Hi, everyone!
I’m really glad you’re here today because we have an extra special experiment planned!
We’re going to teach you how to make something sticky … and gooey … and just a little
bit weird.
I like to call it...
Oobleck!
What’s Oobleck?
It’s an awesome kind of goo that’s lots of fun to make and fun to play with.
And the goo that you and I are going to make today was inspired by a story, by the writer
and illustrator, Dr. Seuss.
Dr. Seuss once wrote a story called Bartholomew and the Oobleck.
It’s about a king who gets bored with normal, everyday weather, so instead he makes sticky
stuff fall from the sky.
Now, what’s neat about the sticky Oobleck we’re going to make today, is that it acts
like both a solid and a liquid, without needing to change temperature, which is really unusual.
Most things behave like either a solid or a liquid when they’re at room temperature,
but not both.
So, how are solids different from liquids?
Well, things that are solid have a definite size and shape.
If you touch it, or move it, or take it from one kind of container into another, it’ll
still stay the same shape as before.
But liquids are things that don’t have a definite size or shape.
Like water.
If you touch it, it moves!
And if you move it from one kind of container into another, it changes its shape to fit
the new container.
So, for example, this toy is a solid.
Whether it’s standing up or knocked over on its side, it stays the same size and the
same shape.
And if we try to put it in this glass, it still keeps its shape, it doesn’t change.
Because ... it’s a solid!
But if we knock over a glass of water, the water spills everywhere, changing its shape.
And if we pour it from this glass into this glass of a different shape, it changes its
shape to fit.
Because, water is a liquid!
And while most things behave like either a solid or a liquid, some things--like Oobleck--can
act like both.
But how?
Let’s find out.
It’s time to make Oobleck!
All you need is a big bowl, a measuring cup, a spoon, some corn starch and, of course,
a grown-up to help you!
Set out your bowl, spoon, and your other ingredients in the kitchen, or anyplace where it’ll
be easy to clean up.
Alright, so first you’re going to start with the cornstarch.
Pour a cup and half into your bowl.
Now measure out a cup of water.
If you want your Oobleck to be a certain color, you can add a few drops of food coloring to
your water.
Squeaks and I will be making ours blue!
Now, you’re going to pour the water slowly into the cornstarch, and start stirring.
Keep stirring until it starts to thicken, and it gets a little hard to the touch.
If it looks too runny, add a little bit more cornstarch.
Once you’re done, it should look like this.
Pretty easy, right?
Now for the best part--playing!
First, swish it around a little bit.
Hhhhh… it moves like water.
And if you tried to pour it into a glass, it would change its shape to fit into the
glass.
Now!
Grab some of the Oobleck in your hand and squeeze it really hard.
Can you feel that?!
It should start to feel like a solid in your hand ... like a little squishy ball the size
of your fist!
Now, slowly open your hands -- over the bowl! -- and let it go.
Once you release the goop, it oozes out between your fingers like a liquid again, and it slowly
loses its solid shape.
So, sometimes Oobleck behaves like a solid, like when you touch it or squeeze it.
It becomes hard and takes a definite shape.
But sometimes, when you let it go, or when it’s on its own in the bowl, it behaves
like a liquid.
So Oobleck is different from that toy or just regular water, because it can be both a solid
and a liquid at room temperature.
And that’s what makes it so fun!
Now!
It’s time to clean up!
When you’re done playing with your goop, don’t throw it in the sink, it might clog
the drain.
Just toss in the trash, or better yet, store it in a sealed bag or container to play with
later!
Squeaks and I are going to keep playing with this batch before we clean up, but we’ll
see you again soon.
Thanks for making Oobleck with us!
And remember, if you have a question about anything you’d like to learn more about,
just let us know by getting help from a grown up, and leaving a comment below or email us
at kids@thescishow.com.
And we’ll see you later!