**Omar Khayyam** (May 18, 1048 – December 4, 1131) was a Persian mathematician, astronomer and poet. He was born in Nishapur, in northeastern Iran, and spent most of his life near the court of the Karakhanid and Seljuq rulers in the period that witnessed the First Crusade.

As a mathematician, he is most notable for his work in the classification and solution of cubic equations, where he provided geometric solutions by intersecting the conics. Khayyam also contributed to the understanding of the parallel axiom. As an astronomer, he designed the Jalali calendar, a solar calendar with a very precise 33-year intercalation cycle.

There is a tradition of attributing poetry to Omar Khayyam, written in the form of quatrains (rubā’iyāt). This poetry became widely known in the world of reading in English in a translation by Edward Fitz Gerald (Rubaiyat de Omar Khayyam, 1859), which was very successful in the orientalism of the turn of the century.

**Life**

Omar Khayyam was born in Nishapur, an important metropolis in Khorasan during medieval times that reached its peak of prosperity in the 11th century under the Seljuq dynasty. Nishapur was then religiously an important center of Zoroastrians. It is likely that Khayyam’s father was a Zoroastrian who had converted to Islam. He was born into a family of tent makers (Khayyam). His full name, as it appears in Arabic sources, was Abu’l Fath Omar ibn Ibrahim al-Khayyam. In the medieval Persian texts it is usually called simply Omar Khayyām. The historian Bayhaqi, who knew Omar personally, provides the full details of his horoscope: “He was Gemini, the sun and Mercury were rising.” This was used by modern scholars to establish their date of birth as May 18, 1048.

His childhood was spent in Nishapur. His gifts were recognized by his first tutors, who sent him to study with Imam Muwaffaq Nīshābūrī, the greatest teacher in the Khorasan region, who taught the children of the highest nobility. In 1073, at the age of twenty-six, he entered the service of Sultan Malik-Shah I as advisor. In 1076, Khayyam was invited to Isfahan by the vizier and political figure Nizam al-Mulk to take advantage of the libraries and learning centers there. His years in Isfahan were productive. It was at this time that he began to study the work of the Greek mathematicians Euclid and Apollonius much more closely. But after the death of Malik-Shah and his vizier (presumably by the sect of the Assassins), Omar lost favor in court and, as a result, soon began his pilgrimage to Mecca. A possible ulterior motive for his pilgrimage reported by Al-Qifti is that he was attacked by the clergy for his apparent skepticism. So he decided to make his pilgrimage as a way to demonstrate his faith and free himself from any suspicion of lack of orthodoxy. Then he was invited by the new Sultan Sanjar to Marv, possibly to work as an astrologer of the court. Later he was allowed to return to Nishapur due to his declining health. Upon his return, he seemed to have lived the life of an inmate. Khayyam died in 1131 and is buried in the Khayyam Garden.

**Maths**

Khayyam was famous during his life as a mathematician. His surviving mathematical works include: A commentary on the difficulties related to the postulates of the Elements of Euclid (Risāla fī šarḥ mā aškala min muṣādarāt kitāb Uqlīdis, completed in December 1077), On the division of a quadrant of a circle (Risālah fī qismah -dā’irah, undated but completed before the treatise on algebra), and In proofs of problems related to Algebra (Maqāla fi l-jabr wa l-muqābala, probably completed in 1079). In addition, he wrote a treatise on the extraction of the binomial theorem and the nth root of the natural numbers, which has been lost.

**Theory of parallels**

A part of Khayyam’s commentary on the Elements of Euclid deals with the parallel axiom. The treatise of Khayyam can be considered the first treatment of the axiom not based on the petitio principii, but on a more intuitive postulate. Khayyam refutes the previous attempts of other mathematicians to prove the proposition, mainly because each of them had postulated something that was in no way easier to admit than the Fifth Postulate itself. Based on Aristotle’s views, he rejects the use of movement in geometry and, therefore, discards Al-Haytham’s different intent. Dissatisfied with the inability of mathematicians to prove Euclid’s assertion of his other postulates, Omar attempted to connect the axiom to the Fourth Postulate, which states that all right angles are equal to each other.

