فارسی
Rubaiyat

Awake! for morningin the bowl of night
 
Has flung the Stone that puts the Stars to Flight:
 
 And Lo! the Hunter of the East has caught
 
 The Sultan's Turret in a Noose of Light.

Astronomy

Khayyam moved to Isfahan in 1074 to help establish a new observatory under the patronage of Malikshah, the Seljuk sultan, and his vizier, Nizam al-Mulk.

There is little doubt that Khayyam played a major role in the creation of the Malikī calendar, the observatory's most significant project. In addition to the calendar, the Isfahan observatory produced the
Zīj Malikshah (of which only a fragment of its star catalogue survives); it seems to have been one of the more important astronomical handbooks.

Several treatises on other scientific topics are also attributed to Khayyam:

a work on music theory that uses ratios to deal with musical intervals, another on weights and balances, and another on a mathematical problem in metallurgy. All of his texts seem to have been taken seriously.


Heliocentric Theory
 
It is sometimes claimed that Khayyam demonstrated that the earth rotates on its axis[32] by presenting a model of the stars to his contemporary al-Ghazali in a planetarium.[33] Whether or not the story is apocryphal, it would only demonstrate the mathematical equivalence of a rotating earth to rotating spheres, as was well known to Khayyam's immediate predecessors, e.g. al-Biruni, and says nothing about heliocentrism, as a spinning earth can be made entirely consistent with geocentric models.
 
The other source for the claim that Khayyam believed in heliocentrism are Edward Fitzgerald's popular but anachronistic renderings[34] of Khayyam's poetry, in which the first lines are mistranslated with a heliocentric image of the Sun flinging "the Stone that puts the Stars to Flight".


Calendar Reform
 
Khayyám is claimed to be a member of a panel that introduced several reforms to the Iranian calendar.[citation needed] On March 15, 1079, Sultan Malik Shah accepted this corrected calendar as the official Persian calendar.
 
This calendar was known as the Jalali calendar after the Sultan, and was in force across Greater Iran from the 11th to the 20th centuries. It is the basis of the Iranian calendar which is followed today in Iran and Afghanistan. While the Jalali calendar is more accurate than the Gregorian, it is based on actual solar transit, similar to Hindu calendars, and requires an ephemeris for calculating dates. The lengths of the months can vary between 29 and 31 days depending on the moment when the sun crosses into a new zodiacal area (an attribute common to most Hindu calendars). This meant that seasonal errors were lower than in the Gregorian calendar.
 
The modern-day Iranian calendar standardizes the month lengths based on a reform from 1925, thus minimizing the effect of solar transits. Seasonal errors are somewhat higher than in the Jalali version, but leap years are calculated as before.


 
Khayyam Scholar
 
2018 November
Thursday
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