* [festive instrumental music]
[cheering]
- Audience: Woot! Woot! Woot!
- Hello, everyone,
and welcome to this very special 48th anniversary
of this very special program.
Number 48
to celebrate the joy of science
and to celebrate the use of science in society.
Are you ready to learn? [cheering]
Are you ready to have some fun? [more cheering]
Well, let's get started then.
[buzzing]
[loud boom]
[surprised exclaims] - Whoa! - What was that?
- Bassam: This was--
Still going. You hear it?
This was an uncontrolled combustion reaction
very different than this controlled combustion reaction
of the candle.
What I had in here is a little bit of alcohol
and it vaporized.
And there are two screws on the side.
And there was a cork that was ejected
when the spark coming from what we call a Tesla coil
ignited the vapor.
I want to show you in this bottle right here,
which doesn't have any alcohol in it, no cork in it--
I'm just going to show you
how the spark jumps across the gap
that separates the two screws.
So let's do this in the dark.
See it in the dark, maybe? Better.
Now you see it, now you don't.
All right, lights back up again, please.
So it is the ignition of the vapor
that caused the chemical energy in the alcohol
to change into mechanical energy
and the cork was ejected.
In my lab, we always obey the safety rules
and that's why you see I have my goggles on
and we have a fire extinguisher ready to be used
just in case something goes out of control.
We're not planning on anything going out of control.
We just have it as a safety precaution.
I'm going to put it on the side here
where you and I know where it is
in case it has to be used.
And that's another thing that we do in my lab
is that we repeat the experiment.
So I'm going to repeat this experiment right here.
Are you ready for this?
[cheering]
Give me a countdown: three...
- Audience: Two, one.
[chemical explodes]
[oohs and ahs] [applause]
[expressing anticipation]
- Let's have a louder countdown: three...
- Audience: Three, two, one.
[chemical explodes]
[oohs and ahs] [applause]
My next experiment is with methane gas.
And I'm going to light a burner
and...
there is a controlled combustion reaction.
I also have a tank of methane right here
which I'm going to open.
It's connected to this little pipe,
clay pipe that I have here.
I'm going to try to bubble this through a soap solution.
So here we go.
[bubbling]
There is methane going in there.
You can see the bubbles.
[cheering]
Let's try, just try--
Oops.
[cheering]
You know the methane is in there-- There it is.
[laughter]
Let's try to get a bubble up there.
There it is.
[laughter]
These are all controlled combustion reactions
which we do very, very safely.
And I'm going to turn off the gas valve here
and also turn this one off as well.
And at this time, I would like you to join me
in welcoming
University of Minnesota Professor Renee Frontiera.
[applause]
Renee is a chemist.
And earlier this year,
she was recognized
by the American Chemical Society
as one of the Top 12 Talented
individuals in the world
because of her determination
and her commitment to science
and to improving the role of science in the society.
So welcome.
- Thank you.
[applause]
Thank you.
I'm so excited to be back in your lab.
- Bassam: You've been in my lab before?
In fact, when I was a kid, I grew up in Madison.
And my parents and I would come to your show
every single year.
We'd sit right about there.
- In fact, your parents are sitting right there.
- Renee: They are, in fact.
- Bassam: Please stand up.
Please stand up, Dr. and Mrs. Frontiera.
[cheering]
And welcome again. - Thank you.
So your show is a big reason why I ended up becoming a scientist
and I would love to do an experiment today.
- Please, please. - Ok.
So, here I have
a piece of solid carbon dioxide actually.
Here's a piece of solid carbon dioxide.
And you'll notice that I'm wearing these gloves.
- Yes. - These are to protect my hands
from the solid carbon dioxide just because it's very cold.
- Bassam: How cold is it?
- Renee: It is minus 78 degrees Celsius.
So that's a very, very cold piece of solid carbon dioxide.
- So I shouldn't touch it with my bare--
- You should not touch it with your hands, yeah.
Gloves are helpful.
- I have my own gloves right here. - Excellent.
So carbon dioxide is very interesting
because you can see
it goes directly from the solid state into a gas, ok?
It doesn't actually become a liquid ever,
and so it's going through this process right now.
And what we chemists call this
directly going from a solid to a gas is "sublimation," ok?
That's a chemical term.
Can you guys all say "sublimation?"
- Audience: Sublimation. - Excellent, yeah.
So carbon dioxide, also known as dry ice,
undergoes sublimation
and it goes directly to this gas that we can't see
and is mixing with the room.
And so I'm going to do an experiment now
with this solid carbon dioxide.
And you can see that I have these cylinders
full of some liquids.
These are all clear liquids,
but they're different colors, right?
You see the colors there?
What about these liquids here? - Audience: Blue. - Blue.
These ones? - Pink.
