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Who set the first clock?
Spaceship Earth Unit | Lesson 2 of 5

# Who set the first clock?

Spaceship Earth Unit | Lesson 2 of 5
Lesson narration:
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DISCUSS:

How do you think the very first clock got set, when there was no other clock to look at?

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DISCUSS:

Long ago, people did not have the concept of hours or minutes. Someone had to come up with these ways to divide a day into parts.

How would this week have gone wrong for you if you could only measure time in days?

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DISCUSS:

Try counting like an Egyptian! Use your thumb to count all of the finger segments on that same hand.

How many finger segments do you have on one hand?

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DISCUSS:

So why do you think there are 24 hours in a day?

See what we thought...

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DISCUSS:

What happens to the shadows as time passes?

How could you use shadows to measure the Sun's position?

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🎉 That’s it for this lesson! How did it go?
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# Why are the shadows moving so fast?

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###### Which direction are you facing when you sit in this chair? North, South, East, or West?

Here's how we figured it out:

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# north

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one of four main directions; when you face north, west is to the left and east is to the right
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# south

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one of four main directions; if you are facing north, it is the direction behind you
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# east

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one of four main directions; if you are facing north, it is to the right
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# west

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one of four main directions; if you are facing north, it is to the left
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# sundial

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a tool that tells time by using the changing direction of shadows caused by the Sun's movement across the sky
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Other
clock by TBIT / cropped, adjusted color
Lesson narration:

Earth & Space Patterns

Earth's Rotation & Daily Shadow Patterns

5-ESS1-2

# Activity Prep

Print Prep

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.

Preview activity
Exploration

#### 20 mins

Hands-On Activity