View transcript
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(bright electronic music)
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(man laughing)
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- [Woman] Can you place the heart.
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- Yeah.
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(upbeat music)
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- Welcome back to Storytime
Science at the Exploratorium.
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Today's episode is Shadows.
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We're gonna be doing a shadow
activity in a little while,
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shadow mapping, but first
we're gonna read a book.
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"Moonbear's Shadow."
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(upbeat music)
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Moonbear's Shadow.
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One day Bear went down to the
pond with his fishing pole
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and a big can of worms.
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While he was putting a worm on his hook,
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he looked down and saw a big fish.
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"I'm going to catch that
fish," thought Bear to himself.
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But when Bear stood up to
throw his line in the water,
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his shadow scared the fish away.
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"Go away, shadow!" Cried Bear,
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but Bear's shadow would not go away.
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"Okay," Said Bear, "if
you won't go on your own,
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"then I'll just have to get rid of you."
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And he put down this fishing
pole and began to run.
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He ran around the pond
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and when he got to the other
side, he kept on running.
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He ran through a field of flowers,
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jumped over the brook
and hid behind a tree.
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"Good," thought Bear.
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"Now shadow can't find me."
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But Bear was wrong.
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When he stepped out from behind the tree,
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the first thing he saw was shadow.
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Nearby was a cliff, Bear
walked over to the cliff
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and looked up.
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"I'll climb so high, Shadow
won't be able to follow me."
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Thought Bear, Bear
climbed higher and higher.
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Until at last he pulled
himself up to the top.
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Huffing and puffing, he smiled with pride.
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Then he looked down and saw shadow.
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Now Bear was very annoyed.
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So he went home and got a hammer
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and some nails to nail
his shadow to the ground.
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He hammered and hammered and hammered,
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but no matter how many nails he hammered,
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he couldn't nail his shadow down.
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'If I can't nail him down." thought Bear,
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"Maybe I can bury him."
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So he got his shovel and dug a hole.
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When the hole was deep and wide,
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he let his shadow fall in the hole.
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Then Bear filled in the hole with dirt.
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And when he was finished,
it was almost noon.
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The sun was high in the sky
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and shadow was nowhere to be seen.
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"At last." Sighed Bear, "No more shadow."
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But now Bear was very tired.
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So he went inside and took a little nap.
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While he slept, time passed,
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and the sun, once again,
cast shadows everywhere.
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When Bear got up and opened
his door, he saw his shadow
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on the floor.
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"Not you again." exclaimed Bear.
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And he slammed the door,
hoping to lock shadow inside.
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But shadow was too quick.
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"Hmmm." Sighed Bear, "How about this?
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"If you let me catch a fish,
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"I'll let you catch one too.
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"Nod your head like this if it's a deal."
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When Bear nodded his
head, shadow nodded too.
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So Bear went back to the pond,
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and once again, threw
his line in the water.
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By this time, the sun was in
a different part of the sky,
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which made it easy for shadow
to keep his part of the deal.
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And when Bear caught that
fish, shadow caught one too.
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(upbeat music)
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We're gonna do a couple
of shadow activities.
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Actually, I did them in advance
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because I kinda need the
sun for the first one.
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This first one is called shadow mapping.
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And I did this out in my
backyard on the sunny day.
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You can also do it inside,
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if you say, have a
tabletop or a countertop
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that gets a lot of sunshine
for a good part of the day
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through a window.
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What I did was I first
cut out some objects.
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A circle, this weird
four-sided shape here,
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a bat because it's always
Halloween at my house.
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And I even cut out a hand,
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I traced my hand and then cut it out.
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And these are cut out of
thicker paper like card stock,
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index card stock because you
don't want regular paper,
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that would be too floppy.
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And what I did was I
then got a sheet of paper
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and I set, let's go with the circle first.
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I set my object at a point
on the piece of paper
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and I made sure it just stayed there.
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Then what I was able to do,
the sun was shining on it,
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so I got a good shadow of this circle
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and I traced around it and
say, I started at 10 o'clock
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in the morning.
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So I traced the shadow at
10 o'clock in the morning.
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Then without moving this
circular shape at all,
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I waited 25 minutes, half an
hour, and the shadow had moved,
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so I traced around the
shadow half an hour later.
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I also could have marked down the time,
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I didn't do it here,
but that's a good idea.
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So I could have written 10
o'clock next to this shadow
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of the circle and 10:30 next
to the shadow of this circle.
