Not only is he known as a poet in medieval history, but he was also a prolific mathematician and astronomer. Haji Omar Khayyam solved the triangle equation with the help of cross-section and intersection of circles. He also spread two-dimensional numbers. Another major contribution of Omar Khayyam was his critique of Euclid's parallel acknowledgment which later introduced non-Euclidean geometry.
At the invitation of the Seljuk Sultan Malik Shah, he set up an observatory in Isfahan, the capital of the Seljuk Sultanate, from where he successfully introduced the "Jalali Calendar", measuring the length of the year. Some of his contemporary scholars called this talented medieval Muslim scientist an atheist, in protest of which he wrote an explosive verse like as:
"Atheists and infidels, you say my name."
The filthy current of slander flows unceasingly.
I will not deny what I have done wrong, but brother,
Will you go to heaven with this ugly insult?"
Our national poet Kazi Nazrul Islam edited the entire Rubaiyat-i-Umar Khayyam in Bengali. Nazrul himself was influenced by Umar's poetic genius. This great man composed his death farewell to some poems, I am ending with respect to his soul in his poems of separation:
''Go to sleep forever, drink wine!
There will be no friends, friends, dear relatives.
I will not come again to say, brother, whatever you say, listen to it.
The flower buds are falling, can it bloom and what else?"
