1. Longitude & latitude Time.

2. SHAPE Shape – The Earth is not a perfect sphere. The Earth is an oblate spheroid. –This means it is slightly flattened at the poles and slightly bulging at the equator. –Polar circumference is slightly smaller than the Equatorial circumference. The Earth DOES NOT look like an egg!

3. EVIDENCE Evidence – (Based on assumptions) - INFERENCE Weight due to Gravity –Gravity acts as a stronger force when objects are closer to the center of the Earth. –The weight of an object is slightly more at the Poles. Explanation – Objects must be closer to the center of the Earth at the Poles Ships “disappear” at the horizon…the last things to see are the tops of the sails. Curvature of the Horizon from a plane Angle to the North Star changes with Latitude The shape of the Earth’s shadow is curved

4. Polaris ► The North Star (Polaris) never changes its place in the sky. When you face it, you are always facing North. ► To find the North Star, first find the Big Dipper. Draw a straight line through the two pointer stars that make up the end of the dipper's bowl and continue this line away from the opening of the bowl until it intersects with Polaris. Big DipperBig Dipper ► Latitude is based on your angle to Polaris

5. http://astro.unl.edu/classaction/animations /ancientastro/dipperclock.html

6. Astrolabe ► The astrolabe give the angle/position of the Sun and stars in the sky.

7. Look at the North Star and point one arm straight at it, and then hold your other arm level with the horizon. The angle between your arms is roughly the degrees of latitude of your location

8. Angle To the North Star Spherical Earth: The angle to Polaris changes depending on your location on a spherical Earth BACK

9. Latitude and Longitude ► The earth is divided into lots of lines called latitude and longitude.

10. Lines ► Longitude lines run north and south and measure west to east. ► Latitude lines run east and west and measure north to south. ► The lines measure distances in degrees. Longitude Latitude

11. Where is 0 degree? ► The equator is 0 degree latitude. ► It is an imaginary belt that runs halfway point between the North Pole and the South Pole. Equator

12. Where is 0 degree? ► The prime meridian is 0 degrees longitude. This imaginary line runs through the Greenwich England, France, Spain, western Africa, and Antarctica. PRIMEPRIME MERIDIANMERIDIAN

13. East West, North South on the Earth ► Let each of the four quarters then be designated by North or South and East or West. N S EW

14. East West, North South on the Earth ► The N tells us we’re north of the Equator. The S tells us we’re south of the Equator. ► The E tells us that we’re east of the Prime Meridian. The W tells us that we’re west of the Prime Meridian. (N, W) (N, E) (S, W) (S, E)

15. East West, North South on the Earth ► That means all points in North America will have a North latitude and a West longitude because it is North of the Equator and West of the Prime Meridian. (N, W) Prime Meridian

16. What is Latitude? ► For Example: ► 40°, 02’,51’’N ► This is close to the latitude where you live. Y X 90°S 90°N

17. What is Longitude? ► The earth is divided into 360 equal slices (meridians) ► 180 west and 180 east of the prime meridian Y X 180°W 180°E

18. See If You Can Tell In Which Quarter These Lon/Lats Are Located ► 1. 41°N, 21°E ► 2. 37°N, 76°W ► 3. 72°S, 141°W ► 4. 7°S, 23°W ► 5. 15°N, 29°E ► 6. 34°S, 151°E AB C D

19. ► 1. B ► 2. A ► 3. C ► 4. C ► 5. B ► 6. D

22. What is Latitude? ► Each degree of latitude is divided into 60 minutes. ► Each minute is divided into 60 seconds. Y X 90°S 90°N This is also true of longitude.

23. What is Latitude? ► Our latitude and longitude might be: ► 40°, 03’,13’’N ► 76°, 29’, 45’’W Y X 90°S 90°N

24. Latitude and Longitude

25. Latitude 45° N 44° N 43° N 42° N 41° N

26. Longitude 73° W 74° W 75° W 76° W77° W78° W79° W

27. 73° W 74° W 75° W 76° W77° W78° W79° W 45° N 44° N 43° N 42° N 41° N Find: 1.43° N, 76 ° W 2.44 ° N, 76 ° W 3.42 ° N, 79 ° W

29. Latitude and Longitude Resources ► Latitude & Longitude Activity Latitude & Longitude Activity Latitude & Longitude Activity ► A Printable Latitude & Longitude Map of the World A Printable Latitude & Longitude Map of the World A Printable Latitude & Longitude Map of the World ► Latitude & Longitude Map Making Latitude & Longitude Map Making Latitude & Longitude Map Making ► Latitude and Longitude Quiz Latitude and Longitude Quiz Latitude and Longitude Quiz

30. Time Zones ► The Earth is divided into 24 time zones, corresponding to 24 hours in a day. ► As the earth rotates, the sun shines in different areas, moving from east to west during the course of a day. ► Places that have the same longitude will be in the same time zone. longitude ► 15 degrees =1 hour