Khayyam was the first to consider the three cases of acute, obtuse and right angle for the angles of the top of a quadrilateral Khayyam-Saccheri, three cases that are exhaustive and mutually exclusive. After proving a series of theorems on them, he showed that Postulate V is a consequence of the right angle hypothesis, and refuted obtuse and acute cases as contradictory. Khayyam’s elaborate attempt to prove the parallel postulate was significant for the later development of geometry, since it clearly shows the possibility of non-Euclidean geometries. It is now known that the hypothesis of the acute, obtuse, and the right angle leads respectively to the non-Euclidean hyperbolic geometry of Gauss-Bolyai-Lobachevsky, to that of Riemannian geometry and to Euclidean geometry.

Tusi’s comments about Khayyam’s treatment of parallels came to Europe. John Wallis, the professor of geometry at Oxford, translated Tusi’s comments into Latin. The geometrical Jesuit Girolamo Saccheri, whose work (euclides ab omni naevo vindicatus, 1733) is generally considered as the first step in the eventual development of non-Euclidean geometry, was familiar with the work of Wallis. The American historian of mathematics, David Eugene Smith, mentions that Saccheri “used the same motto as Tusi’s, even placing letters on the figure in exactly the same way and using the motto for the same purpose.” In addition, he says that “Tusi clearly states that it is owed to Omar Khayyam, and from the text it seems clear that the latter was his inspiration”.

**The concept of real number.**

This treatise on Euclid contains another contribution dealing with the theory of proportions and the composition of proportions. Khayyam discusses the relationship between the concept of reason and the concept of number and explicitly raises several theoretical difficulties. In particular, it contributes to the theoretical study of the concept of irrational number. Disgusted with Euclid’s definition of equal proportions, he redefined the concept of a number by using a continuous fraction as the means of expressing a relation. Rosenfeld and Youschkevitch (1973) argue that “by placing irrational numbers and numbers on the same operational scale, a true revolution in the doctrine of number began.” Similarly, D. J. Struik noted that Omar was “on the way to that extension of the concept of number that leads to the notion of the real number.”

**Geometric algebra**

Rashed and Vahabzadeh (2000) have argued that, due to its complete geometrical approach to algebraic equations, Khayyam can be considered Descartes’ precursor in the invention of analytic geometry. In The Treatise on the Division of a Quadrant of a Circle, Khayyam applied algebra to geometry. In this work, he devoted himself mainly to investigate if it is possible to divide a circular quadrant in two parts, so that the line segments projected from the dividing point to the perpendicular diameters of the circle form a specific proportion. His solution, in turn, employed several curve constructions that led to equations that contained cubic and quadratic terms.

**The solution of cubic equations.**

Khayyam seems to have been the first to conceive a general theory of cubic equations and the first to geometrically solve all kinds of cubic equations, with respect to positive roots. The treatise on algebra contains his work on cubic equations. It is divided into three parts:

(1) equations that can be solved with compass and straight edge,

(2) equations that can be solved by means of conic sections, and

(3) equations that involve the inverse of the unknown.

Khayyam produced an exhaustive list of all possible equations involving lines, squares and cubes. He considered three binomial equations, nine trinomial equations and seven tetranomial equations. For the first and second degree polynomials, he provided numerical solutions by geometric construction. He concluded that there are fourteen different types of cubic that can not be reduced to a lower degree equation. For these he could not achieve the construction of his unknown segment with compass and straight edge. He proceeded to present geometric solutions to all types of cubic equations using the properties of the conic sections. The prerequisite slogans for the Khayyam geometric test include Euclid VI, Prop 13 and Apollonius II, Prop 12. The positive root of a cubic equation was determined as the abscissa of an intersection point of two conics, for example, the intersection of two parables, or the intersection of a parabola and a circle, etc. However, he acknowledged that the arithmetic problem of these cubics was still unresolved, adding that “possibly someone else will know after us.” This task remained open until the sixteenth century, where Cardano, Del Ferro and Tartaglia found in Renaissance Italy the algebraic solution of the cubic equation in its generality.

In effect, Khayyam’s work is an effort to unify algebra and geometry. This particular geometric solution of cubic equations has been further investigated by M. Hachtroudi and has been extended to solve fourth-degree equations. Although similar methods had appeared sporadically from Menaechmus, and developed by the tenth-century mathematician Abu al-Jud, Khayyam’s work can be considered the first systematic study and the first exact method for solving cubic equations. The mathematician Woepcke (1851), who offered translations of the algebra of Khayyam into French, praised him for his “power of generalization and his rigorously systematic procedure.”