- Pink and...? - Purple. - Purple, ok.
So I'm going to take some solid carbon dioxide, some dry ice,
and just dunk it in there, and what do you guys see?
- Audience: Bubbles.
- Bubbles, exactly.
So the carbon dioxide is bubbling.
And what's happening now? What do you see?
[multiple responses from audience]
Exactly.
It changed colors, right?
Are they all done? Did they change?
Yeah, ok.
So what we saw here is a chemical reaction actually.
So the carbon dioxide, it goes from the solid to a gas.
We see these bubbles.
It also reacts and it makes an acid in these cylinders.
And it makes a carbonic acid which causes this color change
because
we put some indicator molecules in here
to tell us what's going on.
So these cylinders have a molecule called Bromothymol Blue
and this is the measure of pH.
It tells us if the solution is acidic or basic
and we can see that it changed color, right?
What color do we end up with?
- Yellow. - Yellow.
So it's more acidic with this bromothymol blue molecule
that we added.
We also had another set
with a molecule called phenolphthalein.
What happen in this case?
We started with pink and what do we get?
- Audience: Clear.
- So they're both clear.
Clear means we can see through it.
But this one is colorless, right?
This one is pink and clear,
this one is clear and colorless.
And this tells us that this one got more acidic as well
with this phenolphthalein molecule.
Ok, and in this last set of beakers,
we've got something that we call a universal indicator.
So this tells us about the pH again.
We went from purple to... What would you guys call this?
- Audience: Orange.
- Orange, yeah, orangish or reddish.
Universal indicator has a bunch of different molecules in it
so we can read out the pH across the whole pH scale,
ok?
So let's try something else.
Can we add some solid CO2 to this cylinder on the left?
- Sure, I got my gloves on now
so I pick up the dry ice, couple chunks of dry ice
and put them in this cylinder right here.
I asked you to focus your attention on this one.
You know, you're free to focus your attention
on anything you want. [laughter]
We live in a free country.
But if you want to follow the experiment that
Renee and I are doing, focus your attention on this one.
As I drop chunks of dry ice into the cylinder,
count out loud how many different color changes you see.
- Audience: One... three.
And you also see
that in each of the cylinders
that Renee and I put solid dry ice
that there is--
what looks like smoke coming off the top here.
But it's not smoke.
It's actually a condensation
of the water vapor on the carbon dioxide gas
that's coming from the sublimation.
And right here, sublimation is happening.
But we can't see it because carbon dioxide gas
is mixing with air which is a mixture of gases.
But over here, it's mixing with liquid so we can see it.
- Yeah, so let's see what else we can do
with this condensed water vapor.
So I'm going to head over here and I've got this nice basin.
What's in this basin?
- Audience: Nothing.
- Nothing except for air.
You guys are smart, ok.
So what I'm going to do is I'm going to take
this big flask of hot water, this is just boiling water,
and I'm going to pour it into my basin.
And what do you all see?
- Audience: Steam.
Actually, you can't see steam. It's invisible.
But we see this condensed water vapor, ok?
We see these little water droplets
that scatter the light, ok?
So now I've got my dry ice, my CO2,
and let's see what happens.
I'm going to dump it in.
[splashing]
[cheering]
Hey, I'm still here.
I'm still here, ok.
Whoa!
[cheers and applause]
Yeah, look at that.
So this mist or condensed water vapor
is the fog that we made
when we reacted this dry ice with our boiling water.
And you can see, it's actually going down, right?
It's going, it's spreading all over the floor.
So if you guys have seen fog in movies,
this is sometimes what they do.
And it's going on the floor
because this mist is more dense than air.
And so it sinks down
and now it's spreading all over the place.
- And you can tell that Renee is still enjoying science
in my laboratory here.
Can't you tell that? - Audience: Yeah.
- Thank you so much, Renee, for coming.
- Thank you, thank you.
- Best wishes to you, thank you.
[applause]
I'd like to ask that you focus your attention now
right over here
where I have a cylinder that's filled with oxygen gas.
I also have a Thermos bottle,
what we call a Dewar flask.
It has in it a very cold liquid.
It's called liquid nitrogen.
I'm going to show you the liquid nitrogen
as I pour it into this other Dewar flask.
So you can see
the liquid nitrogen is boiling
as it fills the Dewar flask.
The temperature of liquid nitrogen
is minus 196 degrees Celsius.
It's really, really cold.
And it hits a warm surface and it boils off.
So we want to fill this up with the liquid nitrogen
and we will know that the glass has reached
the same temperature of minus 196 when the boiling stops.
But we are going to do a couple of other experiments
as that's happening over here.
This oxygen tank is connected to a copper coil
that I'm going to put into the flask,
the Thermos bottle,
that has in it liquid nitrogen.
