Eratosthenes

E196028

ancient Greek mathematician astronomer geographer human librarian poet polymath

Eratosthenes was an ancient Greek polymath best known for remarkably accurately calculating the Earth's circumference and for devising the sieve method for finding prime numbers.

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All labels observed (3)

Label	Occurrences
Eratosthenes canonical	5
Eratosthenes of Cyrene	2
Greek geographer Eratosthenes	1

How this entity was disambiguated

This entity first appeared as the object of triple T1704235 — 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: Eratosthenes
Context triple: [Hellenistic period, notableFigure, Eratosthenes]

A. Aristarchus of Samothrace
Aristarchus of Samothrace was a prominent Hellenistic Greek scholar and head of the Library of Alexandria, renowned for his critical editions and commentaries on Homeric poetry.
B. Aristarchus of Samos
Aristarchus of Samos was an ancient Greek astronomer who proposed a heliocentric model of the universe, placing the Sun at the center and the Earth in motion around it.
C. Eudoxus of Cnidus
Eudoxus of Cnidus was an ancient Greek mathematician and astronomer renowned for developing the method of exhaustion and an influential geometric model of planetary motion.
D. Hipparchus
Hipparchus was an ancient Greek astronomer and mathematician renowned for founding trigonometry and creating one of the first comprehensive models of the motions of the Sun and Moon.
E. Hipparchus of Athens
Hipparchus of Athens was a 6th-century BCE Athenian tyrant of the Peisistratid family, known as a patron of the arts and for his assassination, which became a celebrated event in Athenian democratic lore.
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: Eratosthenes
Target entity description: Eratosthenes was an ancient Greek polymath best known for remarkably accurately calculating the Earth's circumference and for devising the sieve method for finding prime numbers.

A. Aristarchus of Samothrace
Aristarchus of Samothrace was a prominent Hellenistic Greek scholar and head of the Library of Alexandria, renowned for his critical editions and commentaries on Homeric poetry.
B. Aristarchus of Samos
Aristarchus of Samos was an ancient Greek astronomer who proposed a heliocentric model of the universe, placing the Sun at the center and the Earth in motion around it.
C. Eudoxus of Cnidus
Eudoxus of Cnidus was an ancient Greek mathematician and astronomer renowned for developing the method of exhaustion and an influential geometric model of planetary motion.
D. Hipparchus
Hipparchus was an ancient Greek astronomer and mathematician renowned for founding trigonometry and creating one of the first comprehensive models of the motions of the Sun and Moon.
E. Hipparchus of Athens
Hipparchus of Athens was a 6th-century BCE Athenian tyrant of the Peisistratid family, known as a patron of the arts and for his assassination, which became a celebrated event in Athenian democratic lore.
F. None of above. chosen

Statements (48)

Predicate	Object
instanceOf	ancient Greek mathematician ⓘ astronomer ⓘ geographer ⓘ human ⓘ librarian ⓘ poet ⓘ polymath ⓘ
areaOfInfluence	Ancient Mediterranean world ⓘ surface form: Mediterranean world
canonized	as a foundational figure in geography and number theory ⓘ
countryOfCitizenship	Greek Antiquity ⓘ surface form: Ancient Greece
dateOfBirth	c. 276 BC ⓘ
dateOfDeath	c. 194 BC ⓘ
describedAs	Beta ⓘ second only to the greatest scholars of his time ⓘ
educatedAt	Athens ⓘ
employer	Library of Alexandria ⓘ
estimatedValue	Earth's circumference close to modern value ⓘ
ethnicGroup	Greek ⓘ
fieldOfWork	astronomy ⓘ chronology ⓘ geography ⓘ literary criticism ⓘ mathematics ⓘ
influenced	development of number theory ⓘ later geographers ⓘ later mathematicians ⓘ
influencedBy	Greek mathematical tradition ⓘ
knownFor	calculation of the Earth's circumference ⓘ creation of one of the earliest maps of the known world ⓘ early use of parallels and meridians in geography ⓘ invention of the Sieve of Eratosthenes ⓘ work on the chronology of Greek history ⓘ
languageOfWorkOrName	Ancient Greek ⓘ
memberOf	Library of Alexandria ⓘ surface form: intellectual community of Alexandria
nativeLanguage	Ancient Greek ⓘ
notableIdea	systematic sieve for finding prime numbers ⓘ use of a prime sieve up to a given limit ⓘ
notableWork	On the Measurement of the Earth ⓘ Eratosthenes spiral ⓘ surface form: Sieve of Eratosthenes
placeOfBirth	Cyrenaica ⓘ Cyrene ⓘ Tripolitania ⓘ surface form: Libya
placeOfDeath	Alexandria ⓘ
positionHeld	chief librarian of the Library of Alexandria ⓘ
sexOrGender	male ⓘ
timePeriod	Hellenistic period ⓘ
usedMethod	geometric reasoning to estimate Earth's circumference ⓘ measurement of sun angles at Syene and Alexandria ⓘ

How these facts were elicited

Referenced by (8)

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

Hellenistic period → notableFigure → Eratosthenes ⓘ

Library of Alexandria → notableScholar → Eratosthenes ⓘ

Syene → usedBy → Eratosthenes ⓘ

this entity surface form: Greek geographer Eratosthenes

Kyrenaïkē → hasNotableInhabitant → Eratosthenes ⓘ

subject surface form: Kyrenaikē

this entity surface form: Eratosthenes of Cyrene

Strabo → influencedBy → Eratosthenes ⓘ

Mouseion → notableScholar → Eratosthenes ⓘ

subject surface form: Mouseion of Alexandria

Hellenistic astronomy → hasNotableAstronomer → Eratosthenes ⓘ

Eratosthenes spiral → namedAfter → Eratosthenes ⓘ