# Omar Khayyam
## (c. 1048 - 1125)
Persian mathematician, astronomer and poet best known for the *Rubaiyat*;
also helped reform the solar calendar. Khayyam was an outstanding mathematician
and astronomer who wrote several works including *Problems of Arithmetic*,
a book on music and one on algebra before he was 25 years old.
An invitation was sent to Khayyam from shah Malik-Shah
in 1073 asking Khayyam to go to Esfahan to set up an Observatory in
the city. Other leading astronomers were also brought to the Observatory
in Esfahan, and for 18 years Khayyam led the scientists and produced
work of outstanding quality. It was a period of peace during which the
political situation allowed Khayyam the opportunity to devote himself
entirely to his scholarly work.
During this time, Khayyam led work on compiling astronomical
tables, and he also contributed to calendar reform; in 1079 Khayyam
measured the length of the year as 365.24219858156 days. Khayyam also
solved the cubic equation x3 + 200x = 20x2 + 2000 and he found a positive
root of this cube by considering the intersection of a rectangular hyperbola
and a circle. An approximate numerical solution was then found by interpolation
in trigonometric tables. Khayyam seems to have been the first to conceive
a general theory of cubic equations, and perhaps even more remarkable
was that Khayyam stated that the solution of this equation requires
the use of conic sections and not the ruler and compass method, a result
which would not be proven for another 750 years!
Khayyam furthered his mathematical talent in his work,
the *Treatise on Demonstration of Problems of Algebra*, which contained
a complete classification of cubic equations with geometric solutions
found by means of intersecting conic sections. Another achievement in
this text is Khayyam's realisation that a cubic equation can have more
than one solution. He demonstrated the existence of equations having
two solutions, but unfortunately did not appear to have found that a
cubic can have three solutions.
Outside the world of mathematics, Khayyam is best known
as a result of Edward Fitzgerald's popular translation in 1859 of nearly
600 short four line poems, the *Rubaiyat*. Khayyam's fame as a
poet has caused some to forget his scientific achievements, which some
believe were more substantial than his literary work.
**Sources:** O'Connor, J J, Robertson, E F. "Omar Khayyam." School
of Mathematical and Computational Sciences, University of St. Andrews.; *Saudi Aramco World*, January-February 2002. |