I'm going to add more liquid nitrogen right there
and the other thing I'm going to do
is open the valve
so that liquid starts coming out
of this Tygon* tubing.
And now you see I can bend it a little bit,
bend it some, bend it some.
And now it's become stiff.
That's because we're able
to condense a liquid,
liquid oxygen and you can see it coming out of the opening.
So I have a test tube,
I'm going to collect the liquid oxygen in here.
Can you see what color the liquid oxygen is?
[audience responds tentatively]
Liquid oxygen is blue in color.
Now here's a question for you
as you think about this experiment:
The boiling point of liquid nitrogen
is minus 196 degrees Celsius.
Do you think the boiling point of liquid oxygen
is higher or lower
than minus 196?
And don't let the minus sign confuse you.
Is it going to be higher or lower?
You can see that the liquid oxygen is condensing
in the liquid nitrogen that boils at minus 196
so the boiling point of liquid oxygen is?
- Audience: Higher. - Bassam: Higher.
It's actually minus 183 degrees Celsius.
And now liquid oxygen is a very interesting liquid.
It has a much higher concentration
than oxygen that's in the air.
So I'm going to take this out,
set it out here.
And I'm going to do an experiment
using liquid nitrogen,
but also using this horn gap magnet.
I take my pocket knife out.
I put it between the poles of the magnet.
Then you can see it's stuck in there.
I have to really pull it out.
There, I got it out.
So a very powerful magnet.
What I do is I take the liquid nitrogen.
I want everybody to see this clearly.
The liquid nitrogen,
I'm going to put this
in between the poles of the magnet
and you see that the liquid runs right through
as you would expect all liquids to do.
But if I take the liquid oxygen, let's see what happens
when I put the liquid oxygen in there.
[audience oohs and ahs]
The liquid is held between the poles of the magnet.
That tells us that this liquid is magnetic.
In fact, what we say is oxygen is paramagnetic
and it stays in there until it evaporates.
So let's do it again. Here we go.
There is the liquid oxygen.
Have you ever seen a liquid held
between the poles of a magnet before?
- Audience: No.
[applause]
- I really like this experiment
so I'm going to do it one more time.
[laughter]
I can tell you like it too.
At this time, I would like you to welcome
one of the many students I have in my lab.
Would you please join me in welcoming
one of the students that worked in my lab?
Come on out now.
[cheering]
Hello, Bucky.
Welcome.
I am so happy to see you, Bucky.
You can tell that Bucky is a very good science student
because he's wearing his goggles.
Do you see that?
And Bucky is also wearing a "Science is Fun!" button.
Bucky, I know you are a very good student.
And you plan to graduate in how many years?
Let me see this again.
Yeah, he has four and I have five.
[laughter]
We are a little different, yes, yes.
But you're going to graduate in four years.
Everyone should try to graduate in four years.
Everyone.
You follow Bucky's example.
Bucky, I know you've been working on some experiments
in my lab.
And are you ready to show us
one of the experiments you've been working on?
Are you ready for Bucky to do an experiment? [cheering]
Let's go over there.
[applause]
What we have here is a round bottomed flask.
It is filled with ammonia gas,
and there is a beaker of water here.
And then, there is a tube
that connects the flask to the water,
there's a small rubber bulb here,
and then there is
a way of connecting the ammonia gas
that's colorless and invisible
with this tube here.
So I'm going to turn this, and as soon as I turn this,
Bucky, you do your experiment, all right?
[audience oohs and ahs] [laughter]
So this rubber bulb that Bucky used
had a little bit of water in it.
A small amount of water was able to dissolve
all the ammonia that's in there
causing a partial vacuum to form up there.
And then, the water from the beaker was siphoned up
because the air pressure was pushing on it.
[gurgling sound]
Well, that's a noise that we should avoid to make.
You know that, Bucky.
So, of course, we chose to show
that ammonia, when it dissolves in water,
it forms a base.
And so we put an indicator there,
a dye that shows the red color of the indicator
and, of course, we chose red for a reason.
You know that, right?
What reason is that?
Bucky Badger.
[cheers and applause] - Whoo! Whoo-ooo!
- Bucky, I know...
I know because you are a good student
and final exams are coming up,
you have to go study and make sure you do well
on the final exams.
So best wishes to you
and thank you so much, Bucky, for coming.
Thank you so much.
[enthusiastic cheers and applause]
What I'd like to do now is an experiment
where I take a small amount of a solid
called sodium acetate.
I put it in this dish
in two locations.
And then what I want to do is
take a clear and colorless liquid.
It's actually a solution,
a supersaturated solution of sodium acetate.
And what I'm going to do
is pour the liquid on top of the crystals,
and now we'll see what happens.
You can see that the liquid is turning into a solid.
