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View transcript[00:00:00.02] (bright electronic music) [00:00:03.06] (man laughing) [00:00:14.01] - [Woman] Can you place the heart. [00:00:15.05] - Yeah. [00:00:31.01] (upbeat music) [00:00:35.00] - Welcome back to Storytime Science at the Exploratorium. [00:00:39.06] Today's episode is Shadows. [00:00:42.08] We're gonna be doing a shadow activity in a little while, [00:00:46.02] shadow mapping, but first we're gonna read a book. [00:00:49.08] "Moonbear's Shadow." [00:00:52.03] (upbeat music) [00:00:55.02] Moonbear's Shadow. [00:00:57.07] One day Bear went down to the pond with his fishing pole [00:01:02.04] and a big can of worms. [00:01:05.01] While he was putting a worm on his hook, [00:01:08.04] he looked down and saw a big fish. [00:01:13.03] "I'm going to catch that fish," thought Bear to himself. [00:01:17.06] But when Bear stood up to throw his line in the water, [00:01:22.07] his shadow scared the fish away. [00:01:27.04] "Go away, shadow!" Cried Bear, [00:01:31.02] but Bear's shadow would not go away. [00:01:35.04] "Okay," Said Bear, "if you won't go on your own, [00:01:39.04] "then I'll just have to get rid of you." [00:01:42.06] And he put down this fishing pole and began to run. [00:01:46.04] He ran around the pond [00:01:49.01] and when he got to the other side, he kept on running. [00:01:53.01] He ran through a field of flowers, [00:01:55.08] jumped over the brook and hid behind a tree. [00:02:00.03] "Good," thought Bear. [00:02:02.02] "Now shadow can't find me." [00:02:05.08] But Bear was wrong. [00:02:08.06] When he stepped out from behind the tree, [00:02:12.09] the first thing he saw was shadow. [00:02:17.04] Nearby was a cliff, Bear walked over to the cliff [00:02:21.05] and looked up. [00:02:22.09] "I'll climb so high, Shadow won't be able to follow me." [00:02:28.04] Thought Bear, Bear climbed higher and higher. [00:02:33.05] Until at last he pulled himself up to the top. [00:02:38.03] Huffing and puffing, he smiled with pride. [00:02:43.07] Then he looked down and saw shadow. [00:02:48.08] Now Bear was very annoyed. [00:02:51.08] So he went home and got a hammer [00:02:54.00] and some nails to nail his shadow to the ground. [00:02:59.03] He hammered and hammered and hammered, [00:03:02.08] but no matter how many nails he hammered, [00:03:06.04] he couldn't nail his shadow down. [00:03:10.07] 'If I can't nail him down." thought Bear, [00:03:14.05] "Maybe I can bury him." [00:03:17.01] So he got his shovel and dug a hole. [00:03:20.07] When the hole was deep and wide, [00:03:23.06] he let his shadow fall in the hole. [00:03:29.04] Then Bear filled in the hole with dirt. [00:03:32.09] And when he was finished, it was almost noon. [00:03:38.07] The sun was high in the sky [00:03:42.03] and shadow was nowhere to be seen. [00:03:46.09] "At last." Sighed Bear, "No more shadow." [00:03:52.09] But now Bear was very tired. [00:03:55.06] So he went inside and took a little nap. [00:03:59.01] While he slept, time passed, [00:04:02.09] and the sun, once again, cast shadows everywhere. [00:04:10.09] When Bear got up and opened his door, he saw his shadow [00:04:15.03] on the floor. [00:04:17.01] "Not you again." exclaimed Bear. [00:04:20.05] And he slammed the door, hoping to lock shadow inside. [00:04:24.07] But shadow was too quick. [00:04:27.05] "Hmmm." Sighed Bear, "How about this? [00:04:32.09] "If you let me catch a fish, [00:04:36.00] "I'll let you catch one too. [00:04:38.08] "Nod your head like this if it's a deal." [00:04:42.09] When Bear nodded his head, shadow nodded too. [00:04:47.08] So Bear went back to the pond, [00:04:49.06] and once again, threw his line in the water. [00:04:53.07] By this time, the sun was in a different part of the sky, [00:04:59.07] which made it easy for shadow to keep his part of the deal. [00:05:04.07] And when Bear caught that fish, shadow caught one too. [00:05:10.06] (upbeat music) [00:05:13.01] We're gonna do a couple of shadow activities. [00:05:16.04] Actually, I did them in advance [00:05:17.09] because I kinda need the sun for the first one. [00:05:22.00] This first one is called shadow mapping. [00:05:25.03] And I did