In mathematics, he developed a method to solve cubic equations by intersecting a conic section with a circle, as explained in his 1070 Treatise on Demonstration of Problems of Algebra, and his criticism of The Elements (*) may have contributed to the development of non-Euclidean geometry.  
His collaboration with other astronomers led to the creation of the Jalali Calendar, more accurate than the Gregorian and computed from the vernal equinox.  In mathematics, he developed a method to solve cubic equations by intersecting a conic section with a circle, as explained in his 1070 Treatise on Demonstration of Problems of Algebra, and his criticism of The Elements (*) may have contributed to the development of non-Euclidean geometry.  However, he was most notable for composing over a thousand quatrains, many of which were translated by Edward Fitzgerald in 5 editions.  FTP, name this Persian polymath poet whose most famous line from his Rubaiyat may be, A jug of wine, a loaf of bread, and thou. 
His collaboration with other astronomers led to the creation of the Jalali Calendar, more accurate than the Gregorian and computed from the vernal equinox.  
Omar {Khayyam}