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Then I waited another half hour
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and I traced the shadow of
the circle a half hour later
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at 11 o'clock and the shadow has moved.
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Now, it seems like it's moving
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because the sun is moving across
the sky from East to West.
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The sun rises in the
East and sets in the West
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but the sun is not really moving.
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What's moving is the earth.
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The earth is spinning on its
center point, on its axis.
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And it just looks to us
human beings on the earth,
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like the sun is moving across the sky.
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Also, the sun is sort of at
different angles in the sky
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depending on the seasons, but
that's a whole nother story,
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that's a whole nother episode.
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So then I traced the next
half hour, like at 11:30,
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the next circular shadow,
and then the next one.
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So I went from like 10 in the morning,
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to 10:30 to 11 to 11:30 to noon.
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And you can do this for as long as the sun
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is hitting your objects.
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You don't necessarily
need to use an object
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you've made yourself.
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And I put this on a little
stand that has a binder clip.
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You can just get something like a bottle
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or anything that might just stand up.
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And as long as you don't move that object
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that is casting the shadow,
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all you have to do is trace.
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If you don't wanna use a
sheet of paper and a marker,
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you can even do this on the
ground, like on the sidewalk,
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if it's safe for you to
be out on the sidewalk
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or out in the backyard, if
you have a little backyard
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and it's good, sometimes
if you're gonna go out
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on the sidewalk, maybe
to do that with a grownup
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and you can use sidewalk
chalk, just trace the object,
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make sure that object does not move.
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Come back half an hour
later or 45 minutes later
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or 20 minutes later.
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And map the shadow so
that you can have a map
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of how the earth and the sun
are relating to each other.
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(upbeat music)
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Through this I have a few
different objects here.
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This is a tea light holder
that's got ridges on it.
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This is also a tealight holder,
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it's clear, but it's in the
shape of a Lotus flower.
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And this is a little bottle of chili oil.
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So that's why the liquid
inside of here is orange,
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this is very hot oil.
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I like spicy things and use a flashlight.
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And this is just an interesting
way to shine the light
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from the flashlight into
these different objects,
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to get Ooh, it's super, super bright.
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If you're using a regular flashlight,
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you can even turn the lights out,
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so you get even sharper
clear lines between the edges
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of light and the edges of shadow.
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And even though you're
not getting full shadow,
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you are getting areas of
shadow and areas of light.
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Here's that ridged tealight holder.
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Here is the very very
complex, lotus flower shaped
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clear tea light holder.
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So I am not getting a
straight forward shadow
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from this object.
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I'm also not getting
straight forward light
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from this object.
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I'm getting a really
interesting combination
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of shadow and light,
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that's determined by
this oddly shaped piece
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or this ridged shaped piece,
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or this is just a square bottle,
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but shining a light through it,
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doesn't give you just a regular
shadow of the whole bottle,
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and it also doesn't give
you just the regular light
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from shining through the
chili oil in the middle.
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It gives you again, a
combination of light and shadow.
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This stuff is really, really
interesting to experiment with
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because you don't have to
come to any conclusions,
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you can just make observations.
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You can talk about what you see,
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what you think you might be seeing.
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You can come up with more questions.
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So this is just shadow and light play.
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(upbeat music)
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Now it's time for poetry corner.
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I have two shadow poems.
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The first one is "My Shadow" by CJ Hick.
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"I have a shadow hooked to me.
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"Sometimes she's big,
sometimes she's small,
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"sometimes she isn't there at all.
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"She doesn't seem to like the rain.
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"Maybe thunder scares her too.
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"She's gone from me on days like that
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"'cause there isn't much to do.
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"But if it's really sunny
out, she doesn't like to hide.
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"She's hooked right there beside me
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"and we play all day outside."
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And I have a second poem,
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which is about making
shadow puppets on your wall.
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Say it's a full moon outside
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and there's light coming
in through your window.
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This one is called "Shadow Show"
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and it's by Amy Ludwig Van der Water.
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"When birds are snuggled into nests,
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"when night begins to fall,
my hands like making shadows
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"in the spaces on my wall.
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"The moon peaks in my window
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"like a knowing glowing eye,
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"to help my hands turn into
birds and flapping fingers fly.
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"My hands are dogs and dragons
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"for I learn new shapes each night.
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"Shadow shapes of cats and trees
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"dance through the moony light.
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"My hands like telling stories
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"of forest, sky and sea.
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"Whenever we play shadow show,
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"my wall, the moon and me."
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(upbeat music)
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