That's because the crystals of sodium acetate were seeding
and causing the...
sodium acetate to come out a liquid.
Let's see if I can steady my hand
and make this go taller and taller.
How tall do you think I can make this go?
[laughter]
- Audience: More!
- Bassam: More? - Audience: Yeah.
- Ok, keep going.
Keep going.
[excited chatter in audience]
Pretty good, wouldn't you say?
- Audience: Yeah. [boisterous cheers and applause]
- Let me push my luck a little bit
and do what we always do in science,
repeat the experiment. [laughter]
So let's see if my left hand
can produce the same effect.
I can report to you that I feel some heat
coming from the solid, which tells me that
when the supersaturated solution of sodium acetate
changes into a solid, it releases heat.
In fact, you know that the hot packs
that are used for first aid
have the very same sodium acetate in them
and all you have to do is initiate the crystallization.
I can report to you now that this also feels warm.
So this experiment
shows that the reaction releases energy
in the form of heat and we call that an exothermic reaction.
Did you like this experiment?
- Audience: Yeah. [applause]
- At this time, I ask you to join me in welcoming
my longtime colleague and friend, Dr. Rodney Schreiner.
Rodney?
[cheering]
Hello, Rodney. - Hello, Bassam.
- Happy to see you.
- I'm happy to here, especially on this 48th anniversary
of your special program.
- I'm very proud of that, 48 years.
- 48 years, that's amazing, isn't it?
[cheering]
- Yes, yes.
And we chemists like to commemorate anniversaries
featuring the element whose atomic number corresponds
to the anniversary.
- Bassam: Yes. - Do you know which element is--
- Bassam: Of course, I do. It's cadmium right there.
- Cadmium, right there, yes.
Number 48, symbol Cd for Cadmium.
Well, Bassam, I've brought you,
in honor of your 48th anniversary,
a sample of cadmium element.
- Bassam: Oh, it's heavy.
- Rodney: It's very heavy, yes.
It is a heavy metal.
And like most heavy metals, it's toxic.
- Bassam: Oh, that's why it's inside the jar?
- That's why it's in a jar.
So that we don't get it on our hands.
It is toxic.
And as you can see, it is a--
Like most elements, it's a silvery-gray metal,
but it has some unique properties all its own.
And I'd like to show you some of those.
- Bassam: All right.
- And I've got some equipment here to show you.
- It is heavy.
- Yes, it is.
Now, a cadmium like many metals
dissolves in hydrochloric acid.
And when it dissolves,
it produces a clear and colorless solution
of cadmium chloride.
The compound cadmium chloride.
So here is some of that solution.
And I have more of this cadmium chloride solution
in a beaker
and I'm going to add to that solution in the beaker
another clear and colorless liquid.
This is sodium sulfide solution. - Bassam: All right.
- Ok, so I'm going to pour some of the sodium sulfide
into the cadmium chloride.
- Bassam and Audience: Whoooo-oooo-ooo!
That's a beautiful color change, Rodney.
- Yes, yes.
So I started with clear and colorless liquids.
It's no longer clear, is it?
- Audience: No. - No?
Now it's cloudy because a solid formed in there.
And it's no longer colorless, is it?
- Audience: No. - What color is it?
- Audience: Yellow. - It's yellow, yes.
That solid is cadmium sulfide
from the cadmium chloride and sodium sulfide.
And that bright yellow color is used as a pigment.
If you go into an artist supply store,
you will find a bright yellow paint called cadmium yellow.
It contains cadmium sulfide, and there you can compare.
- Bassam: Is it safe to handle? Is it poisonous?
- No, this pigment and that paint is poisonous.
So artists need to be careful when they handle this paint.
And near the cadmium yellow paint,
you may find a paint called cadmium red.
Here's a tube of cadmium red.
Cadmium red doesn't contain cadmium sulfide.
It contains cadmium selenide.
- Selenide? - Selenide.
- Yes? - Yes.
It's a compound of selenium and cadmium.
- And it's red in color?
- It's red, yes, but it comes in different varieties.
This cadmium red paint,
you can get it in cadmium red deep, or cadmium red medium,
or cadmium red light.
And the light is sort of an orange-red,
and this is the deep red,
and the other one is, the medium is,
as you might expect, in between.
Now they are different colors because cadmium sulfide,
selenide color
depends on
the size of the particles.
So I've got here samples
of cadmium selenide
of different sizes.
Tiny, tiny particles suspended in a liquid.
And you can see they are different colors
and the size of the particles here
are about a billionth of a meter.
- A what?
- A billionth of a meter.
That's really, really tiny.
So tiny that you cannot see the individual particles,
but as we go across this range of colors,
the size of the particles just about doubles.
So you can see as the particles get bigger,
the colors get darker.
