FIRST GRADE - EXPLAINING SHADOWS

OBJECTIVES:

VOCABULARY
shadow
angle

MATERIALS:
·         White butcher paper (or white surface)
·         Heat lamp (or larger flashlight)
·         Personal flashlights (at least one per team of two)
·         Shadow stick (can use Dry Erase markers since they stand up on their own)

BACKGROUND:

Have you ever noticed that your shadow is longest in the early morning and in the late afternoon? To tell the time ancients used the position of  sun in the sky At noon, when the sun is overhead there is little or no shadow at all. Long time ago people observed that, and used this principle in making of world’s earliest clock, a sun dial.

Look at the illustration to the right and notice the direction of the shadow is away from the source.  During midday it would be the shortest, and in afternoon it would be on the opposite side. 

PROCEDURE:

1.    Ask students this riddle:

I follow you around in the light, I say good bye to you in the night? Who am I? Shadow!

2.    Tell students their long term project will deal with shadows from the sun so it is important to understand  how shadows work.  Are there shadows in the classroom?  Why or why not?.  If you have the projector on talk about shadow puppets.  Might show them an object and have them predict what the shadow would be like.  Go outside (optional) and have the students find their shadow.  Ask them to see if they can make their shadow longer or shorter.

3.     Illustrate how shadows change during the day if you are outside.  You can use this flash animation. http://www.schoolsobservatory.org.uk/astro/esm/shadows

4.    Use the shadow stick in front of some white surface or butcher paper.  Use a heat lamp or flashlight to project different angles.  Have students predict where they think the shadow will  project.  Have students predict what they think the shadow will look like.  Engage the class into determine how to make it larger or smaller.  The heat lamp would represent the Sun.

5.    Use a white piece of paper and put a  marker (with flat head) standing in the center.  Have the students experiment with different angles as they try and make the shadows move around.  Ask students how can they make the longest shadow?  Shortest?  Fattest?  Thinnest? Have them demonstrate to you or the class how to position the light to get no or little shadow vs. really long shadows

6.    May want to have students design a shadow object with their hands and give a few students time to show their creation and rest of class figure out what it is.

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