Alabama STEM Explorers s is made possible by the generous support of Hudson Alpha Institute for Biotechnology Southern Research.

Solving the world's hardest problems the Holle Family Foundation, Alabama Works Alabama STEM Council, Alabama Mathematics, Science, Technology and Engineering Coalition, Alabama Math, Science and Technology Initiative.

This is taking way too long.

What does he tank instead?

It's so much easier.

Perfect.

Oh Why does it fly up like that?

How was I supposed to know it would do that?

Why do some balloons flap like that anyways.

I think I'm going to find out.

Thanks for joining us on today's episode of Alabama STEM Explorers.

I'm Katherine and I'm Anderson and Anderson, and I are here at Southern Research in Birmingham, Alabama.

I was just telling Katherine about my balloons.

I know how one went up and all the others went to the ground.

Oh, I bet you were using a helium tank to blow up the balloon that floated to the ceiling.

Am I right?

Well, yes.

But why does that change anything?

So it all comes down to density, dentistry, no density.

And since helium is less dense than air, that balloon will float to the ceiling, but a balloon filled with air is going to stay on the ground.

Does that make sense?

Kind of, but I don't know what density is.

Why does density even matter?

Exactly, exactly what exactly it matters.

All matter.

So this table, your tennis shoes, the balloon.

All matter is made up of density, or it has a certain density and density is just a characteristic property of something.

So, for example, this balloon is long and skinny and shaped like a dog, or this balloon is round in circular or characteristic property of you would be how tall you are.

Or that you have the greatest hair of all time.

Thank you.

So it's just one way to describe something.

That's exactly right.

And so to calculate density, you need to know a couple of things.

You need to know the mass and the volume.

But here we can break it down with this example So what we have in front of us is a car parking lo that is the square.

Got it.

All right.

So there there are a lot of cars in this parking lot.

Would you say that the parking lot is full?

Yes.

Yeah.

OK, so we can describe this parking lot as it is a pretty dense lot.

OK, but now I'm going to take some cars away.

Has the size of the parking lot changed?

No, no.

But there are less cars in it, and so it is less dense.

Does that make sense?

I think I got it, but I'm still not getting it too much.

OK, well, I have an idea.

Let's break it down with an experiment.

Do you want to do that?

Yes, please.

All right, let's do it.

I love this experiment so much because it's something that our viewers at home can do pretty easily.

So all you need are a few of a few cans of your favorite beverage, a fish tank and your hand.

So this is what we're going to do.

And said, I have this soda, this lemon lime soda, I'm going to hand it to you.

Do you think this soda will sink or float sink?

OK, go ahead and put it into the water.

Let's see.

All right, well, is it going to flow, is it going to sink is sinking interesting?

So why do you think it is going to sink because it has a lot of soda in it?

All right, good answer.

What about this one?

This is a citrus soda sink or flat, same size, same shape sink.

OK, thrown in there?

Oh, that one definitely saying that one down really, really fast.

All right.

How about this one orange soda?

Sink or Float Sink?

OK, all right.

You're going to really go to this.

Absolutely, Anderson, you are a smart kid.

Is it going to float?

Is it going to sink?

It is going to sink, ladies and gentlemen.

OK, all right.

Here we go.

Diet orange soda float.

Sink OK, try it out.

Anderson, you are a smart kid.

Oh, interesting.

It is floating.

Ha.

Let's try this one.

Let's try this diet.

Lemon lime soda.

It is also floating, OK, one more diet cola.

Floating, OK, so why do you think some of these cans are sinking and some of them are floating?

Maybe because of the diet, that is a very good hypothesis, Anderson.

So maybe let's test.

Here's a sparkling water.

So sink or float float.

OK, let's try.

Let's see.

OK, very good.

It flows, so that is really interesting, so the diet soda and the sparkling water all floated to the top.

So let's figure out why does that happen when something that we could do to figure that out?

Maybe look at the labels.

Great idea.

Let's check them out.

So here is a sparkling water.

What do you think we can compare on the labels to figure it out?

Um.

Sugars.

Sugar, OK, cool, so let's look, let's compare.

Here's our Sprite and our diet sprite.

So how many sugars are in the Sprite?

Um, 38 grams, 38 grams, what about this one?

zero, zero grams?

That's right.

And so this experiment is showing you how density works.