Now, not only does the color
depend on the size of the particles,
there's another property I want to show you.
And to show you that one,
I'm going to use this lamp
which you may recognize.
It is-- if I can get it to go on--
There, do you recognize that?
- Audience: Black light. - A black light, exactly.
And what I'm going to do is I'm going to set the black light
in front of these tubes.
And then I'm going to remove the white background.
And then we're going to turn off the lights.
- Audience: Whoo-hoo! Yeah!
- Rodney: Ohhhh, yes, something altogether different.
[applause]
Thank you.
Yes, they glow very nicely, and the color they glow,
also depends on the size of the particles.
The particles that are really tiny
give off short wavelength light
which is sort of greenish here,
and the bigger particles give off long wavelength light,
which is the red end.
So we see.
- Bassam: Do these particles have any practical use?
- Rodney: Yes, these are also sometimes called quantum dots
in the nanotech field.
And they're being studied for solar energy conversion
and for display panels like television sets
and you can see why.
They're very colorful.
- And the cadmium selenide is a semiconductor.
- Cadmium selenide is a semiconductor also.
- And that reacts to the changes in the UV light
depending on the size of the particle.
- Right, right, yes.
Now, while I've been working with cadmium metal
I've also been working with another metal,
one which is not toxic.
And I have a sample of it here.
This is iron in the form of a pipe.
[clink, clink, clink] Iron, metal.
- Bassam: It's safe to handle. - It's safe to handle.
This iron is not toxic at all.
But when I was experimenting with this
I discovered that I could pour sound.
- What?
- I can pour sound.
- You can pour sound? - Yeah, you want me to show you?
- Yes, would you like to see how he does that?
[applause]
- Ok.
I'll need your help, but I need--
There's a torch. - Yes.
- What we need to do is we need to get hot air
flowing through the tube in order to make the sound.
- All right.
- So if you start the torch, [torch flame hisses]
and then I'm going to hold the flame vertical, yes,
and I'm going to hold the pipe over it.
Now the hot air is flowing through
and it's making a sound that you can hear
but you're also listening to the torch.
So what we should do is turn off the torch.
[whistling]
There, now you can hear the sound.
And I can pour it into the cup. [whistling stops]
And I can pour it back. [whistling resumes]
[laughter]
And I can pour it into the cup. [whistling stops]
[cheers and applause]
And I can pour it back. [whistling]
- You're very good at this.
You're not spilling any of it.
[laughter] - I don't know.
Eventually. I must have spilled some.
- You spilled some? - It's gone.
- Oh, let's do it again. - Ok.
- Want to see it again?
- Want to see that again, ok.
- Audience: Yeah, yeah!
- Rodney: You get hot air going through the pipe.
You can kinda hear it whistling now,
but the torch is making so much noise.
We turn off the torch.
[whistling]
There. [whistling continues]
Pour it into the cup. [whistling stops]
Pour it back. [whistling]
Pour it into the cup. [whistling stops]
Pour it back. [whistling]
Let's see, could I do it again?
[whistling stops]
And...
Ahhhh...
Oh, well.
[cheers and applause]
How many of you believe that I'm actually pouring sound?
[laughter]
I don't see many hands.
Actually I'm not pouring sound,
I'm doing something completely different.
You want me to explain what I'm doing?
- Audience: Yeah. - Ok.
First, this tube is not completely empty,
there's something in the end of it.
And I'm going to see if I can show it to you.
At the end of the tube, let's see, aim it, there we go.
I think you can see there's a screen inside the tube
near the end.
So when I hold this, let's see,
when I hold it over the flame the screen gets hot,
then when I turn this vertically
that hot screen heats air, the hot air becomes less dense
and it rises through the tube
and it draws more through.
So it keeps going while the tube is vertical.
When I turn it horizontal
it can no longer rise through the tube
and so no longer makes noise.
When I return it to vertical it goes through,
rises and makes noise again.
So that's all that is involved.
This has nothing to do with it.
[laughter]
- Thank you so much, Rodney.
Thank you, thank you.
[applause]
My next experiment uses this book.
I actually wrote this book.
It says Chemical Demonstrations .
There's my name down here.
You see at the bottom down there?
So with your permission, I'm going to open the book
and just remind myself of the instructions
for the next experiment, all right?
Is that ok if I did that?
- Child in Audience: No.
[audience oohs]
- This is not an ordinary book.
This is a hot book.
[laughter]
It's actually not a book at all.
It's the book cover.
And on the inside I have two batteries
that have stored in them chemical energy.
And then I have the filament from a light bulb up here,
and then there's a wick that I soaked with lighter fluid
when you were not looking.
[laughter]
And down here, you can see there's a small button.
Now when I push the button,
which I haven't done yet,
because the book is where?
