time. Can anyone tell me how long it takes for Earth to revolve around the sun one time?”
Introduction:
-Draw a human figure on the small portion of a sticky note. Dim the lights in the room for the demonstration.
-Say to the class, “Let’s look at this globe. What things do you notice about this globe? Let’s find where we live on this globe.” ----Point out Virginia on the globe. Attach the tiny sticky note with the figure drawn on it to Virginia. Make sure that the little figure is looking toward the North Pole. This little figure is going to represent us as we talk about the globe.
-Tell the students that as we talk about the movements of the sun and Earth, we will pretend that we are standing in Virginia and facing the North Pole. This is our point of view or frame of reference.
Procedure: Rotation of the Earth Demonstration 1:
-Ask the students, “Can anybody tell me what the word rotate means?”
-Ask all of the students to rotate, and have one student be the rotate sign holder, holding up the sign every time you say the word rotate. Have another student hold up a sign labeled spin to remind the students that rotate means to spin. Turn the globe slowly counterclockwise, and explain that Earth rotates in a counterclockwise direction.
-Say, “This light we have set up represents the sun. We will now be getting up and rotating in place. As you rotate, imagine that your nose is you and the top of your head is the North Pole.”
-Make a prediction about what it looks like on Earth.
-Notice that your nose goes through a repeating cycle — night (away from light) – day (facing light) – night – day – night – day, and so on. Also, the sun seems to rise in the east and set in the west, but it’s really you who is moving, not the light (sun).
-Demonstrate the same phenomenon — the sequence of night and day — using the globe. Be sure to point out the little figure that represents us. Follow the little figure through several cycles of night and day. “Where is the sun when the little figure sees the dawn start?” “Where is the sun when the little figure is ready for lunch around noon?” “Where is the little figure when it’s sunset?” “Where is the little figure when it’s night?” Depending on the ability level of your students, you may want to add that this is why the stars, moon, and planets also appear to rise and set.
-Emphasize that these objects aren’t really moving across our sky from east to west, but that Earth’s rotation makes all of these objects look like they are moving — rising and setting.
- Show “Earth's Rotation Diagram” that demonstrates why the sun appears to move across the sky because of Earth’s rotation. Be sure to tell the students that Earth and the sun are not drawn to scale. Ask, “Can anyone tell how long it takes Earth to rotate once on its axis, from noon to noon?”
Step-by-step explanation: