you will know easier why the Greeks philosophers made a conclusion that the earth is round and sherical

1. HOW THE GREEKS KNEW
THAT THE EARTH IS
SPHERICAL ?

2. GREEK HISTORY
 It all started as a
philosophical concept
developed by the
Greeks around the 6th
century BC. It wasn’t
until the 3rd century BC
when Hellenistic
astronomy came to the
conclusion that the
earth was in fact
physically spherical.

3.  At first, there was no
real explanation of how
the Greeks came up
with this conclusion,
other than their
observation on the
change of the stars
when they traveled.

4. Pythagoras and
Plato taught their
students that the world
was round but they had
no justification or
proof.

5. The round Earth
theory didn't get a
proper
explanation until
Aristotle (384-322
BC) made three
important
observations:

6. ARISTOTLE IMPORTANT OBSERVATIONS:
 Every portion of the
Earth tends toward the
center until by
compression and
convergence they form
a sphere.
 Travelers going south
see southern
constellations rise
higher above the
horizon; and
 The shadow of Earth
on the Moon during a
lunar eclipse is round.

7.  This knowledge was then passed from generation
to generation.
 It was then spread to the eastern world where they
thought that the earth was a flat disk floating in an
ocean surrounded by a spherical sky, as explained
by the Mesopotamian mythology.