[laughter]
Before I push the button,
I should move the book away from my face, right?
[laughter]
When the button is pushed, the chemical energy
that's stored in here changes into electrical energy
and the filament lights up.
This filament is like all filaments in light bulbs,
except LEDs.
It gives off light energy and also heat.
And remember from the fire triangle,
we need three things to have a fire.
You need something that burns,
oxygen, usually from the air,
and then you need... what?
A source of ignition.
So what should I do?
[multiple responses from audience]
Move the book away from my face.
[laughter]
And then push the button.
I don't have enough fluid there,
but I want to show you how this really works.
So I will get my lighter fluid.
And I want you to see how it's done, like so.
I close the book, put this on the side,
open the book.
What should I do next? - Audience: Push it away!
- Move it away from my face, yes.
I push the button.
And what's happening?
There it is.
- Audience: Whoa!
- So we teach about the fire triangle
not to help start fires
but to help put out fires.
Did you like this experiment?
- Audience: Yeah! [applause]
At this time, I would like you to welcome
a high school junior who is working in my lab.
Please welcome Isabelle Krier.
[cheers and applause] Hello, Isabelle.
[applause]
Very happy to see you. - Nice to see you.
- We're going to do some experiments.
You've been working on these experiments,
among other things.
And the experiment I'm going to do
is to take this colored liquid--
I you look near the top you can see
that it has a purple tinge.
It's so concentrated that it's dark.
I'm going to add to it a clear and colorless liquid
and we'll see what happens.
You ready? - Yeah.
- All right.
[oohs and ahs]
So what I did
is to bleach the color.
Color is something that we all really enjoy
and that's what you've been working on here.
So what do you have here, Isabelle?
- I have two beakers of nickel sulfate solution.
- Nickel sulfate.
And what's the green color?
- The nickel in the solution is what makes it green.
- All right.
- So I can add some clear liquids here.
[audience oohs and ahs]
- Bassam: That's pretty.
- Isabelle: And now I'll add ethylenediamine.
[audience oohs and ahs]
- Bassam: All the blue is gone
and now I see violet, purple.
You have one more? - I have one more.
- Clear and colorless? - Yup.
- Let's see what's going to happen.
Oh, and if you don't mix it
you can see the two layers, right?
Now mix it to see what happens.
So beautiful color changes
always arouse our curiosity
and make us think about
the beautiful, complex world that we live in.
Now in my lab, we have many, many talented people.
Isabelle is one of them.
And I know that you are a musician.
- Mm-hmm. - What do you play?
- The violin.
- She plays the violin.
Would you like to hear Isabelle play the violin?
[applause]
- All right, so I play the violin.
And my violin's made out of wood.
And then I can make sound in my violin
with the four strings that all make different sounds.
I can also create sound with my bow,
which is also made out of wood,
but on this side it's horse hair
so that I can make sound by bowing against the strings.
[dramatic violin music]
*
[cheers and applause]
- Bravo, Isabelle.
She not only excels in doing colorful scientific experiments,
but she excels in making us all enjoy
the beautiful music that she's played.
Thank you very much, Isabelle.
Thank you so much, thank you.
[applause]
In this experiment, I want to call your attention
to what I have in the large beaker.
And it is very obvious
to anyone who looks at the cans
that one is floating and one is sinking.
And I ask you to think about the difference
between what's in the cans
that causes the diet drink to float
and the regular drink not to float.
I'm going to give you a hint.
You know the difference between a hint and a clue?
A hint is something that someone tells you or gives you.
A clue is something that you find on your own.
You know how you run around sometimes and you say,
"I have no clue"?
[laughter]
That's because you haven't found one yet.
Well, here's my hint.
This is 39 grams,
almost 40 grams
of sucrose, of sugar.
This is what is used
to add as a sweetener
to the diet drink.
So that's my hint and you can think about
this explanation that you come up with.
By the way, when you visit my website,
scifun dot org,
you will find, in the upper left corner,
you'll find an icon.
And you click on that
and it takes you to a place
where there are instructions
for experiments you can do at home.
This is one of those experiments,
and many other experiments
so please visit the website and enjoy the experiments,
as well as everything else that is on my website.
- Ho-ho ho-ho-ho-ho-ho Merry Christmas!
Ho-ho-ho-ho-ho Ho-ho-ho-ho-ho!
[applause]
Ho-ho-ho-ho-ho Merry Christmas!
Ho-ho-ho-ho-ho.
Ho-ho-ho-ho-ho Merry Christmas!
Merry Christmas to all!
Ho-ho-ho. - Hello, Santa!
- Hello, Bassam! How are you?
- Welcome to my lab. - Thank you.
- I'm so happy to see you again. - I'm so glad to be here again.
- Did you get my list? - It was a pretty long list.
- No, it wasn't all that long.
