(lively music) (fire whooshing)
(lively trumpet music) (fire whooshing)
- I'm Dr. Anna Ploszajski.
I'm a material scientist, which means that I'm interested
in all sorts of different materials
that we build our world with,
metals, plastics, ceramics, even natural materials,
like wood and wool.
And what material scientists do is they zoom in
and have a look at what atoms are up to inside materials.
So the very tiniest building blocks of matter.
When I was 16 years old at school and starting to decide
what I might want to do with my life,
there were two real options available to me.
One was going to study material science at university
and the other was going to music college
to become a professional trumpet player.
I decided to go down the scientific route,
but I never lost my love of music.
And now as a scientist, it's a great joy to be able
to bring those sorts of passions together
in order to discover the physics of music.
(lively music)
Allow me to demonstrate.
A trumpet, at its most basic, is just a long tube.
And I've got a hose pipe here to demonstrate.
When you start to play a note in a trumpet,
what you're doing is you're vibrating the air inside
and you start that vibration going
from the lips by going like this
(Anna blowing)
into a special little piece called a mouthpiece.
(mouthpiece blowing)
And that vibration begins the air inside the trumpet moving
and you can create a pretty basic trumpet
out of a mouthpiece and a tube.
(tube blowing)
It even sounds kind of trumpet-y at that point.
Now, the shape of the trumpet at this point
is just a very straight long tube
but if we put a plastic funnel in the end,
it starts to sound even more trumpet-y.
(tube blowing)
And we can even play different notes
on this very basic instrument
(tube blowing)
to explain how that happens,
I'm gonna turn to fire.
(fire crackling)
So I brought you over to the theater
to show you my Rubens tube.
I made this tube myself from a long copper pipe.
I drilled a series of holes along the top,
fitted a gas connector to that end
and a flexible rubber membrane to this end.
And the Rubens tube is an experiment
that should show us the shape
of the sound waves that are coming out of my trumpet.
(gas hissing)
(fire whooshing)
When I blow down the end of my trumpet,
this mouthpiece starts a vibration
and that vibration travels down all the air
inside the trumpet.
It sets up a sound wave if you like, inside the instrument.
And that sound wave is made up
of areas of high and low air pressure.
And the more sections of high
and low air pressure you have, the higher the pitch
of the note that will come out of the end of the instrument.
In other words, the higher the frequency of the sound.
It can be a bit difficult to imagine areas of high
and low air pressure inside an opaque object like a trumpet.
So that's where the Rubens tube comes in
because when I put the end
of my trumpet against this rubber membrane,
it transfers the sound wave into this rubber membrane
and that rubber membrane transfers it into the propane,
which is gonna mimic what's happening inside the trumpet.
Right, let's give it a go.
So what I'm gonna do first
is play a few relatively low pitches of note.
(trumpet playing)
The higher the pitch of the note that I play,
the more you'll be able to see these waves appearing.
And you'll see that there are more
and more of them as I go higher and higher up.
(trumpet playing)
So if the important thing is the air vibrating
inside the tube, then maybe it doesn't really matter
what the tube itself is actually made of.
Let's see how far we can push this idea.
What I'm gonna show you is a series
of trumpets made of different materials.
Now, the original one is this.
This is just made out of a very thin brass material.
And listen to what it sounds like.
(trumpet playing)
A concrete trumpet.
This has been cast in exactly the same shape
as that other one.
And see if you can hear the difference.
(trumpet playing)
A chocolate trumpet, same shape.
Let's have a listen.
(trumpet playing)
(Anna chuckling)
A jelly trumpet made out of just normal jelly
that you can have at home
but in four times the recommended concentration
to make it nice and firm.
We've got our mouthpiece stuck in the edge.
(trumpet playing)
Almost the same. (Anna chuckling)
The final trumpet that I want to show you is an ice trumpet.
It's actually very, very beautiful.
Starting to melt in my hands.
Okay, have a listen to this.
(trumpet playing)
It's the same sound.
It's amazing.
So all of those different materials were able
to make trumpets that sound exactly the same.
So it kind of proves, maybe not great
for material scientists, that in the case of trumpets,
the material itself doesn't actually matter.
It's the shape of the air inside
that is vibrating and producing that sound.
Today we make trumpets out of brass.
But throughout history, trumpets have been made out
of all sorts of different materials.
In ancient history, people made trumpets
out of conch shells and wood.
Anything that came to hand in the natural world
and that you could blow down that would make a sound
would constitute an early trumpet.
When metal workers started to get involved,
the earliest trumpets would've been made out
of the metals that we could find in nature.
So that means metals like gold and silver,
stuff that existed that we could find and beat
into the shape of a trumpet.
Tutankhamun was found
with two ceremonial trumpets in his tomb.
These were made out of gold and silver
and they're very, very beautiful instruments.
In those days, trumpets were mostly used
for military purposes to instruct soldiers out
on the battlefield.
And this tradition of the military element
of trumpet playing has remained throughout the centuries.
In the Bronze Age,
we started to make trumpets out of bronze.
This was an alloy of copper and tin
and it was much more durable
than the softer metals of gold and silver that preceded it.
After that point, with the invention of brass,
trumpets start to be made out of that material.
Brass is a lovely material for instruments.
It's what's called a sonorous material.
It helps to support the vibrations
in the air inside the instrument.
So if you ever see like cymbals on a drum kit,
those are made of brass as well.
The addition of valves like this on the trumpet came about
at the same time as the invention of the steam engine
because the same metallurgical technology was required
to precision engineer these sorts
of very tight-fitting metal valves
and valves like this exist in engines like steam engines.
And so the trumpet evolved
alongside other sorts of engineering.
And what this does is it changes the length
of the instrument and with different combinations of these,
as well as different harmonics available
to the trumpet player, we can play all of the notes
that a piano can play, but with just three buttons.
So then brass is a material that has been particularly close
to my heart through my life playing the trumpet.
And the stories that it can tell are everything
from the physics of music to the history of metallurgy.
I hope that after you've seen this,
you'll be able to start recognizing the stories
that materials tell in your own lives too.
(lively music)
("Happy Birthday" music playing)