Relative Positon and Motion - The Sun's Motion and Shadows Lesson Notes

Concept - Motion can be measured and represented on a graph. This belongs with measurement, graphing, or communication.

Outcome - Motion and position of the sun is described relative to the flagpole. Children will describe the relative motion of the sun with respect to the flagpole.

Disequilibrium might occur as the students mark the position of the shadow for the flagpole and see what happens. They might realize that what they thought was going to happen with the shadow of the flagpole throughout the day, didn’t happen, something else did.
Equilibrium might occur. When the students try to explain what happened. Students might point to the Sun and imagine the line that the light travels to hit the flagpole and see how that line can be extended through the pole to the shadow of the flagpole. Then by repeating the process as the Sun moves across the sky students can construct a visualization and reason to explain the motion of the shadow relative to the Sun.

Exploration is when the children go to the playground to collect observational evidence of what happens to a shadow. As they watch the shadow they may claim that it is moving, but they aren’t sure because it is soooo slow. So if a student doesn’t suggest to mark the shadow, then the teacher might lead them to the idea. If the playground is paved it is fun to trace the shadow with sidewalk chalk. Then repeat the process every half hour or so.

Invention starts whenever the children begin to talk about what is happening and continues until an explanation for the shadow in question is created, or all shadows on the playground, or all shadows every where. Depending on the how many investigations or activities the children and teacher desire to do.

Expansion is related to the way that the concept or generalization is written or described for the lesson. Notice how the expectations of what students need to know and understand change as the wording of the generalization changes.
The shadow of the flag pole is cast and moves relative to the position of the Sun and its motion.
Shadows are cast and move according to the position of the Sun and the object relative to it.
Shadows are cast and move according to the position of the object relative to the position and motion of the Sun.
Shadows are cast and move according to the position and motion of an object relative to the position and motion of the Sun.
Shadows position and motion are determined by the position and motion of an object relative to the position and motion of a light source.
As the breadth of what is expected to be known is widened the number of investigations or activities that would be necessary for the children to construct that understanding will increase. Therefore, the scope of the generalization is directly related to what could be used as an expansion. For example each of the statements above could represent an expansion for the one directly above it. Think about it. Does it make sense?
What about the very last one? It describes all objects and all shadows, There is not anything else to expand on with relationships of motion of light and shadow. So is there an expansion? What other relationships are there between the position and motion objects? Would one of them be appropriate for expansion? What about the phases of the moon? Position of planets and moons in the solar system? and more...

Process skills - observation, change, systematic collection of data, reasoning cause from effect. A procedure similar to what is used above can be created for each of the skills. Seperate activities can be created and sequenced, but it is better if the sequence is part of the science content (physical, life, earth).

Dr. Robert Sweetland's Notes ©