Maragheh observatory
Encyclopedia
Maragheh observatory is an astronomical observatory which was established in 1259 CE by Nasir al-Din al-Tusi
, an Iranian
scientist
and astronomer
. Located in the heights west of Maragheh
, East Azarbaijan province
, Iran
, it was once considered one of the most prestigious observatories in the world.
. This meridian served as Prime meridian
for the tables in the Zij-i Ilkhani
, as we nowadays apply the meridian which passes the Royal Greenwich Observatory.
The Maragha observatory was the largest observatory in its time, consisting of a series of buildings occupying an area of 150 metres in width and 350 metres in length. One of these buildings was a dome
which allowed the sun's rays to pass through. There was also a library consisting of 40,000 volumes, which were plundered from other libraries by the Mongol Empire
during its invasions across Persia
, Syria
and Mesopotamia
. Astronomers from across Persia, Syria, Anatolia
and even China
were gathered at the observatory, and the names of at least twenty of them who worked at the observatory are known. It is believed that several Chinese astronomers
worked at the observatory and that they introduced several Chinese methods of computation
. The Maragha observatory was also reported to have had over a hundred students studying under Nasir al-Din Tusi at the observatory, and was also the first observatory to benefit from the revenues of waqf
trust funds. After al-Tusi's death, his son was appointed the director of the institution, but it was later abandoned by the middle of the 14th century. A visit to the ruins of the observatory later inspired Ulugh Beg
to construct his own large observatory at Samarkand
to continue the astronomical research of the Maragha school from where it left off.
Hulegu Khan believed that many of his military successes were due to the advice of astronomers (who were also astrologer
s), especially of Nasīr al-Dīn al-Tūsī
. Therefore when Tusi complained that his astronomical tables were outdated, Hulagu gave a permission to build a new observatory in a place of Tusi's choice. According to books like Jam-e-ttavarikhe rashidi (Persian: جامع التواريخ رشيدي), saf-e-elhofreh (Persian: صاف الحفره), favat-o-lvafiyyat (Persian: فوات الوفيات) the building of the rasad khaneh started in 1259 (657 A.H.). The library of the observatory contained 40,000 books on many subjects, related to astrology/astronomy as well as other topics. Bar-Hebraeus
late in his life took residence close to the observatory in order to use the library for his studies. He has left a description of the observatory.
A number of other prominent astronomers worked with Tusi there, such as Muhyi al-Din al-Maghribi
, Mu'ayyid al-Din al-'Urdi, from Damascus
, and Qutb al-Din al-Shirazi
. The observatory also attracted scholars from beyond the Islamic world, such as Hulagu's Chinese astronomer
Fao Munji, whose Chinese astronomical experience brought further improvements to the Ptolemaic
system initially used by Tusi. It also attracted scholars from the Byzantine Empire
, most notably Gregory Choniades
, who studied under Shams ad-Din al-Bukhari, an astronomer who worked at the famous observatory under al-Tusi. Choniades later translated the Zij-i Ilkhani
, compiled at the observatory, into Byzantine Greek and took it to the Byzantine Empire. He may have been responsible for the transmission of the Tusi-couple
to Europe, where it eventually influenced Copernican heliocentrism
.
For his planetary models, Tusi invented a geometrical technique called a Tusi-couple
, which generates linear motion from the sum of two circular motions. He also determined the precise value of 51 arcsec for the annual precession of the equinox
es and contributed to the construction and usage of some astronomical instruments including the astrolabe
.
And after 12 years of intense work by Khaje Nassir od-Din Tussi and the other prominent scientists the observations and planetary models were compiled in the Zij-i Ilkhani
, which later still influenced Copernicus. The tables were published during the reign of Abaqa Khan
, Hulagu's son, and named after the patron of the observatory. They were popular until the 15th century.
It is not known with certainty until when it had been active. It turned into ruins as a result of frequent earthquakes and lack of funding by the state. Shah Abbas the Great
arranged for repair, however, this was not commenced due to the king's early death.
The remains inspired Ulugh Beg
to construct his observatory in Samarkand
in 1428.
Hulegu's older brother, Khublai Khan also constructed an observatory, the Gaocheng Astronomical Observatory
in China.
A star globe from the observatory made in 1279 is now preserved in Dresden
, Germany
. It is a rare example of decorative art from Iran
of the 13th century, designed by M. Ordi and made of bronze
, inlaid with silver
and gold
.
The "Maragha Revolution" refers to the Maragheh
school's revolution
against Ptolemaic
astronomy. The "Maragha school" was an astronomical tradition beginning in the Maragheh observatory and continuing with astronomers from the Damascus mosque
and Samarkand observatory
. The Maragha astronomers attempted to solve the equant
problem and produce alternative configurations to the Ptolemaic model. They were more successful than previous astronomers in producing non-Ptolemaic configurations which eliminated the equant and eccentrics
, were more accurate than the Ptolemaic model in numerically predicting planetary positions, and were in better agreement with empirical
observation
s. The most important of the Maragha astronomers included Mo'ayyeduddin Urdi
(d. 1266), Nasīr al-Dīn al-Tūsī
(1201–1274), Najm al-Dīn al-Qazwīnī al-Kātibī
(d. 1277), Qutb al-Din al-Shirazi
(1236–1311), Sadr al-Sharia al-Bukhari (c. 1347), Ibn al-Shatir
(1304–1375), Ali Qushji (c. 1474), al-Birjandi
(d. 1525), and Shams al-Din al-Khafri (d. 1550).
