Eratosthenes
Eratosthenes was a Greek scholar of the third century BCE, best known for calculating the Earth's circumference with remarkable accuracy using geometry and shadow measurements.
He served as chief librarian at Alexandria and made contributions to geography, mathematics, and astronomy.
His name appears in the Sieve of Eratosthenes, an algorithm for finding prime numbers still taught today.
Greece's capital city
- PlatoGreek philosopher, academy founder
- AristotleGreek founder of formal logic
- ArchimedesGreek polymath, physicist
- academyInstitution of learning
philosophy · Hellenic · agora · gymnasium · polis · classical · antiquity
Circle's outer measurement
- EarthOur world
- stadionGreek unit of length
- gnomonSundial's shadow-casting projection
- shadowLight blocked by object
solstice · Alexandria · well · geometry · calculation · arc · meridian · distance
Mesh filtering utensil
- primeReadying for action
- algorithmFinite problem-solving procedure
- compositeMade of distinct parts
- multiplesQuantities divisible evenly
integers · number theory · factorization · sequence · divisibility · arithmetic · theorem · proof
Egyptian Mediterranean port
- scrollsRolled written records
- papyrusAncient plant-derived writing material
- catalogingSystematic organization into records
- PtolemaicEarth-centered astronomical system
scholarship · collection · preservation · chronology · archives · bibliography
Creating geographic representations
- mapSpatial representation of terrain
- latitudeGeographic or personal freedom
- longitudeEast-west angular distance
- projectionSomething that extends outward
hemisphere · equator · meridian · coordinates · Nile · exploration · topography · atlas
Celestial bodies researcher
- geographerEarth and place scholar
- mathematicianProfessional in abstract quantities
- philosopherStudent of fundamental questions
- poetWriter of verse
music theorist · Hellenistic · intellectual · tutor · versatility · Renaissance man
Athens
Greece's capital city
- PlatoGreek philosopher, academy founder
- AristotleGreek founder of formal logic
- ArchimedesGreek polymath, physicist
academy · philosophy · Hellenic · agora · gymnasium · polis · classical · antiquity
circumference
Circle's outer measurement
shadow · solstice · Alexandria · well · geometry · calculation · arc · meridian · distance · accuracy
sieve
Mesh filtering utensil
multiples · integers · number theory · factorization · sequence · divisibility · arithmetic · theorem · proof · perfect number
Alexandria
Egyptian Mediterranean port
- scrollsRolled written records
- papyrusAncient plant-derived writing material
- catalogingSystematic organization into records
Ptolemaic · scholarship · collection · preservation · chronology · archives · bibliography
cartography
Creating geographic representations
- mapSpatial representation of terrain
- latitudeGeographic or personal freedom
- longitudeEast-west angular distance
projection · hemisphere · equator · meridian · coordinates · Nile · exploration · topography · atlas
astronomer
Celestial bodies researcher
- geographerEarth and place scholar
- mathematicianProfessional in abstract quantities
- philosopherStudent of fundamental questions
poet · music theorist · Hellenistic · intellectual · tutor · versatility · Renaissance man
- Greek scienceAristotle, Archimedes, Euclid, Ptolemy, Hippocrates
- MathematiciansEuclid, Gauss, Euler, Archimedes, Pythagoras
- ancient AlexandriaLighthouse of Alexandria, Serapeum, Ptolemy, Cleopatra, Alexander the Great
- Ancient ScholarsPlato, Aristotle, Pythagoras, Euclid, Archimedes
- ancient scienceAristotle, Plato, Ptolemy, Galen, Pythagoras
- AstronomersGalileo Galilei, Johannes Kepler, Nicolaus Copernicus, Edwin Hubble, Carl Sagan