For better Printing: pdf version
Materials:
Axis holder (from Act. 3)
Flashlight
Poof ball*
Three 5/8” nails
8” skewer
*Material Note: The Poof balls used are foam nerf-type balls. Each has two colors, which works well to distinguish hemispheres. They are available at stores like K-Mart and WalMart for just under $2 each
Explore:
1. Insert the pointed end of the skewer into the 23.5° hole in the holder.
2. Position the light so approximately half of the globe is in the light. Look for the shadow mark to help you.
3. Place one nail so that it is in the northern hemisphere about 45° north of the equator. Place another so that it is about
45° south of the equator along the same line of longitude.
Place a third nail at the equator along the same line of longitude.
4. Turn the skewer slowly. Observe how the parts of the globe move into and out of the light.
5. Observe the shadows of the nails.
A. Does the sun rise at the same time for all three locations or at different times? Explain.
B. Is there the same number of daylight hours at the three locations?
Explain what you find.
Explore some more:
1. Move your light source 180°, or half way around, so that the other end is facing the light.
2. Turn the ball so that all of the nails are in the dark. Observe as you turn the ball and the nails come into the light.
A. Does the sun rise at the same time for each nail? Do you get the same results as the last time? Explain.
B. Tell what season it is in the northern hemisphere when the North Pole is tilted toward the light.
C. Tell what season it is in the northern hemisphere when the North Pole is tilted away from the light.
Explore some more:
1. Place one of the nails near the South Pole and another near the North Pole. Leave the one at the Equator.
2. Turn the ball so the nail at the Equator is in the dark.
A. What do you notice about the nail at the North Pole?
What do you notice about the nail at the South Pole?
3. Turn the ball slowly so the nail at the Equator comes into and then goes out of the light.
B. What do you notice about the nail at the North Pole?
C. What do you notice about the nail at the South Pole?
4. Move the light source 180°, or half way around. Repeat steps 2 and 3 above.
D. Explain what happens now as you move the nail at the Equator into and out of the light.
Polar Light Home: Land of the Midnight Sun
Activity 1: How Long will my Shadow Grow?
(Keeping a shadow tape through the year)
Activity 2: How does the surface affect the light we see?
Activity 3: Preparing an axis holder for The Shadow Shows
Activity 4: The Shadow Shows (The Reason for the Seasons) Part 1
The Shadow Shows (The Reason for the Seasons) Part 2