Mathematician, astronomer, philosopher, poet (B. Nishapur, / Persia, 18th May 1048 – D. Nishapur 4th December 1131) He was a well-known mathematician, scholar and poet from Persia under the Seljuk rule. Even though available knowledge about his life is not reliable, the importance of those sources should not be underestimated. Omer Khayyam’s full name was Giyaseddin Ebu'l Feth Bin İbrahim El Hayyam and he was the son of a tentmaker. His byname, meaning tentmaker, was derived from his father’s profession. His family was from the Town of Nishapur or from its vicinity. He was already famous as mathematician when he was invited, by Malik-Shah I, to work together with Abu el-Muzaffar İsfizâri and Maymûn b. Nacib el Vâsiti in readjustment of Persian Calendar in 1074-75. He was regarded as the greatest polymath of the East after Avicenna while he was still alive. It was said that Omar Khayyam, who had important works on medicine, physics, astronomy, algebra, geometry, higher mathematics and poetry, knew all the learning of his time. Unlike everyone, he didn’t put down most of his works on paper, yet he was the real inventor of the most of theorems we heard of today.
After he completed his education, he wrote Cebir Risaliyesi (al-Cebir) and Rubaiyat, which brought his reputation up to today, in Samarkand. Three famous people of that era, Nizam al-Mulk, Hasan-i Sabbah and Omer Khayyam came together in that city. Malik-Shah I, the Padishah of that era, trusted his vizier Nizam al-Mulk , whose name meant good order of the kingdom and who lived fulfilling his name, very much. Nizam al-Mulk, who met Omer Khayyam in Samarkand, first invited him to Isfahan. When they met there, he spoke of the kingdom and he asked Omer Khayyam to help him make his dreams about the kingdom come true. Yet, Omer Khayyam didn’t want to involve in the state affairs and he rejected him. He wanted to stay away from tricks in the palace until his death and he moved to Samarkand, Bukhara and Isfahan, which were the centers for science of that era, to expand his knowledge. He died on 4th December 1131 in Nishapur where he was born.
Omer Khayyam, well known in the world of mathematics for his works on Euclid’s parallel postulate, is also famous as the poet of Rubaiyat in our country and in the Western world with the interpretation of Fitzgerald (1859). Interest in Khayyam is highly intense. For instance, having submitted intellectual and artistic achievement of Persian culture in his study called History of Western Philosophy; Bertrand Russell spoke highly of Khayyam and regarded him as “the sole person he knew as both mathematician and poet.” The reprints of Omer Khayyam’s works in recent years have confirmed the importance of his mathematical studies. Currently, his mathematical works are reviewed in three categories. 1) Formulation of basic algebraic geometry, 2) Studies on theory of proportionality, 3) Studies on theory of parallels. Thanks to the new findings mentioned above, it was understood that Omer Khayyam’s mathematical works were far more important than it had been thought before. United Nations Educational, Scientific and Cultural Organization (UNESCO), arranged an international colloquium in 1999 to celebrate Khayyam’s achievements and decided to print Khayyam’s important mathematical works. Within the scope of UNESCO’S project called “Beyt-ül Hikme” Roshdi Rashed, a well-known Egyptian historian of science, who lives in Paris and Bijan Vahabzadeh, who is known for his doctorate on Omer Khayyam, took on the task of critical edition of Khayyam’s important manuscripts about mathematics, some of which were known and some not known then. That critical edition was first printed in French and then in English.
Even though the information about Khayyam’s life is very limited, it is known that he left a certain number of philosophic works behind. Khayyam is also matched with a Persian poet of Rubaiyat, who was an incognito but well respected. The question of who wrote Rubaiyat raised issues between historians and historians of mathematics.
Rashed says “to the best of my belief, we lack of the information which will help us identify those two geniuses (poet and mathematician). None of the information given by historians such as Beyhaki, Arudi, Sefadi, İbn-ül Esir about the mathematician Khayyam does mention about the poet Khayyam; on the other hand, the ones who mention about poet does not speak of any mathematician”. According to Rashed, association of poet Khayyam and mathematician Khayyam occurred long after the composing of Rubaiyat. It is controversial whether the composer of Rubaiyat and mathematician and philosopher Khayyam was the same person or not.
