Nasir al-Din al-Tusi +Search for Videos

Muslim scholar |
notability = Persian+ Muslim+ scholar+
Islamic Golden Age+
Al-Tusi Nasir.jpeg
'''Nasīr al-Dīn Tūsī'''
Khawaja Nasir
17 February 1201 (11 Jamadi al-Ula 597)
df=yes|1274|06|25|1201|02|18 (18 Dhu'l-Hijjah 672)
Twelver+ Shī‘ah+
Ilm al-Kalam+, Islamic Philosophy+, Astronomy+, Mathematics+, Chemistry+, Biology and Medicine+, Physics+, Science+
Evolution+, Spherical trigonometry+, Tusi-couple+
| works =''Rawḍa-yi Taslīm'', ''Tajrid al-'Aqaid'',
''Akhlaq-i-Nasri'', ''Zij-i ilkhani+'',
''al-Risalah al-Asturlabiyah'',
''Al-Tadhkirah fi'ilm al-hay'ah''
Avicenna+, Fakhr al-Din Razi+, Mo'ayyeduddin Urdi+
Maitham Al Bahrani+, ibn Khaldun+, Qutb al-Din Shirazi+, Ibn al-Shatir+, Copernicus+

'''Khawaja Muhammad ibn Muhammad ibn Hasan Tūsī''' ( He was of the Ismaili+-, and subsequently Twelver+ Shī‘ah+ Islam+ic belief.Citation| last =Ṭūsī | first =Naṣīr al-Dīn+ Muḥammad ibn Muḥammad | author-linkJames Winston Morris, "An Arab Machiavelli? Rhetoric, Philosophy and Politics in
Ibn Khaldun’s Critique of Sufism", Harvard Middle Eastern and Islamic Review 8 (2009), pp 242–291. [] excerpt from page 286 (footnote 39): "Ibn Khaldun’s own personal opinion is no doubt summarized
in his pointed remark (Q 3: 274) that Tusi was better than any other later Iranian scholar".
Original Arabic:
Muqaddimat Ibn Khaldūn : dirāsah usūlīyah tārīkhīyah / li-Aḥmad Ṣubḥī Manṣūr-al-Qāhirah : Markaz Ibn Khaldūn : Dār al-Amīn, 1998. ISBN 977-19-6070-9.
Excerpt from Ibn Khaldun is found in the section:
الفصل الثالث و الأربعون: في أن حملة العلم في الإسلام أكثرهم العجم
(On how the majority who carried knowledge forward in Islam were Persians)
In this section, see the sentence where he mentions Tusi as more knowledgeable than other later Persian ('Ajam) scholars:
. و أما غيره من العجم فلم نر لهم من بعد الإمام ابن الخطيب و نصير الدين الطوسي كلاما يعول على نهايته في الإصابة. فاعتير ذلك و تأمله تر عجبا في أحوال الخليقة. و الله يخلق ما بشاء لا شريك له الملك و له الحمد و هو على كل شيء قدير و حسبنا الله و نعم الوكيل و الحمد لله.

Nasir al-Din Tusi was born in the city of Tus+ in medieval Khorasan+ (in north-eastern Iran+) in the year 1201 and began his studies at an early age. In Hamadan and Tus he studied the Qur'an+, Hadith+, Shi'a+ jurisprudence, logic, philosophy, mathematics, medicine and astronomy.Dabashi, Hamid. "Khwajah Nasir al-Din Tusi: The philosopher/vizier and the intellectual climate of his times". Routledge History of World Philosophies. Vol I. History of Islamic Philosophy. Seyyed Hossein Nasr and Oliver Leaman (eds.) London: Routledge. 1996. p. 529

He was apparently born into a Shī‘ah family and lost his father at a young age. Fulfilling the wish of his father, the young Muhammad took learning and scholarship very seriously and travelled far and wide to attend the lectures of renowned scholars and acquire the knowledge which guides people to the happiness of the next world. At a young age he moved to Nishapur+ to study philosophy under Farid al-Din Damad and mathematics under Muhammad Hasib+.Siddiqi, Bakhtyar Husain. "Nasir al-Din Tusi". A History of Islamic Philosophy. Vol 1. M. M. Sharif (ed.). Wiesbaden:: Otto Harrossowitz. 1963. p. 565 He met also Farid al-Din 'Attar+, the legendary Sufi+ master who was later killed by Mongol invaders and attended the lectures of Qutb al-Din al-Misri+.

In Mosul+ he studied mathematics and astronomy with Kamal al-Din Yunus+ (d. 639/1242). Later on he corresponded with Sadr al-Din al-Qunawi+, the son-in-law of Ibn al-'Arabi+, and it seems that mysticism, as propagated by Sufi+ masters of his time, was not appealing to his mind and once the occasion was suitable, he composed his own manual of philosophical Sufism in the form of a small booklet entitled ''Awsaf al-Ashraf'' "The Attributes of the Illustrious".

As the armies of Genghis Khan+ swept his homeland, he was employed by the Ismailis+ and made his most important contributions in science during this time when he was moving from one stronghold to another. He was captured after the invasion of the Alamut+ castle by the Mongol+ forces.

Tusi has about 150 works, of which 25 are in Persian+ and the remaining are in Arabic+, and there is one treatise in Persian, Arabic and Turkish+ (?)

Here are some of his major works:
*''Kitāb al-Shakl al-qattāʴ'' Book on the complete quadrilateral. A five volume summary of trigonometry.
*''Al-Tadhkirah fi'ilm al-hay'ah'' – A memoir on the science of astronomy. Many commentaries were written about this work called Sharh al-Tadhkirah (A Commentary on al-Tadhkirah) - Commentaries were written by Abd al-Ali ibn Muhammad ibn al-Husayn al-Birjandi+ and by Nazzam Nishapuri+.
*''Akhlaq-i-Naseri'' – A work on ethics.
*''al-Risalah al-Asturlabiyah'' – A Treatise on astrolabe.
*''Zij-i ilkhani+'' (''Ilkhanic Tables'') – A major astronomical treatise, completed in 1272.
*''sharh al-isharat'' (''Commentary on Avicenna's Isharat'')
*''Awsaf al-Ashraf'' a short mystical-ethical work in Persian
*''Tajrīd al-iʿtiqād'' (Summation of Belief) – A commentary on Shia doctrines.

+">Tusi couple++" style="color: #CCCCCC;">+

During his stay in Nishapur, Tusi established a reputation as an exceptional scholar. "Tusi’s prose writing, which number over 150 works, represent one of the largest collections by a single Islamic author. Writing in both Arabic+ and Persian+, Nasir al-Din Tusi dealt with both religious (“Islamic”) topics and non-religious or secular subjects (“the ancient sciences”).H. Daiber, F.J. Ragep, "Tusi" in Encyclopaedia of Islam. Edited by: P. Bearman, Th. Bianquis, C.E. Bosworth, E. van Donzel and W.P. Heinrichs. Brill, 2007. Brill Online. Quote: "Tusi's prose writings, which number over 150 works, represent one of the largest collections by a single Islamic author. Writing in both Arabic and Persian, Nasir al-Din dealt with both religious ("Islamic") topics and non-religious or secular subjects ("the ancient sciences")." His works include the definitive Arabic versions of the works of Euclid+, Archimedes+, Ptolemy+, Autolycus+, and Theodosius of Bithynia+.

Tusi convinced Hulegu Khan+ to construct an observatory for establishing accurate astronomical tables for better astrological predictions. Beginning in 1259, the Rasad Khaneh observatory+ was constructed in Azarbaijan+, west of Maragheh+, the capital of the Ilkhanate Empire+.

Based on the observations in this for the time being most advanced observatory, Tusi made very accurate tables of planetary movements+ as depicted in his book ''Zij-i ilkhani+'' (''Ilkhanic Tables''). This book contains astronomical tables for calculating the positions of the planets and the names of the stars. His model for the planetary system is believed to be the most advanced of his time, and was used extensively until the development of the heliocentric model in the time of Nicolaus Copernicus+. Between Ptolemy+ and Copernicus+, he is considered by many to be one of the most eminent astronomers of his time.

For his planetary models, he invented a geometrical technique called a Tusi-couple+, which generates linear motion from the sum of two circular motions. He used this technique to replace Ptolemy+'s problematic equant+ for many planets, but was unable to find a solution to Mercury, which was solved later by Ibn al-Shatir+ as well as Ali Qushji+. The Tusi couple was later employed in Ibn al-Shatir+'s geocentric model+ and Nicolaus Copernicus+' heliocentric+ Copernican model+. He also calculated the value for the annual precession of the equinox+es and contributed to the construction and usage of some astronomical instruments including the astrolabe+.

Ṭūsī criticized Ptolemy's use of observational evidence to show that the Earth was at rest, noting that such proofs were not decisive. Although it doesn't mean that he was a supporter of mobility of the earth, as he and his 16th-century commentator al-Bīrjandī+, maintained that the earth's immobility could be demonstrated, but only by physical principles found in natural philosophy. Tusi's criticisms of Ptolemy were similar to the arguments later used by Copernicus in 1543 to defend the Earth's rotation.

About the real essence of the Milky Way, Ṭūsī in his ''Tadhkira'' writes:
"The Milky Way, i.e. the galaxy, is made up of a very large number of small, tightly-clustered stars, which, on account of their concentration and smallness, seem to be cloudy patches. because of this, it was likend to milk in color."

Three centuries later the proof of the Milky Way consisting of many stars came in 1610 when Galileo Galilei+ used a telescope+ to study the Milky Way and discovered that it is really composed of a huge number of faint stars.

In his ''Akhlaq-i-Nasri'', Tusi put forward a basic theory for the evolution of species. He begins his theory of evolution with the universe+ once consisting of equal and similar element+s. According to Tusi, internal contradictions began appearing, and as a result, some substances began developing faster and differently from other substances. He then explains how the elements evolved into minerals, then plants, then animals, and then humans. Tusi then goes on to explain how hereditary+ variability was an important factor for biological evolution of living thing+s:Farid Alakbarov (Summer 2001). , ''Azerbaijan International+'' '''9''' (2).

Tusi discusses how organisms are able to adapt+ to their environments:

Tusi recognized three types of living things: plants, animals, and humans. He wrote:

Tusi then explains how humans evolved from advanced animals:

In chemistry+ and physics+, Tusi stated a version of the law of conservation of mass+. He wrote that a body of matter+ is able to change, but is not able to disappear:

Nasir al-Din Tusi was a supporter of Avicennian logic+, and wrote the following commentary on Avicenna+'s theory of absolute proposition+s:

Al-Tusi was the first to write a work on trigonometry independently of astronomy. Al-Tusi, in his ''Treatise on the Quadrilateral'', gave an extensive exposition of spherical trigonometry+, distinct from astronomy. It was in the works of Al-Tusi that trigonometry achieved the status of an independent branch of pure mathematics distinct from astronomy, to which it had been linked for so long.

He was the first to list the six distinct cases of a right triangle in spherical trigonometry.

This followed earlier work by Greek mathematicians+ such as Menelaus of Alexandria+, who wrote a book on spherical trigonometry called ''Sphaerica,'' and the earlier Muslim mathematicians Abū al-Wafā' al-Būzjānī+ and Al-Jayyani+.

In his ''On the Sector Figure'', appears the famous law of sines+ for plane triangles.

: \fraca\sin A = \fracb\sin B = \fracc\sin C

He also stated the law of sines for spherical triangles, discovered the law of tangents+ for spherical triangles, and provided proofs for these laws.

A 60-km diameter lunar crater+ located on the southern hemisphere of the moon+ is named after him as "Nasireddin+". A minor planet+ 10269 Tusi+ discovered by Soviet+ astronomer Nikolai Stepanovich Chernykh+ in 1979 is named after him.

*List of modern-day Muslim scholars of Islam+
*List of Iranian scientists+
*List of Shi'a Muslims+
*Persian science+
*Science in the medieval Islamic world+
*Shen Kuo+


*Encyclopædia Iranica, "AḴLĀQ-E NĀṢERĪ", G.M. Wickens []
*Encyclopædia Iranica, "AWṢĀF AL-AŠRĀF", G.M. Wickens []
*Encyclopædia Iranica, "Nasir al-Din al-Tusi" George Saliba []

* ()
*Kerry Magruder, , University of Oklahoma
*. An 18th century Sanskrit translation of Nasir al-Din al-Tusi's recension of Euclid's'' Elements''.

Scholars of Khorasan:
Islamic astronomy:
Islamic mathematics:
Islamic philosophy:
Medieval Philosophy:

Nasir al-Din al-Tusi+ Khawaja Muhammad ibn Muhammad ibn Hasan Tūsī (Persian: محمد بن محمد بن الحسن طوسی‎) (born 17 February 1201 in Ṭūs, Khorasan – died on 25 June 1274 in al-Kāżimiyyah district of metropolitan Baghdad), better known as Nasīr al-Dīn Tūsī (Persian: نصیر الدین طوسی‎; or simply Tusi in the West), was a Persian polymath and prolific writer: An architect, astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, theologian and Marja Taqleed.