1. Perspective with Maps
April 18, 201

2. -A planetary system is a star and all of the planets, moons, and other objects and materials that orbit that star.
Until recently we knew only of one system named for the star that rules, Sol.
-We have found distant planets in our galaxy and it is estimated there are billions more to be discovered.

3. To help us with the size of the universe, lets first look at our own surroundings. This is called a frame of reference.
It can be as small as a turtle tank or as large as the state of Wisconsin.

4. Ground View
From close up, we are able to see details of something less than 100 meters away.

5. Aerial View (Bird’s Eye View)
When we look at a map, often we are seeing the overhead or bird’s-eye view.
This is the looking DOWN ON view.

6. At a higher elevation, and we can barely see any detail.

7. Back up even further, and the white house isn’t even a speck on the map.

8. From space, we can not see any resolution at all of the white house, nonetheless Washington DC.

9. Now…imagine how big the stars are that we can still see with resolution from our Earth!

10. Maps
Maps – A way of representing a two-dimensional surface.
We use maps to understand a perspective of where we are.
Resolution – The ability to discern two objects as separate from on another.
We see things as being separate by using the rods and cones in our eyes.
At about 100 meters away, we begin to blur objects, making it one.

11. http://primaxstudio.com/stuff/scale_of_univers e/
Scale of the Universe e/

12. Round vs. Flat Earth
March 30, 2011

13. Question to consider: How do you know?
Tell me how?
What is definite?
2000 years ago, how did people figure out the Earth is round?

14. Round Earth vs. Flat Please read the article you have been assigned.
You will need to find 5 points that you feel are most important in defending this argument.
Present in a paragraph what you feel are most defining of this theory.
You will also be presenting these ideas to the class.

15. Shadows
April 18, 2012

16. Shadows
Evidence that the Earth is round, came from careful observations of lunar eclipses.
The shadows crossing the Moon ALWAYS present a curved leading edge and a cured trailing edge, indicating that the round object is casting the shadow.

17. Read about Eratosthenes
You are going to make similar shadow observations to Erathosthenes, 2000 years ago.
Read about Eratosthenes
(Page 73 in TE)

18. Review
Longitude - - the lines which run from the North pole to the South Pole (top to bottom)
Latitude - - run around the globe (like ladder rungs). The half way line is called the equator.

19. Light Rays always travel in straight lines
Because the sun is so large and so far away, all rays of light hitting anywhere on Earth are parallel to one another.

20. A pole casts a shadow only when the sun shines on its side, not when the Sun shines right on its top.
Poles in a row on a flat surface cast identical shadows, poles on a curved surface cast shadows of different lengths.
The different lengths of shadows observed by Eratosthenes suggested to him that the surface if Earth was curved, not flat.

21. Day and Night
April 1, 2011