Kind: captions
Language: en
So, Dr. Phil, uh, what's going on here?
Okay, what we've got here is a metal
pipe with a whole lot of holes in it.
We're pumping gas through it, and we've
lit it up, as you can see. So, we have
like a whole lot of, uh, Bunson burners
all in a row.
Whole bunch of little flames burning
gas. And, um, this is all very pretty,
but what does it have to do with
science?
Just you wait.
I've got a speaker on the end here.
Whoa.
So, there you go.
You're pumping a sound through the pipe
now. Is that right?
That's right.
It's quite an annoying sound, Phil.
Let me change it.
[Music]
Okay. A few changes happening.
Yeah. So, there's these areas where the
flame is higher and other areas where
the flame is not as high. What's causing
that?
Well, it kind of looks like a wave,
doesn't it?
Yeah, it definitely does look like a
wave. But I mean, what is it showing us?
Why is it got these high points and low
points?
Well, sound is a wave. When I speak, my
vocal cords vibrate air which sends a
wave to your eardrum, vibrates your
eardrum, and that's how you detect
sound.
Okay. So, how is this sound wave
changing the height of these flames?
Well, the wave is actually areas of high
pressure and low pressure in air. So
there's actually a sort of compression
traveling through and that's what we can
see is the compression in the pipe here.
There's area where there's high
pressure, areas where there's low
pressure
and that results the higher pressure is
obviously pushing the gas out uh faster
and so we're getting these higher
flames.
That's right in a simplistic way. Pretty
complex situation, but what about if we
change it?
So you made it a higher pitch now.
And I noticed that these peaks are sort
of getting closer together.
That's right. Yeah. So, we've actually
changed the wave by having a different
frequency. We've made a shorter
wavelength.
We've changed the sound wave.
Changed the sound wave.
We've made a higher pitch. So, that's a
higher frequency.
Yep. It's vibrating faster. And to get
all those vibrations in, it has to do it
in a shorter space.
In a shorter wavelength. Very
shorter wavelength.
Okay. But, uh, this is all very
interesting, but you know, it's killing
my ears. So, what are we going to do?
Let's go for something a bit more
musical, shall we?
All right. Let's try a fairly simple
tone. So, I'll just whistle.
[Music]
So, that's uh not bad. Let's have a
let's have a listen to someone singing.
You know anyone who can sing a bit?
I I don't know anyone who can really
sing. Oh, jeez. All right. It's just
chem a
and me are made of these at times.
Hey, do you know any Mozart?
I don't.
I'm sure I'm sure you know a bit of
Mozart. Maybe you heard it in the womb.
Here go. Have a have a try of this.
I'll just warm the orchestra up.
Ready, you guys? Thank you.
[Music]
[Applause]
My mother.
[Music]
[Applause]
[Music]
Very good.
[Music]