I've been good. Haven't I been good?
- Audience: Yeah. [applause]
- Oh, thank you.
Did I get anything that's on my list?
- Let me take a look at my bag here and let's see.
- All right, all right.
- Oh, let's see, I think maybe I do have an item for you
that was on your list.
I'm not sure why, but here you go.
And you can open this now before Christmas.
- Right now? - Yes.
- All right. I'd like to.
- Yes. - Yeah.
And I don't want to drop it here so I gotta be careful how--
- That's right. - How I open it here.
Oh, do you know what this is?
- Child in Audience: A picture.
- This is the "Sunflowers"-- "Sunflower"
by the famous artist...?
- Audience: Van Gogh. - Van Gogh.
And what pigment did Van Gogh use?
Cadmium sulfide.
Oh, Santa, thank you so much.
I'm going to hang this in my office year-round.
I'm going to enjoy the artistry of Van Gogh
and all the different shades
of cadmium sulfide that are in here.
Thank you so much, Santa.
- I knew you'd enjoy that, yes, yes.
- Thank you, thank you. [applause]
Did I get anything else?
- Oh, let's look again.
- He hesitated a little bit, right? [laughter]
- Yes, I do find one more for you.
There you go. - Oh, all right.
- And, again, you can open that now too.
- Open this one too? - Sure.
- Oh! Oh! Oh!
Do you know what this is? - Audience: No.
- This is a bow tie, a "Science is Fun"bow tie.
[laughter]
And when I go to a formal event,
a black tie event,
do you think I'm going to wear a black tie?
- Audience: No. - No way.
I'm going to wear this tie.
Thank you so much, Santa.
That's really, really very nice of you.
- You're welcome. - Thank you, thank you.
- I happen to have one more that wasn't on your list.
And this is a special present from the elves and I to you.
- Oh.
- We made this in our laboratory up at the North Pole.
- Yeah, yeah? Open it now?
- Open it, please.
- Oh my goodness.
It looks like a wire. - It is.
- And it spells, it spells what? What does it spell?
- Audience: Ice.
- I-C-E. Is this a--
- It's a very, very special type of wire
that has some really interesting properties.
- What's so special about it other than spelling I-C-E?
- Well, let's do a few experiments
and we can discover that together, ok?
- All right.
- The first thing I'd like you to do
is take it out of there. - Take it out, ok.
- And--
- Pull it out, all right.
- Pull it out. - I pulled it out.
- And just kind of stretch it gently.
- Stretch it? - Stretch it.
- Ok, "gently," he said.
I'm stretching. - Yeah, that way.
Yeah, ok, stretch it a little more.
- A little more? - A little more. - More?
- Well, sure, a little more than that.
- But the letters are disappearing.
- Well, I'll show you its special property,
but keep stretching and let's see what happens to it.
- I don't see I-C-E anymore.
- Santa: Did you ruin it? - Huh?
- Did you ruin it? - No.
- Ok.
Well, let me show you the special properties of this.
- Yeah.
- If you've got some source of heat around,
maybe some hot water perhaps?
- We have lots of hot water.
- Let me grab my goggles here.
- Ok, you put your goggles on.
Santa is a good science person.
I'm sure you and the elves in the workshop
obey all the safety rules.
- All the time, indeed, indeed. - All right, I have this.
- Now what I'd like you to do
is just take your hot water source
and just very carefully just hold it over that
and stick some of it into there and see what might happen.
- Audience: Whoa!
[laughter]
- You like that?
[applause]
Santa, in my lab we like to repeat the experiments.
- I think we should, by all means.
-Should I repeat the experiment? All right.
- Now that you know what's going on, yes.
- Ok, pull, pull, pull like this.
- Santa: Pull, pull, pull, pull. There it is.
- All right, so this special wire now is,
it looks like that. - Does it spell 'ice'?
I don't think so. - It doesn't spell ice.
It's appropriate that it spells ice.
- It is, indeed.
-Related to where you come from.
- That's what we did, right? - What do I do now?
- Get it near hot water and see what happens.
- In the hot water. All right, above the hot water.
I don't even have to put it in there.
Just the hot, ok, I'll put it in there.
And there it is again.
You still like it?
[applause]
Santa, Santa, this is really special.
What's it made of?
- It's a special alloy of nickel and titanium called Nitinol
or also known as memory metal.
- Memory metal.
- It has its own memory. - I can see that it remembers--
- Santa: It really is.
- Bassam: What shape it was before I stretched it,
and that's why he likes it.
So does it have any practical applications?
- Oh, it does.
It's phenomenal since it was discovered.
One of them that's really kinda neat is
it makes orthodontic braces
and the heat from your mouth
makes it want to go back to its original form,
so it keeps pressure on your teeth all the time.
