Omar Ibn Khayyam, the prominent Iranian Muslim mathematician, astronomer, philosopher, and poet

Compiled by: Syed Ali Shahbaz
On 18th of the Islamic month of Zil-Qa'dah in 439 AH, the prominent Iranian Muslim mathematician, astronomer, philosopher, and poet, Ghiyas od-Din Omar Ibn Ibrahim Khayyam, was born in Nishapour, Khorasan, in northeastern Iran. He studied in Balkh, Samarqand and Bukhara, before joining the court of the Seljuq ruler, Malik Shah, as scientific advisor.
He set up an observatory in his hometown and led work on compiling astronomical tables. To him goes the credit of reforming the solar hijri calendar on the basis of the Spring Equinox, which is still in use in Iran, Afghanistan, Tajikistan, and parts of Central Asia, the Caucasus, Iraq, Anatolia, and the Subcontinent. This calendar, known as Jalali, is more perfect than the Gregorian Christian calendar that was imposed on Muslim countries by the colonialists after World War 1.
Among Khayyam's works, his book on algebra was until the last century taught as textbook in Iran. In geometry, he reformed the generalities of Euclid and contributed to the theory of parallel lines.
His contributions to other fields of science included developing methods for the accurate determination of specific gravity. He is known to English-speaking readers for his "quatrains" (Rubaiyyaat), whose English translation was published in 1859 by Edward Fitzgerald, although in the Islamic east he remains the astronomer and mathematician that he was, rather than a poet, since whatever he composed of poetry were casual expressions during his rare leisure hours after strenuous scientific studies and experiments.
He died at the age of 85 and was buried in his native Nishapour in the courtyard of the shrine of Imamzadah Mahruq, a descendant of Prophet Mohammad (SAWA).