and more often presumed than investigated.
3. the difference between a technical diagram, a schematic drawing and a work of art.

While it doesn't seem unreasonable to suppose these two Voynich diagrams fall somewhere between the first and the second class of diagram, I have to say that a very great deal of rubbish has been written about imagery in this manuscript from a prevalent but ill-thought-out assumption that the manuscript's drawings were aiming at exact literalness, representation exactly to relative scale and at being a  'scientific' product.  The primary evidence hardly offers support for any one of those contentions, and few have paused to consider and contextualise the reason for that, let alone to explain just what  'scientific' is supposed to mean - and where - before 1440.

As it happens, for these two diagrams, I'd agree that their style of drawing is so closely met by that of chartmakers working in part of the western Mediterranean during the fourteenth- and early fifteenth-centuries that these two were very likely intending to represent apparent relative magnitude, but I would be inclined to believe their informing texts were made centuries earlier - which means that positions for the stars are likely to be 'out' - and all the more so because there is obviously no intention at absolute relative size, or precise relative position.  

I'd suggest the best place to start researching this would be the oldest known globes, and then the later astrolabes, before considering modern sky-charts.

NAMES:  Ptolemy, of course, had never heard of the 'Arab' star-names, any more than had Hipparchus.  Even when one investigates - as I did, of course - the range of variants in name, and in orthography .. even within Latin Europe... to 1440,  that variety is so great that not even the collations by e.g.  Hinkley-Allen or Paul Kunitzsch) get them all.   

In fact, I think we'd be extremely lucky to find the Vms diagrams have 'standard' names or standard forms for those names.  And this even if the intention had been to inscribe 'Arab' star-names.  Has anyone looked into other thirteenth and fourteenth century terms - say, Mongol, or native Egyptian or even the names given by minorities in Latin Europe?  (In another post, while looking into this, I quoted some forms in which star-names occur in a couple of the Latins' mercantile and naval texts).

Note - I have put 'Arab' in quotes because some of these  'Arabic' star-names are simply translations of the Romans' descriptive terms, or translations or transliterations from Greek, and  even from Syriac (e.g. al Gabbar) and in one case from some extremely ancient contact with southern India, for the Arabs used a word for the Pleiades as a lunar mansion ('Thurayya') which originates in ancient Tamil, though so long part of the Arabs' vocabulary that a folk etymology was created for it.

As ever, a good, solid, conservative place to begin this sort of work is Emilie Savage-Smith's Study of Islamicate celestial globes

Hope this helps.

Thankyou Dianne. I'll check out your links. There is so much guesswork on the language side. The Arabic star names don't show definite enough patterns to be clear. Even something obvious like the "o" symbol sounding like "al" is impossible to test properly.
Andrew

There's also an older discussion here: You are not allowed to view links. Register or Login to view.

Andrew -
I should have added links to a couple more:
Polaris id.
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On Ptolemy I'd recommend:

M.J.L. Young, J.D. Latham and R.B. Serjeant, Religion, Learning and science in the 'Abbasid period (CUP 1990).  


Here is the diagram for easy reference: gained from Soler's chart: Here polaris for the North emblem imo; Moon for South;  Spiral-armed sun is emblem  for East .. which I found rather interesting.




Since I've recently moved from 'wordpress.com'... here are a couple of the posts again:
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and as caution on supposing modern star-names and orthography will be those in a fifteenth-century ms.

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Cheers

Thanks Diane.

I am currently looking at what look like constellations on f68v1. The one at the 3 O'Clock position looks very much like Orion. The star in the middle of the row of 3 where the belt would be looks like it has been squashed in, not where I would put a random star. It is possible to get a list of potential constellations based upon this position, going around the sky- Gemini was next at 5 O'Clock

If this is Orion then all the similar diagrams added together show up to 41 potential constellations in total, close to the 44 constellations the Greeks found. I don't think the diagram with 12 sets of stars on it is the zodiac constellations though (67r1) - the order of the stars with lots of arms doesn't match the bright stars in those constellations.

Andrew