(Intro)

Jessi: Oh, I'm sorry, Squeaks, it's too cold to go sledding today.  I know.  Oh, hey, everyone.  Squeaks and I were supposed to play outside today, but as you can see, it's freezing.  Squeaks is taking it pretty hard, but just because we're stuck inside doesn't mean we can't have fun, and I have a great idea.  We've done tons of awesome experiments together and lots of them can be done with things you can find around your house.  They're perfect for a day like today, so let's take a look at one of my favorites.

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.

There are lots of other kinds of experiments you can do in the kitchen, too.  With a little bit of sand, sugar, and water, you can even mix up your own super sciency potions.  

I love to mix stuff up - sometimes I like to go into the kitchen, grab some ingredients and put them together just to see what happens. It's kinda like we're making magic potions. 

When you mix stuff together, sometimes you'll notice that interesting things start to happen. For example, sometimes one of the ingredients might seem to disappear. And at other times, the ingredients just kinda hang out together, and don't really mix up.

So when we mix things together, we can pretend we're making potions but what we're really doing is better than magic - it's Science! Let's try to make a few pretend potions and see what we can learn about them.

For our first mixture, all you'll need is a clear container, a spoon, some water and some play sand. Fill the container with water. Water is a great start to any potion. Now, put a big spoon of sand into the container and mix it around.

What do you see? What's happening? When you mix the sand and the water really fast, the sand spreads out in the glass pretty evenly. You can see the sand floating around in the water. But once you stop stirring and you wait just a few seconds, what happens? The sand settles to the bottom of the container. The sand and the water separate.

So what kind of potion did we make? We made something called a suspension. In a suspension, the ingredients that you mix together can be separated from each other once they've been mixed. Often when you let your mixture sit, the heavier ingredients will fall to the bottom of the container like our sand did. And if you poured your mixture through a filter like a paper towel or a coffee filter, you could separate the sand from the water!

Let's try it! You can see that the water falls into the glass while the sand stays on the filter. You've unmixed your potion!

Now let's try a different kind of a potion. We can use water again but  this time, instead of adding sand, let's add a few spoonfuls of sugar. Mix the sugar around with a spoon like you did with the sand.

What's going on? The sugar is small and grainy like the sand, and at first it might seem like we're making another suspension but keep stirring. What's happening now?

Whoa! It looks like the sugar is totally disappearing into the water but it didn't actually disappear. You can see for yourself if you take a sip of our potion... it tastes sweet! The sugar is still in there but you can't see it anymore. That's because in the water, the sugar dissolves or breaks down into smaller and smaller pieces until it gets mixed into the water evenly. This kind of potion is called a solution.

Solutions are mixed together totally evenly and they can't be unmixed. Even if you let the glass of water stand still for a long time, the sugar won't settle to the bottom. If you wanted to try and filter the sugar out like the sand, all of it would just pour right through.

Now let's make another couple of potions, and based on what we've learned, let's see if we can figure out if it's a suspension of a solution. This time, instead of an open container, we'll put a lid on so we can mix things up really well.

Pour some water into the jar until it's about halfway full. Then, add a few drops of food coloring, any color that you'd like. Now, cover up your jar and shake it up! What happened to the food coloring? The coloring is mixed up and if you let the jar sit... the coloring doesn't settle to the bottom. Since the ingredients don't separate, it must be a... solution!

Next, we'll add a totally new ingredient: oil! You can use vegetable oil or olive oil. Put some into the jar, and then put the lid on. And now... shake! Shake your jar all over the place, try and mix the water and oil together. When we set the jar down, what happens? Look! The oil forms big globs in the water, and after you let it set, the oil and water totally separate. What kind of potion do you think this is? If you said suspension, you're right!

So now you know two kinds of mixtures you can make: suspensions, where the ingredients combine together, but can separate again; and solutions, where one ingredient dissolves, or breaks up into teeny tiny pieces, into the other, and solutions can't be separated.  Keep mixing stuff together and let us know what kinds of cool potions you make.

I love making gooey slime and mixing potions, but Squeaks has his own special way to pass the time when he can't go outside.  He likes to do art, and believe it or not, there's a lot of science in art, especially when it comes to the paints, crayons, and markers that we use to create our masterpieces.  Here's a special experiment we did that will teach you how to make your own watercolors.  Oh, this is really good, Squeaks.

Hi everyone! Squeaks and I were just getting ready to make some paintings, but we can't find our paint. Luckily, Squeaks taught me how to make my very own watercolors, and I'd like to share how you can make them for yourself.

First, we'll need to make our paints in a place where it's OK to be a little messy. We're going to make our watercolors here, in the kitchen.

Next, let's find the ingredients that we'll need to make our watercolors. We'll need baking soda, white vinegar, cornstarch, and, to color our paint, food coloring. And, finally, let's find paper towels, a bowl, a tablespoon for measuring, a regular spoon for stirring, and something that our watercolors will dry in. We're going to use an ice tray, but you could use something else like a muffin tin or some just cups.

See this big measuring spoon? This is a tablespoon. We'll use it to measure our ingredients. We'll begin by combining 4 tablespoons of baking soda with 2 tablespoons of cornstarch in the bowl. After you've mixed these two ingredients, you'll need to add 3 to 4 tablespoons of vinegar to your bowl. This mixture is fun, because it gets all fizzy. You'll want to mix the ingredients with a spoon until the fizzing stops. The mixture will be ready when it's not clumpy, but a liquid.

Now that we've added these ingredients, we'll spoon the mixture into 6 of the cubes of our ice-cube tray. Let's fill our cubes to about half way to the top.

After we've filled our cubes, let's add some color. We're going to start with primary colors. Do you remember what the primary colors are? That's right! Red, yellow, and blue. We'll add a few drops of each color into separate cubes, and combine them into our mixture with our spoon. It might feel a little bit sticky, but it's easy to break up and mix in. You'll also want to wipe off your spoon between colors so they don't mix with each other.

All right, so we've got red, yellow, and blue, but I think that we could use some green, orange, and maybe some purple. We know that we can mix colors to create new ones. So, can you tell me how to make green? I'm thinking yellow mixed with, that's right, blue! We'll add just one drop of blue, since it's pretty dark. Then I'll add some yellow until I get the color I want. What do you think Squeaks? I think it's pretty good, too. Now, how will we make orange? Yeah! We'll mix some red with some yellow. And, finally, what colors should I mix together to make purple? You got it! Blue and red.

Now that we've got all of our colors mixed, we need to set our ice tray in a spot where it can sit and the mixture can dry out. The watercolors can dry at different times. So your paint might be ready overnight, or it could take up to a couple days.

Once your watercolors are dry, they should look like this. Once our paints are dry, we'll grab a piece of paper, a paintbrush, and some water, and we will be ready to paint.

I think Squeaks and I can agree that one of our favorite things to do on a really cold day is to make a nice cozy blanket fort, and our friend Sophie is the best blanket fort builder around.  Remember when we went to her house and she taught us how to build one?

Hey there! Squeeks and I are just hanging out, building a blanket fort. That’s right! We built a fort...inside our fort! I bet you’ve built a fort before, too. If you use your imagination, you can come up with all kinds of creative ways to make a space of your own, for reading, snacking and -- hiding! You can use cushions, blankets, and even furniture. But no matter how you build them, all forts have one really important thing in common; they need forces to stay together. You might remember that we’ve talked about forces before—they’re the pushes and pulls that objects put on each other. Forces are everywhere. And experts called engineers are always studying forces, so they can design and build things like skyscrapers and bridges. So when you build your fort... you’re thinking like an engineer! Now, if you’re gonna become a successful fort builder, one of the forces you'll need to get to know is called tension. Tension is just another word for pulling something tight, so it’s a force that pulls rather than pushes. And if tension sounds familiar, it’s because we’ve talked about it before! When an awesome SciShow Kids viewer wrote in to us to ask why bridges were so strong, we learned that tension is one of the forces that help suspension bridges hold up the cars and trucks that drive across them. And that’s because the bridge is held up by cables…and the cables are pulled tight by heavy anchors that are sunk deep into the ground on either side of the bridge. When the cables are pulled, it creates tension, which holds up the bridge! So! How can you build a fort using the same force that holds up giant structures like the Golden Gate Bridge? Well, to make tension, you'll need something you can pull tight, like a sheet from the linen closet. Next, you can grab a couple of chairs, a few nice heavy books and then put the ends of the sheet over the backs of the chairs. Then you can put the books on each corner of the sheet, so it’s stretched tight. The heavy books acts like anchors, pulling the corners of the sheet away from each other. This stretches the sheet tight, and causes tension, just like the suspension bridge. And now, you have a nifty roof for your fort! But that’s just one way that you can use tension to build a fort. Let’s try another design. How about tying a string to a big, heavy, sturdy piece of furniture, like a bedpost? Then you can pull the string tight, and tie the other end to something heavy, too. Once you've done that, you can drape the sheet over the string, anchor the edges of the sheet with your heavy books, and then you'll have a tent! This tent-fort is actually a tension two-fer! Because: We’ve used tension in two different places. The string is pulled tight between the two pieces of furniture, and the sheet is being pulled up by the string, and down by the weight of the books. Without tension, that floppy sheet wouldn’t have any shape. You could say: The force makes the fort! All you'll need now is a flashlight and some snacks. 

You see, Squeaks, being stuck inside isn't so bad.  With a little bit of imagination, you can turn your house into your own laboratory, and those are just a few of the experiments you can do.  You can check out the SciShow Kids experiments playlist to find way more.  Thanks for joining us today.  If you want to keep learning and having fun with Squeaks and me, hit the red subscribe button and we'll see you next time here at the Fort.  

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