**Binomial theorem and root extraction.**

In his algebraic treatise, Khayyam alludes to a book he had written about extracting the nth root from numbers using a law he had discovered that did not depend on geometrical figures. This book was probably titled The Difficulties of Arithmetic (Moškelāt al-hesāb), and it is not current. Depending on the context, some mathematics historians such as DJ Struik believe that Omar must have known the formula for the expansion of the binomial {\ displaystyle (a + b) ^ {n}} (a + b) ^ n, where n is a positive integer The case of power 2 is explicitly stated in Euclid’s elements and the case of maximum power 3 was established by Indian mathematicians. Khayyam was the mathematician who noticed the importance of a general binomial theorem. The argument supporting the claim that Khayyam had a general binomial theorem is based on his ability to extract roots. The arrangement of numbers known as Pascal’s triangle allows you to write the coefficients in a binomial expansion. This triangular matrix is sometimes called the triangle of Omar Khayyam.

**Astronomy**

In 1074, Omar Khayyam was commissioned by Sultan Malik-Shah to build an observatory in Isfahan and to reform the Persian calendar. There was a panel of eight academics working under Khayyam’s direction to make large-scale astronomical observations and review the astronomical tables. The recalibration of the calendar was set the first day of the year at the exact moment of the passage of the Sun’s center through the vernal equinox. This marks the beginning of spring or Nowrūz, a day when the Sun enters the first degree of Aries before noon. The resulting calendar was named in honor of Malik-Shah as the calendar of Jalālī and was inaugurated on Friday, March 15, 1079. The observatory itself was disused after the death of Malik-Shah in 1092.

The calendar of Jalālī was a true solar calendar in which the duration of each month is equal to the time of the passage of the Sun through the corresponding sign of the zodiac. The calendar reform introduced a unique 33-year intercalation cycle. As indicated by Khazini’s work, Khayyam’s group implemented an intercalary system based on the four-year and five-year years. Therefore, the calendar consisted of 25 ordinary years that included 365 days and 8 leap years that included 366 days. The calendar remained in use throughout Greater Iran from the eleventh century to the twentieth century. In 1911, the Jalali calendar became the official national calendar of Qajar Iran. In 1925, this calendar was simplified and the names of the months were modernized, resulting in the modern Iranian calendar. The Jalali calendar is more accurate than the Gregorian calendar of 1582, with an error of one day accumulating more than 5,000 years, compared with one day every 3,330 years in the Gregorian calendar. Moritz Cantor considered it the most perfect calendar ever devised.

One of his students, Nizami Aruzi of Samarcand, relates that Khayyam apparently did not believe in astrology and divination: “I did not notice that he (sardyl Omar Khayyam) had a great belief in astrological predictions, nor have I seen or heard of Any of the great scientists who had such a belief. ” While working for Sultan Sanjar as an astrologer, he was asked to predict the weather, a job that apparently did not go well for him. George Saliba (2002) explains that the term ‘ilm al-nujūm, used in several sources in which references to the life and work of Omar can be found, has sometimes been translated incorrectly to mean astrology. He adds: “from the middle of the tenth century, according to the enumeration of the Farabi sciences, that this science, ‘ilm al-nujūm, was already divided into two parts, one related to astrology and the other to theoretical mathematical astronomy . “

A popular statement of the effect that Khayyam believed in heliocentrism is based on Edward FitzGerald’s popular but anachronistic interpretation of Khayyam’s poetry, in which the first lines are erroneously translated with a heliocentric image of the Sun’s release “The Stone that sets to the Stars in Flight. “

**Other works**

It has a brief treatise dedicated to the principle of Archimedes (in the full title, In the deception of knowing the two amounts of gold and silver in a composite of the two). For a gold compound adulterated with silver, he describes a method to more accurately measure the weight per capacity of each element. It involves weighing the compound in both air and water, since the weights are easier to measure exactly than the volumes. By repeating the same thing with gold and silver, one finds exactly how much heavier than water, gold and silver. This treatise was widely examined by Eilhard Wiedemann, who believed that Khayyam’s solution was more precise and sophisticated than that of Khazini and Al-Nayrizi, who also discussed the issue elsewhere.

Another short treatise refers to the musical theory in which he analyzes the connection between music and arithmetic. Khayyam’s contribution consisted in providing a systematic classification of the musical scales and discussing the mathematical relationship between the notes, minor, major and tetrachords.

