Groundhog Day and Shadows...

It’s Groundhog Day!  

While a groundhog is a fun and quirky way to make a prediction, it’s not terribly scientific.  In fact, the Science Mommy read today that Phil, the groundhog, has about a 39% accuracy rate.  

 Shadows however, can be interesting to observe, make predictions about and explain.

Ages:  This one is for the Big Kid Scientists

Materials: 2 pencils, clay, flashlight, large piece of paper  OR  sunny day, driveway, sidewalk chalk

Set-Up Procedure:

• Find a room that can be made quite dark when the lights are out
• Place the large paper on a table or on the floor
• Roll the clay into a ball, poke one of the pencils into the ball and place it in the center of the paper.

Big Questions:  What determines the direction a shadow falls?  What determines the length of a shadow?  

Investigation Procedure:

• Make the room as dark as possible
• Use your flashlight and the pencil stuck in clay, to cast a shadow.
• Use your other pencil to trace the shadow (this may work better if you have a partner…one to hold the flashlight and the other to trace the shadow)
• Think of a way to record the position of the flashlight.
• Move the flashlight and predict where the shadow will now fall.  Predict how long it will be.
• Move the flashlight around, tracing the shadows and recording the position of the flashlight until you have enough data to write a rule that answers the Big Questions.
• What else did you learn while you were doing this investigation?  How can you share your discoveries?  The Science Mommy would love to hear about what you’ve learned.

2^nd Investigation Procedure:

• On a bright, sunny day draw an X on your driveway with sidewalk chalk.
• While you stand on the X, ask a partner to trace your shadow with sidewalk chalk.
• Label the first shadow with the time of day.
• Repeat this process every 30 minutes throughout the day. After you have a couple of shadow tracings, can you predict the shape/size/direction of the next shadow?
• Think about the shadow tracings and the Big Questions.  Do you have enough data to answer the questions?  What else do you need to know?
• What else did you learn while you were doing this investigation?  How can you share your discoveries? The Science Mommy would love to hear about what you’ve learned.

Groundhog picture from: http://animals.nationalgeographic.com/animals/mammals/groundhog/