Al-Zarkali was a Spanish Muslim instrument maker, astrologer and important astronomer. He invented a form of the astrolabe.
Mathematical Profile (Excerpt):
- Before we give some details of al-Zarqali's life, we need to give some background to al-Andalus, Muslim Spain, in which he grew up.
- It was in Córdoba that al-Zarqali grew up.
- It was realised that al-Zarqali was not only expert as an instrument maker, but he was also highly intelligent.
- We should now look at some of al-Zarqali's accomplishments.
- The Spanish Arab Ibrahim ibn Yahya al-Zarqali (Azarquiel) invented a type of astrolabe known in Europe as the azafea (from Arabic al-safiha, plate) ...
- These tables contained much copied from earlier tables such as those by al-Khwarizmi, al-Battani and Ptolemy, but they also contained the observations of al-Zarqali and the other members of Qadi ibn Said's large astronomy group which consisted of both Muslim and Jewish scholars.
- It is claimed that al-Zarqali observed the sun for twenty-five years and the moon for thirty years.
- It is interesting to compare work being carried out in Toledo by al-Zarqali and his group with that being carried out in Esfahan by the group set up there by Omar Khayyam who was about twenty years younger than al-Zarqali.
- Let us look at some other of al-Zarqali's achievements.
- We know from references in other sources that in this book al-Zarqali details the motion of the solar apogee, giving it a motion of 1° in 279 years.
- This is based on an earlier work of the 3rd or 4th century, but has modified data from the observations of al-Zarqali and his colleagues in Toledo.
- Al-Zarqali wrote one work on astrology, the main interest in this work being the magic squares which he used to make talismans.
- It was here that al-Zarqali suggested that the centre of Mercury's epicycle followed an oval shaped path which he described as 'like a pine nut' in his book on the motion of the seven planets written about 1081.
- Barbastro, not far south of the Pyrenees, fell to the Christians in 1063 so the process was going on throughout the time that al-Zarqali led the astronomers of Toledo.
- At this time al-Zarqali fled from Toledo and returned to his home town of Córdoba which was further south and still under Muslim control.
- Córdoba was controlled by al-Mutamid of Seville who supported al-Zarqali for a few years and he was able to continue his observations with the help of one of his students.
- By that time al-Zarqali was no longer supported and it is unlikely that he did any scholarly work during the final ten years of his life.
- A look at the references to this article shows at once that al-Zarqali's name and achievements have continued to be kept alive.
Born 1029, Córdoba, Spain. Died 15 October 1100, Córdoba, Spain.
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Thank you to the contributors under CC BY-SA 4.0!
Adapted from other CC BY-SA 4.0 Sources:
- O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive