Support fo Curious Crew is provided by MSU Federal Credit Union, offering a variety of accounts for children and teens of all ages while teaching lifelong saving habits.

More information is available at MSUFCU.org.

Also by the Consumers Energy Foundation, dedicated to ensuring Michigan residents have access to world class educational resources by investing in nonprofits committed to education and career readiness.

More information is available a Consumersenergy.com/foundation and by viewers like you.

Thank you.

Hi, I'm Rob Stevenson and this is Curious Crew.

Welcome to the show, everybody.

We always like to start every episode with a couple of discrepant events because discrepant events stimulate Curiosity.

That's exactly right.

And I've got some fun ones for you today.

In fact I want to direct your attention to this little tube that I have right here.

Strange thing about this tube is there's another tube inside the tube.

But you might also notice that I have something else inside there.

Alejandro, can you tell what that is inside?It's a piece of cotton.

You're exactly right.

And is there anything else inside the tube?

Some air.

Excellent.

Okay, now what we're going to do is I'm going to place this little syringe inside, this little plunger, and I'm going to push this down and then screw this tight.

Now, Skyler, I would like you to predict for me what would happe if I pushed that plunger down.

It's going to squash the cotton for sure.

I love it.

Now we're dealing with a tube like this.

Safety first.

Everybody, let's get some goggles on here and watch this close.

I'm going to try to do it quickly.

Oh my gosh.

What?

What?

Okay, That was strange.

Okay.

You can take off your goggles for just one second.

I actually call this a torch tube, and I think you can see why.

Now, there's something else I want to show you.

And it has to do with thi little can called an air duster.

Olivia, what do we use an air duster for?

Well, I think people use it to clean keyboards.

Yeah, like a computer keyboard.

You spray the dust and on dust goes flying all the way around the room.

But it's off the computer keyboard.

Excellent.

Okay, now, before we do this, I'm going to try to get a measurement of the can because I'm curious what the temperature is.

Skyler, I'm going to turn this.

I want you to tell me what that says.

71.4, 71.4 degrees.

Keep that in mind.

Yep, that's a Fahrenheit temperature.

We're going to put these back on safety first.

Now, I'm going to trigger this for about 2 seconds.

And if you listen, you'll hear it come out.

Oh, yeah, we can hear it.

And I to do it for two more seconds.

We can hear that now.

You can take off your goggles.

I'm going to get another temperature reading here.

And what do you notice there, Skyler?

It's 70.8.

It's now gone down to 70.

Can you touch that can?

It's cold.

Okay, That's kind of strange.

I've got a torch tube over here, and I've got this col compression going on over here.

Now, I'm going to invite three of you to do a little scientific modeling to see if you can explain these.

By the end of the show.

You can use your background, knowledge, anything that you learned throughout the episode to revise your thinking.

Anybody want to participate in a modeling moment today?

Okay, Kian, Varcia and Aikem you three.

Now, does anybody have a guess what we're going to be investigating today?

Olivia, what do you think?

Something to do with air?

We are going to investigat the science of compressed air.

Be sure to stick around.

There's an air of mystery about this topic.

Okay, let' see if we can figure these out.

That surprised me tha the cotton was able to ignite.

I think that the only other thing in the tube was air.

How could it ignite without a spark?

I noticed that Dr.

Rob pushed the plunger really fast.

Do you think it would've worked if he pushed it slowly?

Maybe Dr.

Rob could try that for us.

The cold compression is confusing.

Skyler said the can felt really cold.

How could air make the can cool down so fast?

Gases are a very interesting form of matter, although they are usually invisible, we can see and feel their effects on things.

Imagine we had microscope eyes and could see gas particles inside a closed cylinder.

We could observe a lot of tiny particles constantly moving in every direction and bouncing into one another and off the inside of a container.

Those gas particles have spaces in between them, which means they can ge squished together or compressed.

Those are some packed particles.

So let's see if we can make some sense of compressed air.

Okay.

We're going to start with these syringes.

Now.

I want you to look at it closely.

These are 60 milliliter syringes and what's inside of this right now, Alice?

Air.

That's exactly right.

We got a lot of air inside there.

Now, I've given you each a little pink eraser and I'm going to ask you to turn your syringe ove and put it on your pink eraser and can the air particles get out now?

Alejandro?

No.

No We've got them trapped inside.

So now let's pretend we have microscope eyes.

If we could see wha those air particles are doing.

The strange thing about air particles, they're just moving around.

All they do really, really fast is they go in a straight line and bump into somebody and then bump into somebody and bump into another.

So they keep bumping and bumping, whether they're bumping into each other or the inside of the syringe.

If they're all bumping around, that would create a force, wouldn't it?

Yeah, And we could actually feel that force and we can measure that force.

And we know that for every inch, those particles are going to produce a force of 14.7 pounds.

That's almost 15 pounds for every inch.

Okay, Skyler, what can we do to get them to bump into each other even more often?

Give it less space, definitely.

Okay, let's try this.

I'm going to ask you to push it halfway down.

Go down to the 30 and.

Oh, my gosh.

Can you feel that?

It's so hard.

It's really hard.

Okay.

Why is it hard?

Well, the particles are closer together.

They're bumping into each other more, which means it's no longer 15 pounds.

It's 30 pounds.

Can you make it down to the 20?

Can you make it out of the 20?

I'm trying to get it to 30.

Oh my gosh 20?

We've just increased it up to 45 pounds of pressure.

Can you make it to the 15?

This is 60 pounds.

Oh my gosh.

Take a break.

Oh, that was a lot of force.

Yeah we couldn't see those particles, but we could feel them.

They were bumping and bumpin and pushing really, really hard.

Now let's see if we can see it.

Take it out.

Take the plunge right up.

I'm going to give us each a little mini marshmallow.

Okay.

Put the little mini marshmallow drop it right inside there and let's put it in at 60 milliliters again.

Put it back on your eraser.

Oh, no.

Oh, yes.

And now let's think about this.

If we start to make the space smaller, those air particles are goin to start to hit our marshmallows more.

Oh, no.

More.

Let's push.

Let's push.

Oh, my gosh.

My marshmallow is shrinking.

It's shrinking.

Oh, my gosh.

It's shrinking.

Now, watch.

If we even lift it back up, it might make our marshmallow bigger.

Go ahead.

Oh, relax and inflate a little bit.

So here's what we have to remember.

When we have those particles that are bumping into each other, if we give them less space, they're going to bump into each other more often and more forcefully.

And now, you know, that is really impressive particle power.

Earth's air is made of different kinds of gas particles, including 78% nitrogen and 21% oxygen, as well as traces of carbon dioxide, argon, water vapor and other gases.

When those air particles bump into things on Earth, those collective collisions produce an impressive force averaging 14.7 pounds per square inch.

We say that equals on atmosphere, but compressed gas particles are closer together, so they bump into everything more often.

If all those particles were in half as much space their total bump force doubles.

Two atmospheres.

Wow, almost 30 pounds per square inch.

So we know that compressed air particles have spaces in between.

Right now, I would like to do a quick little investigation with this plastic bag.

When you look at this plastic bag, how would you describe it, Sydney?

It's partially inflated.

You're right So I've blown some air in there.

And would you say, Varsha, that there's a lot of compressed air in that?

Probably not Because there's a lot of space.

Yeah, there's still some space left over so I can push down.

So it's partially inflated.

But when I do this, what about now Kian?

I think there's a lot more compressed air in that side of the bag, A lot more compressed air over here in this side.

I'm going to use that little toy to hold that place.

And I want to try something.

I would like to drop this block onto the compressed air part.

Everything seems to be steady, so I know that the particles are bouncing around in there pretty consistently.

What is going to happen Sydney If I drop this?

It's going to launch your star up.

Whoa.

That was a good prediction an that was a pretty good launch.

Now, how did that actually happen Kian?

I think it forced the compressed air underneath the start causing it to launch.

That's exactly right.

And we can actually see that.

Now, look, the compression is no longer over here.

It's been pushed to the sides and it happens really fast.

Let's try this scaling up a little bit.

I've got a tube over here.

Varsha, would you be so kind as to go sit on the front of this tube now as she sits down?

It's kind of like the star on here.

It's partially inflated and we have now compressed more of the air here at the back.

Prepare yourselves.

I'm coming in for a landing now.

Of course.

Could you feel that, Varsha?

Yeah.

Okay.

The air was pushing you up.

Nice job.

You can get up and I' going to put this in its place.

Kian I'm going to have you drop down on your knees and see if we have a reaction on the little beach ball there whenever you're ready.

Oh, nice job.

And of course, you saw tha happens really fast, doesn't it?

You're down.

It's up Now.

Let's think about that.

If we have those compresse air particles closer together, the energy can transfer even faster going through.

How many of you like tubing?

Water tubing?

Yeah, me too.

So the next tim you're tubing behind the boat, you can be like, Oh, this is like riding a cushion of air, compressed air, that is.

Have you ever pumped up a flat basketball?

Basketballs require a certain amount of compressed air to be able to bounce.

Well, with each stroke of the pump, more air particles are pushed through the hose and the needle into the inner rubber bladder.

As the number of particles increases so do the number of collisions among the particles and with the walls of the bladder, which also increases the total pressure on every inch of the ball.

And that pressure, well, that can be measured with a gauge.

Looks like you stopped at the perfect pressure.

And what a bounce.

STEM challenge.

So have you been having fun investigating compressed air today?

Yeah.

I'm so glad and I've got a fun STEM challenge for you.

In fact, we are going to leverage the power of compressed air to propel a little car.

And I know you'v all got some materials selected.

You ready to start your builds?

All right, Have fun.

Okay.

The straw.

It could go like, in between.

Yeah.

So he'd actually, like, go.

It's finished.

Yeah.

Okay.

That's a good idea.

We are trying to make a air compressed car.

I think we should put, like, this little tapes for a little bit friction.

We're going to put the balloon through here and then blow it up.

But I think we should put some tape on the edges just so it doesn't pop.

Oh, for the balloon you have to have tape.

I'm using the cardboard.

A balloon, wooden sticks, and tape.

Oh, I think I got it.

Looks like you got this.

We are using snap sticks, a balloon and wheels.

Our team is using wooden dowels and a medium sized balloon.

We're trying to make the thing flat.

Like, not like all the way flat.

We took the snap six and added the connectors on each end.

And then we connected them all together, adding the wheels on the ends and then threading the balloon through it.

Oh, no, my wheel fell apart.

It was pretty challenging getting the wheels on since they weren't staying the way we wanted to, but we figured out if we put them in the right order and stuck them on in the right place, that they would work just fine That looks about right, right?

Yeah, I like it.

Good job guys.

Does it matter?

Yay.

It doesn't matter what side we're going to put this on?

Well, these are looking great, you guys.

Nice job.

Now, I've got an idea.

We're going to move the tables out of the way, blow up some balloons I'm going to see how they roll.

You guys ready to try it?

Yeah.

This should be really fun.

Well, let's take a look at these cars first.

Alice, what did your team use here on this car?

So we used spools, straws, wooden sticks, balloon, cardboard and tape.

Awesome.

Okay, let's go down together, because I know you're holding the back of that.

And when you're ready, we're going to let it go and we'll see what it does.

3, 2, 1.

Nice job.

Good job, Good job.

That was the weirdest sound.

That's hilarious.

We got a couple more to test.

So, Max, what did you and Aikem use in this prototype?

For our prototype, we use straws, tape a balloon and wooden dowels and wooden sticks.

Okay.

And so you've got this bottle here.

Why do you have this tape around the bottle?

We have the tape here on the bottle.

So the balloon doesn't pop when we inflated, which is already in place Okay.

And it's hard to inflate.

And you actually had to blow that up right through the bottle.

Okay, Let's go ahead and put it down and we'll see how it does.

Well, aim it right over that direction.

There you go.

Nice job.

Another great prototype.

Excellent job.

We've got one more to look at.

Okay.

Our last prototype.

Now, Sydney, what did your team use here?

We're using snap sticks, wheels and a balloon.

Excellent.

And I see that he had to blow it up right through the end.

This should be interesting.

All right.

Kian go and put it down.

We're going to see how it does as he lets it go.

Oh, look at that.

Nice job.

Nice job.

These were some really fun prototypes.

Try making your own compressed air car and see how far yours can travel.

The crew's compressed ai cars were cool, but did you know engineers experimented with this technology too?

Both Europe and the United States have been designing different air compression engines.

Some small car prototypes only run on compressed air, can drive up to 50 miles per hour and have a rang of about 100 miles in the city.

Hybrid vehicles combine compressed air technology at slower speeds with gasoline engines at higher speeds.

It's predicte those hybrids may get up to 120 miles per gallon.

Amazing.

You each inflated a balloon.

But I want us to think about what those air particles are actually doing inside the balloon right now.

What are they doing in their Aikem?

They're colliding and bumping into each other.

That's right.

They're colliding.

They'r bumping into each other.

Okay.

Now, if we gave them an opening, what might happen, Max?

It'll probably release all the air and fly away, make noise.

Right.

So we're going to have a force coming out with those air particles rushing out, and it would fly away.

I'm going to ask that you not let go of it.

So it flies away.

But I do want you to release the neck of the balloon because I want you to feel the force ready.

Go ahead.

Get it set up so you can feel the force and go ahead and let it go.

Nice.

Okay.

You can feel that, right?

Not a ton of force, but you could feel those air particles moving out.

All right.

Go ahea and put those down for a second.

And I want you to take a look at this.

Olivia, what have we go right here?

An air compressor.

And what this can do using the motor.

It can take air particles in the room and stuff them in here, and it keeps putting more and more and more of them in here until those particles are really bumping a lot.

Now, we know at normal air pressure, air particles bump into things at about 14.7 pounds.

Can you read the gauge?

135 pounds, 135 pounds for every inch of this tank.

They're pushing at 135 pounds.

Max, how can this withstand that much force?

Well, it' metal.

It's very rigid.

Perfect.

So here we're going to try something.

What would happen i I moved some of these particles into this balloon using this little trigger?

But I just kept going and kept going and kept adding more.

What's going to happen Aikem?

It's going to pop.

Oh, my gosh, I think we should try this.

But safety first.

Okay, Safety first.

Let's get some goggles on here.

And I'm going to put this balloon right over this little nozzle and I'm going to see if we can inflate it.

Oh, oh, oh, oh, oh, oh, Oh, my goodness.

Wow.

That's handling.

Oh, okay.

That was impressive.

We can take these off.

Now, Olivia, look at the gauge again.

What do you notice?

It went down a lot.

It went down a lot because we let some of those air particles out right?

Now, I want to do something else.

We know there's still a lot of air particles in here.

We know they still want t come out really, really badly.

I have a little opening right there called a pressure release valve.

And I'm going to pull it out.

And I want you to put your hand right there to feel it.

But before we do this, this is quite noisy, so we're going to put some little earplugs in just to protect ourselves a little bit.

And if you reach around, straighten out your ear canal, you can put that right inside and then do the same thing with the other one.

Safety first.

Oh, yeah, that's good.

You guys ready?

Yeah.

Oh, hand there.

Here it goes.

Okay, go take that.

Did you feel it?

Yeah.

There's a lot of forces in it.

Oh, my gosh.

So much force, in fact, that we can take this to a construction site, hook the tube u to a special kind of nail gun.

And this can actually put nails directly into wood.

Now, that was a lot more force than what you felt with the balloon, wasn't it?

Okay, this gives me another idea.

Let's think about this.

If we put some water in this and compress about 50 pounds of air in here per square inc and then let let the opening go.

What's going to happen you guys?

It's going to shoot up.

Oh, I think we should try this.

Let's try this outside.

Okay, So we're going to put this in here and seal that up, push it right down inside, and then we have to lock it in with this little holding pin right down here.

Max, you ready?

Let's get this thing pumped.

Go for it.

Let's go through the air.

Coming it all ready?

Good, good, good.

Keep going, Keep going.

Oh, yeah.

Oh, yeah.

That's good that's good.

Okay you guys go back to the front.

I'm going to pull this pin.

Don't touch the handle.

Pulling that pin, okay.

Three, two, one.

Oh, you see spin, did you see it spin?

Good job.

Good job.

Compressed air.

You got to love it.

Have you ever opened a bottle of soda pop after it was shaken?

Yikes.

Why would it do that?

Well, when the liquid was put in the bottle at the factory, it was also pressurized with carbon dioxide gas.

It's also surprising to discover that a one liter soft drink contains 6 to 8 grams of carbon dioxide.

That's a lot of pressure.

Well, now that your bottle safely open, you can enjoy the fizzy bubbles and that preserved flavor.

Are you curious about careers in science?

Hi, I'm Aikem, and today I'm with Jessica Rook.

Hi, Jessica.

Can you tell me what you do and where we are?

I'm the owner and CEO of Final Approach Detailing here in Okemos Michigan, where we're at today.

At Final Approach Detailing, we're a specialty service provider.

My day can consist of things like interior and exterior detailing, paint protection film, window tinting.

When it comes to detailing, it's not just about the skill of detailing.

You really have to have a deep understanding of the science, surface tension and dynamics of force and how that relates to engineerin and the math that goes into it.

Really understandin how chemicals work, how machines work, and tools work is critical to be able to provide detailing services at the level that we do.