Some have described their achievements in the 13th and 14th centuries as a "Maragha Revolution", "Maragha School Revolution", or "Scientific Revolution
before the Renaissance
". An important aspect of this revolution
included the realization that astronomy should aim to describe the behaviour of physical bodies
in mathematical
language, and should not remain a mathematical hypothesis
, which would only save the phenomena. The Maragha astronomers also realized that the Aristotelian
view of motion
in the universe being only circular or linear
was not true, as the Tusi-couple
showed that linear motion could also be produced by applying circular motion
s only.
Unlike the ancient Greek and Hellenistic astronomers
who were not concerned with the coherence between the mathematical and physical principles of a planetary theory, Islamic astronomers insisted on the need to match mathematics with the real world surrounding them, which gradually evolved from a reality based on Aristotelian physics
to one based on an empirical and mathematical physics
. The Maragha Revolution was thus characterized by a shift away from the philosophical foundations of Aristotelian cosmology
and Ptolemaic astronomy and towards a greater emphasis on the empirical observation and mathematization
of astronomy and of nature
in general, as exemplified in the works of Ibn al-Shatir
, Ali Qushji, al-Birjandi
and al-Khafri.
Other achievements of the Maragha school include the first empirical
observation
al evidence for the Earth's rotation on its axis by Tusi and Qushji, the separation of natural philosophy
from astronomy by Ibn al-Shatir and Qushji, the rejection of the Ptolemaic model on empirical rather than philosophical grounds by Ibn al-Shatir, and the development of a non-Ptolemaic model by Ibn al-Shatir that was mathematically identical to the heliocentric Copernical model
.
Mo'ayyeduddin Urdi
(d. 1266) was the first of the Maragheh astronomers to develop a non-Ptolemaic model, and he proposed a new theorem, the "Urdi lemma". Nasir al-Din al-Tusi
(1201–1274) resolved significant problems in the Ptolemaic system by developing the Tusi-couple
as an alternative to the physically problematic equant
introduced by Ptolemy. Tusi's student Qutb al-Din al-Shirazi
(1236–1311), in his The Limit of Accomplishment concerning Knowledge of the Heavens, discusses the possibility of heliocentrism
. Al-Qazwīnī al-Kātibī, in his Hikmat al-'Ain, wrote an argument for a heliocentric model, though he later abandoned the idea.
Ibn al-Shatir
(1304–1375), in his A Final Inquiry Concerning the Rectification of Planetary Theory, eliminated the need for an equant by introducing an extra epicycle, departing from the Ptolemaic system in a way very similar to what Nicolaus Copernicus
later also did. Ibn al-Shatir proposed a system that was only approximately geocentric, rather than exactly so, having demonstrated trigonometrically
that the Earth was not the exact center of the universe. Unlike previous astronomers before him, Ibn al-Shatir was not concerned with adhering to the theoretical principles of natural philosophy
(or Aristotelian physics
), but rather to produce a model that was more consistent with empirical
observations. For example, it was Ibn al-Shatir's concern for observational accuracy which led him to eliminate the epicycle in the Ptolemaic solar
model and all the eccentrics, epicycles and equant in the Ptolemaic lunar model
. His model was thus in better agreement with empirical observation
s than any previous model produced before him. While previous Maragha models were just as accurate as the Ptolemaic model, Ibn al-Shatir's geometric model was the first that was actually superior to the Ptolemaic model in terms of its better agreement with empirical observations. His work thus marked a turning point in astronomy, which may be considered a "Scientific Revolution before the Renaissance".
Y. M. Faruqi wrote:
Ibn al-Shatir’s rectified model, which included the Tusi-couple and Urdi lemma, was later adapted into a heliocentric model
by Copernicus, which was mathematically achieved by reversing the direction of the last vector connecting the Earth to the Sun in Ibn al-Shatir's model.
An area of active discussion in the Maragheh school, and later the Samarkand
and Istanbul
observatories, was the possibility of the Earth's rotation. Supporters of this theory included Nasir al-Din al-Tusi
, Nizam al-Din al-Nisaburi (c. 1311), al-Sayyid al-Sharif al-Jurjani (1339–1413), Ali Qushji (d. 1474), and Abd al-Ali al-Birjandi (d. 1525). Tusi was the first to present empirical
observation
al evidence of the Earth's rotation, using the location of comet
s relevant to the Earth as evidence, which Qushji elaborated on with further empirical observations while rejecting Aristotelian
natural philosophy
altogether. Both of their arguments were later described again by Nicolaus Copernicus
in 1543.
To save the installation from further destruction, Cultural Heritage Organization of Iran
built a dome
-framed shelter and it plans to hold an exhibit of astronomical devices used at Maragheh observatory.
The observatory is currently covered with a dome-framed brass
structure and is situated two miles west of Maragheh.
Nasir al-Din al-Tusi
Khawaja Muḥammad ibn Muḥammad ibn Ḥasan Ṭūsī , better known as Naṣīr al-Dīn al-Ṭūsī , was a Persian polymath and prolific writer: an astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, theologian and Marja Taqleed...
