[funky upbeat music] [singer] We can, we can, we can We can, we can, we can We can, we can, we can Mini Fab Science Lab We can ask big questions We can figure it out Let’s investigate in the Mini Fab Science Lab [Eleanor] Hi, Ava.

[Ava] Mmm Ava, are you eating cereal in the middle of the day?

Yes, yes.

It is great brain food.

Brain food?

All right, you’ve convinced me.

We need to brainstorm what we’re going to do today.

Well, I was thinking sciencey or crafty.

Wait, Eleanor, did you just pour the milk first?

I just love to see the cereal pieces float together.

It’s like they’re swimming towards each other because they’re friends.

It’s kind of cute.

When it floats together, it’s called surface tension.

[Eleanor] Surface tension?

Ava, is there science in my cereal?

Yep, the molecules in milk like to stick together.

And when you add cereal to the milk, the surface tension forces them to clump together.

But I don’t see anything in the milk besides the cereal.

How do I know the surface tension is there if I can’t see it?

Now that sounds like a big question.

We can ask big questions.

We can figure it out.

It’s time to head to the Mini Fab Science Lab.

[upbeat music] I am so excited.

How can you see something that’s invisible?

Well, with science, and we need a few things to see.

We need milk, food coloring, dish soap, and Q-tips, and some paper.

Now, to start this milk soap experiment so we can see surface tension, step one, Eleanor, can you pour the milk inside of the dish?

Got it.

Careful, careful.

[Ava] OK, great.

Now I’ll choose my favorite color to add to the milk.

I’m going to go with green.

[Eleanor] I choose red and pink.

[Eleanor] I think this is the prettiest science experiment Ever!

Just wait.

It’s going to get even prettier.

See how the colors are sitting on top of the milk?

[Eleanor] Yeah.

Oh, why doesn’t the milk mix with the colors?

[Ava] Great question.

The soap molecules break down the surface tension of the milk and food coloring.

[Eleanor] Molecules?

[Ava] They’re really itty bitty tiny groups of atoms that cling to each other.

They’re so small that you cannot see them with your eyes.

Oh, groups of atoms.

Because the milk molecules want to hold themselves together, they try to block other liquids from breaking them apart.

The surface tension of the milk will not let the food coloring through.

But look what happens when you add a little bit of soap.

Eleanor, can you use a Q-tip to gently put some of the soap on the plate?

[Eleanor] Wow, that’s amazing.

But why does the soap make the colors mix in?

[Ava] Well, that’s a great question.

When you add soap to the milk, the soap molecules are able to break apart the surface tension with the milk and the food coloring.

[upbeat music] [Eleanor] I get it.

If you couldn’t break the surface tension, the colors couldn’t mix.

You’re exactly right.

It’s so pretty.

[Eleanor] I wish I could take this home.

I know my dad would think this is so cool.

You totally can.

Science can also be art, too.

Take some watercolor paper.

Got it.

[Ava] Gently lay it on top of the milk where the color is.

Pull it off very gently.

Wow, look at how pretty it is.

It swirls.

Isn’t science cool?

Now we’re going to let it dry, and then you can take it home later.

I love it.

I can’t wait to show my dad.

Ava, this looks a lot like tie dye.

That makes me wonder, is this how they put colors on clothes, too?

Do people who dye our clothes use surface tension?

Now that’s a big question, and I know just the person we can ask.

You do?

I do.

Mom, can I call Dr. Williams at North Carolina State School of Textiles?

We have a big question.

[Mom] Yes, but tell her I said hello.

Yay, so exciting.

Please call Dr. Williams from NCSU.

[soft keyboard music] Hi, Ava.

Hi Dr. Williams.

And my mom says hi, too.

Well, hello to mom.

And who’s this?

I’m Eleanor.

Nice to meet you.

You, too, Eleanor.

What brings you to the Wilson College of Textiles today?

Well, we have a big question.

We’ve been learning all about surface tension today.

We saw our cereal float together, and then we did a milk soap experiment.

And now we want to know, how do people add color to clothes?

Does it involve surface tension?

Now that is a big question.

Surface tension does play a role in dyeing fabric because it can make it hard for color to spread out.

We use soap to dye our textiles, but we typically call it a surfactant instead.

Soap is actually a type of surfactant.

In dyeing, when we dye fabrics, we use special surfactants to help the color spread evenly.

What’s a surfactant?

Surfactants break down the surface tension of water, allowing dyes and other chemicals to spread out and cover the fabric.

Come on, let me show you.

See how this dye spreads out on the fabric that was treated with the surfactant?

And look here.

This fabric wasn’t treated with the surfactant.

See how the dye just stays in one spot?

Ooh, so soap was our surfactant.

Totally.

Soap is a surfactant, which is why our experiment worked.

Right you are, girls.

Without surfactants, the color would just sit on top of the textile fabric instead of soaking in.

How do you add color to the clothes you make there?

Another great question, Ava.

There are actually a few ways we can add color to clothing.

Sometimes we dye yarns, like nylon.

Then the colored yarn is used to make clothes.

Other times, a garment, like a t-shirt, is sewn together first and dyed afterward.

One way we do that is to mix the clothing with dye, like you see here.

I never knew there were so many ways to color clothes.

It looks so complicated.

Science might seem tricky at first, but once you crack the code, everything clicks into place.

And wow, does it all make sense.

I couldn’t have said it better myself, Ava.

Thank you, Dr. Williams, for teaching us so much today.

I can’t wait to tell my mom all about it.

Fantastic.

I hope you have a colorful day, girls.

[Ava and Eleanor] Bye, Dr. Williams.

[upbeat music] Mom, Dr. Williams said hi, and guess what?

[Mom] What’s that, Ava?

We learned even more about surface tension in dyeing fabrics.

Dr. Williams showed us how to dye yarn, fabric, and how to print on cloths.

Isn’t science cool, Eleanor?

Very cool.

[Mom] Well, it sounds like you two Had a wonderfully colorful time.

We sure did, but now I’m really hungry.

Oh, yeah, our cereal with the science in it.

I’m going to break the surface tension with my spoon.

Me too.

And now mine’s a little soggy, and I just like it like that.

Me too.

I love cereal.

And science.

[upbeat music] Mini Fab Science Lab is a production of PBS North Carolina in partnership with the North Carolina Department of Health and Human Services Division of Child Development and Early Education.

[upbeat music]