Today I polished my knowledge of STEM with Jessica Rook.

Explore your possibilities.

And now back to Curious Crew.

We know air particles can get squished together and then they bump into things more often.

We could see that with the syringe in the mini marshmallows.

And because Dr.

Rob can press the torch tube air particles so fast, it must have had higher pressure and temperature.

That makes sense.

I'm sorry to wonder if the air dust is actually in the can.

It sounds as though there is some liquid inside.

So have you had fun investigating compressed air today?

Yeah.

Awesome.

Now it's time for us to return to these discrepant events.

At the beginning, I know these were kind of confusing.

So what have we figured out about this torch tube Aikem?

Well, when the space in the tube decreases, the pressure of the particles increase.

That makes sense, right?

If there's less space, those particles are bumping into each other more often and more forcefully.

That makes sense.

But how can that ignite the cotton Kian?

When the pressure goes up, so does the temperature.

That's exactly right.

And you saw how fast I pushed it down.

So we were increasing the pressure really, really fast, which means we increase th temperature really, really fast.

Now, the amazing thing about cotton, cotton will ignite at 378 degrees Fahrenheit.

It's about 210 Celsius, believe it or not.

We exceeded that in this tube hitting almost 500 degrees.

That is amazing to me.

So we could actually catch that on fir without actually having a spark, just using air particles, bumping into each other really fast and really hard.

Now, I want to do this again.

I've put a fresh piece of cotton in there.

You can see it inside the tube.

And the other thing that I want to point out real quick is there are these O-ring right on the end of the plunger.

Now, those O-rings have a really important job.

They're going to make sure that it is air tight.

So all the air particles are trapped at the bottom.

Okay.

So we're going to put this in and I'm going to screw it down tight and then safety first, my friends.

Let' get some goggles on.

All right.

So you guys ready?

Yeah.

Okay, let's try this.

Dr.

Rob can we do it slowly this time?

You want me do it slowly?

Yeah, we can try that.

What do you think's going to happen?

I don't think it will even catch on fire.

It's hard to do it slow.

Oh, well, that's really not very exciting, is it?

Oh, okay.

Clearly, nothing happened now.

We were still compressing the particles.

Right.

But if we do it slowly that heat has time to dissipate around the other particles around of the tube.

So it's way more interesting if we do it fast, let's try it fast and see what we get.

Oh, that was really good.

Nice job.

You can take those off.

Now these are called adiabatic compressions.

No time for that heat to dissipate.

Okay.

What have we figured out about the cold compression, Varsha?

Well, we don't think it's actual air inside of the can because we can have a liquid inside and get that cold as well as discharged.

You could hea there is a liquid inside there.

You're right.

How many of you have ever, when you like, discharge or let air out of a tire, like a bicycle tire.

If you've ever felt that air come out, it's kind of cool, right?

Not like this.

This is way colder.

And that's because it's a different gas.

It's actually not air.

Good thinking.

This is a very strange gas called Difluoroethane.

Difluoroethane, uh huh.

Now, the strange thing about this gas, when you squish it and squish it and squish it and squish it, six atmospheric pressures, si times, it turns into a liquid.

So when this can is ready it's half liquid and half gas.

When we triggered that, the gas was coming out, we could hear it.

We could hear it coming out.

Right.

But that meant the liquid that was still left started to turn into a gas as well.

And when that happened, the remaining liquid, it got colder, a lot colder.

And you could feel that it was so, so cold.

Now, the amazing thing about this is it's not air at all.

We call it an air duster, but it's not air at all, so we probably should rename it Difluoroethane duster sort of just rolls right off the tongue, doesn't it?

Well, it looks like we've solved the mystery of these air compressed phenomena.

So remember, my friends, sta curious and keep experimenting.

Get your curiosity guide and see more programs at wkar.org.

Support for Curious Crew is provided by MSU Federal Credit Union, offering a variety of accounts for children and teens of all ages while teaching lifelong saving habits.

More information is available at MSUFCU.org.

Also by the Consumers Energy Foundation, dedicated to ensuring Michigan residents have access to world class educational resources by investing in nonprofits committed to education and career readiness.

More information is available a Consumersenergy.com/foundation and by viewers like you.

Thank you.

You guys are doing great.

You guys doing great.

That was the one, my friends.

That was the one.

So what, Standby.

Got a little excited there.

Curious Crew Season 11 Episode 4 STEM Results.

Take one.

Woohoo Olivia.