, an Iranian
Iranian peoples
The Iranian peoples are an Indo-European ethnic-linguistic group, consisting of the speakers of Iranian languages, a major branch of the Indo-European language family, as such forming a branch of Indo-European-speaking peoples...
scientist
Islamic science
Science in the medieval Islamic world, also known as Islamic science or Arabic science, is the science developed and practised in the Islamic world during the Islamic Golden Age . During this time, Indian, Iranian and especially Greek knowledge was translated into Arabic...
and astronomer
Islamic astronomy
Islamic astronomy or Arabic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age , and mostly written in the Arabic language. These developments mostly took place in the Middle East, Central Asia, Al-Andalus, and North Africa, and...
. Located in the heights west of Maragheh
Maragheh
Maragheh also Romanized as Marāgheh and Marāghen) is a city in and the capital of Maragheh County, East Azerbaijan Province, Iran. At the 2006 census, its population was 146,405, in 38,891 families....
, East Azarbaijan province
East Azarbaijan Province
East Azerbaijan Province or East Azarbaijan Province is one of the 31 provinces of Iran. It is in the northwest of the country, bordering Armenia and the Republic of Azerbaijan, and the provinces of Ardabil, West Azerbaijan, and Zanjan...
, Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
, it was once considered one of the most prestigious observatories in the world.
Description
Considerable parts of the groundwork are preserved in the ruins. In a 340 to 135 m² citadel-like area stood a four-story circular stone building of 28 m diameter. The mural quadrant to observe the positions of the stars and planets was aligned with the meridianMeridian (astronomy)
This article is about the astronomical concept. For other uses of the word, see Meridian.In the sky, a meridian is an imaginary great circle on the celestial sphere. It passes through the north point on the horizon, through the celestial pole, up to the zenith, through the south point on the...
. This meridian served as Prime meridian
Prime Meridian
The Prime Meridian is the meridian at which the longitude is defined to be 0°.The Prime Meridian and its opposite the 180th meridian , which the International Date Line generally follows, form a great circle that divides the Earth into the Eastern and Western Hemispheres.An international...
for the tables in the Zij-i Ilkhani
Zij-i Ilkhani
Zīj-i Īlkhānī or Ilkhanic Tables is a Zij book with astronomical tables of planetary movements. It was compiled by the Persian astronomer Nasir al-Din al-Tusi in collaboration with his research team of astronomers at the Maragha observatory...
, as we nowadays apply the meridian which passes the Royal Greenwich Observatory.
The Maragha observatory was the largest observatory in its time, consisting of a series of buildings occupying an area of 150 metres in width and 350 metres in length. One of these buildings was a dome
Dome
A dome is a structural element of architecture that resembles the hollow upper half of a sphere. Dome structures made of various materials have a long architectural lineage extending into prehistory....
which allowed the sun's rays to pass through. There was also a library consisting of 40,000 volumes, which were plundered from other libraries by the Mongol Empire
Mongol Empire
The Mongol Empire , initially named as Greater Mongol State was a great empire during the 13th and 14th centuries...
during its invasions across Persia
History of Iran
The history of Iran has been intertwined with the history of a larger historical region, comprising the area from the Danube River in the west to the Indus River and Jaxartes in the east and from the Caucasus, Caspian Sea, and Aral Sea in the north to the Persian Gulf and the Gulf of Oman and Egypt...
, Syria
Syria
Syria , officially the Syrian Arab Republic , is a country in Western Asia, bordering Lebanon and the Mediterranean Sea to the West, Turkey to the north, Iraq to the east, Jordan to the south, and Israel to the southwest....
and Mesopotamia
Mesopotamia
Mesopotamia is a toponym for the area of the Tigris–Euphrates river system, largely corresponding to modern-day Iraq, northeastern Syria, southeastern Turkey and southwestern Iran.Widely considered to be the cradle of civilization, Bronze Age Mesopotamia included Sumer and the...
. Astronomers from across Persia, Syria, Anatolia
Anatolia
Anatolia is a geographic and historical term denoting the westernmost protrusion of Asia, comprising the majority of the Republic of Turkey...
and even China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
were gathered at the observatory, and the names of at least twenty of them who worked at the observatory are known. It is believed that several Chinese astronomers
Chinese astronomy
Astronomy in China has a very long history, with historians considering that "they [the Chinese] were the most persistent and accurate observers of celestial phenomena anywhere in the world before the Arabs."...
worked at the observatory and that they introduced several Chinese methods of computation
Chinese mathematics
Mathematics in China emerged independently by the 11th century BC. The Chinese independently developed very large and negative numbers, decimals, a place value decimal system, a binary system, algebra, geometry, and trigonometry....
. The Maragha observatory was also reported to have had over a hundred students studying under Nasir al-Din Tusi at the observatory, and was also the first observatory to benefit from the revenues of waqf
Waqf
A waqf also spelled wakf formally known as wakf-alal-aulad is an inalienable religious endowment in Islamic law, typically denoting a building or plot of land for Muslim religious or charitable purposes. The donated assets are held by a charitable trust...
trust funds. After al-Tusi's death, his son was appointed the director of the institution, but it was later abandoned by the middle of the 14th century. A visit to the ruins of the observatory later inspired Ulugh Beg
Ulugh Beg
Ulugh Bek was a Timurid ruler as well as an astronomer, mathematician and sultan. His commonly-known name is not truly a personal name, but rather a moniker, which can be loosely translated as "Great Ruler" or "Patriarch Ruler" and was the Turkic equivalent of Timur's Perso-Arabic title Amīr-e...
to construct his own large observatory at Samarkand
Samarkand
Although a Persian-speaking region, it was not united politically with Iran most of the times between the disintegration of the Seleucid Empire and the Arab conquest . In the 6th century it was within the domain of the Turkic kingdom of the Göktürks.At the start of the 8th century Samarkand came...
to continue the astronomical research of the Maragha school from where it left off.
History
Astrologer
An astrologer practices one or more forms of astrology. Typically an astrologer draws a horoscope for the time of an event, such as a person's birth, and interprets celestial points and their placements at the time of the event to better understand someone, determine the auspiciousness of an...
s), especially of Nasīr al-Dīn al-Tūsī
Nasir al-Din al-Tusi
Khawaja Muḥammad ibn Muḥammad ibn Ḥasan Ṭūsī , better known as Naṣīr al-Dīn al-Ṭūsī , was a Persian polymath and prolific writer: an astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, theologian and Marja Taqleed...
. Therefore when Tusi complained that his astronomical tables were outdated, Hulagu gave a permission to build a new observatory in a place of Tusi's choice. According to books like Jam-e-ttavarikhe rashidi (Persian: جامع التواريخ رشيدي), saf-e-elhofreh (Persian: صاف الحفره), favat-o-lvafiyyat (Persian: فوات الوفيات) the building of the rasad khaneh started in 1259 (657 A.H.). The library of the observatory contained 40,000 books on many subjects, related to astrology/astronomy as well as other topics. Bar-Hebraeus
Bar-Hebraeus
Gregory Bar Hebraeus was a catholicos of the Syriac Orthodox Church in the 13th century...
late in his life took residence close to the observatory in order to use the library for his studies. He has left a description of the observatory.
A number of other prominent astronomers worked with Tusi there, such as Muhyi al-Din al-Maghribi
Muhyi al-Din al-Maghribi
', was a Muslim astronomer and mathematician born in Spain, worked in Damascus, Syria and eventually in the Maragha observatory in Maragha, Ilkhanate of Persia, where he worked under the guidance of Nasir al-Din Tusi.Muhyi al-Din is most known for his works in trigonometry, Book on the theorem...
, Mu'ayyid al-Din al-'Urdi, from Damascus
Damascus
Damascus , commonly known in Syria as Al Sham , and as the City of Jasmine , is the capital and the second largest city of Syria after Aleppo, both are part of the country's 14 governorates. In addition to being one of the oldest continuously inhabited cities in the world, Damascus is a major...
, and Qutb al-Din al-Shirazi
Qutb al-Din al-Shirazi
Qotb al-Din Shirazi or Qutb al-Din al-Shirazi was a 13th century Persian Muslim polymath and Persian poet who made contributions astronomy, mathematics, medicine, physics, music theory, philosophy and Sufism.- Biography :...
. The observatory also attracted scholars from beyond the Islamic world, such as Hulagu's Chinese astronomer
Chinese astronomy
Astronomy in China has a very long history, with historians considering that "they [the Chinese] were the most persistent and accurate observers of celestial phenomena anywhere in the world before the Arabs."...
Fao Munji, whose Chinese astronomical experience brought further improvements to the Ptolemaic
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...
system initially used by Tusi. It also attracted scholars from the Byzantine Empire
Byzantine Empire
The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...
, most notably Gregory Choniades
Gregory Choniades
Gregory Choniades was a Byzantine Greek astronomer. He travelled to Persia where he learnt Persian mathematical and astronomical science which he introduced into Byzantium upon return from Persia and founded an astronomical academy at Trebizond...
, who studied under Shams ad-Din al-Bukhari, an astronomer who worked at the famous observatory under al-Tusi. Choniades later translated the Zij-i Ilkhani
Zij-i Ilkhani
Zīj-i Īlkhānī or Ilkhanic Tables is a Zij book with astronomical tables of planetary movements. It was compiled by the Persian astronomer Nasir al-Din al-Tusi in collaboration with his research team of astronomers at the Maragha observatory...
, compiled at the observatory, into Byzantine Greek and took it to the Byzantine Empire. He may have been responsible for the transmission of the Tusi-couple
Tusi-couple
The Tusi-couple is a mathematical device in which a small circle rotates inside a larger circle twice the diameter of the smaller circle. Rotations of the circles cause a point on the circumference of the smaller circle to oscillate back and forth in linear motion along a diameter of the larger...
to Europe, where it eventually influenced Copernican heliocentrism
Copernican heliocentrism
Copernican heliocentrism is the name given to the astronomical model developed by Nicolaus Copernicus and published in 1543. It positioned the Sun near the center of the Universe, motionless, with Earth and the other planets rotating around it in circular paths modified by epicycles and at uniform...
.
For his planetary models, Tusi invented a geometrical technique called a Tusi-couple
Tusi-couple
The Tusi-couple is a mathematical device in which a small circle rotates inside a larger circle twice the diameter of the smaller circle. Rotations of the circles cause a point on the circumference of the smaller circle to oscillate back and forth in linear motion along a diameter of the larger...
, which generates linear motion from the sum of two circular motions. He also determined the precise value of 51 arcsec for the annual precession of the equinox
Equinox
An equinox occurs twice a year, when the tilt of the Earth's axis is inclined neither away from nor towards the Sun, the center of the Sun being in the same plane as the Earth's equator...
es and contributed to the construction and usage of some astronomical instruments including the astrolabe
Astrolabe
An astrolabe is an elaborate inclinometer, historically used by astronomers, navigators, and astrologers. Its many uses include locating and predicting the positions of the Sun, Moon, planets, and stars, determining local time given local latitude and longitude, surveying, triangulation, and to...