The writers, mentioned above, compares Descartes’ work called Geometry and his other works to Khayyam’s works. They claim that Descartes’ works on algebraic equation of geometric theory should be regarded as the complement of Khayyam’s works, by emphasizing that Descartes’ works should be reviewed in the view of Khayyam’s and Tusi’s works .
After all, the book does not only enlighten works of a Muslim mathematician but also enlightens the progress of early period modern mathematics. Without this work, the historian would not completely understand the works of Descartes and would misjudge the birth of modern science which changed the world. UNESCO, which contributed a great deal to our understanding of history of mathematics by taking on an edition of Khayyam’s works, should be thanked. Works of Rashed and Bahabzadeh emphasized that, we shouldn’t consider mathematician Khayyam and poet Khayyam as the same person unquestioningly.
Omer Khayyam also did scientific researches by observing the sky in his observatory which he built in three years in Isfahan. He, himself, detected his own birth date so precisely with the help of astronomers’ accuracy. Omer Khayyam, who was invited to Merv by Sultan Celalettin Malik-shāh, was the leader of a panel formed to establish a new calendar. He made a great effort for the calendar, colloquially known as “Omer Khayyam Calendar” but today known as “Jalali Calendar”. While that calendar using the solar year leads to an error of 1 day in 5000 days, the “Gregorian Calendar” we use today leads to an error of 1 day in 3330 years. It shows how Khayyam’s knowledge of astronomy was further than his era.
According to a rumor about the usage of the letter “X” to denote unknowns in mathematics, Omer Khayyam indicated unknowns as “şey” in equation while he studied on algebraic in Samarkand. That word was written as “xey” in Spanish works in Andalusia and in time it took the form of “X” and then it became universal letter “X” to denote unknowns.
Ziyc-i Melikşahi (About astronomy and calendar), Kitabün fi'l Burhan ül Sıhhat-ı Turuk ül Hind (About geometry), Risaletün fi Berahin İl Cebr ve Mukabele (About algebraic and equation), Müşkilat'ül Hisab (About arithmetic), İlm-i Külliyat (About general principles), Nevruzname (About calendar and detection of new year beginning), Risaletün fil İhtiyal li Marifet (About detection of volume of gold and silver in golden and silver items), Risaletün fi Şerhi ma Eşkele min Musaderat (About method of solving Euclidean problem), Risaletün fi Vücud (About ontology in philosophical), Muhtasarun fi't Tabiiyat (About science of physic), Risaletün fi'l Kevn vet Teklif (About philosophy), Levazim'ül Emkine (About climates of residence areas and changes in the weather), Fil Cevab Selaseti Mesâil ve fi Keşfil Hicab (Answer to three matters and about necessity of polar opposites in the universe ), Mizan'ül Hikem ( about knowing the values of diamond jewelry without extracting its diamonds ), Abdurrahman'el Neseviye Cevab (about manifestation of Allah in forming universe and in obligation of prayers), Nizamülmülk (A biography of a vizier, his friend), Eş'arı bil Arabiyye (Rûba in Arabic, T.N.: Arabian quatrain), Fil Mutayat (About principles of science).
REFERENCE: Rıza Tevfik Bölükbaşı / Ömer Hayyam’ın Felsefesi (1919), Hüsey,n Rıfat / Ömer Hayyam: Manzum Rubâî Tercemeleri (1943), Ömer Rıza Doğrul / Ömer Hayyam (Harold Lamb’dan, 1944), Vasfi Mahir Kocatürk / Ömer Hayyam’dan Rubailer (1955), İslâm Ansiklopedisi (1964), Rashed ve Roshdi / Batılı Bilim Nosyonu: “Batılı Bir Görüngü Olarak Bilim” (Çev. Bekir S. Gür, 1994), Bertrand Russell / A History of Western Philosophy (2. Basım 2004), Çeşm-i Şarâbât’ta Yıldızlar (Ömer Hayyam’dan çeviri şiirler, 2004), İhsan Işık / Ünlü Bilim Adamları (Türkiye Ünlüleri Ansiklopedisi, C. 2, 2013) - Encyclopedia of Turkey’s Famous People (2013).