1. Day and Night- understanding the day/night cycle Karen Lucas 09/15/09

3. Taken from http://dc.doe.in.gov/Standards/AcademicStandards/StandardSearch.aspx

5. Background Information The earth rotates on its axis every 24 hours resulting in the day and night cycle. Picture taken from http://msnucleus.org/membership/html/k-6/uc/earth/1/uce1_1a.html

6. Pre- Activity Discussion Ask the students to have a paper and pencil to record their predictions and observations. 1. Show students a pencil, and tell them that it will represent Earth’s axis. Wrap foil around the pencil in a ball and explain that the foil will represent Earth. 2. Discuss with students what the words “rotation” and “tilt” mean. 3. Select a student to tilt and rotate the pencil, demonstrating how Earth moves.

7. Pre- Activity Discussion con’t Tell students that they are going to model the process of nightand day. By rotation and tilting the model. Ask students to write down how long a full day is, and what they believe causes the night-and-day cycle.

8. Activity 1. Show students the globe, and tell them it represents Earth. Help them identify the axis. Explain that a flashlight will represent the sun’s rays. 2. Tape a piece of paper over your city/state so that students can see where they live. 3. Turn off the lights and shine the flashlight at the piece of paper on the globe. 4. Ask students: “Is there light shining on our city/state now? What do you think will happen as I turn the globe on its axis?” Have the students record on paper.

9. Activity con’t 5. Slowly rotate the globe while holding the flashlight in the same spot. 6. Stop the globe when it has rotated halfway. Ask students: “Now is there light shining on our city/state? Is the other side of the globe in the dark or the light?” Have the students right down their observations. 7. Discuss with students that it takes 12 hours for Earth to rotate halfway and it takes 24 hours for a full rotation. Taken from activity : http://www.indianastandardsresources.org/files/sci/sci_4_3_8.pdf

10. Example Observations When its daytime where I live its still night time in different countries. Sometimes when its night time for a county they still can see part of the sun. There are different time zones because of the sun. Questions How long is the day and night cycle? If I took a plane ride from where I live during daytime to the other side of the earth would I lose time or gain time?