So the volume of this can of soda is the same exact as this can of soda.

But the difference is the mass.

And so when you add the same volume but a different mass than the one with the greater mass is going to sink because it is more dense.

Does that make sense?

Yeah.

OK, so I have one more story.

I want to show you.

I need to close your eyes, Anderson.

All right.

Close your eyes and I'm going to put two sodas in your hand.

Hold them up here.

So, yeah.

All right.

And now we're going to tell me which one is heavier.

Hmm.

This one before I open your eyes?

Yeah, that is right.

So the root beer is definitely heavier than the diet root beer And if you don't believe me, try it at home, you can really tell a difference.

And it's because the amount of sugar that is inside these beverages, does that make sense?

It does.

All right.

So you are getting pretty good at this.

I say we do one more experiment to test your skills.

OK. All right.

So the last density experiment that we're going to do, it seems like a little bit of magic, but really, it's just some pretty cool science.

So what we have here is we have a candlestick that Anderson broke earlier and you can go ahead and tell the viewers at home it is a real candlestick, right?

Yes, definitely real candlestick.

All right.

And so what we're going to do is we are going to make predictions and we are going to see it.

The candlestick will sink or float.

So Anderson, I would like you to drop this into that beaker.

Is it going to sink or float?

I think it will sink.

OK, why don't you think that?

Because it's bigger?

OK, good idea.

Let's throw it in there.

And I think she's a very smart kid.

All right.

You want to throw this one in the other beaker sink or float float?

All right.

What do you think that because it's smaller, so it'll weigh less?

OK, well, let's take it out.

Let's see hot.

It's loaded.

You are absolutely right.

OK, so those were good answers.

Now let's see what will happen if we take this big candlestick and we put it over there.

It's floating, it's floating now, what if we put this little one over here, it is sinking.

What can be going on?

Let's think about this.

So the candlesticks are the same, right?

They came from the same candlestick.

They're just smaller pieces.

And so what that means is that the density of both pieces of candlestick, they are the same.

They are the same, right?

Right So why would they float in one beaker and sink in the other beaker?

Maybe they're different solutions.

That is a great hypothesis, Anderson, and we can test that hypothesis by calculating the density of the solution inside of our beakers.

So I'm going to take these candlesticks out.

Can we go now we have a scale right here, and so the first thing that we need to do.

We only want to calculate the mass of the solution.

So we are going to tier the scale or zero it out.

Just press that button right here.

OK, perfect.

Good job.

And now when we weigh our beakers it will only give u the mass of what is inside, so we are going to weigh this beaker.

And it is.

It says it is 1000 grams.

So this one has a mass of 1000 grams, OK, and a volume of 1000 milliliters that will give us a density of one gram per milliliter.

And you guys might know this, but that is That's water.

So water has a density of one gram per milliliter second beaker.

What is our mass for this one?

Is that the solutions mass?

786.

That's right.

786.

So this the mass of this is 786 grams.

The volume is 1000 milliliters.

So that is going to give us a density of 0.786 grams per milliliter.

So the densities of the solution are different, which is why our candlestick floats in one and sinks in the other.

Does that make sense?

Yeah, starting to.

OK, great.

So does it kind of tie back to the balloon Are you starting to understand why that balloon went up into the air?

I think so.

OK, great.

Hi, my name is Kennedy, and I want to know why are bubbles around?

Scientists refer to bubbles as minimum surface structures.

This means that they always hold the gas or liquid inside of them with the least possible surface area.

The geometric form with the least surface area for any given volume is always a sphere.

Around shape bubbles around when they float free through the air, and individual bubbles will always be round.

But when bubbles attach to one another, they could create all sorts of shapes.

I got interested in construction growing up, I grew up on a farm in New York, and when I was a little kid, they built a big pole barn out at our house and I was just fascinated by that.

After that, I studied mathematics and some some technology stuff in high school, and those teachers really encouraged me to kind of chase that dream.

After that, I went to Auburn University and I have a building science degree.

I used STEM every day and my job.

I'm a chief pre-construction manager.

And so that job is putting together a team of estimates to figure out how much a construction project like this is going to cost.

I work with engineers and and design firms throughout that process, and we work back and forth together trying to figure out what we're building and how much that's going to cost, how long it's going to take, how much equipment we need in order to do that.