**Poetry**

The first allusion to the poetry of Omar Khayyam is by the historian Imad ad-Din al-Isfahani, a younger contemporary of Khayyam, who identifies him explicitly as a poet and as a scientist (Kharidat al-qasr, 1174). One of the first copies of Rubyat by Omar Khayyam is by Fakhr al-Din Razi. In his work Al-tanbih ‘ala ba’d asrar al-maw’dat fi’l-Qur’an (ca. 1160), he cites one of his poems (corresponding to the quartet LXII of the first edition of FitzGerald). Daya in his writings (Mirsad al-‘Ibad, ca. 1230) cites two quartets, one of which is the same as the one already reported by Razi. An additional historian is quoted by the historian Juvayni (Tarikh-i Jahangushay, ca. 1226-1283). In 1340, Khajari includes thirteen Khayyam quatrains in his work containing an anthology of the works of famous Persian poets (Munis al-ahrār), two of which have been known so far from the oldest sources. A comparatively late manuscript is that of Bodleian MS. Ouseley 140, written in Shiraz in 1460, which contains 158 rooms in 47 folios. The manuscript belonged to William Ouseley (1767-1842) and was purchased by the Bodleian Library in 1844.

There are occasional quotations of verses attributed to Omar in texts attributed to authors of the thirteenth and fourteenth centuries, but they are also of dubious authenticity, so skeptical scholars point out that the whole tradition can be pseudepigraphic.

Hans Heinrich Schaeder in 1934 commented that the name of Omar Khayyam “must be removed from the history of Persian literature” due to the lack of any material that can be attributed to him with confidence. De Blois (2004) presents a bibliography of the tradition of the manuscript, concluding pessimistic that the situation has not changed significantly since the time of Schaeder. Five of the quartets later attributed to Omar are found 30 years after his death, cited in Sindbad-Nameh. While this states that these specific verses were in circulation in Omar’s time or shortly after, it does not imply that the verses are his. De Blois concludes that, at least, the process of attribution of poetry to Omar Khayyam seems to have begun as early as the 13th century. Edward Granville Browne (1906) points out the difficulty of separating the authentic from the spurious quatrains: “although it is true that Khayyam wrote many pages, it is difficult, except in some exceptional cases, to affirm positively that he wrote some of them attributed to him” .

In addition to the Persian quartets, there are twenty-five Arabic poems attributed to Khayyam which are attested by historians such as al-Isfahani, Shahrazuri (Nuzhat al-Arwah, ca. 1201-1211), Qifti (Tārikh al-hukamā, 1255), and Hamdallah Mustawfi (Tarikh-i Guzida, 1339).

Richard N. Frye (1975) emphasizes that there are other Persian scholars who occasionally wrote quatrains, among them Avicenna, Ghazzali and Tusi. He concludes that it is also possible that the poetry with Khayyam was the fun of his leisure hours: “these brief poems seem to have been often the work of scholars and scientists who composed them, perhaps, in moments of relaxation to build or entertain the interior circle of his disciples. “

The poetry attributed to Omar Khayyam has contributed greatly to his popular fame in the modern period as a direct result of the extreme popularity of the translation of such verses into English by Edward FitzGerald (1859). The Rubaiyat of Omar Khayyam of FitzGerald contains loose translations of quartets from the Bodleian manuscript. It was so successful in the end of the century period that a bibliography compiled in 1929 lists more than 300 separate editions, and many more have been published since then.

**Philosophy**

Khayyam considered himself intellectually a student of Avicenna. According to Al-Bayhaqi, he was reading metaphysics in Avicenna’s Book of Healing before he died. There are six philosophical articles that are believed to have been written by Khayyam. One of them, On Existence (Fi’l-wujūd), was originally written in Persian and deals with the subject of existence and its relation to universals. Another article, entitled The need for contradiction in the world, determinism and subsistence (Darurat al-tadād fi’l-‘ālam wa’l-jabr wa’l-baqā ‘), is written in Arabic and deals with the free agency and determinism. . The titles of his other works are On Being and Necessity (Risālah fī’l-kawn wa’l-taklīf), The Treatise on the Transcendence of Existence (Al-Risālah al-ulā fi’l-wujūd), About the knowledge of the universal principles of existence (Risālah dar ‘ilm kulliyāt-i wujūd), and the Commitment relating to natural phenomena (Mukhtasar fi’l-Tabi’iyyāt).

