Khayyam measured the length of the year as 365.24219858156 days. Two comments on this result. Firstly it shows an incredible confidence to attempt to give the result to this degree of accuracy. We know now that the length of the years is changing in the sixth decimal place over a person's lifetime. Secondly it is outstandingly accurate. For comparison the length of the year at the end of the 19th century was 365.242196 days, while today it is 365.242190 days.

In his algebra book, Khayyam refers to another work of his which is now lost. In the lost work Khayyam discusses Pascal's triangle but he was not the first to do so since the Chinese may have discussed Pascal's triangle slightly before this date.

The algebra of Khayyam is geometrical, solving linear and quadratic equations by methods appearing in Euclid's Elements . Khayyam discovered a geometrical method to solve cubic equations. He did this by intersecting a parabola with a circle but, at least in part, these methods had been described by earlier authors such as Abu al-Jud.

Khayyam also gave important results on ratios giving a new definition and extending Euclid's work to include the multiplication of ratios. He poses the question of whether a ratio can be regarded as a number but leaves the question unanswered.

His name Khayyam ("Tentmaker") may have been derived from his father's trade. He received a good education in the sciences and philosophy in his native Neyshabur (Nishapur) and in Balkh and then went to Samarkand, where he completed an important treatise on algebra. He made such a name for himself that he was invited by the Seljuq sultan [Index] Malik-Shah to undertake the astronomical observations necessary for the reform of the calendar. He was also commissioned to build an observatory in the city of Esfahan in collaboration with other astronomers. After the death of his patron in 1092, Omar went on a pilgrimage to Mecca. Returning to Neyshabur he taught and served the court from time to time by predicting events to come. Philosophy, jurisprudence, history, mathematics, medicine, and astronomy are among the subjects mastered by this brilliant man. Unfortunately, few of his prose writings survive; these include a few brief tracts on metaphysics and a treatise on Euclid.

He was in his time as famous as his contemporaries Avicenna and Hassan-e Sabah, mainly for the writing of many scientific treatises. Hundreds of Rubaiyat are today attributed to Omar Khayyam. Many are deemed apocryphal but 72 certified authentic Rubaiyat are collected in the book The Wine of Nishapur - Poems by Omar Khayyam. 

Mausoleum of the great poet and mathematician of Iran, Hakim Omar-e-Khayyam which is situated in a beautiful garden in Nishapur. This mausoleum was constructed in 1341 A.H. (1962 A.D.).

In 1859 Edward Fitzgerald (1809-83), British scholar and poet, published his translation of The Rubaiyat which, as many argue, little or nothing may be by Omar-e-Khayyam:

--->