In this unit, students explore the rotation of the Earth. Using their own bodies as kinesthetic models, they demonstrate how the Earth rotates on its axis every 24 hours. They also examine shadow patterns throughout the day and use that information to create shadow clocks.
THIS LESSON WAS REVISED ON JULY 1, 2019. Here is a link to the previous version.
In this lesson, students come to understand that the setting Sun isn’t moving, the Earth is spinning. In the activity, Spinning Earth, students use their bodies as a kinesthetic model of the Earth to understand how the speed of the Earth’s spin affects the length of a day.
One needs to be yellow to color the Sun and the other should be a dark color such as purple, blue, or black.
Colored pencils or markers will also work.
We suggest students work in pairs. Homeschool students will need a partner for the activity.
All students will be standing up and spinning in place throughout the activity with a place to view their paper Sun model. We find that placing the Sun model on a desk and standing about a foot behind the desk works well.
If you have a lamp or bright light, you can also use this as a model for the Sun. Just remind students NOT to look directly at the bulb.
In this lesson, students will learn why our ancestors divided the day into hours and how clocks measure the Sun’s apparent movement. In the activity, Make a Shadow Clock, students make their own sundials. First, students use flashlights indoors to understand how the position of the light affects the time shown on the clock. Then, students take their shadow clocks outside to see how the position of the Sun can tell them the time of day.
Shadow Clock Template printout
Use Google to find your latitude, then print your clock template.
We suggest students work in pairs. Homeschool students can work on their own.
Prep Shadow Clock Templates
Each Shadow Clock printout has two templates on it. Once you print these out, cut each in half so that each student will have one.
Label Classroom Walls with Cardinal Directions — North, South, East, West
When students are experimenting in the classroom, they need to orient their Shadow Clocks so the arrow points North.
Make four signs — North, South, East, and West.
Here’s one easy way to figure out where each sign goes:
Open Google Maps and enter your school’s street address.
Zoom in on your school and look at surrounding streets and landmarks.
North is always up on Google Maps. Find a landmark that’s to the north of your school.
Put North on the wall that’s closest to that landmark.
Face North. Put West on the wall to your left, East on the wall to your right, and South on the wall behind you.
Find North Outside and Draw Arrows with Chalk
The main activity is completed indoors, but we recommend that students test their Shadow Clocks outside on a sunny day. They’ll need to orient their Shadow Clock with the arrow pointing North. We recommend that you sketch several compass roses on the ground in chalk to serve as workstations.
The easiest way to find exact North when you are outside is to use a Shadow Clock. Turn the shadow clock to match the current time. Now the compass rose you made on the Shadow Clock will be properly oriented.
A magnetic compass, whether an old-fashioned kind or those available on many smartphones (such as iPhone’s compass app), actually points toward the Earth’s magnetic North Pole, which is slightly off from the geographic North Pole, depending on where you are. It may cause some error, depending on your location.
Lesson 3: Axis, Rotation, & Time
No materials required.
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