- Are you feeling curious?

Today on Curious Crew, - Listen to how the sound changes.

- We turn it up.

- So we got a high one, and a low one.

- With some good vibrations for a pitch perfect lesson in sound frequency.

- Isn't that fun?

- 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.

More information is available at ConsumersEnergy.com/foundation.

Consumer's Energy Foundation supporting education and building sustainable communities in Michigan's hometowns.

And by viewers like you.

Thank you.

- Hi, I'm Rob Stevenson and this is - [All] Curious Crew.

- Welcome to the show everybody.

We always like to start every show with a couple of discrepant events because discrepant events stimulates - [All] Curiosity - That's exactly right.

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

And in fact, I'm gonna start with a quick question.

Jannelyn, have you ever blown into an empty bottle?

- I have.

(laughing) - And what happens when you blow into an empty bottle?

- We can make very beautiful sounds.

- Oh beautiful sounds like this, perhaps.

Okay.

So now we've got a wondering and Jacob I have a question for you.

I've got another bottle way over here that has a lot of water in it.

What is it gonna sound like if I blow into this bottle with a lot of water?

Do you think it's gonna sound the same or is it gonna sound different?

- I think it's gonna sound different.

- And how is it gonna be different?

- I think that it's gonna make a higher sound.

- All right, let's see.

- That was a really good prediction.

And so we are noticing then, oh yes, we're noticing that that sound is gonna change depending on how much water is in there, okay.

Here's something else I want to point out to you.

If I hit this, Nash, what do you think is gonna happen when I hit this?

- I think is gonna sound lower pitch.

- Okay.

Let's hear it.

Let's compare it to the other side.

Now, interesting.

Listen.

I'm going up.

This was low, and now it's high.

Okay.

That's perplexing.

I got something else I wanna show you.

I've got some more bottles here, my friends.

These ones are hanging over a speaker.

And in fact, I'm gonna send a tone right through this thing and see what happens to my bottles.

We'll give this just a moment.

Oh, I'm getting it now.

Do you notice how it changed direction?

And now it's starting to move the other way.

It was rotating one direction and now it's going the other direction.

This is perplexing.

I'm gonna turn this off for just a second.

Does anybody have a guess what we're gonna be talking about today?

What do you guys think?

Nash, what do you think?

What do you think?

- Are we gonna be talking about sound?

- Yes.

We're gonna be talking about sound, specifically, sound frequency.

And I'm gonna ask three of you to put some brain power to see if you can figure out the explanations of these phenomenon.

Who would like to try that?

Okay.

Carmella, Nash, Sasha, you guys are gonna be doing that and we'll let you talk in a few minutes, stick around.

It's gonna be a lot of fun.

- Okay.

Let's see if we can figure out some of these bottle phenomena.

- It's surprising that blowing into the empty bottle makes a low sound, but a high sound when Dr.

Rob hit it with the dowel.

- But in the bottle carousel, the sound from the speaker seem to cause the whole system to rotate.

I wonder if that's got something to do with the pitch of the sound.

- I was thinking about that too.

And if the speaker has to be that close to the carousel.

- Sound is energy that comes from objects vibrating.

If you were to knock on the table, that impact would cause the table particles to vibrate and they would bump into the air particles all around the table sending pulses of energized air particles called "compression waves" in every direction.

When those vibrating air particles get to our ears, our brains interpret the vibration as sound.

If the vibrations happen quickly, we hear a high sound.

But if it happens slowly, we hear a low sound.

- Were those discrepant events interest in you guys?

- [Both] Yes.

- Okay.

Now we gotta start making sense of this idea of sound frequency and to really unpack this I'm going to use some rulers that I've got clamped to an I-beam that's clamped to the table.

This one way down at the end is only hanging over by seven centimeters.

And what I'm gonna do is I want to give it a little flick and I want you two to notice what you observe with the wiggle.

So you might notice that that's pretty fast.

It almost stops abruptly.

Doesn't it?

- It doesn't last pretty long.

- Tough, not last really long at all.

Take a look at the next one.

And Jacob, I want to ask you a question about this one.

So watch it some close.

Does that one look like it's easier to see the wiggle?

- Yeah.

It's easier to see it because it's wiggling slower.

- Oh, that's a really good observation.

Okay.

Now watch what happens as the sticks get longer and longer, and longer, and longer, and longer, and longer, and longer, and longer, and longer, and longer, and longer, and longer, and longer, (mimics wiggling sound) - Now that one looks really funny, cause it is so slow.

That vibration is actually causing a whole disturbance in the air, around the sticks.

As they bounce up and down, they hit those air particles and we get these little pressure waves that go up and up and up and out and out away from the stick.

When I did this one back here, could you hear a sound?

Listen.

Jannelyn can you hear something?

- Yeah, the sound is definitely clearer in the green ruler.

- Okay.

So you can hear that one.

And does this one make a sound?

- It's not as defined, but there's definitely still a sound.

Now listen, as we get longer, we start hearing less and less and less.

This is because of the frequency of that movement.

All right.

If those waves are not happening very quickly getting to our ears, we actually can't hear it.

Now, If I had an elephant in the room it might be able to hear this one.

So this is all about frequency wavelength and the sound that gets to us that we hear as different pitches.

Now I have something else I want to share with you.

I've got a couple of balloons and I've sent some balloons to you guys as well.

In one of my balloons, I put a penny.

Just an ordinary penny and I tied up the top.

And in the other balloon, I put a hex nut.

And in the other balloon, I put a hex nut.

I'm going to swing the penny in the balloon first.

And let me know if you hear anything unusual.

- Can you just slide it around?

Just sort of sliding around.

That very exciting.

Okay.

Let's listen to this one.

Okay.

Now I know you guys each have one.

I want you to try this, go ahead.

Swing yours first, Jacob, go ahead and swing it.

And then I'll have Jannelyn and swing hers.

That's awesome.

Jannelyn, let me hear yours?

Okay, I got a question for you Jannelyn, when you're swinging it, what did it feel like?

- Well, it felt very tingly in my hand with the vibration.

There are a lot of vibrations up here.

- And could you tell when you started going faster, did that change how it felt for you?

- Yeah.

I definitely felt more vibrations as I was moving it around faster - Okay.

- and I could just feel that the nut was moving around really quickly too.

- So you guys thinking about sound it produced by vibrations, right?

That's what we hear.

Now, if we can swing this around faster, we get the vibrations to happen more quickly, more frequent waves going through the latex through the air, to our ears which we hear as a higher, higher pitch.

Okay.

Jacob, you try it one more time.

Awesome.

Let's join them, Jannelyn.

This is the nutty balloon and boy, is it fun?

Sound frequency.

Amazing.

- Imagine a tuning fork that gets bumped the times would go back and forth at a certain speed which hits particles in the air that we hear a sound.

This short tuning fork vibrates quickly.

So it hits air particles more frequently.

We hear that as a higher sound, but the longer fork vibrates more slowly making a lower sound.

If you look closely at the base of the tuning fork, there is often a letter that shows the note it produces and a number that tells us how many times it vibrates each second.

Wow.

659?

Wow.

659?

Wow.

659?

That is some quick wiggling.

- Boy, have I got something fun to show you guys.

This is my pipe-aphone.

And you can see that I made it out of what?

Pipes.

A whole lot of pipes, two inch plastic PVC pipe.

I want to play this using a shoe insert.

And I'm just going to bop the top of this pipe.

And I want you guys to listen closely to the sound that it makes.

Okay?

So notice that.

And if I were to follow this pipe down, I see that it goes down and then it hooks right back up.

This is not a very long pipe, but the one next to it's a little bit longer.

Listen to how the sound changes and how about the longer one.

Okay.

I gotta show you this one but to show you this, I have to turn it around.

Now, this pipe is really long.

Now, this pipe is really long.

It starts here.

It goes all the way down to the bottom all the way back up curves around one more time.

And then it ends.

Now let's think about this, you guys.

If I've got a longer pipe, is it a low sound or a high sound?

Rishabh, what do you think?

- I think it'll produce a low sound.

- You're right.

And this is because there's more air inside this pipe.

If there's more air, there's more air to vibrate.

And so that means it's going to vibrate more slowly.

And so we have a lower frequency which we hear as a lower pitch.

Let's just play for just a second so you can hear how some of these notes combined together.

(crowd cheering) - Isn't that fun?

This is my pipe-aphone and this has worked great.

Just a shoe insert.

And when it goes bad, I can get another one.

So I want to show something else to you really quick.

You each have a little xylophone.

That's right there.

And I have one too.

Rishabh, can you just strike a few of the notes?

Nice.

And Sasha, will you also do that?

Okay.

Sasha, I have a question for you.

Now, some of the bars are long and some of the bars are short.

The short bars, what sort of a pitch are those producing?

- A higher pitch.

- A higher pitch.

You are correct.

Now.

Let's think about it this way.

If we had more air inside the pipes, we were having a lower pitch.

If we have more mass in the bar, we have a lower pitch.

There is more to vibrate.

And so it is gonna vibrate more slowly which means we hear it as a lower pitch.

If you look underneath the keys on some of your xylophones you might even notice a little part that's called a damper.

And that damper actually is a little floating piece sometimes like in mine and it will stop the vibration so it doesn't go on too long.

There's also this little bar underneath actually is designed to amplify the sound.

So we've got amplified sound that is then dampened by that little piece of plastic underneath there.

Nice job.

Isn't that cool?

When we start thinking about instruments sound frequency is an important part of it.

Isn't it?

How about if you guys play a little bit, I'll play a little bit and this'll play us out.

Nice job, sound frequency.

So much fun.

- If an object vibrates one time per second, we describe its frequency as one hertz.

That means something that has a frequency of five hertz, vibrates five times every second.

Most people can hear in the range of 20 to 20,000 hertz but there are animals that can hear infrasound which is lower than 20 hertz like the elephant, whale, hippo, rhino, giraffe, alligator, and tiger.

Other animals can hear higher than 20,000 hertz or ultrasound.

Like the dog, cat, mouse, or bat.

And a dolphin can hear at 150,000 Hertz.

Now that's high.

- STEM Challenge.

- So have you guys been having fun learning about sound frequency today?

- [All] Yeah.

- Awesome.

I have a fun STEM challenge for you, actually.

When we start thinking about sound frequency I'm reminded of different kinds of instruments.

And this one is a pretty special one to me.

I brought this back from Africa and this is a pen pipe and listen carefully, which is really kind of cool.

So you guys are gonna be making your own pen pipe today.

Only you're making them out of straws.

Are you ready?

- [All] Yeah.

- All right.

Let's go ahead and get started on your builds.

- All right.

We'll go for it.

- We made these little fun straw pen pipes.

They're basically like a flute except there's a bunch of tiny straws.

- And we use scissors to cut each of the tubes into shorter pieces so you can get different frequencies and different sounds.

- When I had a tape, the sliders, and the straws it was hard because I was scared they're gonna come apart and they almost did but then I flipped it around and then I just taped that side.

So it was fine.

- Yes.

Whoops.

- Every time I cut a straw they always fly around and they're everywhere now.

- I was surprised that mine worked because all the measurements were not very even - This experience was really fun because I gotta learn more about frequencies and pitches.

I think it looks good.

I like it.

- So are you guys just about ready to show us your straw pen pipes?

- [All] Yeah.

- Let's take a look at what you've got here.

Oh, nice.

Double strap there.

Okay.

Jacob, would you do a quick blow right across the top of your pen pipe there?

Awesome.

All right Jannelyn.

Let's hear yours.

And Rishabh, how about you?

- [Dr.

Rob] Did you guys have fun making these?

- [All] Yeah.

- That's pretty cool.

You can make your own straw pen pipe, all you need series of straws, some scissors, a ruler, and you can have your own little pen pipe band.

Let's play them out.

You guys, let's play, let's play.

- Many instruments use vibrating columns of air to produce different sounds.

But if you notice how the size of the instrument can change the pitch of the sound.

Piccolo's are a great example.

They're only 12 and a half inches long and produce a really high pitch sound.

The tuba is a much bigger instrument.

In fact, if we could stretch it out, it would reach 27 feet.

That's a lot of distance for the air to vibrate.

So it has a much lower frequency of vibrations and a much lower sound.

Sounds terrific!

- So do you guys had fun so far?

- [All] Yeah.

- Awesome.

I've got some really interesting things I wanna show you.

I don't know if either of you have ever seen an oscilloscope here before, but this is an amazing device.

And in fact it can actually take sound and electronically show it to us as waves.

And so, what's really interesting is you'll notice that it is reacting right now from my talking and that's because I've got a microphone right on the table.

I also have a speaker and I've got a tone generator.

Now this is where it gets really fun.

I'm gonna turn on the tone generator and the speaker's gonna produce a sound which is gonna get picked up by the microphone which is then gonna get sent over to the oscilloscope and it's going to electronically show us the sound waves.

Okay.

So I'm gonna turn this up just a little bit.

And right now I have it at a pretty low frequency.

And in fact, I'll be quiet for a second.

So you notice the wave.

Do you see how it's getting closer and closer and closer?

Okay.

Now watch this.

I also have a little whistle.

I'm gonna blow on this whistle and I want you to notice just how many wavelengths you see on there.

It's gonna be a lot.

That is a lot.

Now, one of the things that's amazing about this is you're seeing the wavelengths and the oscilloscope will not only show the wavelengths but also how loud something is.

So if we have the big, big waves going up we know it's really, really, really loud.

But if we see many, many waves on the screen we know that this has a short wave length which has a high frequency, which we hear as high pitch.

Now here's something else I want to show you.

I have a little pipe here and I believe each of you has a pipe as well.

And if I'm not mistaken, Carmela, hold yours up.

I think yours is smaller than mine.

And I think Nash is sort of in between the two of ours in size.

Carmella, would you just blow into your pipe?

Just leave it open and blow into it.

Nice, Nash let me hear yours.

Okay.

And let me hear mine.

Now, what we're gonna do is we're gonna close the bottom and I want you guys to predict how is the sound going to sound different when we blow in it this time?

Carmela, what do you think?

- I think it's gonna be lower pitch.

- A lower pitch.

What do you think Nash?

- I also think it's gonna be a lower pitch.

- Let's try it.

Carmela, you do yours first.

It was lower, wasn't it?

Nash, let me hear yours.

Let's listen to mine.

We're definitely getting lower.

So, this is what it sounded like open.

Now let me explain that.

I showed you on the oscilloscope how we could get those wavelengths shorter and shorter and shorter and shorter, right?

Now, when we close up this tube we actually double the wavelength which makes a lower sound.

which makes a lower sound.

Isn't that interesting?

I like to call this one, the tubular twist.

Sound frequencies' amazing.

- Engineers continue to use both infrasonic and ultrasound in clever ways.

Ultrasound can be used to locate tiny flaws and nettles or other materials to make sure damaged parts aren't used in products like an airplane or bicycle.

Sound frequencies can even be used by doctors to diagnose different injuries in athletics and car accidents, and even for astronauts in space.

Now that sounds great.

- Are you curious about careers in Science?

- Hi, I'm Genesis.

And today I'm here with Dr. Liz McCullagh.