**Religious points of view**

A literal reading of Khayyam’s quartets leads to the interpretation of his philosophical attitude towards life as a combination of pessimism, nihilism, epicureanism, fatalism and agnosticism. This opinion is taken by Iranologists such as Arthur Christensen, H. Schaeder, Richard N. Frye, E. D. Ross, E.H. Whinfield and George Sarton. Conversely, jayyamic quartets have also been described as Sufi mystical poetry. However, this is the opinion of a minority of scholars. In addition to his Persian quartets, JCE Bowen (1973) mentions that Khayyam’s Arabic poems also “express a pessimistic outlook that is entirely in keeping with the perspective of the deeply reflective, rationalist philosopher who is historically known to have been Khayyam” . Edward FitzGerald emphasized the religious skepticism he encountered in Khayyam. In his preface to the Rubáiyát, he affirmed that “he was hated and feared by the Sufis,” and denied any pretense of the divine allegory: “his Wine is the true Juice of the Grape: his Tavern, where he should have it: his Saki, the meat and the blood that was shed for him. ” Sadegh Hedayat is one of the most notable defenders of Khayyam’s philosophy as agnostic skepticism, and according to Jan Rypka (1934), he even considered Khayyam as an atheist. Hedayat (1923) states that “while Khayyam believes in the transmutation and transformation of the human body, he does not believe in a separate soul, if we are lucky, our body particles would be used to make a jar of wine”. In a later study (1934-35), he argues that Khayyam’s use of Sufi terminology, as “wine”, is literal and that he resorted to the pleasures of the moment as an antidote to his existential grief: “Khayyam took refuge in wine to ward off bitterness and dull the edge of your thoughts. ” In this tradition, the poetry of Omar Khayyam has been cited in the context of the New Atheism, for example. in The Portable Atheist by Christopher Hitchens.

Al-Qifti (ca. 1172-1248) seems to confirm this vision of Omar’s philosophy. In his work, The History of Learned Men, he reports that Omar’s poems were uniquely Sufi in style, but that they were written with an antireligious agenda. He also mentions that at one point he was accused of impiety, but went on a pilgrimage to show that he was pious. The report says that, upon returning to his hometown, he hid his deepest convictions and practiced a strictly religious life, going to the place of worship in the morning and at night.

In the context of a piece entitled On Knowledge of the Principles of Existence, Khayyam supports the Sufi path. Csillik (1960) suggests the possibility that Omar Khayyam could see in Sufism an ally against orthodox religiosity. Other commentators do not accept that Omar’s poetry has an anti-religious agenda and interpret his references to wine and drunkenness in the conventional metaphorical sense common in Sufism. French translator J. B. Nicolas argued that Omar’s constant exhortations to drink wine should not be taken literally, but should be viewed in Sufi terms as representative of an enlightened state. The opinion of Omar Khayyam as Sufi was defended by Bjerregaard (1915), Idries Shah (1999) and Dougan (1991), who attributes the reputation of hedonism to FitzGerald’s translation failures, arguing that Omar’s poetry should be understood as “deeply esoteric.” On the other hand, Iranian experts, such as Mohammad Ali Foroughi and Mojtaba Minovi, unanimously rejected the hypothesis that Omar Khayyam was a Sufi. Foroughi stated that Khayyam’s ideas may have been consistent with those of the Sufis at times, but there is no evidence that he was formally a Sufi. Aminrazavi (2007) states that “the Sufi interpretation of Khayyam is possible only by reading his Rubā’īyyāt extensively and stretching the content so that it conforms to the classical Sufi doctrine.” In addition, Frye (1975) emphasizes that Khayyam was rejected by several famous Sufi mystics who belonged to the same century. This includes Shams Tabrizi (spiritual guide of Rumi), Najm al-Din Daya, who described Omar Khayyam as “an unhappy philosopher, atheist and materialist”, and Attar, who did not consider him a mystical companion but a free-thinking scientist What penalties are expected from now on.

