Paper plate
Pencil
Plasticine or modeling clay
Marker or pen (for writing numbers)
Ruler (optional, for marking equal distances)
Introduction:
Explain how sundials work by using the position of the sun and the shadow cast by the gnomon (the stick or pencil) to tell time. Discuss the history of sundials and their use in ancient civilizations.
Prepare the Sundial:
Mark the Plate: On the back of the paper plate, use a marker or pen to write the numbers 1 through 12 at equal distances around the edge. These numbers represent the hours of the day.
Create the Gnomon: Make a small hole in the center of the paper plate. This will be where the pencil (gnomon) is inserted.
Assemble the Sundial:
Insert the Pencil: Insert the pencil through the hole in the center of the plate. The pencil should stand upright and be centered on the plate.
Secure with Plasticine: Use plasticine to secure the pencil in place, making sure it doesn’t move and is firmly attached to the plate.
Set Up the Sundial:
Synchronize with Current Time: Place the sundial in a sunny location. Rotate the sundial so that the shadow of the pencil aligns with the current hour on the sundial (you can use a regular clock to help with this).
Observe and Record: Over the course of the day, observe the position of the shadow and how it aligns with the numbers on the sundial. Record the times at which the shadow falls on each number.
Reflect and Discuss:
Share Observations: Discuss the results with students. Talk about how the position of the shadow changes throughout the day and how it corresponds to the passage of time.
Discuss Accuracy: Reflect on the accuracy of the sundial and factors that might affect its precision, such as the angle of the sun and the position of the sundial.
Extension Activity (Optional):
Make a Sundial Calendar: Create additional sundials for different times of the year or different locations to see how the shadow’s length and position change with the seasons.
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