Like I said, they the design team usually uses design software and I use estimating software to do that.

So a lot of computer back and forth drawings, 3D software but also engineering, figuring out how big the crane needs to be and things like that often work with high schoolers who are interested in construction.

And what we try to encourage them is to continue on in their in their high school career with their mathematics.

If you want to do what I did engineering a lot of the people I work with, study engineering, I study building sciences a lot of the same things.

So just same with your sciences and your math and continuing on because you know what we do every day.

While it does involve a lot of math and science.

We're not sitting at a desk every day, all the time we work in teams.

It's it's exciting to pursue a job.

It's also exciting to get to build a job.

It's fun to come out here to the job site and see what you saw on paper or in a 3D plan.

Come to real life and know that someday somebody is going to be in a in a doctor's office here.

If if this is a career, you're interested, you can go really far in this world and the the jobs that you can d are varied.

You can be a superintendent, you can be a pre-construction manager like me, be a project manager like like others you've seen.

And there's there's just kind of the sky's the limit in this career.

Hi, I'm Neal and Nilah and I are here at the Hudson Alpha Institute for Biotechnology Nilah can you take these six blocks and make a stack of them?

Yes.

Excellent.

Thank you very much.

Now, can you take these seven liquids and stack them for me?

How would I do that?

It's a little tricky to stack liquids.

Yeah, but we're going to actually use a property of these liquids called density now.

Density is a measure of how much of a substance is packed into a specific area.

In scientific terms, it's a relationship between the mass and the volume of an object.

And it's a property of everything.

Each thing has its own density.

We can take advantage of liquids that have different densities because they will stack on top of each other with the heavier densities at the bottom.

OK, so we're going to start.

I've already put honey in the container.

Honey is our most dense of all of our liquids.

OK. Next, we're going to start with corn sirup so poor that in just pour it right straight down the center, try not to touch the sides.

I love this activity because you can do this at home with things that you probably have in your pantry.

You just have to know the specific densities.

All right, good.

And so now you can see that we've separated out.

We've got our lighter layer of corn sirup and our darker layer of honey.

OK, how about blueberry sirup?

All right.

Excellent dishwashing liquid.

OK. All right.

You're doing a great job not getting it on the side.

OK, now we're going to work with water and water is we're going to is a little tricky.

We want to make sure that we don't mix it.

So instead of pouring it straight in, we're actually going to use a turkey baster, OK?

And so you're going to actually get the water and then you're going to set it right above where the syrup I mean, the the dishwashing soap is and then squeeze it in.

OK.

Right along the glass, that's right.

OK. Go ahead and finish that one off.

That's good.

It doesn't have to get all of it.

OK, now going ahead, we're going to next do the cooking oil, and we know that oil and water don't mix.

That has nothing to do with their densities.

They're just substances that don't mix.

So you can actually slowly pour this in along the side.

I'm going to rinse out the turkey baster while you do that OK, now the layer that's going to go on top is rubbing alcohol.

That's our last one, and you can use the turkey baster and again, try to have it go down the side of the glass.

And do that one slowly, you do not want it to mix with the layers underneath.

There you go.

Great.

OK.

So what you've managed to do quite nicely is stack all of these liquids going from our heaviest, most dense, all the way up to our lightest.

So we've got 1234, five, six, seven stacked layers, really nice.

Yes.

Now what we can do with this because we know what these densities are.

There we go.

These happen to be all the densities we can now take things where we don't know the density, OK?

And we can see where they land.

So why don't you take that cherry tomato, OK and drop it straight in?

Drop it right?

Go a little closer to the surface.

All right, and now drop it in.

Let's see where it goes.

Ah, it's a little tricky to see, but it is actually right here between the dishwashing liquid and the water.

So if we look over here, our cherry tomatoes density is between these two.

Mm-Hmm.

Why don't you try this screw?

OK, let's see what it does.

Oh, ah, all right, so we're has settled, it is it's floating right in between the corn sirup and the honey.

So we know that the screw sits right here.

All right.

Let this one.

Yeah, this is full of air, and it's buoyant, so it's going to just float up on top.

And then last, let's try that nylon bead that you've got.

And that nylon bead has stopped between the dishwashing soap and the blueberry syrup OK, let's actually calculate the density of our honey.

OK, so I've got a container.

