This is a First Draft …
Our interest here is in the scientific developments that
took place in the Islamic world. We will
look at a few of the most famous of the Islamic scientists, and only mention
very briefly the political context in each case: the spread of Islam over much
of the known world, and the subsequent political changes, were very
complex. For example, after
Omar Khayyam was
born in Nishapur, in present-day northeastern
His main contribution to that subject is a serious attack on cubic equations, such as finding x given that 2x3 – 2x2 + 2x – 1 = 0. This particular problem has a geometric origin:
Given that for the right-angled triangle shown, the sum of the height and the shortest side is equal to the hypotenuse, find the ratio of the length of the shortest side to that of the other side.
Later Malik Shah, the third Seljuk sultan, and his Persian
vizier al-Mulk, invited Khayyam to head up his observatory in
Unfortunately for Khayyam, his friend the vizier was
murdered by a terrorist group, the Assassins, who specifically targeted
important political figures, on the road to
Omak Khayyam is also famous for his writings, such as the Rubaiyat. However, these have a distinctly irreligious flavor, and he had to tread carefully to minimize trouble with the Muslim religious authorities.
Note: many of the above facts are from the St Andrew’s website.
Nasir al-Din al-Tusi was born in Tus, in northwest
He studies as a child at a mainly Shia religious school in Tus, followed by secondary education in Nishapur. However, around 1220, the Mongols invaded the area, causing much destruction. Al-Tusi found refuge with the Assassins in their mountain fortress at Alamut :
It isn’t clear whether or not al-Tusi was actually a prisoner, but it is clear that he did some important scholarly work in this relatively quiet environment, writing on astronomy, mathematics, philosophy and ethics.
Nevertheless, when the Mongols, led by Ghengis Khan’s grandson Hulagu (pictured below), took Alamut in 1256, al-Tusi switched sides, and the Mongols appointed him their scientific advisor.
Al-Tusi was with the Mongols when they attacked
After Hulagu destroyed
Al-Tusi himself developed plane and spherical trigonometry and wrote the first complete book on the subject. He also made the first really significant advance on Ptolemy’s Almagest. Although Ptolemy’s work described the planetary motions well, it contained some aesthetically unappealing features—it had strayed far from Plato’s long ago suggestion that all should be described in terms of combinations of circular motions. In particular, accounting for the lack of coplanarity of planetary orbits required what amounted to an up-and-down linear component in planetary motion. Perhaps al-Tusi’s most famous achievement was to demonstrate how such motion could be generated by a combination of two circular motions, see the animation at Tusi couple!
Here’s his original explanation, from a Vatican exhibit: