al-qirān al-Tūsī

E1022093

al-qirān al-Tūsī is a geometric device from medieval Islamic astronomy, devised by Nasir al-Din al-Tusi to generate linear motion from the sum of two circular motions and used to refine Ptolemaic planetary models.

All labels observed (1)

Label Occurrences
al-qirān al-Tūsī canonical 1

How this entity was disambiguated

Statements (46)

Predicate Object
instanceOf astronomical mechanism ⓘ
geometric device ⓘ
mathematical model ⓘ
aim to avoid non-uniform equant motion in Ptolemaic theory ⓘ
to reconcile uniform circular motion with observed planetary motion ⓘ
alsoKnownAs Tusi couple ⓘ
appliesTo planetary models of Jupiter ⓘ
planetary models of Mars ⓘ
planetary models of Saturn ⓘ
planetary models of Venus ⓘ
basedOn composition of uniform circular motions ⓘ
category geometric couple ⓘ
coordinateSystem plane geometry ⓘ
countryOfOrigin medieval Islamic world ⓘ
describedIn works of Naṣīr al-Dīn al-Ṭūsī ⓘ
developer Naṣīr al-Dīn al-Ṭūsī ⓘ
dimension two-dimensional mechanism ⓘ
etymology "al-qirān" refers to coupling or conjunction ⓘ
field astronomy ⓘ
celestial mechanics ⓘ
geometry ⓘ
mathematics ⓘ
hasPart diameter of the smaller circle ⓘ
large circle ⓘ
point on the diameter ⓘ
smaller circle ⓘ
historicalPeriod medieval period ⓘ
inception 13th century ⓘ
influenced Renaissance astronomy ⓘ
geometric kinematics ⓘ
late medieval astronomical models ⓘ
languageOfName Arabic ⓘ
mathematicalRepresentation sum of two sinusoidal functions with equal amplitude and opposite phase ⓘ
motionType circular motion ⓘ
linear oscillatory motion ⓘ
namedAfter Naṣīr al-Dīn al-Ṭūsī ⓘ
city of Ṭūs via Naṣīr al-Dīn al-Ṭūsī ⓘ
property preserves uniform angular velocity in component circles ⓘ
produces exact linear motion from two circular motions ⓘ
tradition Islamic astronomy ⓘ
usedFor eliminating the equant in Ptolemaic astronomy ⓘ
generating linear motion from circular motions ⓘ
modeling planetary latitude and longitude ⓘ
refining Ptolemaic planetary models ⓘ
usedIn Maragha school of astronomy ⓘ
linked to: Maragha observatory

non-Ptolemaic planetary models ⓘ

How these facts were elicited

Referenced by (1)

Full triples — surface form annotated when it differs from this entity's canonical label.

Tusi couple → alsoKnownAs → al-qirān al-Tūsī ⓘ