I've got ten mils of honey in that graduate cylinder and we've got a balance here that will, that'll measure.

Now I've already set the balance in such a way that the balance actually is going to subtract out the weight of the graduate cylinder.

So now we're going ahead and put that on top of the balance.

All right, and tell me what it measures.

31.32 grams.

OK.

The formula for density is density is mass over volume, and there's our mass.

OK. And then how much?

What's our volume there?

How many can you read in the graduate cylinder?

How many mils we have?

We have ten Mils.

OK. All right.

So I just realized that I forgot to actually take out the weight of the cylinder when I plugged the the mass back in.

So that's OK because what we're going to do is we'll grab another cylinder and will weigh that and then we'll subtract that out.

I actually know that the weight of those cylinders is enough that actually when I subtract out the cylinder, I should get about 14 grams.

So we're just going to assume that I've actually done that.

Science doesn't always work the first time to try something And so what that would be would be 14 grams over ten mils which is 1.4.

And that's about the density that we know our honey is.

OK, so you could actually do that with every single one of these different pieces.

So you stacked our blocks, you stacked our liquids.

Mm hmm.

We figured out our individual measures.

You can try this at home with lots of different things.

You can try different kinds of cooking oil.

You can try different types of syrup from the store and see if they actually all have the same density or not.

This is a great activity to just explore the relationshi between the mass of something and its volume.

All right.

So that's it.

Well done on our stacking in both directions in Iowa.

You did a really fantastic job.

Thank you.

Nice work.

Well, my name is Panetta Woodbury.

I am a project manager for Brasfield and Gorrie construction company.

I have a civil engineering degree from the University of Alabama.

I became interested in construction when I was in the seventh grade I did, as a hobby, used to build things out of wood.

So one night he decided to raise my mother's living room floor.

So overnight we had raised the floor.

So from there, I learned that I wanted to go into constructio because I like to watch nothing become something in my job every day.

I like to use my technology to come up with looking at drawings and coming up with what's the best way to make sure we build the correct thing on the project.

I use STEM every day in my career of construction for the technology side, in the mathematics side, on the technology side.

We used to make sure we're efficient in building what we need to build our drawers, our own app.

So we use that to check drawings.

I check what we're actually building in a field.

I use the mathematics side a lot because I manage the money that's given for the job.

I use it more like a checkbook.

I'm given a certain amount of money to use and use that right contracts and stuff to stay within that budget to make sure we spend the money that's needed to build a job.

So I'm constantly working with the money side, with my subcontractors in my home.

My team, they don't work on it.

My advice to a young person is coming up would be tfind something that you want to do so.

You don't have to work a day in your life.

one reason I chose my career is because I like watching nothing become something and to be able to go to a job site every day and see how it develops.

one of the project I'm working on now, I'm finishing up is the stadium So I was able to go out there when it first started in a be able to watch that that particular project unfold to a something that I could dro by and go to eBay to watch a football game in the future.

So that's rewarding to me.

My name may not be on the bill.

I can say I helped build that.

And that's one thing I can say.

When you find a career, find a career that you love to do, find a career that you feel that's rewarding to you, no matter what their career is.

Because once you find that you'll never have to work at your life because you enjoy going to work every day.

Thanks for watching Alabama STEM Explorers.

If you missed anything or you want to watch something again, you can check out our website at Alabama STEM Exporeres dot org.

Maybe you have a question we could answer here on the show, and you might grab a cool T-shirt.

Feel free to send us a video question or an email on our website.

Alabama STEM Explorers dot org.

Thanks again for watching.

We'll be back next week.

Alabama STEM Explorers is made possible by the generous support of Hudson Alpha Institute for Biotechnology, translating the power of genomics into real world results.

Southern Research Solving the world's hardest problems The Holle Family Foundation established to honor the legacy of Brigadier General Everett Holly and his parents, Evelyn and Fred Holley, champions of servant leadership Alabama works a network of interconnected providers connecting business and industr needs to a highly skilled and trained workforce.

Alabama STEM Council dedicated to improving STEM education, career awareness and workforce development across Alabama.

Alabama Mathematics, Science, Technolog and Engineering Coalition for Education advocating for exceptional STEM education in Alabama.

Alabama Math, Science and Technology Initiative, the Alabama Department of Education's initiative to improve math and science teaching statewide.