# Omar Khayyám

Hakim Omar Khayyám was born in Naishápúr (Nishapur), a city in northeastern Persia, Khorassán, in the second half of the 11th century, on May 18, 1048, and died on December 4, 1131. During his life he became famous for his contributions to mathematics and astronomy, a reputation that probably served to eclipse his talent for poetry. In addition to being a poet, Khayyám was a mathematician and astronomer, now recognized in his own country and internationally for his works in the literature and science of his time.

In the West, it became known in English-speaking countries because of Edward FitzGerald's translation of his main work, the Rubaiyat, published in 1859. Khayyám's works on algebra were widespread in Europe during the Middle Ages; in the astronomical sciences, he was known to have contributed to the reform of the Persian calendar and numerous astronomical tables.

Researcher Edward B. Cowell quotes in Calcutta Review No. 59:

• When Malik Shah ordered the reform of the Persian calendar, Omar was one of eight men of science assigned to do so; The result was the Jalali Era (named after one of the king's names, Jalal-ud-din).
The computation made, quotes another eminent researcher, Edward Gibbon, surpasses the accuracy of the Julian Calendar, and approaches the accuracy of the Gregorian Calendar.

Khayyám measured the length of the year at 365,24211958156 days. If we take into account that this measurement was made in the middle ages and without the advanced features of current technology, this value shows incredible accuracy with respect to the currently known values. We now know that the length of days during a person's lifetime varies after the sixth decimal place. The accuracy achieved by Khayyám is phenomenal: for comparison, we must mention that the length of the year at the end of the nineteenth century was 365,242,196 days, today it is 365,242,190 days.

In his algebra book, Khayyám refers to his other works which, unfortunately, are now lost. In these works he discussed the Pascal Triangle, but he was not the first to do so: in earlier times, the Chinese had done so. Khayyám algebra is geometric in nature, having solved linear and quadratic equations by methods that are present in Euclid's geometry. However, he discovered a method for solving cubic equations by intersecting a parable with a circle, but at least in part this method had already been described by other authors as Abud al-Jud.

Khayyám contributed important results in the study of the relationships and ratios of rays in Euclid's geometry, including the problem of their multiplication. The name Khayyám comes from the term "tentmaker," a craft he learned from his father.

Neychabur, his homeland, is 115 kms west of Mashad in Khorasan province. This ancient city, besides being the homeland of Khayyám, was also the birthplace of another great Persian poet, the mystic Attar-e Neyshabury. Neyshabur has been known since ancient times as a world center for exporting turquoise (Firouz-e). Omar Khayyám received a good education in science and philosophy in his homeland, Nayshabur, and in Balk, another city of Iran.

After graduating, he headed to Samarkand, where he completed an important treatise on algebra. In such a way it became known that he was invited by Sultan Seljuq Malik-Shah to make the astronomical observations cited, and to reform the calendar. Khayyám was also commissioned to build an astronomical observatory in Esfahan City in collaboration with other astronomers. After the death of his patron in 1092, he made a pilgrimage to Mecca. Returning to Neyshapur, he began to teach and teach in court from time to time, making astronomical and astrological predictions.

Among the fields of knowledge that he mastered were philosophy, mathematics, astronomy, jurisprudence, history, and medicine. From his prose, unfortunately, he survived very little; Of his works there remain only a few on metaphysics and on Euclid's theorems. Khayyam stood out for his extraordinary poetic sense, expressed in the The Rubaiyat. The poetic side of the Persian, since it was rediscovered by Edward FitzGerald around 1859, is the best known today and has been the inspiration of many poets of our time, including Jorge Luiz Borges and Fernando Pessoa. Working on concepts related to the depths of the human soul and psyche, Khayyam wrote the most beautiful pages of universal literature.

Omar Khayyam's philosophy strikes us to this day, reminding us of Epicurus, yet deeply Persian in his boldness and resignation. Khayyam's poetry incorporates philosophical opinions that survive to this day, and concern ontology, universal concepts, free will, predestination, and moral obligations. Also in it are clear references to the relationship between the human being with the Creator and the latter with man, in a reciprocity of responsibilities and care.

According to E. FitzGerald, it is interesting to note that the poet, like other prominent Islamic thinkers, although influenced by Greek philosophy, especially Aristotle, did not absorb the most abstract aspects of that way of thinking. Khayyám preferred to express himself through figures of an Epicurean rhetoric that, while bold for its time, made it obscure in life and forgotten, years after his death, in its own land.