|Istanbul's astronomers at work, with just two western instruments - a world, or maybe celestial, globe (front center) and a carriage-clock (middle far right).
The main-man is Taqi al-Din ibn Muhammad ibn Ma'ruf, the Director of Istanbul Observatory. He's one of the two senior astronomers (wearing largest turbans) standing behind the table, one holding the astrolabe, an early analog computer, in which they are clearly interested.
Just to confuse us, western Assyriologists also refer to Mesopotamian constellation-lists - i.e. text documents - as `astrolabes'.
That seems a bit silly.
The astrolabe's origin is mysterious, probably well before 400 CE, maybe in the Arab / Persian world, which inherited both genius and records from the Babylonians and the ancient Greeks.
Like the Antikythera Mechanism
Wiki ref, a working video, & project updates.
The astrolabe computer can solve celestial navigation problems, including checking the `time'.
"Abu Abdullah Mohammed ibn Musa al-Khwarizmi al-Magusa was possibly the most influential of the intellectually adaptive Arab mathematicians at a time when the Europeans were trapped in a primitive fundamentalism, with its resulting intolerance and persecution of secular knowledge" - `Number'
Analysis of the family name shows original home of Al-Khwarizmi's family was Khorezm (ancient Persia), and that an ancestor had been a Magus - a scientist / priest, follower of Zoroaster.
Al-Khwarizmi came to study and teach in Baghdad's `House of Wisdom' or Bayt al-Hikma - a research center founded by the Khalif al-Mamun (son of Harun al-Raschid of `Arabian Nights' fame).
His studies produced the work on arithmetic which introduced `Arabic' numbers to the West, along with first use of a `zero' sign, without which no useful maths could evolve. The version seen by Westerners was in translation, and began with "Dixit Algorismi..." or "Thus said al-Khwarizmi"
Which was how many westerners came to believe that `Algorismi' was some great Prince or Magician who had `decreed' methods of calculation. Later that word changed to "algorithm" and came to mean `a routine used to solve a particular problem', as we do now when adding, subtracting, multiplying and dividing.
For about three hundred years Western bankers (usurers), traders and accountants clung to the Greek and Roman `letters used as numbers' system; maybe because it was harder for uneducated people to understand or work out - so giving the usurers more power to cheat.
Eventually our familiar nine `Arabic' numbers (and the zero sign) won out. Al-Khwarizmi however referred to the numbers as `Hindi', since they'd been imported from India originally.
Al-Khwarizmi also wrote "A Brief account of the Methods of al-Jabr and of al-Muqabala" which showed us ignorant Westerners how to do "Algebra".
[ Al-jabr = `transformations` ]
Abu Yousuf Yaqub Ibn Ishaq al-Kindi was born at Kufa around 800 C.E. and worked as an all-round scientist and philosopher at the `House of Wisdom', latterly during the rule of Khalif al-Mutawakkil, who once, angered by al-Kindi's impartial views, "confiscated all his books". These were, however, returned later.
Al-Kindi was a complete natural philosopher, that is to say - mathematician, physicist, astronomer, physician, geographer and an expert in music. He made original contributions in all of these fields. On account of this he became known as `The Philosopher of the Arabs'.
In mathematics, he wrote on the number system and laid the foundation of a large part of modern arithmetic. The Arabic system of numerals was largely developed by al-Khwarizmi, but al-Kindi also made rich contributions to it. His work in spherical geometry assisted him in astronomical studies.
In chemistry, he opposed the idea that base metals can be converted to precious metals - which the West carried on believing for many centuries. He was also the first recorded physician to try determining efficient dosage rates of medicines for individuals.
In physics, he made original discoveries in geometrical optics and wrote a book on it which was later relied upon and much used by Roger Bacon (13th Cent.).
Al-Kindi's `Theory of Universal Radiation' contradicted the Greek idea of vision being caused by a "ray" emitted by the eye. He really foretold the "light quantum" - the photon.
