The problem was also taken up by Muslim astronomers, including the illustrious Al Khwarizmi (9th century), Al Battani (9th-10th century), Ibn Yunus
(11th century), and Al Tusi (13th century), and they came up with prediction criteria based on the angle between the moon and the sun in the sky (9 to 11 degrees) on that evening.
His study of metaphysics began when he followed courses taught by the famous Nestorian, Christian translator, and student of Aristotle, Matta ibn Yunus
In the Cairo manuscript, for example, a biography for Ibn Yunus
is incomplete, but it is far longer and essentially complete in fols.
Can we isolate the contribution of Islamic scholars such as Alhazen, who made significant contributions to the principles of optics; Al-Kindi, who discussed the theory of relativity within the scope of physics for the first time; Al-Biruni, who correctly calculated the densities of many minerals and Ibn Yunus
, who invented the pendulum as a timing device and established rules of physics before Galileo from the enlightenment of the West?
or Abu al-Hasan 'Ali bin 'Abd al-Rahman bin Ahmad bin Yunus al-Sadafi al-Misri was a scholar of astronomy who was under the patronage of Caliph al-Hakim of the Fatimid Dynasty in Egypt.
The author mentions scholars such as: "Jabir ibn Haiyan, al-Kindi, al-Khwarizimi, al-Farghani, al-Razi, al-Masudi, al-Tabari, Thabit ibn Qurra, al-Battani, Hunain ibn Ishaq, Abdul-i-Qasim, al-Farabi, Ibrahim ibn Sinan, al-Biruni, Ibn Sina, Ibn Yunus
, al-Karhi, Abdul-i-Wafa, Ali, ibn Abbas, Ibn al-Jazzar, Ibn al-Haitham, Ali ibn Isa, al-Ghazzali, al-Zarqali, and Omar Khayyum" (61) who have contributed significantly to current Western practices and philosophies.
We find excellent scientists such as the mathematician and theologian Kamal al-Din ibn Yunus
and the professors of the legal School of Baghdad, al-Nizamiyyah, among those whom Goldziher classifies among "the orthodox".
The astronomer Ibn Yunus
had waited for over an hour until the first stars could be recognised in the evening twilight.
As a member of the International Astronomical Union's Task Group for Lunar Nomenclature, El Baz proposed naming lunar features after historic Arab scientists, such as astronomer Ibn Yunus
Shaikh Zayed was pleased that the map showed the names of the ancient Arab scientists who were around during the golden era of Islam such as Abu Al Fada, Beruni, Al Battani and Ibn Yunus
and others," he said.
Apart from his appearance in Daftary's overview of hidden Imams and Mandis in Ismaili history, however, he is represented here only by a sixteenth-century picture of the astronomer/astrologer Ibn Yunus
presenting his astronomical tables to the caliph.
See, for instance, Ta'rlkh Ibn Yunus