ANCIENT GREEK
AND
PHILOSOPHERS
Specific Learning Outcomes
At the of the lesson, the learners should be able to:
► Write
the summary of ancient
Greek two domains view
► Tabulate the different material
elements and motion
according to the two-domain
view
► List the naked-eye
astronomical proofs that the
earth is spherical.
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When do you think is a scientific
theory rejected?
Is scientific theory final?
Astronomy
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Comparison
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PYTHAGORAS
c. 570-c. 495 BC
Universe is mathematical;
mathematics as the best way to
express the truth about the
Universe; Sun, moon, Earth as
Spherical; placed earth as the
center of the Universe
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PLATO
c. 427- c. 347 B.C
Attainment of perfection as
absence of change; mathematical
symmetries to demonstrate the
perfect shapes; celestial spheres
being crystalline and contains the
moon, the Sun and Stars;
explaining the shadows ”Saving
the Apperances”.
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Followed previous models
of the universe but added
auxiliary spheres to
provide appropriate tilt to
the planet’s path
EUDOXUS
408-355 B. C.
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Two-Domain System with
terrestrial domain containing four
elements that tries to attain
perfection by being in their
natural location relative to the
center of the Universe: the center
of the Earth.
ARISTOTLE
384-322 B. C.
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Celestial Domain
https://www.youtube.com/watch?v=6SzjlsuyTdk
► The
Model of Celestial Bodies
celestial domain is
everything from the sphere
of the moon up. Everything
in the celestial domain is
made of ether, whose
natural motion is circular.
► DIURNAL
► ANNUAL
► PRECESSION OF
EQUINOXES
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Diurnal Motion
► apparent
daily motion of the sky from east to
west
► Resulted from Earth’s rotation from east to
west
► The axis of this apparent motion coincides
with Earth’s axis of rotation
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Annual Motion
►Referred
to the events or
phenomenon that came anually
►It refers to the motion of Earth in
its orbit around the sun
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https://www.youtube.com/watch?v=xpem2lDNgwo
PRECESSION OF EQUINOXES
►Gradual
shift in the orientation of
Earth’s axis of rotation
►Precession moves westward along
the ecliptic relative to fixed stars
►26,000 years
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Terrestrial Domain
► The
terrestrial domain is the
region below the sphere of
the moon.
►
►
Model of Celestial Bodies
Everything in the terrestrial domain is
made of the four elements: earth, air,
fire and water.
These elements move with rectilinear
motion
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TWO DOMAIN VIEW OF THE UNIVERSE
DOMAIN
TERRESTRIAL
DOMAIN
ELEMENTS
MOTION
FIRE
AIR
WATER
alteration
Natural
violent
EARTH
CELESTIAL DOMAIN
ETHER
Perfect motion: circular and
constant speed
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Concept of
Spherical
Earth
BOOK
REVIEW
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Observations leading to the belief that the Earth is round.
►Observing
Lunar Eclipse
►Parallax
►Simultaneously
measuring the
length of the shadows
http://www.physlink.com/Education/askExperts/ae535.cfm
Check it out: Summary of evidence for a spherical earth
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Martensson
Determining the size of the Earth by Eratosthenes[edit]
Under the assumption that the Sun is very far away, the ancient Greek
geographer Eratosthenes performed an experiment using the differences in the
observed angle of the Sun from two different locations to calculate the
circumference of the Earth. Though modern telecommunications and timekeeping
were not available, he was able to make sure the measurements happened at the
same time by having them taken when the Sun was highest in the sky (local noon)
at both locations. Using slightly inaccurate assumptions about the locations of two
cities, he came to a result within 15% of the correct value.
Caption lorem ipsum
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Thank
You