Seyyed Hossein Nasr maintains that it is “reductive” to use a literal interpretation of his verses (many of which are of uncertain authenticity to begin with) to establish the philosophy of Omar Khayyam. Instead, he adduces Khayyam’s interpretative translation of the treatise Discourse on the Avicenna Unit (Al-Khutbat al-Tawhīd), where he expresses orthodox views on Divine Unity according to the author. The prose works that are believed to be of Omar are written in a peripatetic style and are explicitly theistic, and deal with issues such as the existence of God and theodicy. As Bowen noted, these works indicate their participation in the problems of metaphysics rather than in the subtleties of Sufism. As evidence of Khayyam’s faith and / or conformity to Islamic customs, Aminrazavi mentions that in his treatises he offers greetings and prayers, praising God and Muhammad. In most biographical extracts, he is mentioned with religious honorifics such as Imām, The Pattern of Faith (Ghīyāth al-Dīn) and The Evidence of Truth (Hujjat al-Haqq). He also points out that biographers who praise their religiosity generally avoid making reference to their poetry, while those who mention them often do not praise their religious character. For example, the account of Al-Bayhaqi, previous to some years of other biographical notices, speaks of Omar as a very pious man who professed orthodox views until his last hour.

On the basis of all existing textual and biographical evidence, the question remains somewhat open, and as a result, Khayyam has received markedly conflicting assessments and criticisms.

**Reception**

The various biographical extracts that refer to Omar Khayyam describe him as an unparalleled scientific knowledge and achievements during his time. Many called him by the epithet of the king of the wise. Shahrazuri (deceased in 1300) considers him a great mathematician and affirms that he can be considered as “the successor of Avicenna in the various branches of philosophical learning”. Al-Qifti (deceased in 1248), although he disagrees with his views, admits that he “had no rival in his knowledge of natural philosophy and astronomy.” Despite being hailed as a poet by several biographers, according to Richard Nelson Frye, “it is still possible to argue that Khayyam’s status as a poet of the first rank is a relatively late development.”

Thomas Hyde was the first European to call attention to Omar and to translate one of his quatrains into Latin (History of the Venetian religion Persarum eorumque magorum, 1700). Western interest in Persia grew with the movement of Orientalism in the 19th century. Joseph von Hammer-Purgstall (1774-1856) translated some of the poems of Khayyam into German in 1818, and Gore Ouseley (1770-1844) into English in 1846, but Khayyam remained relatively unknown in the West until after Rubaiyat’s publication of Edward FitzGerald Omar Khayyam in 1859. At first, FitzGerald’s work was unsuccessful, but it was popularized by Whitley Stokes from 1861 onwards, and the Pre-Raphaelites greatly admired it. In 1872, FitzGerald printed a third edition that increased interest in work in America. In the 1880s, the book was well known throughout the English-speaking world, to the extent that numerous “Omar Khayyam Clubs” and an “end of siècle cult of the Rubaiyat” were formed. Khayyam’s poems have been translated into many languages; many of the more recent ones are more literal than those of FitzGerald.

FitzGerald’s translation was a factor that rekindled interest in Khayyam as a poet, even in his native Iran. Sadegh Hedayat in his Songs of Khayyam (Taranehha-ye Khayyam, 1934) reintroduced Omar’s poetic legacy in modern Iran. Under the Pahlavi dynasty, a new white marble monument, designed by the architect Houshang Seyhoun, was erected on his grave. A statue of Abolhassan Sadighi was erected in Laleh Park, Tehran, in the 1960s, and a bust of the same sculptor was placed near the Khayyam mausoleum in Nishapur. In 2009, the state of Iran donated a pavilion to the United Nations Office in Vienna, inaugurated at the Vienna International Center. In 2016, three Khayyam statues were unveiled: one at the University of Oklahoma, one in Nishapur and one in Florence, Italy. More than 150 composers have used the Rubaiyat as their source of inspiration. The first composer was Liza Lehmann.

FitzGerald interpreted Omar’s name as “Tentmaker,” and the English name of “Omar the Tentmaker” resonated in English-speaking popular culture for a time. Thus, Nathan Haskell Dole published a novel called Omar, The Tentmaker: A Romance of Old Persia in 1898. Omar the Tentmaker of Naishapur is a historical novel by John Smith Clarke, published in 1910. “Omar the Tentmaker” is also the title of a 1914 work by Richard Walton Tully on an eastern stage, adapted as a silent film in 1922. American General Omar Bradley was nicknamed “Omar the Tent-Maker” in World War II. The name has also been registered as an expression of slang for “penis”.

The lunar crater Omar Khayyam was named in his honor in 1970, as was the minor planet 3095 Omarkhayyam discovered by the Soviet astronomer Lyudmila Zhuravlyova in 1980.

In celebration of his 971 birthday, Google launched a Google Doodle commemorating it.