PhySciSHS Q4 Week1
PhySciSHS Q4 Week1
PhySciSHS Q4 Week1
l
Technolog
y
Unit
ETUlay Online Tutorial
Physical Science
Q4 Week 1 : Modern Astronomy & Examples of
Astronomical Phenomena Before the Advent of
Telescopes & Modern Astronomy
Quarter 4 Week 1
At the end of the session you will be able to;
• Explain how the Greeks knew that the Earth is spherical (S11/12PS -IVa -
38 )
• Cite examples of astronomical phenomena known to astronomers before
the advent of telescopes (S11/12PS -IVa -41)
• Explain how Brahe’s innovations and extensive collection of data in
observational astronomy paved the way for Kepler’s discovery of his laws
of planetary motion (S11/12PS -IVa -44)
What I Know
What I Know
1. They are much noted for their contribution in
different fields. They were not only great
philosophers but great scientists and
mathematician as well
KRGEES
GREEKS
What I Know
2. It claims that the planets moved in a
complicated system of circles. This model also
became known as the Ptolemic System.
CIMELOTP LEDOM
PTOLEMIC MODEL
What I Know
3. The shape of the Earth. It has bulging equator
and squeezed poles.
TOBALE RODIHSPE
OBLATE SPHEROID
What I Know
4. It was believed to be in fixed position in the
sky. However, when the Greeks traveled to places
nearer the equator, like Egypt, they noticed that it
is closer to the horizon
THONR SRAT
NORTH STAR
What I Know
5. A student of Plato and considered as one of the
greatest philosophers of his time; his earth-
centered view dominated for almost 2,000 years.
SARTITLOE
ARISTOTLE
Ancient Astronomy
What is It
• As early as 500 B.C., Greeks
already believed that the
Earth’s shape was round, not
flat.
• Pythagoras first proposed the
spherical earth
What is It
Earth’s true shape –
OBLATE SPHEROID
(bulging at the equator
and squeezed poles.
What is It
• Anaxagoras (in 500 to 430
B.C.), supported the spherical
earth idea of Pythagoras
• Anaxagoras observed that the
shadow Earth cast on the moon
during a lunar eclipse was
circular
What is It
Aristotle (around 340 B.C.)
included the following in his
argument supporting a
Spherical Earth:
What is It
• position of the North Star
• the shape of the moon and
the Sun
• ships disappearing over the
horizon
What is It
How did the ancient Greeks
come up with the
measurement of the
spherical Earth?
What is It
Eratosthenes measured the
Earth’s circumference with
a stick and a knowledge of
the distance from
Alexandria to Syene.
What is It
What is It
• The angle of a shadow casted by a stick at noon on
the summer solstice in Alexandria was about 7.2
degrees (1/50 of a complete circle)
• Distance of Alexandria to Syene is 500 miles)
• He computed the circumference of the Earth to be
approximately 40,000 kilometers
Greek Astronomers
Anaxagoras explained the
causes of the phases of the
moon
Greek Astronomers
Eudoxus proposed that
the Sun, moon and five
known planets and the
stars are attached to fixed
spheres that revolved
around the stationary
Earth.
Greek Astronomers
Hipparchus made a
compilation of 850 stars
and developed a method for
predicting lunar eclipses.
Greek Astronomers
Claudius Ptolemy proposed
the geocentric model
(Ptolemic system) that says
the Sun, moon and other
planets move in circular
orbits around the Earth
Greek Astronomers
Astronomical Phenomena Before the Advent
of Telescopes
Rising and Setting of the Sun
Babylonian and
Egyptians used a
gnomon in
systematically
observing the motion
of the sun.
Phases of the Moon
Lunar Eclipses
Solar Eclipses
Daily and Annual Motion of Stars
https://wakelet.com/wake/0rl67Jsz9YQ1FETi-MCPS
Educationa
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Technolog
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Unit
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