.
And after 12 years of intense work by Khaje Nassir od-Din Tussi and the other prominent scientists the observations and planetary models were compiled in the Zij-i Ilkhani
Zij-i Ilkhani
Zīj-i Īlkhānī or Ilkhanic Tables is a Zij book with astronomical tables of planetary movements. It was compiled by the Persian astronomer Nasir al-Din al-Tusi in collaboration with his research team of astronomers at the Maragha observatory...
, which later still influenced Copernicus. The tables were published during the reign of Abaqa Khan
Abaqa Khan
Abaqa Khan , also Abaga , or Abagha Khan, was the second Mongol ruler of the Persian Ilkhanate. The son of Hulagu Khan and Yesuncin Khatun, he reigned from 1265–1282 and was succeeded by his brother Tekuder Khan...
, Hulagu's son, and named after the patron of the observatory. They were popular until the 15th century.
It is not known with certainty until when it had been active. It turned into ruins as a result of frequent earthquakes and lack of funding by the state. Shah Abbas the Great
Abbas I of Persia
Shāh ‘Abbās the Great was Shah of Iran, and generally considered the greatest ruler of the Safavid dynasty. He was the third son of Shah Mohammad....
arranged for repair, however, this was not commenced due to the king's early death.
The remains inspired Ulugh Beg
Ulugh Beg
Ulugh Bek was a Timurid ruler as well as an astronomer, mathematician and sultan. His commonly-known name is not truly a personal name, but rather a moniker, which can be loosely translated as "Great Ruler" or "Patriarch Ruler" and was the Turkic equivalent of Timur's Perso-Arabic title Amīr-e...
to construct his observatory in Samarkand
Samarkand
Although a Persian-speaking region, it was not united politically with Iran most of the times between the disintegration of the Seleucid Empire and the Arab conquest . In the 6th century it was within the domain of the Turkic kingdom of the Göktürks.At the start of the 8th century Samarkand came...
in 1428.
Hulegu's older brother, Khublai Khan also constructed an observatory, the Gaocheng Astronomical Observatory
Gaocheng Astronomical Observatory
Gaocheng Astronomical Observatory, also known as the Dengfeng Observatory, is a World Heritage Site in Duke Zhou Gong's shrine, Gaocheng Town, near Dengfeng in Henan Province, China. This site has a long tradition of astronomical observations, from the time of the Western Zhou up to the early Yuan...
in China.
A star globe from the observatory made in 1279 is now preserved in Dresden
Dresden
Dresden is the capital city of the Free State of Saxony in Germany. It is situated in a valley on the River Elbe, near the Czech border. The Dresden conurbation is part of the Saxon Triangle metropolitan area....
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
. It is a rare example of decorative art from Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
of the 13th century, designed by M. Ordi and made of bronze
Bronze
Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...
, inlaid with silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
and gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
.
Maragha Revolution
Maragheh
Maragheh also Romanized as Marāgheh and Marāghen) is a city in and the capital of Maragheh County, East Azerbaijan Province, Iran. At the 2006 census, its population was 146,405, in 38,891 families....
school's revolution
Revolution
A revolution is a fundamental change in power or organizational structures that takes place in a relatively short period of time.Aristotle described two types of political revolution:...
against Ptolemaic
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...
astronomy. The "Maragha school" was an astronomical tradition beginning in the Maragheh observatory and continuing with astronomers from the Damascus mosque
Umayyad Mosque
The Umayyad Mosque, also known as the Great Mosque of Damascus or formerly the Basilica of Saint John the Baptist , is located in the old city of Damascus, is one of the largest and oldest mosques in the world...
and Samarkand observatory
Ulugh Beg Observatory
The Ulugh Beg Observatory is an observatory in Samarkand, Uzbekistan. Built in the 1420s by the Timurid astronomer Ulugh Beg, it is considered by scholars to have been one of the finest observatories in the Islamic world at the time and the largest in Central Asia before it was destroyed in 1449...
. The Maragha astronomers attempted to solve the equant
Equant
Equant is a mathematical concept developed by Claudius Ptolemy in the 2nd century AD to account for the observed motion of heavenly bodies....
problem and produce alternative configurations to the Ptolemaic model. They were more successful than previous astronomers in producing non-Ptolemaic configurations which eliminated the equant and eccentrics
Deferent and epicycle
In the Ptolemaic system of astronomy, the epicycle was a geometric model used to explain the variations in speed and direction of the apparent motion of the Moon, Sun, and planets...
, were more accurate than the Ptolemaic model in numerically predicting planetary positions, and were in better agreement with empirical
Empirical
The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....
observation
Observation
Observation is either an activity of a living being, such as a human, consisting of receiving knowledge of the outside world through the senses, or the recording of data using scientific instruments. The term may also refer to any data collected during this activity...
s. The most important of the Maragha astronomers included Mo'ayyeduddin Urdi
Mo'ayyeduddin Urdi
Mu’ayyad al-Din al-’Urdi was an Kurdish Muslim astronomer, mathematician, architect and engineer working at the Maragheh observatory...