Liz, can you tell me where you are and what you do?

- I am actually at Oklahoma State University where I studied Neuroscience.

I'm really interested in how we, or more accurately, the brain tells us where a sound is coming from.

Most of my job, but actually involves working with students.

So I meet with my students in the field.

We've been collecting some wild rodents from around Oklahoma.

So we bring them back into the lab and then see how their brains respond to all those different sounds stimulate.

- What's the most rewarding part of your job?

- Have you ever had that "Aha!"

Moment where something just clicks and you're like, "Oh, I get it."

That is my favorite part of the job is when finally the experiment works just suddenly being like, "Yes, aha!".

- After talking with Dr. Liz McCullagh, Neuroscience sounds like a blast.

Explore your possibilities!

- And now, back to Curious Crew.

(upbeat music) - So I have these bottles here and if I blow into one with less water, we hear a lower pitch.

There's more air in the bottle and it's vibrating slower.

So we hear a lower pitch.

- That's like Dr.

Rob's pipe-aphone.

The pipes that have more length made a lower sound.

And with the xylophones, we were noticing that the bossed dampers underneath that slowed down the vibration.

I wonder if that happens with the water in the bottles too.

- And I was thinking about how the sound creates the compression waves that fly through the air.

I think the speaker does that as well because you can see the speaker moving back and forth.

I wonder if that's what's causing the bottles to spin.

- So did you guys have fun learning about sound frequency today?

- [All] Yeah.

- Awesome.

Now I know three of you have been pretty hard at work trying to figure out these discrepant events we did at the beginning of the show.

Carmella, what have you guys figured out so far?

- Well, we know that as drum thing vibrates faster, it has a higher pitch and we saw that with the oscilloscope and the wiggling ruler.

- And the volume makes a difference too.

When there was more air on a bottle, or the pipe-aphone, the air takes longer to vibrate and makes a lower sound.

That means blowing in empty bottle will make a lower sound.

- Okay.

So when I blew into the empty bottle just because there's more volume, we get a lower sound, than if we blow into this one, over here.

Okay.

But if that's the case, why does it make a difference that it's high when I hit it?

- We think that has something to do with the water and the resistance that has on the glass when it's vibrating like the dampers on the xylophone.

- I can show this to you in other way.

Just get that pitch in your head there.

Now I'm going to add some resistance.

Do you hear how it is changing pitch and getting lower because there's more resistance.

And so it changes the overall pitch.

Isn't that cool?

Okay.

So Nash, what did you guys figure out on the bottle carousel over here?

- We knew that the sound was like a compression wave moving particles through the air.

We can even see the speaker moving to cause those waves.

We wondered if the right frequency could cause the air inside the bottles to consistently vibrate to propel the bottle.

- Cause you'll notice that when I turned on the generator I was playing around with the dial and I was trying to get a specific frequency.

In fact, I put it about 97 hertz, which means it's actually vibrating, the speakers vibrating at 97 times a second.

Which is amazing.

But what happens is, we send these little pulses of energy up through the air and if we get the right frequency, it matches what would happen in the bottle.

If I were to blow into the bottle and listened to the pitch, it's gonna be a similar pitch as what's coming out of the speaker.

And therefore we get that energy moving through the bottle and it pushes the bottle along and actually gets it to start to rotate.

Amazing.

You guys did a great job today.

Hope you had fun with sound frequency.

So remember, my friends.

- [All] Stay curious!

- And keep experimenting.

- Get your CuriosityGuide 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.

More information is available at ConsumersEnergy.com/foundation.

Consumers Energy Foundation supporting education and building sustainable communities in Michigan's hometowns.

And by viewers like you.

Thank you.

- Do some dance moves.

- [Dr.

Rob] It's like you've, kid some on me.

And I'm gone.

Well done.

Yeah, high five.

Oh my gosh, Nash, Carmela, you guys.

That was perfect.