His studies and discoveries were wide: the total number of books written by him was 241, most prominent being these - Astronomy 16, Arithmetic 11, Geometry 32, Medicine 22, Physics 12, Philosophy 22, Logic 9, Psychology 5, Music 7.
He was known as Alkindus in Latin - some of his books translated into Latin during the Middle Ages were "Risalah dar Tanjim", "Ikhtiyarat al-Ayyam", "Ilahyat-e-Aristu", "al-Mosiqa", "Mad-o-Jazr", and "Aduiyah Murakkaba".
Gheyas ad-Din Abu al-Fath Omar Khayyam was a scholar who wandered from one observatory to another. He worked thus in Samarkand, Isfahan, Rey, Merv and elsewhere in Central Asia.
He also studied and wrote of Euclid's works, and formulated mathematical treatises. But his main work was astronomy; he reformed the Arabic calendar and drew up - using his own and Babylonian observations - astronomical tables so precise that smallest error could occur only once in 5,000 years.
He eventually became court astronomer to Sultan Alp Arslan, at Nishapur (Khayyami's own birthplace - in modern Iran). His mathematical work reformed many primitive Greek `rules' and he more than quadrupled the equations solvable by al-Khwarizmi's books.
However, most of us remember him for his `Rubai'yat' - his poetry, where he gently - and bravely, given the setting - affirmed the greatest gifts to men were the love of a woman, and the intellectual release found in wine, which he expressed with -
"I often wonder what the Vintners buy, One half so precious as the Goods they sell."
The `Rubaiyat' is published by Shahriar Shahriari at www.okonlife.com/poems/index.htm and links.
`Rubai' is a four line verse: where lines 1 & 2 speaks of major and minor accepted `truths', line 3 states a dilemma, contradiction or conclusion, and line 4 confirms or re-asserts the conclusion, with emphasis
The dawn is here; arise my lovely one,
Pour the wine, but slowly, and touch the lute,
For those who are here will not stay long,
While those departed never will return
The Moving Finger writes, and, having writ,
Moves on : nor all thy Piety nor Wit
Shall lure it back to cancel half a Line,
Nor all thy Tears wash out a Word of it
The grass that grows by every stream,
Like angelic smiles faintly gleam
Step gently, cause it not to scream
For it has grown from a lover's dream
A Book of Verses underneath the Bough,
A Jug of Wine, a Loaf of Bread - and Thou
Beside me singing in the Wilderness --
Oh, Wilderness were Paradise enow!
Myself when young did eagerly frequent
Doctor and Saint, and heard great Argument
About it and about: but evermore
Came out by the same Door as in I went
While the Rose blows along the River Brink,
With old Khayyam the Ruby Vintage drink:
And when the Angel with his darker Draught
Draws up to thee -- take that, and do not shrink
There was a Door to which I found no Key:
There was a Veil through which I could not see:
Some little Talk awhile of Me and Thee
There seemed -- and then no more of Thee and Me
One Moment in Annihilation's Waste,
One moment, of the Well of Life to taste --
The Stars are setting, and the Caravan
Starts for the dawn of Nothing -- Oh, make haste!
Think, in this batter'd Caravanserai
Whose Portals are alternate Night and Day,
How Sultan after Sultan with his Pomp
Abode his destined Hour, and went his way
If he was around today he'd probably say - like bikers do - "Keep the Faith"
Quote 1 - from `Islamic Astronomy' by David A King - `Astronomy before the Telescope' - 1996 British Museum Press ISBN 0-7141-2733-7.
Quote 2 - from `Number - from ancient civilizations to the computer' 1991 ISBN 0-00-654484-3 by Professor John McCleish, who added - "Although the Arabs were ferocious in war, in peace their life-style was tolerant and civilized. They brought to the arts, and to science in particular, a no-nonsense practicality which rescued intellectual activity from Greek frivolity and Roman intolerance and which continues to permeate scientific study to this day. ... More than any other investigators, in any other culture before them, they exploited the test of practice and experiment in the quest for scientific truth."
Professor McCleish's background to Arab science, however, when McLeish writes `Arab', he usually means `Arab / Persian'.