ANCIENT CIVILISATION AND
ASTRONOMY
ANCIENT
GREEK ASTRONOMY
The earliest days of astronomy:
1. It was very dark at night since there were no artificial lighting.
2. Certain behaviours and patterns became obvious;
• The sky is vast and very impressive as it appeared to be a huge sphere turning
on an axis. There was a north and south pole and an equator. Stars rose in the
east and set in the west as if they were attached to this vast sphere. Hence the
concept of the celestial sphere.
The first Greek Astronomers
• Greek Astronomers were at their peak between 700 BC- 300 AD
• At first, the ancient Greek were very superstitious as they believed that the world
was very supernatural but later turned their views to natural theories.
• The first Greek Astronomers includes;
i. Thales the Astronomer
ii. Anaximanda
iii. Pythagoras
iv. Plato
v. Eudoxus of Cnidus
vi. Autolycus
vii. Aristarchus of Samos
viii. Eratosthenes
ix. Hipparchus
x. Ptolemy
THALES THE ASTRONOMER
•
Thales was one of the seven sages of
Greece who was best in mathematics,
astronomy and philosophy
•
Thales described a simple model of a
small flat Earth surrounded by a sheet of
water, with a single vast sphere
• He predicted the solar eclipse
ANAXIMANDA
•
Anaximanda was the first speculative
astronomer who follows after Thales
•
He made many achievements on the
idea of the sun being 27 times larger
than earth
PYTHAGORAS
•
Pythagoras was the first to suggest that
there was a harmony of the spheres,
and that the sun, planets, moon and
stars’ movements could be described by
mathematics
•
He’s probably one of the first people to
believe that the earth is round
• His followers were called Pythagoreans
PLATO
• Plato believed in the idea that the sun, stars
and moon were fixed onto concentric spheres
that are rotating inside one another
• He proposed that the stars formed the
outermost sphere, then followed by planets, the
sun, the moon and lastly the earth at the centre
of it all
EUDOXUS OF CNIDUS
• Eudoxus Of Cnidus was a great astronomer
and mathematician though his work has been
lost
• He advanced well in identification of
constellation
•
He believed that earth rest at the centre and
27 concentric spheres rotate around this center.
AUTOLYCUS
• Autolycus believed in Eudoxus’s
work
• He wrote that "any star which rises and
sets always rises and sets at the same
point in the horizon."
ARISTARCHUS OF SAMOS
• Aristarchus Of Samos is the first ancient
Greek astronomer and a mathematician
to represent the first heliocentric model
•
even though he was right people at
first laughed at his theory
•
He tried to estimate the size and
distances of the heavenly bodies
ERATOSTHENES
• Eratosthenes made more advancements
on ARISTARCHUS OF Samos’s theories
as he calculated the size of the earth.
• He discovered that the size of the earth
was 25 000 miles around but he was 1
000 miles of
HIPPARCHUS
• Hipparchus was famous for using
science to form his theories and was
the greatest ancient astronomical
observer
• He is the first whose quantitative
and accurate models for the motion
of the sun and moon to survive’
• He calculated the distance of
heavenly bodies using trigonometry
CLAUDIUS PTOLEMY
• Ptolemy presented a useful tool for
astronomical calculations in his Handy
Tables
• He believed that earth was at the centre
of the universe according to his
observation
• Most of his work was based on
Hipparchus’s work
•
After Ptolemy there were no more ancient Greek astronomers therefore Greek
astronomy ended.
•
though the Greek astronomy ended, their ancient theories on astronomy paved a
way for modern physics on astronomy and those theories are now been proven to
be correct, some are discarded and refined as time goes on.
REFERENCE
• For more information on Greek astronomy;
i. Go to Biust library and search for documentary in Greek astronomy
ii. Thurston, H., Early Astronomy. Springer
iii. Pedersen, Olaf (1993). Early Physics and Astronomy: A Historical
Introduction (2nd ed.)
Thank you for you undivided
attention