Island Science

islandThis charming little island really floats! Thanks to some well-placed wine corks, the island (and 2 little sailboats) will bob away in your bathtub, pool, or water table. This project is also a good way to introduce a some science terms to the story time set – namely, prediction, testing, saturation, buoyancy, and capillary action.

floating islandWe read An Island Grows, written by Lola M. Schaefer and illustrated by Cathie Felstead (Greenwillow Books, 2006). This non-fiction rhyming book follows the growth of an island from the first tremors of an underwater volcano to a busy and colorful island community. Don’t miss the last page which is full of the scientific information behind the book’s charming rhymes. 

You’ll need:

  • 1 box (mine was 4” x 4” x 4”)
  • 1 box cutter
  • A selection of patterned paper
  • 3 small squares of fabric (approximately 2″-3″)
  • 3 short pieces of thin ribbon (approximately 3″)
  • 1 small seashell (optional)
  • 1 paper towel tube
  • 1 corrugated cardboard base (approximately 8″ x 9″)
  • Green construction paper
  • Brown construction paper
  • White construction paper
  • Flower stickers (optional)
  • 20 wine corks
  • Scissors, tape, and glue stick for construction
  • Markers for decorating
  • Hot glue

Begin with your island home. Use the box cutter to cut a door and three windows in the sides of a box. Decorate the outside of the box with markers and add a roof of patterned paper (or construction paper). Use tape (or hot glue) to attach fabric squares to the insides of the box, right above each window. Knot a piece of ribbon around the fabric squares to create a window sash. Finish by hot gluing a small shell to the door to serve as a doorknob.

houseNow for your palm tree! Start by cutting 3″ off the top of a paper towel tube. If you’d like, you can use markers to draw rings around the tree. Next, cut 4 rectangles from the green construction paper (approximately 2″ x 5.5″ each). Cut each rectangle into a leaf shape, and make small cuts around the edges so it better resembles a palm frond.

palm leavesTape the palm fronds to the paper towel tube (I taped mine to the inside of the tube, but younger children might find it easier to tape them to the outside). To make coconuts, cut small circles out of the brown construction paper, then attach them to the tree with little loops of tape.

palm treeAt this time, I’d like to give a shout out to Anou, age 8, who came up with the coconut portion of our craft. I was in our library’s program area, trying to find a way to make three-dimensional looking coconuts that didn’t require hot glue. Anou walked up, offered the tape loop suggestion, and it looks great! Brilliant Anou, thanks!

With the house and tree complete, it’s time to make your base. Start with a 8″ x 9″ piece of corrugated cardboard (I cut ours from copy paper boxes). Use the glue stick to attach green construction paper to one side of the base. Then hot glue the house and the tree to the top of the base. It’s important to keep the house and the tree fairly close together in the center of the base. This will keep your island balanced while it’s floating on water.

fairly close togetherOnce the house and tree are attached, add a little landscaping with green construction paper fringes and flower stickers (or just draw flowers on the base with markers). We also used red file label stickers to create stepping stones leading to the front door of the house.

stepping stonesTo make your island and sailboats float, you’ll need 20 corks. Since we needed to prepare enough supplies for 24 kids, we needed lots of corks (480 to be exact). So we hit up a couple local wine shops and bars (thank you Public Wines, Cool Vines, Princeton Corkscrew, and Yankee Doodle Tap Room). But the real jackpot was a restaurant called Mediterra. They had THESE stashed in their kitchen. Woo hoo!

corks To make your island’s “cork stilts,” begin by hot gluing 4 corks together like this:

four corksRepeat this step three more times until you have 4 stilts (composed of four corks each). Hot glue the stilts to the bottom of the cardboard base like so:

cork stilts on baseWe had to do a little trial and error to determine the total number of corks needed to get this project to work. You can turn our experimentation into story time science by doing the following…

Fill a dish tub with water and set it on a table. Have three different bases prepped. The first base is cardboard with no corks.

base 1

The second base is cardboard with cork stilts. The stilts are two corks each.

base 2The third base has cork stilts too. These stilts are 4 corks each.

base 3

  1. Start by saying “Let’s take a look at these bases and predict which one will work best for our island.” After the kids make their predictions, say “Time to test them out!”
  2. Place Base 1 in the tub. It will immediately become saturated. Ask “What happened? What do we need to change to make this float and stay dry?”
  3. Place Base 2 in the water. It will float, but barely above the water. Eventually, water will begin saturating into the bottom and edges of the base. Ask “Is this any better? What’s the problem now?”
  4. Place Base 3 in the water. The base will float above the water, keeping the island dry. Say “It finally worked! Any guesses why?”

During the experiment, you can refer to the concepts of saturation, density and buoyancy. A cork floats on the water because it is less dense than the water. This gives the cork buoyancy, meaning that upward force on the cork is equal to the weight of the cork. The cardboard base, however, was just too heavy for the 2 cork stilts. As a result, Base 2 sunk down and got wet. But Base 3, the 4 cork stilts, did the trick! They gave the island enough buoyancy to lift the cardboard (and the house & tree) above the water level.

