THE DISCOVERY OF THE DISCOVERY OF ERATHOSTENEERATHOSTENE

How the Greeks calculated the How the Greeks calculated the radius of the earthradius of the earth

SummarySummary

Introduction : The Greek scientistsIntroduction : The Greek scientists

I.I. The life of ErathosteneThe life of Erathostene

II.II. The measurement of the radius of the The measurement of the radius of the earthearth

III.III. The impact of this discoveryThe impact of this discovery

The Antique Greek world had a major role The Antique Greek world had a major role in the development of the Western in the development of the Western civilizationcivilization

Founders of:Founders of:

• PhilosophyPhilosophy

• DémocracyDémocracy

• PhysicsPhysics

• MathematicsMathematics

• AstronomyAstronomy

Some scientists from the VII century Some scientists from the VII century BC to the II century BCBC to the II century BC

In chronological order:In chronological order:• ThalèsThalès• PythagorePythagore• HippocrateHippocrate• AristoteAristote• EuclideEuclide• ArchimèdeArchimède• AristaqueAristaque• ErathostèneErathostène• HipparqueHipparque• PtoléméePtolémée

I . The life of ErathostèneI . The life of Erathostène

II. The measurement of the II. The measurement of the radius of the earthradius of the earth

Why at the same time the obelisk of Syene has not shadow, but that of Alexandria is in a clear projecting ?

Erathosthène’s mindErathosthène’s mind

III. The impact of this discoveryIII. The impact of this discovery

• The circumference of the earthThe circumference of the earth

• Exploration possibilitiesExploration possibilities

Named after EratosthenesNamed after Eratosthenes • Eratosthenes crater on Eratosthenes crater on

the moonthe moon

• Eratosthenian period Eratosthenian period in the lunar geologic in the lunar geologic timescaletimescale

• Eratosthène astéroidEratosthène astéroid

THANK YOU FOR YOUR ATTENTIONTHANK YOU FOR YOUR ATTENTION