1. Evidence for the Earth Being Round
Comparison to other round astronomical Objects
Shadow During Lunar Eclipse
Ships Sinking Below Horizon
Circumnavigation of the Earth
Circumnavigate – to travel around
Time Zones
Position of Celestial Bodies
Photos from Space
Nature of Gravity
No Evidence to the Contrary

2. Shadow During Lunar Eclipse
Aristotle used the round shape of the Earth’s shadow during a lunar eclipse to argue for a round shaped Earth
Why does the moon during a total lunar eclipse have a red cast? We will discuss this in three weeks.

3. Ships Sinking Below Horizon
Ships sink below the horizon, but can still be viewed from higher elevations

4. Circumnavigation of the Earth
Circumnavigate – to travel around
Traveling in any single direction will eventually lead back to starting point

5. Time Zones Time varies by longitudinal position Sunrise 6 am Sun Noon
Midnight
Sunset
6 pm

6. Position of Celestial Bodies
Use the North Star as an example. Someone on the north pole looks straight up to see the north star, while someone in Richmond looks at an angle to see the north star.
Where does someone in the southern hemisphere see the north star?
North Star

7. Shadows Cast by Sun on Earth

8. Photos From Space

9. Nature of Gravity Gravity pulls equally in all directions.
This is why the earth is round.