Astronomy & Observations


 Writing on the Islamic impact in astronomy, Rybka does not fail to make the customary remark how in the history of astronomy little attention is given to the Islamic role in the progress of the science. Pannekoek, for instance, only devotes seven pages to the subject,[1] and the Muslim theory of planetary motion, hardly taking any interest in his work, and even Dreyer is also guilty of some neglect.[2] In both books, Rybka points out, there prevails the same defect observed in most other works, namely that the role of Muslim astronomers was simply to transmit what was found in Ptolemy’s Almagest.[3] Pannekoek, hence, says:

‘The Muslims did not go beyond Ptolemy, and when they did, it was from preference to Aristotle.’[4]


‘There was a brilliant rise in Arabian astronomy, but no significant progress. After some centuries it died down.’[5]

Then, the same author concludes his short outline on Muslim astronomy, saying that:

‘Arabian scientists certainly observed diligently; they constructed new instruments, and in astronomy they seem to have displayed more practical activity than did the Greeks. Also the accuracy of their work often surpasses the results of Antiquity. Their aim, however, was not to further the progress of science-this idea was lacking throughout-but to continue and to verify the work of their predecessors.’[6]

This view is shared by the overwhelming majority of historians, such as Duhem, in whose words:

‘The revelations of Greek thought on the nature of the exterior world ended with the ‘‘Almagest,'' (by Ptolemy) which appeared about A.D. 145, and then began the decline of ancient learning. Those of its works that escaped the fires kindled by Mohammedan warriors were subjected to the barren interpretations of Mussulman commentators and, like parched seed, awaited the time when Latin  Christianity would furnish a favourable soil in which they could once more flourish and bring forth fruit.’[7]

A view shared by Perroy:

‘All or nearly all (Muslim astronomers), follow the practice of plagiarism of the Middle Ages, inspiring themselves for more than half of the works of Ptolemy, whose text they copied.’[8]

Dreyer tells us:

‘Though Europe owes a debt of gratitude to the Arabs for keeping alive the flame of science for many centuries and for taking observations, some of which are still of value, it cannot be denied that they left astronomy much as they found it.’[9]


‘When the Europeans again began to occupy themselves with sciences, they found astronomy practically in the same state in which Ptolemy had left it in the second century.’[10]


This view is common to the overwhelming majority of writing on the history of astronomy.[11] But there is even worse than this, i.e when Islamic astronomy is completely blotted out. J.P. Verdet, for instance, in a History of astronomy, jumps from Ptolemy to Copernicus, skipping nearly 1500 years.[12]      And so does Neugebauer in his Astronomy and History.[13]


These views, however, are wholly contradicted by history as seen in the following outline.



1. Islamic Astronomy: Inanities of Historical Writing:


First and foremost, Islamic astronomy is not a replica of Greek astronomy, nor was it stimulated in its rise by Greek astronomy. The Greek legacy in this field, as in all other sciences, was only a tool for the Muslims, a tool as good and as limited as others, the Hindu, the Chinese, the African, the Roman, and the pre-Islamic, which all acted as means (tools) for the Islamic civilisation. The Chinese source, rather than the Greek, in fact, played a much greater part than any other in the thriving Islamic civilisation. This has already been partly seen in the first part of this book, and the chapters on the diverse sciences, in this part, will confirm this point. The following will also confirm, and highlight that the foundation of Islamic science, the real inspiration, comes not from Greece but from the faith, i.e Islam. The final part of this work will make this point abundantly clear. But here, in relation to the subject of astronomy, it is worth beginning by showing how faith inspired the rise of Islamic astronomy.

[1] A. Pannekoek: A History of Astronomy (George Allen and Unwin Ltd; London; 1961).

[2] E. Rybka: Mouvement des Planetes dans l’Astronomie des Peuples de l’Islam; in Convegno; op cit; pp. 579-93;  at p. 579.

[3] Ibid.

[4] A. Pannekoek: A History of Astronomy; op cit; p.  170.

[5] Ibid.

[6] Ibid; p.169.

[7] P. Duhem: Medieval Physics, in R. Palter edition: Toward Modern Science (The Noonday Press; New York; 1961), Vol 1;  pp 141-159; Quote at p. 141; This article is a reprint from ‘Physics, history of,'' Catholic Encyclopaedia, XII (1911), pp 47-52.

[8] E. Perroy: Encore Mahomet et Charlemagne in Bedeutung; op cit; pp. 266-75, at p.271.

[9] J.L.E. Dreyer: A History of Astronomy from Thales to Kepler (Dover Publications Inc, New York, 1953), p.249.

[10] Ibid; p.279-80.

[11] Such as in:

- O. Pedersen: Early Physics and Astronomy (Cambridge University Press, 1974).

-J. Delambre: Histoire de l'Astronomie Ancienne (Johnson Reprint Collection; New York, 1965).

-Or many Websites as seen in the late 1990s, such as at:

[12]  J. P. Verdet: Une Histoire de l'Astronomie (Le Seuil, Paris, 1990).

[13] O. Neugebauer: Astronomy and History (Verlag, 1983).

Astrolabes, Spherical astrolabe, Quadrant


The Role of Islam in the Rise of Astronomy

 Hoskin and Gingerich provide a good introductory section on Islamic astronomy in one of their latest works.[1] In a five or so pages, they detail how observation of the faith confronted Muslims with problems they had to resolve, which led to their developing aspects of mathematical astronomy to resolve such problems.

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Greek Vs Islamic Astronomy
 The assertion that Islamic astronomy is a mere reproduction of Greek astronomy is groundless as this chapter will abundantly show. Briefly are considered here some fundamental differences between Islamic and Greek astronomy.
First, Muslim astronomers dealt with a considerable number of subjects Ptolemy never addressed or contemplated, or could even address or contemplate, all subjects, which are today the realm of modern astronomy.

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The Accomplishments of Muslim Astronomy at a Glance
 Astronomy was one of the earliest sciences to thrive in Islam. In the 8th century, Al-Fazari (d.777) became the first to construct astrolabes. The astrolabe was a multi functional instrument that served for nearly ten centuries to make all sorts of calculations. Al-Fazari also wrote on the armillary sphere, and the calendar.[1] Soon after, Mash’allah (d.815) took part with the Persian al-Naubakht in the preliminary surveying of the foundation of Baghdad in 762-763. His De Mercibus, is the oldest scientific work in Arabic,[2] and was translated by Gerard of Cremona in the 12th century.

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 The use of instruments made it possible to reach precise calculations, and also resolve first hand astronomical problems. Precision, from the early stages of Islamic civilisation occupying the highest concern of Islamic scholars. Thabit Ibn Qurra (b.826), for instance, stated that pure Greek reasoning cannot always match observation in accuracy, declaring ‘What is perceived by sense does not lend itself to such precision.'

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 The established wisdom holds that observatories are a late invention of Europe. Those who recognise the Islamic origins of observatories, still consider them a late and a short-lived institution. Here follows evidence proving both positions wrong.

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Transfer of Muslim Astronomy to the Christian West
 The home of Muslim astronomy in Europe, of course, was Spain. It was from Spain, that the early treatises on the astrolabe travelled North of the Pyrenees in the late 10th century following exchanges between Lorraine and Muslim Spain. John, Abbot, of Gorze (in Lorraine) travelled to Spain as a result of exchanges between Abd Errahman III, caliph of Cordoba, and the German emperor Otto the Great during the years 970-74.

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      The Deferent and the Ecliptic