- Very interesting.
- It's used in medical devices inside of our body sometimes
and switches that are heat activated.
It's fantastic. - It is.
It's, and I really--
- I knew you'd like it. I knew you would.
- Thank you. Do I get to keep it?
- You get to keep it, yes. - Thank you so much, Santa.
I really appreciate that. Thank you, thank you.
[applause]
Very thoughtful of you, Santa.
- You're very welcome. - Thank you.
I know, I know you have many, many other stops to make.
- I do. - So thank you for coming by.
I don't want you to be double parked
and get a ticket out there.
- No, no, no, ok.
- So thank you so much, Santa, for coming in.
- All right, Bassam. Merry Christmas.
Ho-ho-ho-ho-ho Ho-ho-ho-ho-ho!
Merry Christmas!
Oh, I'm watching you guys.
Ho-ho-ho-ho-ho Merry Christmas!
Ho-ho-ho-ho-ho!
- I have candles.
I'm going to put the candles right here,
and, of course, I'm going to light the candles.
It's the season, right,
to light candles?
So there's the first one.
There's the second one.
There's the third one.
Four, five, six.
And what I want to do is take a flask
and put some dry ice in the flask.
So I need to put my gloves on
because solid carbon dioxide, dry ice,
is at a temperature of minus 78 degrees Celsius.
So I'm going to put that, those chunks in there.
Oops, I missed.
That's all right.
And dry ice changes from being a solid
to a gas directly without melting
by a process we call sublimation
and that's what's happening right now.
But carbon dioxide has another interesting property.
Let's see if I can now take the carbon dioxide
and pour it down the steps here.
Here we go.
Ta-da!
[cheers and applause]
At this time, I would like you to join me
in welcoming one of my former students,
who now works at the UW
and he's actually in charge of the demonstration laboratory
in the Chemistry Department.
Please welcome Mr. Jim Maynard.
Hello, Jim.
[applause]
What do you have for us here?
- So, this is my experiment.
And in this experiment,
which is a large glass tube stoppered at both ends,
I actually have a greenhouse gas in here, a major one.
- Which one is that?
- This is nitrous oxide. - And it's colorless.
- It is a clear and colorless liquid.
Now it doesn't burn, but it does support combustion.
- I see.
- And so we're going to do an experiment with it now
and I have a couple of things on here I'm going to need.
I have this box and it has a syringe
and a small Erlenmeyer flask
with a clear and colorless liquid in it.
It's called carbon disulfide.
It's in here because sulfides
are generally very nasty smelling chemicals,
and so we're going to prevent that
from making the environment any less good than it is now.
And I have this torch.
And so now what I'm going to do
is I'm going to take some of this carbon disulfide,
we're going to put it in this syringe
and I'm going to introduce it
into this cylinder with the gas.
So if you'll excuse me.
Ok, so here we are.
And my syringe,
and I'm going to put it in here
and draw out some of this liquid.
Don't worry, it doesn't hurt a bit.
[laughter]
So I'm going to get a certain amount of this
and then I am going to inject it in here.
Ok, and there's the liquid flowing down the tube.
It has a high vapor pressure
so it forms a vapor very quickly.
Now I'm going to mix it in a rather special way.
All right, we're just mixing now.
One,
two,
and a half, ok.
All right, so I think we are now sufficiently mixed
to run the experiment.
If you could light my torch for me, professor.
[gushing gas noise]
I felt a little bit of pressure there
as the vapor pressure pops the stop.
On the count of three, in the dark, please.
- Watch out for some loud sounds.
- Ok, on the count of three.
- Audience: One, two, three.
[explosion]
[audience oohs and ahs]
[applause]
[laughter]
- Did you see how fast that explosion was?
Did you see the beam of light come down right away
as soon as he put the torch to it?
Now I ask you to look at the monitor
because we're going to show you the same reaction
in slow motion.
You won't hear any sound.
There it is.
Very, very rapid combustion reaction.
Releases energy in the form of light,
in the form of sound and also in the form of heat.
Now what is this yellow stuff that's on the inside, Jim?
- So this yellow substance is one of the products
of the reaction.
It is actually sulfur, elemental sulfur.
So when you add carbon disulfide
to nitrous oxide and ignite it
your products are nitrogen gas,
carbon dioxide gas, and solid sulfur.
This is one of the most exothermic reactions people do
and this has been used as a demonstration
for well over a century.
- Fantastic.
Thank you so much, Jim. Thank you.
[applause]
Well, you've been a wonderful audience
coming to join in the celebration
of the 48th anniversary of this program.
And that's why I want to salute you
by doing my grand finale.
- Audience: Ooh!
[applause]
Thank you all very much. Thank you.
Come on out.
[cheers and applause]
* [festive instrumental music]