(d. 1266), Nasīr al-Dīn al-Tūsī
Nasir al-Din al-Tusi
Khawaja Muḥammad ibn Muḥammad ibn Ḥasan Ṭūsī , better known as Naṣīr al-Dīn al-Ṭūsī , was a Persian polymath and prolific writer: an astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, theologian and Marja Taqleed...
(1201–1274), Najm al-Dīn al-Qazwīnī al-Kātibī
Najm al-Dīn al-Qazwīnī al-Kātibī
Najm al-Dīn al-Qazwīnī al-Kātibī was a Persian Islamic philosopher and logician of the Shafi`i school. A student of Nasir al-Din al-Tusi, he is the author of two major works, one on logic, Al-Risala al-Shamsiyya, and one on metaphysics and the natural sciences, Hikmat al-'Ain.-Logic:His work on...
(d. 1277), Qutb al-Din al-Shirazi
Qutb al-Din al-Shirazi
Qotb al-Din Shirazi or Qutb al-Din al-Shirazi was a 13th century Persian Muslim polymath and Persian poet who made contributions astronomy, mathematics, medicine, physics, music theory, philosophy and Sufism.- Biography :...
(1236–1311), Sadr al-Sharia al-Bukhari (c. 1347), Ibn al-Shatir
Ibn al-Shatir
Ala Al-Din Abu'l-Hasan Ali Ibn Ibrahim Ibn al-Shatir was an Arab Muslim astronomer, mathematician, engineer and inventor who worked as muwaqqit at the Umayyad Mosque in Damascus, Syria.-Astronomy:...
(1304–1375), Ali Qushji (c. 1474), al-Birjandi
Al-Birjandi
Abd Ali ibn Muhammad ibn Husayn Birjandi was a prominent 16th century Persian astronomer, mathematician and physicist who lived in Birjand, Iran.- His works :...
(d. 1525), and Shams al-Din al-Khafri (d. 1550).
Some have described their achievements in the 13th and 14th centuries as a "Maragha Revolution", "Maragha School Revolution", or "Scientific Revolution
Scientific revolution
The Scientific Revolution is an era associated primarily with the 16th and 17th centuries during which new ideas and knowledge in physics, astronomy, biology, medicine and chemistry transformed medieval and ancient views of nature and laid the foundations for modern science...
before the Renaissance
Renaissance
The Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...
". An important aspect of this revolution
Revolution
A revolution is a fundamental change in power or organizational structures that takes place in a relatively short period of time.Aristotle described two types of political revolution:...
included the realization that astronomy should aim to describe the behaviour of physical bodies
Physical body
In physics, a physical body or physical object is a collection of masses, taken to be one...
in mathematical
Islamic mathematics
In the history of mathematics, mathematics in medieval Islam, often termed Islamic mathematics or Arabic mathematics, covers the body of mathematics preserved and developed under the Islamic civilization between circa 622 and 1600...
language, and should not remain a mathematical hypothesis
Hypothesis
A hypothesis is a proposed explanation for a phenomenon. The term derives from the Greek, ὑποτιθέναι – hypotithenai meaning "to put under" or "to suppose". For a hypothesis to be put forward as a scientific hypothesis, the scientific method requires that one can test it...
, which would only save the phenomena. The Maragha astronomers also realized that the Aristotelian
Aristotelianism
Aristotelianism is a tradition of philosophy that takes its defining inspiration from the work of Aristotle. The works of Aristotle were initially defended by the members of the Peripatetic school, and, later on, by the Neoplatonists, who produced many commentaries on Aristotle's writings...
view of motion
Motion (physics)
In physics, motion is a change in position of an object with respect to time. Change in action is the result of an unbalanced force. Motion is typically described in terms of velocity, acceleration, displacement and time . An object's velocity cannot change unless it is acted upon by a force, as...
in the universe being only circular or linear
Linear
In mathematics, a linear map or function f is a function which satisfies the following two properties:* Additivity : f = f + f...
was not true, as the Tusi-couple
Tusi-couple
The Tusi-couple is a mathematical device in which a small circle rotates inside a larger circle twice the diameter of the smaller circle. Rotations of the circles cause a point on the circumference of the smaller circle to oscillate back and forth in linear motion along a diameter of the larger...
showed that linear motion could also be produced by applying circular motion
Circular motion
In physics, circular motion is rotation along a circular path or a circular orbit. It can be uniform, that is, with constant angular rate of rotation , or non-uniform, that is, with a changing rate of rotation. The rotation around a fixed axis of a three-dimensional body involves circular motion of...
s only.
Unlike the ancient Greek and Hellenistic astronomers
Greek astronomy
Greek astronomy is astronomy written in the Greek language in classical antiquity. Greek astronomy is understood to include the ancient Greek, Hellenistic, Greco-Roman, and Late Antiquity eras. It is not limited geographically to Greece or to ethnic Greeks, as the Greek language had become the...
who were not concerned with the coherence between the mathematical and physical principles of a planetary theory, Islamic astronomers insisted on the need to match mathematics with the real world surrounding them, which gradually evolved from a reality based on Aristotelian physics
Aristotelian physics
Aristotelian Physics the natural sciences, are described in the works of the Greek philosopher Aristotle . In the Physics, Aristotle established general principles of change that govern all natural bodies; both living and inanimate, celestial and terrestrial—including all motion, change in respect...
to one based on an empirical and mathematical physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
. The Maragha Revolution was thus characterized by a shift away from the philosophical foundations of Aristotelian cosmology
On the Heavens
On the Heavens is Aristotle's chief cosmological treatise: it contains his astronomical theory and his ideas on the concrete workings of the terrestrial world...
