Janelle Durham

Shadow Science for Groundhog’s Day

The science of light and shadow is one of the core science concepts* for prekindergarten and early elementary school. (And shadow experiments are easy and fun!) Groundhog’s Day provides a fun excuse for studying shadows. Here are some ideas for learning about shadow science for Groundhog’s Day.

What is Groundhog’s Day?

It is observed on February 2 of each year. The story is that on that day if a groundhog sees its shadow, it will go back into its den and winter will last six more weeks. If it does not see its shadow, spring will arrive soon. This is from a Pennsylvania Dutch tradition, which is based on superstitions from German-speaking countries, where they watch for a bear or a badger to see their shadow.

Is there any scientific truth to this story? Nope. And I tell kids that. But it’s a fun story.

Shadow Activities

Make a Shadow Puppet

The most obvious activity is to make a groundhog shaped puppet, and then explore shadows using that. Just go to Pinterest and search for groundhog puppet and you’ll find countless examples. In my class, rather than having every kid create the same art project, we like to give more flexibility to make what they want. At the preschool level, we offer cookie cutters, white crayons and black cardstock or lightweight cardboard. The kids trace the cookie cutter, cut it out, and tape it to a craft stick or straw handle. For kindergarten to first grade, you could create templates for them to trace. Older children can draw whatever they want, but the key concept to explain is that they are drawing the outline of a shape (and cutouts if desired), not drawing details on the paper that won’t show in the shadow.

Explore Shadows

Once the puppet is made, you can use it in this shadow exploration, or you can use any other object, like a toy, or even your hand. This can be a demo you lead, or you can give every child their own flashlight to explore with. Dim the lights, and use a flashlight (or your phone’s flashlight or an old-fashioned overhead projector.) Shine the light on the wall. Then put an object between the light and the wall.

Have the kids notice how the object blocks the light. I talk about how the light gets “stuck” on the object and can’t pass through. (Optional: you could use a spray bottle of water to show how the object would also block water from hitting the wall.) Have them notice how the shadow is the same basic shape of the object, and if we put up different objects, they make different shaped shadows.

Have the children notice how the shadow changes as you move the flashlight around. If the light is far away, the shadow is small. When the light is close, the shadow is big. If the light is above the the object, the shadow is below it. If the light is behing the object, the shadow is in front of it.

An optional extension to this is to talk about how outdoors, our shadows change during the day. Early in the day, when the sun is low, our shadows are long and stretched. In the middle of the day, when the sun is high in the sky, our shadows are close by our feet. Later on, at outside time, if you’re lucky enough to hae a sunny day, you can observe this. You could even put a groundhog puppet outside, and notice how his shadow is different between morning recess and afternoon recess.

Shadows on Cloudy Days

(Prep for this demo: cut a cloud shape out of wax paper, tracing paper, or something that lets some light pass through but not all the light. For the pictures below, I made a simple groundhog puppet, then took a picture of what the shadow looked like when I shone the flashlight directly on it, vs. when I shone the light through a folded tissue and you can see there was no shadow.)

Now that the kids understand shadows, talk about why the groundhog might see his shadow sometimes but not other times. Shine the flashlight on the groundhog puppet to show how on a bright sunny day they have a clear shadow. Then hold the cloud up between the light and the groundhog. “But if there are clouds in the sky, they disperse the light. They scatter it and only let some light through. There may not be enough light to create a shadow.”

Translucent, Transparent, Opaque

Offer a variety of objects to explore. Some let all the light pass through – they’re transparent. Some let some light through but may distort shapes or change the color of the light – those are translucent. Opaque objects block all the light. If you have an overhead projector they provide a great surface for this exploration.

Tracing Shadows

You can set up a station where a light is shining on a flipchart or an easel with paper. Put an object between the light and the paper. The children can trace the shadow of the object.

Shadow Play

You can set up a bright light children can dance around in front of to see their shadows on the wall, or create a shadow screen they can dance behind.

Books

Here are a few suggestions. The book titles have Amazon affiliate links – you can learn more about the book there and can choose to get it from your local library or buy it (I do get a small bonus from Amazon if you do) and a link to a video where you can preview the book.

More Ideas

For more info on the screen and for lots more shadow science ideas, including songs and book recommendations, check out my full post on light and shadow. If you’re looking for more fun and easy science projects to do with kids, there’s hundreds more ideas on this site! Check them out now, or bookmark it for later. (Or follow me on Facebook or Instagram.)

* New York State Prekindergarten Learning Standards say: “Discusses the effects of the sun (e.g., provides light, creates shadows, and the warming effect on living organisms and nonliving things.)” Next Generation Science Standards for 1st grade say “Objects can be seen if light is available to illuminate them or if they give off their own light. Some materials allow light to pass through them, others allow only some light through and others block all the light and create a dark shadow on any surface beyond them, where the light cannot reach.”

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