this out in my backyard on the sunny day. [00:05:29.03] You can also do it inside, [00:05:30.07] if you say, have a tabletop or a countertop [00:05:33.06] that gets a lot of sunshine for a good part of the day [00:05:38.04] through a window. [00:05:40.02] What I did was I first cut out some objects. [00:05:45.09] A circle, this weird four-sided shape here, [00:05:49.05] a bat because it's always Halloween at my house. [00:05:53.07] And I even cut out a hand, [00:05:55.06] I traced my hand and then cut it out. [00:05:57.08] And these are cut out of thicker paper like card stock, [00:06:01.07] index card stock because you don't want regular paper, [00:06:04.04] that would be too floppy. [00:06:06.03] And what I did was I then got a sheet of paper [00:06:10.01] and I set, let's go with the circle first. [00:06:14.03] I set my object at a point on the piece of paper [00:06:20.05] and I made sure it just stayed there. [00:06:23.05] Then what I was able to do, the sun was shining on it, [00:06:26.07] so I got a good shadow of this circle [00:06:30.03] and I traced around it and say, I started at 10 o'clock [00:06:34.00] in the morning. [00:06:35.03] So I traced the shadow at 10 o'clock in the morning. [00:06:39.09] Then without moving this circular shape at all, [00:06:44.01] I waited 25 minutes, half an hour, and the shadow had moved, [00:06:50.09] so I traced around the shadow half an hour later. [00:06:55.05] I also could have marked down the time, [00:06:57.02] I didn't do it here, but that's a good idea. [00:06:59.06] So I could have written 10 o'clock next to this shadow [00:07:02.04] of the circle and 10:30 next to the shadow of this circle. [00:07:06.07] Then I waited another half hour [00:07:09.02] and I traced the shadow of the circle a half hour later [00:07:13.06] at 11 o'clock and the shadow has moved. [00:07:17.04] Now, it seems like it's moving [00:07:20.01] because the sun is moving across the sky from East to West. [00:07:26.02] The sun rises in the East and sets in the West [00:07:29.08] but the sun is not really moving. [00:07:32.07] What's moving is the earth. [00:07:34.08] The earth is spinning on its center point, on its axis. [00:07:40.00] And it just looks to us human beings on the earth, [00:07:43.06] like the sun is moving across the sky. [00:07:46.07] Also, the sun is sort of at different angles in the sky [00:07:50.02] depending on the seasons, but that's a whole nother story, [00:07:54.00] that's a whole nother episode. [00:07:55.07] So then I traced the next half hour, like at 11:30, [00:08:00.05] the next circular shadow, and then the next one. [00:08:04.01] So I went from like 10 in the morning, [00:08:06.04] to 10:30 to 11 to 11:30 to noon. [00:08:09.06] And you can do this for as long as the sun [00:08:12.06] is hitting your objects. [00:08:14.04] You don't necessarily need to use an object [00:08:17.09] you've made yourself. [00:08:19.00] And I put this on a little stand that has a binder clip. [00:08:23.06] You can just get something like a bottle [00:08:26.06] or anything that might just stand up. [00:08:30.00] And as long as you don't move that object [00:08:32.09] that is casting the shadow, [00:08:35.05] all you have to do is trace. [00:08:37.08] If you don't wanna use a sheet of paper and a marker, [00:08:41.06] you can even do this on the ground, like on the sidewalk, [00:08:46.02] if it's safe for you to be out on the sidewalk [00:08:49.06] or out in the backyard, if you have a little backyard [00:08:52.06] and it's good, sometimes if you're gonna go out [00:08:54.07] on the sidewalk, maybe to do that with a grownup [00:08:57.04] and you can use sidewalk chalk, just trace the object, [00:09:03.00] make sure that object does not move. [00:09:05.08] Come back half an hour later or 45 minutes later [00:09:09.06] or 20 minutes later. [00:09:11.06] And map the shadow so that you can have a map [00:09:16.01] of how the earth and the sun are relating to each other. [00:09:20.08] (upbeat music) [00:09:23.05] Through this I have a few different objects here. [00:09:27.09] This is a tea light holder that's got ridges on it. [00:09:35.01] This is also a tealight holder, [00:09:36.08] it's clear, but it's