Tusi couple
E311985
The Tusi couple is a geometric device from medieval Islamic astronomy that generates linear motion from the sum of two circular motions, later influencing Copernican models of planetary motion.
All labels observed (2)
| Label | Occurrences |
|---|---|
| Tusi couple canonical | 5 |
| Tusi couple theory (in Tusi’s oeuvre) | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T2931338 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Tusi couple Context triple: [Islamic astronomy, introducedConcept, Tusi couple]
-
A.
Archimedes' spiral
Archimedes' spiral is a classical mathematical curve that winds outward from a fixed point at a constant rate as it revolves around that point.
-
B.
Cartesian circle
The Cartesian circle is a famous alleged circular reasoning in René Descartes’ Meditations, where his proof of God’s existence and his justification of clear and distinct perceptions appear to depend on each other.
-
C.
Bernoulli lemniscate
The Bernoulli lemniscate is a figure-eight–shaped algebraic curve that serves as a classic example in the study of complex analysis, elliptic functions, and special constants.
-
D.
Several Circles
Several Circles is an abstract painting by Wassily Kandinsky that explores pure geometric forms and color relationships through a dynamic composition of overlapping circles.
-
E.
On the Measurement of the Circle
On the Measurement of the Circle is a mathematical treatise by Archimedes in which he rigorously approximates the value of π and explores properties of circles.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Tusi couple Target entity description: The Tusi couple is a geometric device from medieval Islamic astronomy that generates linear motion from the sum of two circular motions, later influencing Copernican models of planetary motion.
-
A.
Archimedes' spiral
Archimedes' spiral is a classical mathematical curve that winds outward from a fixed point at a constant rate as it revolves around that point.
-
B.
Cartesian circle
The Cartesian circle is a famous alleged circular reasoning in René Descartes’ Meditations, where his proof of God’s existence and his justification of clear and distinct perceptions appear to depend on each other.
-
C.
Bernoulli lemniscate
The Bernoulli lemniscate is a figure-eight–shaped algebraic curve that serves as a classic example in the study of complex analysis, elliptic functions, and special constants.
-
D.
Several Circles
Several Circles is an abstract painting by Wassily Kandinsky that explores pure geometric forms and color relationships through a dynamic composition of overlapping circles.
-
E.
On the Measurement of the Circle
On the Measurement of the Circle is a mathematical treatise by Archimedes in which he rigorously approximates the value of π and explores properties of circles.
- F. None of above. chosen
Statements (44)
| Predicate | Object |
|---|---|
| instanceOf |
astronomical model
ⓘ
geometric model ⓘ mathematical device ⓘ |
| alsoKnownAs | al-qirān al-Tūsī ⓘ |
| approximateDateOfDevelopment | 13th century ⓘ |
| category |
Geometric transformations
ⓘ
History of astronomy ⓘ Islamic scientific inventions ⓘ |
| constructedFrom | two circular motions ⓘ |
| describedIn |
Tadhkira fi ilm al-hay'a
ⓘ
Treatise on the Tusi Couple ⓘ |
| developedAt | Maragha observatory ⓘ |
| developedIn | medieval Islamic astronomy ⓘ |
| documentedIn |
Arabic scientific manuscripts
ⓘ
Latin translations of Islamic astronomical works ⓘ |
| field |
astronomy
ⓘ
geometry ⓘ history of science ⓘ |
| geometricConfiguration | small circle rolling inside larger circle of twice its diameter ⓘ |
| hasComponent |
diameter point
ⓘ
large circle ⓘ small circle ⓘ |
| historicalContext | Islamic Golden Age ⓘ |
| impact | contributed to reform of planetary theory before Copernicus ⓘ |
| influenced |
Copernican heliocentric model
ⓘ
Nicolaus Copernicus ⓘ |
| influencedWork | De revolutionibus orbium coelestium ⓘ |
| influenceType | precursor to later kinematic models in Europe ⓘ |
| inventedBy | Nasir al-Din al-Tusi ⓘ |
| mathematicalProperty | composition of two equal-speed circular motions with opposite directions ⓘ |
| motionTypeGenerated | linear motion ⓘ |
| namedAfter | Nasir al-Din al-Tusi ⓘ |
| property | generates linear oscillation from uniform circular motions ⓘ |
| provides | kinematic model for linear harmonic motion ⓘ |
| purpose | to reconcile uniform circular motion with observed planetary anomalies ⓘ |
| radiusRatio | 2:1 ⓘ |
| relatedConcept |
Ptolemaic equant
ⓘ
linked to:
Ptolemaic system
Urdi lemma ⓘ epicycle-deferent model ⓘ |
| resultingPath | straight line segment ⓘ |
| usedFor |
eliminating equant in Ptolemaic astronomy
ⓘ
modeling planetary motion ⓘ |
| usesConcept |
epicyclic motion
ⓘ
uniform circular motion ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Tusi couple Description of subject: The Tusi couple is a geometric device from medieval Islamic astronomy that generates linear motion from the sum of two circular motions, later influencing Copernican models of planetary motion.
Referenced by (6)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Tusi couple