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Spaceship Earth    Mystery 2

Mystery 2 image

In this Mystery, students will learn why our ancestors divided the day into hours and how clocks measure the Sun’s apparent movement.

Beginning Exploration (1 of 10)
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Beginning Exploration (2 of 10)

DISCUSS:

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

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Beginning Exploration (3 of 10)
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Beginning Exploration (4 of 10)

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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Beginning Exploration (5 of 10)
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Beginning Exploration (6 of 10)

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?

Reveal answer...

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Beginning Exploration (7 of 10)

DISCUSS:

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

See what we thought...

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Beginning Exploration (8 of 10)
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Beginning Exploration (9 of 10)

DISCUSS:

What happens to the shadows as time passes?

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

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Beginning Exploration (10 of 10)
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Beginning Activity Prep
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Activity: Make a Shadow Clock
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Beginning Complete!

You've completed the Exploration & Activity!

If you have more time, view the assessment, reading and extension activity in the optional extras.

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Optional Extras

Below are ideas for extending this topic beyond the activity & exploration which you just completed.
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Why are the shadows moving so fast?

Click here to play video

Answer:

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

Hint: Watch the shadow and think about what it tells you about the Sun’s movement. Click here to play video

Here's how we figured it out:

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How is the movement of the clock’s hands like the movement of the shadow?

Click here to play video

Answer:

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Activity: Moving Shadow Game

Here’s a game to play outside on a sunny day. Find a place where the shadow of a building or wall makes a straight line. Mark that line with chalk.

Ask students to predict where the shadow will be in 15 minutes. Mark their guesses with other colors of chalk.

In 15 minutes, mark where the shadow ended up. How close were the guesses? Try again to see if you can do better.

This game is best when the sun is low in the sky. Don’t play at noon, when the sun is high in the sky.

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Image & Video Credits

Mystery Science respects the intellectual property rights of the owners of visual assets. We make every effort to use images and videos under appropriate licenses from the owner or by reaching out to the owner to get explicit permission. If you are the owner of a visual and believe we are using it without permission, please contact us—we will reply promptly and make things right.

Other
clock by TBIT / cropped, adjusted color