Overview The revolution of the earth around the sun is a phenomenon that is hard for many children to deal with concretely. The notion that it is the earth that moves and not the sun goes against their apparent daily observation. The concept of rotation of the earth on its axis is equally incomprehensible to children. These phenomena of movement are crucial for the understanding of 'Day and Night'

Purpose This activity will help children to more fully understand our planet's relationship to the sun.

Objectives Children will be able to:

iii. Explain the phenomenon of Day and Night.

Resources/Materials No special materials are required

Activities and Procedures

Teaching method and activities

On the school grounds find a shadow cast by a fence post, tree, or any other object. Have the children observe the length and position of the shadow. Children may then make predictions about any changes that occur in the length and direction of the shadow throughout the day.

Allow the children to observe the shadow throughout the day. The children should then make predictions about the shadow's length and angle of the ray to the earth if it is measured at the same time every day. The children should also measure the shadow each day and graph the results. (12:00 noon is an ideal time)

At the end of each week find the average length of the shadow and angle of the suns rays to the earth. The children will see a change in the shadow's length and the angle of the sun's rays.

Tying it all together Students should conclude from their data that the position of the earth to the sun changes with the seasons. Hence in spring the shadow will show that the angle between the rays and earth has grown bigger and the sun is more directly overhead thus producing warmer temperatures.

Assessment The teacher should relate this lesson with similar lessons in this series. Attempts should be made to assess which of the lessons are most appropriate to a particular class or age group.

Suggestions/Modifications

• Students should be able to explain in words or pictures why the length of the shadows change over time.
• Students may compare the average monthly temperatures from the neighboring countries in order to see the effect that location from the equator plays on a country's climate.
• Students may chart the time of sunset throughout the year to note the changes.