Time for sailboats! Cut a small sail (mine were about 2″ tall) out of white construction paper, and color both sides with markers. Hot glue the sail to one side of a cork (make sure the paper doesn’t extend below the cork). Then, hot glue a second cork next to the first.

cork boatWe discovered that, as the corks get wet, the water seeps up the sail, pulling the ink with it. This is capillary action…in action!

before and after boatsIf you’d like to turn the sailboat activity into a quick science lesson, create the boat you see in the “Before” photo above. For best results, make sure the marker extends all the way to the base of the paper sail. Fill a dish tub or plastic plate with water. Then:

  1. Show the kids the boat. Say: “This sailboat needs a little more decoration. Want to see a super cool way to decorate the sail – without drawing on it?”
  2. Place the sailboat in the water. It takes a few minutes to really get started, so you might have to go for a couple rounds of “Row, Row, Row Your Boat” while you wait.
  3. Talk briefly about capillary action (i.e. the ability of water to flow up or though something – sometimes in defiance of gravity itself) and how they just observed the water moving up the paper sail, carrying the ink with it!
  4. If you’d like, you can prep a bunch of sailboats with different color inks, and see if the different colors move up the sail at different rates.

And that’s it! Your island and sailboats are complete! Float them in a bathtub, dish tub, baby pool, water table, or, in my case, the giant fountain outside of the Woodrow Wilson School of International and Public Affairs (that’s Ai Weiwei’ s Circle of Animals/Zodiac Heads you see in the background). The perfect place for an island getaway, yes?

fountainLooking for some more island experiments? Do you like coconuts? Check out this post!

Yes, They Do Float

coconut experimentI’m talking about coconuts of course. If you’re ever stranded on a tropical island and need to make an escape raft…yes, coconuts do indeed float. This experiment was part of To Be Continued, our reading program for 6 to 8 year-olds. You can read about some of our other activities here and here.

We read Nim’s Island by Wendy Orr (Yearling, 1999). Nim is a little girl who lives on a beautiful, yet isolated, tropical island with her scientist father, Jack. When Jack leaves for a three day research trip at sea, Nim is left alone on the island with her friends Fred the marine iguana, Selkie the sea lion, and Chica the sea turtle. The family hut is equipped with a laptop computer, and Nim is delighted to learn that Alex Rover, world-famous adventure novelist, has written Jack to inquire if it is possible to build a coconut raft. So far, so good…but…Jack doesn’t return as expected, days pass, and Nim finds her surivival skills put to the test. Her correspondence with Alex (i.e. Alexandra!) Rover continues, and another story begins to unfold. A story about facing fears, courage, and love.

The kids asked many questions during the reading of this book (more on that below), but the one that intrigued me the most was – do coconuts really float? I decided that we needed to find out.

coconut Finding coconuts wasn’t difficult. Whole Foods Market carries them in their produce section, as did Wegman’s, a local grocery chain here. I never realized how cute coconuts were – in a hairy sort of way.

I put the coconuts in one dish tub, and filled another dish tub with water. The experiment was ready!

coconut experiment set upBut before we embarked on some coconut science, I set a tropical mood by handing out colorful leis and putting on an Echoes of Nature: Ocean Waves CD (Delta Music, 1993).

leisI let everyone pick up the coconuts and examine them. Then we took a vote. Who thought the coconuts were going to float? Why? Who thought they were going to sink? Why? Coconuts are very hard and rather heavy. So they’re going to sink, right? I rolled them into the water. They floated!

they float

Then we moved to a different table to try yet another coconut experiment – a taste test!

coconut waterCoconut water is all the rage these days. It’s the actual liquid that comes from inside a coconut (as opposed to coconut milk, which is made from the grated meat of the coconut). This is the stuff Nim drinks in the book, so we tasted it! The reactions to the flavor, as you can see, were a bit mixed…

taste testBut everyone gave it a good try (one little girl even asked her mom if she could get some for home!). Typically, I don’t do food in my programs (you can read more about this in my food allergy post). And, in fact, one of the kids participating in this program did have a food allergy to dairy. But the connection to the book was so fabulous, I decided to put in some legwork to make it possible.

First, I checked Vita Coco labels to see if there was any potential contamination with dairy products (there’s not, it’s actually a vegan product). I doubled checked with the company. Then, the week before the activity, I approached the mother of the child with the food allergy and explained what I wanted to do and what I had learned from the company. I brought the Vita Coco packaging with me so she could check the label herself. After Mom gave the OK, we were good to go!

Having floated coconuts and tasted coconut water, we had one more connection to make. In the books, Nim plays coconut soccer with Fred, Selkie, and Chica. Unfortunately, it was raining outside so we couldn’t try our version of it, but we did try coconut bowling!

coconut bowling 2Basically, I set up two sets of 6 toilet paper tube “pins” and let ‘em rip! And there you have it. Three fabulous Nim’s Island activities, all inspired by the humble, yet surprisingly versatile, coconut!

A few of the other questions that came up during this book were:

  1. What’s a machete?
    A quick trip to Google images solved this one.
  2. What does a marine iguana, sea lion, and sea turtle look like?
    Google images again!
  3. What’s the difference between an ocean and a sea?
    A sea is part of the ocean partially enclosed by land (from National Ocean Service)
  4. Are coconut pearls real?
    Apparently, they’re a myth. Boo.