Episode 11

Hmm, hmm,
a-ha. As you can see, Christian,
I have on the hot pot gloves and I've had--that you've
got safety glasses on, and mine are, too,
because today we're gonna do some experiments that
are sort of dangerous, so if you don't mind
I'll do 'em. Okay? You know what this is? It's a pressure cooker. What happens
inside there? Well, when you put
the weight on top then the--and you put
water inside with something in there
it'll--the water will turn into steam
and it will want to expand more
and there is no room for it to get out, so it's
so much pressure in there.

And that's why it's called
a pressure cooker, right? And just to make sure
that we understand there's pressure inside
your mo--your mother has a pressure cooker? -Yes.
-Has she ever blown up a balloon with it? -No.
-Probably not, no. Okay, but you see there's--
ordinarily there's a relief valve in there,
but I'll put that balloon on the top then we said
we needed a weight? Weight to stop all
the leakage. Okay. Now I've had that on low,
do I have to turn it up? Maybe just a tad.

Okay, I'll turn
up the stove. Now you can see the pressure
going up, right? Now I don't wanna let
it go too far because if that balloon
would break we'd have hot water
flying all over the place, yeah, so, but, anyway,
that proves that, certainly, there's pressure
inside there, right? But now let's actually
measure the pressure, and we can do that
with a gauge. See that gauge down
there on the table? Yeah. Okay.

I'll put the cork
back in the hole in the top of the pressure
cooker again. Hot? Yeah. And now we'll put
the gauge in there. Some pressure cookers
come with a gauge like this built right into it.

In fact, this one originally
had such a pressure gauge because on the back side here
you can read how much pressure you should have to cook
for the various things. Okay, we'll turn it on. What do we need now? The weight. