Earth in Space: Hellenistic era
Earth in Space: Hellenistic era
Earth in Space: Hellenistic era
Owe Dahren, 2001
Greek visual evidence for the
shape of the Earth
Eratosthenes’ method
for the circumference of
the Earth
Earth in Space: Hellenistic era
Hipparchos’
construction for the
distance to the Moon
(solar eclipse)
Aristarchos’
construction for the
distance to the Sun
Hipparchos’ construction for the distance to
the Moon (lunar eclipse)
Earth in Space: Hellenistic era
Hipparchos’ model of
the Sun’s orbit Ptolemy’s model of a
planetary orbit
Hipparchos’ model of
the Moon’s orbit
Earth in Space: Hellenistic era
The Antikythera mechanism, c 100 BC (Freeth et al, Nature 444 (2006) 587)
Earth in Space: Hellenistic era
Earth in Space: Hellenistic era
Earth in Space: Islamic era
Earth in Space: Islamic era
Earth in Space: Copernicus
Earth in Space: Tycho Brahe
Earth in Space: Johannes Kepler
Earth in Space: Isaac Newton
Newton’s cannon
An elliptical orbit,
A diagram showing centripetal
from the Principia
force, by Hooke