in the shape of a Lotus flower. [00:09:41.07] And this is a little bottle of chili oil. [00:09:44.09] So that's why the liquid inside of here is orange, [00:09:47.06] this is very hot oil. [00:09:49.07] I like spicy things and use a flashlight. [00:09:54.00] And this is just an interesting way to shine the light [00:09:57.07] from the flashlight into these different objects, [00:10:01.04] to get Ooh, it's super, super bright. [00:10:04.01] If you're using a regular flashlight, [00:10:05.08] you can even turn the lights out, [00:10:07.06] so you get even sharper clear lines between the edges [00:10:12.04] of light and the edges of shadow. [00:10:14.06] And even though you're not getting full shadow, [00:10:17.01] you are getting areas of shadow and areas of light. [00:10:21.03] Here's that ridged tealight holder. [00:10:25.06] Here is the very very complex, lotus flower shaped [00:10:31.01] clear tea light holder. [00:10:34.04] So I am not getting a straight forward shadow [00:10:37.08] from this object. [00:10:39.00] I'm also not getting straight forward light [00:10:42.00] from this object. [00:10:43.02] I'm getting a really interesting combination [00:10:45.08] of shadow and light, [00:10:48.00] that's determined by this oddly shaped piece [00:10:51.06] or this ridged shaped piece, [00:10:53.05] or this is just a square bottle, [00:10:57.07] but shining a light through it, [00:11:00.02] doesn't give you just a regular shadow of the whole bottle, [00:11:05.03] and it also doesn't give you just the regular light [00:11:08.06] from shining through the chili oil in the middle. [00:11:11.06] It gives you again, a combination of light and shadow. [00:11:16.00] This stuff is really, really interesting to experiment with [00:11:19.07] because you don't have to come to any conclusions, [00:11:22.09] you can just make observations. [00:11:25.05] You can talk about what you see, [00:11:28.04] what you think you might be seeing. [00:11:30.05] You can come up with more questions. [00:11:33.03] So this is just shadow and light play. [00:11:39.08] (upbeat music) [00:11:43.09] Now it's time for poetry corner. [00:11:47.04] I have two shadow poems. [00:11:49.02] The first one is "My Shadow" by CJ Hick. [00:11:55.00] "I have a shadow hooked to me. [00:11:58.01] "Sometimes she's big, sometimes she's small, [00:12:01.01] "sometimes she isn't there at all. [00:12:04.03] "She doesn't seem to like the rain. [00:12:06.06] "Maybe thunder scares her too. [00:12:09.04] "She's gone from me on days like that [00:12:12.06] "'cause there isn't much to do. [00:12:15.02] "But if it's really sunny out, she doesn't like to hide. [00:12:20.07] "She's hooked right there beside me [00:12:23.03] "and we play all day outside." [00:12:27.09] And I have a second poem, [00:12:30.05] which is about making shadow puppets on your wall. [00:12:34.08] Say it's a full moon outside [00:12:36.09] and there's light coming in through your window. [00:12:39.04] This one is called "Shadow Show" [00:12:42.04] and it's by Amy Ludwig Van der Water. [00:12:47.05] "When birds are snuggled into nests, [00:12:51.00] "when night begins to fall, my hands like making shadows [00:12:57.04] "in the spaces on my wall. [00:13:00.06] "The moon peaks in my window [00:13:02.09] "like a knowing glowing eye, [00:13:06.04] "to help my hands turn into birds and flapping fingers fly. [00:13:13.01] "My hands are dogs and dragons [00:13:16.04] "for I learn new shapes each night. [00:13:19.08] "Shadow shapes of cats and trees [00:13:23.03] "dance through the moony light. [00:13:26.07] "My hands like telling stories [00:13:29.09] "of forest, sky and sea. [00:13:33.03] "Whenever we play shadow show, [00:13:36.03] "my wall, the moon and me." [00:13:39.07] (upbeat music) [00:13:42.03]
Is your shadow your BFF? Is it always with you, even on cloudy days? When the Sun is directly overhead? At night? Can your shadow show you how the Sun and the Earth work together? Can you make indoor shadows?
Join the Exploratorium's own Vivian Altmann as she reads Moonbear's Shadow by Frank Asch and leads a related activity (and a bonus mini-activity!).
Pier 15
(Embarcadero at Green Street)
San Francisco, CA 94111
(415) 528-4444