and Ptolemaic astronomy and towards a greater emphasis on the empirical observation and mathematization
Islamic mathematics
In the history of mathematics, mathematics in medieval Islam, often termed Islamic mathematics or Arabic mathematics, covers the body of mathematics preserved and developed under the Islamic civilization between circa 622 and 1600...
of astronomy and of nature
Nature
Nature, in the broadest sense, is equivalent to the natural world, physical world, or material world. "Nature" refers to the phenomena of the physical world, and also to life in general...
in general, as exemplified in the works of Ibn al-Shatir
Ibn al-Shatir
Ala Al-Din Abu'l-Hasan Ali Ibn Ibrahim Ibn al-Shatir was an Arab Muslim astronomer, mathematician, engineer and inventor who worked as muwaqqit at the Umayyad Mosque in Damascus, Syria.-Astronomy:...
, Ali Qushji, al-Birjandi
Al-Birjandi
Abd Ali ibn Muhammad ibn Husayn Birjandi was a prominent 16th century Persian astronomer, mathematician and physicist who lived in Birjand, Iran.- His works :...
and al-Khafri.
Other achievements of the Maragha school include the first empirical
Empirical
The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....
observation
Observation
Observation is either an activity of a living being, such as a human, consisting of receiving knowledge of the outside world through the senses, or the recording of data using scientific instruments. The term may also refer to any data collected during this activity...
al evidence for the Earth's rotation on its axis by Tusi and Qushji, the separation of natural philosophy
Natural philosophy
Natural philosophy or the philosophy of nature , is a term applied to the study of nature and the physical universe that was dominant before the development of modern science...
from astronomy by Ibn al-Shatir and Qushji, the rejection of the Ptolemaic model on empirical rather than philosophical grounds by Ibn al-Shatir, and the development of a non-Ptolemaic model by Ibn al-Shatir that was mathematically identical to the heliocentric Copernical model
Copernican heliocentrism
Copernican heliocentrism is the name given to the astronomical model developed by Nicolaus Copernicus and published in 1543. It positioned the Sun near the center of the Universe, motionless, with Earth and the other planets rotating around it in circular paths modified by epicycles and at uniform...
.
Mo'ayyeduddin Urdi
Mu’ayyad al-Din al-’Urdi was an Kurdish Muslim astronomer, mathematician, architect and engineer working at the Maragheh observatory...
(d. 1266) was the first of the Maragheh astronomers to develop a non-Ptolemaic model, and he proposed a new theorem, the "Urdi lemma". Nasir al-Din al-Tusi
Nasir al-Din al-Tusi
Khawaja Muḥammad ibn Muḥammad ibn Ḥasan Ṭūsī , better known as Naṣīr al-Dīn al-Ṭūsī , was a Persian polymath and prolific writer: an astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, theologian and Marja Taqleed...
(1201–1274) resolved significant problems in the Ptolemaic system by developing the Tusi-couple
Tusi-couple
The Tusi-couple is a mathematical device in which a small circle rotates inside a larger circle twice the diameter of the smaller circle. Rotations of the circles cause a point on the circumference of the smaller circle to oscillate back and forth in linear motion along a diameter of the larger...
as an alternative to the physically problematic equant
Equant
Equant is a mathematical concept developed by Claudius Ptolemy in the 2nd century AD to account for the observed motion of heavenly bodies....
introduced by Ptolemy. Tusi's student Qutb al-Din al-Shirazi
Qutb al-Din al-Shirazi
Qotb al-Din Shirazi or Qutb al-Din al-Shirazi was a 13th century Persian Muslim polymath and Persian poet who made contributions astronomy, mathematics, medicine, physics, music theory, philosophy and Sufism.- Biography :...
(1236–1311), in his The Limit of Accomplishment concerning Knowledge of the Heavens, discusses the possibility of heliocentrism
Heliocentrism
Heliocentrism, or heliocentricism, is the astronomical model in which the Earth and planets revolve around a stationary Sun at the center of the universe. The word comes from the Greek . Historically, heliocentrism was opposed to geocentrism, which placed the Earth at the center...
. Al-Qazwīnī al-Kātibī, in his Hikmat al-'Ain, wrote an argument for a heliocentric model, though he later abandoned the idea.
Ibn al-Shatir
Ala Al-Din Abu'l-Hasan Ali Ibn Ibrahim Ibn al-Shatir was an Arab Muslim astronomer, mathematician, engineer and inventor who worked as muwaqqit at the Umayyad Mosque in Damascus, Syria.-Astronomy:...
(1304–1375), in his A Final Inquiry Concerning the Rectification of Planetary Theory, eliminated the need for an equant by introducing an extra epicycle, departing from the Ptolemaic system in a way very similar to what Nicolaus Copernicus
Nicolaus Copernicus
Nicolaus Copernicus was a Renaissance astronomer and the first person to formulate a comprehensive heliocentric cosmology which displaced the Earth from the center of the universe....
later also did. Ibn al-Shatir proposed a system that was only approximately geocentric, rather than exactly so, having demonstrated trigonometrically
Trigonometry
Trigonometry is a branch of mathematics that studies triangles and the relationships between their sides and the angles between these sides. Trigonometry defines the trigonometric functions, which describe those relationships and have applicability to cyclical phenomena, such as waves...
that the Earth was not the exact center of the universe. Unlike previous astronomers before him, Ibn al-Shatir was not concerned with adhering to the theoretical principles of natural philosophy
Natural philosophy
Natural philosophy or the philosophy of nature , is a term applied to the study of nature and the physical universe that was dominant before the development of modern science...
