1

• Source: "A cursory review of Muslim Observatories", Salah Zaimeche, August 2002, pub #4020.
• Problem 1: Zaimeche writes:

  Early in the ninth century, on the orders of Caliph Al-Mamun (813-833), Muslim astronomers had also measured the earth's circumference...That was six hundred years before in Europe it was admitted the planet was not flat.

  This is inaccurate because knowledge of the Earth's sphericity persisted in Europe throughout the Middle Ages, at least among the intelligentsia. For example, Bede, in the 8th century, writes: "The reason why the same [calendar] days are of unequal length is the roundness of the Earth, for not without reason is it called "the orb of the world" on the pages of Holy Scripture and of ordinary literature. It is, in fact, a sphere set in the middle of the whole universe." (§32, De temporum ratione; translated on p. 91 of Bede: The Reckoning of Time, translated by Faith Wallis, Liverpool University Press, 1999.) The current version of our Flat Earth article ([1]) cites many other European authors who were aware of the Earth's sphericity at various points throughout the Middle Ages.
• Problem 2: Zaimeche writes, in reference to Al-Battani:

  He also worked on the timing of the new moons, the length of the solar and sideral year, the prediction of eclipses, and the phenomenon of parallax, carrying us `to the verge of relativity and the space age,' Wickens asserts.

  The problem here is that the source being quoted (G. M. Wickens, "The Middle East as a world centre of science and medicine, Introduction to Islamic Civilization, ed. by R. M. Savory, Cambridge University Press, 1976, pp. 111-118) does not say what Zaimeche claims it says. Wickens writes:

  Battānī worked on such matters as the timing of new moons, the length of the solar and the sidereal year, the prediction of eclipses, and the phenomenon of parallax. The latter is of fundamental concern for astronomers; it also brings us to the verge of relativity and the space-age.

  So, Wickens writes that parallax is what brings us to the verge of relativity and the space-age (not, as Zaimeche says, al-Battani.)

2

• Source: "Anaesthesia 1000 Years Ago (I)", Adnan A. Al-Mazrooa and Rabie E. Abdel-Halim. The authors write:

  The medicinal remedies reported by Dioscorides are thus of Islamic origin.

  This is impossible as Dioscorides wrote in the 1st century AD.

3

• Source: "The Astronomical Clock of Taqi Al-Din: Virtual Reconstruction", Salim T. S. Al-Hassani.

The author writes:

The evidence so far shows that Peter Heinlein might have been the first person to achieve a spring powered watch in 1524, he managed to incorporate the spring into his clock in 1556, while the first spring powered watch did not appear in England until 1580.

The implication is that spring-powered clocks did not appear until the 1500s. This is not correct as this technology had been developed by the middle of the 1400s:

As the "Burgundy clock" in the Germanische Nationalmuseum in Nuremberg shows, the technology of spring-drive cum fusee had been perfected by around 1430. As long as this drive for clocks was still a rare novelty, it is recognizable in the texts from the added comment "without weights." For example, in 1459 the French king had five clocks built, among them one "demi orloge doré de fin or sans contre poix."

(from History of the Hour, Gerhard Dohrn-van Rossum, University of Chicago Press, 1996, ISBN 0226155110, p. 121)

4

• Source: front page, as of 15-X-2010.
• Quote: sidebar says: "What is Taught: Snell is credited with the laws of reflection and refraction. However, Ibn Al-Haitham discovered the same phenomena in the 11th century." (The sidebar changes randomly upon reloading the page, so it may take a few tries before this comes up.)
• Comment: The phenomena of reflection and refraction are not the same as their laws. The phenomena were known to Ptolemy, who wrote about them in his treatise on optics (translated e.g. in Trans. Amer. Phil. Soc. 86, #2.) Ptolemy also gives the law of reflection, that is, that the angle of incidence equals the angle of reflection (III.3; p. 131 in the translation mentioned previously.) Therefore, these discoveries predate Ibn Al-Haytham. Ibn Al-Haytham also did not discover Snell's law of refraction (see A. I. Sabra, Isis 85, #4, pp. 685-686.) [According to R. Rashed, Snell's law was found by Abū Saʿd al-ʿAlāʾ ibn Sahl, although the Sabra piece I just mentioned calls this into question.]

5

• Source: front page, as of 15-X-2010.
• Quote: sidebar says: "In the Fort Nelson Museum a huge bronze cannon sits in the court yard. Cast in two peices in 1464 by the order of the Sultan Mehmed II, no such split guns existed in Europe before then. How did it end up in London? And why is it so unique?" (Again, the sidebar is randomized, so this might not appear upon first loading the page.)
• Comment: The sidebar is referring to the Dardanelles Gun. According to our current version [2] of the Wikipedia article Grose Bochse, the Grose Bochse was cast earlier, in 1408, and was also a several-piece gun. (I have not verified this Wikipedia article against its cited source.)