Austin Dacey in the Skeptical Inquirer:
Just as soon as anyone notes the dismal state of science in contemporary Muslim-majority countries, someone else with a little knowledge of history will observe that the Islamic world was once the center of the scientific world, and Arabic was once the lingua franca. From the eighth to the end of the fourteenth centuries, the most important work in the fields of mathematics, astronomy, optics, and medicine took place under Muslim rule.
Before Europe’s first university had opened in Bologna, the House of Wisdom in Baghdad was amassing a library that reportedly housed as many as four hundred thousand volumes. There, under the patronage of the Abbasid dynasty, Arabic-speaking scholars—including Persians, Christians, Jews, and others—translated Greek texts by authors such as Aristotle, Plato, Pythagoras, Euclid, Ptolemy, Hippocrates, and Galen, as well as material in Persian, Syriac, and Sanskrit. It was not until the twelfth and thirteenth centuries that this ancient learning came to Europe, primarily by way of Muslim Spain. As late as the seventeenth century, European colleges still relied on the Canon, a medical textbook by Avicenna, the Latinized name of the medieval physician and polymath Ibn Sina.
This Golden Age is rightly held up as one of the glories of Arabic-Islamic civilization. However, it only makes more pointed the question of how Arabic-language science (defined broadly as natural philosophy) came to be so rapidly and totally surpassed by European science.
More here.