(or Aristotelian physics
Aristotelian physics
Aristotelian Physics the natural sciences, are described in the works of the Greek philosopher Aristotle . In the Physics, Aristotle established general principles of change that govern all natural bodies; both living and inanimate, celestial and terrestrial—including all motion, change in respect...
), but rather to produce a model that was more consistent with empirical
Empirical
The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....
observations. For example, it was Ibn al-Shatir's concern for observational accuracy which led him to eliminate the epicycle in the Ptolemaic solar
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
model and all the eccentrics, epicycles and equant in the Ptolemaic lunar model
Lunar theory
Lunar theory attempts to account for the motions of the Moon. There are many irregularities in the Moon's motion, and many attempts have been made over a long history to account for them. After centuries of being heavily problematic, the lunar motions are nowadays modelled to a very high degree...
. His model was thus in better agreement with empirical observation
Observation
Observation is either an activity of a living being, such as a human, consisting of receiving knowledge of the outside world through the senses, or the recording of data using scientific instruments. The term may also refer to any data collected during this activity...
s than any previous model produced before him. While previous Maragha models were just as accurate as the Ptolemaic model, Ibn al-Shatir's geometric model was the first that was actually superior to the Ptolemaic model in terms of its better agreement with empirical observations. His work thus marked a turning point in astronomy, which may be considered a "Scientific Revolution before the Renaissance".
Y. M. Faruqi wrote:
Ibn al-Shatir’s rectified model, which included the Tusi-couple and Urdi lemma, was later adapted into a heliocentric model
Copernican heliocentrism
Copernican heliocentrism is the name given to the astronomical model developed by Nicolaus Copernicus and published in 1543. It positioned the Sun near the center of the Universe, motionless, with Earth and the other planets rotating around it in circular paths modified by epicycles and at uniform...
by Copernicus, which was mathematically achieved by reversing the direction of the last vector connecting the Earth to the Sun in Ibn al-Shatir's model.
An area of active discussion in the Maragheh school, and later the Samarkand
Samarkand
Although a Persian-speaking region, it was not united politically with Iran most of the times between the disintegration of the Seleucid Empire and the Arab conquest . In the 6th century it was within the domain of the Turkic kingdom of the Göktürks.At the start of the 8th century Samarkand came...
and Istanbul
Istanbul
Istanbul , historically known as Byzantium and Constantinople , is the largest city of Turkey. Istanbul metropolitan province had 13.26 million people living in it as of December, 2010, which is 18% of Turkey's population and the 3rd largest metropolitan area in Europe after London and...
observatories, was the possibility of the Earth's rotation. Supporters of this theory included Nasir al-Din al-Tusi
Nasir al-Din al-Tusi
Khawaja Muḥammad ibn Muḥammad ibn Ḥasan Ṭūsī , better known as Naṣīr al-Dīn al-Ṭūsī , was a Persian polymath and prolific writer: an astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, theologian and Marja Taqleed...
, Nizam al-Din al-Nisaburi (c. 1311), al-Sayyid al-Sharif al-Jurjani (1339–1413), Ali Qushji (d. 1474), and Abd al-Ali al-Birjandi (d. 1525). Tusi was the first to present empirical
Empirical
The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....
observation
Observation
Observation is either an activity of a living being, such as a human, consisting of receiving knowledge of the outside world through the senses, or the recording of data using scientific instruments. The term may also refer to any data collected during this activity...
al evidence of the Earth's rotation, using the location of comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
s relevant to the Earth as evidence, which Qushji elaborated on with further empirical observations while rejecting Aristotelian
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...
natural philosophy
Natural philosophy
Natural philosophy or the philosophy of nature , is a term applied to the study of nature and the physical universe that was dominant before the development of modern science...
altogether. Both of their arguments were later described again by Nicolaus Copernicus
Nicolaus Copernicus
Nicolaus Copernicus was a Renaissance astronomer and the first person to formulate a comprehensive heliocentric cosmology which displaced the Earth from the center of the universe....
in 1543.
Current status
Cultural Heritage Organization of Iran
Iran Cultural Heritage, Handcrafts and Tourism Organization is an educational and research institution overseeing numerous associated museum complexes throughout Iran. It is administered and funded by the Government of Iran....
built a dome
Dome
A dome is a structural element of architecture that resembles the hollow upper half of a sphere. Dome structures made of various materials have a long architectural lineage extending into prehistory....
-framed shelter and it plans to hold an exhibit of astronomical devices used at Maragheh observatory.
The observatory is currently covered with a dome-framed brass
Brass
Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.In comparison, bronze is principally an alloy of copper and tin...
structure and is situated two miles west of Maragheh.
External links
- Maragheh observatory at Iranian Cultural Heritage Organization Documentation Center
- Scientists who made a difference
- Research Institute for Astronomy and Astrophysics of Maragha
- On Maragheh observatory at RIAAM
- Contribution by Parviz Tarikhi with illustrations
- Inside the protecting dome
- Copy of the celestial globe
- Al-Urdi's Article on 'The Quality of Observation', FSTC Limited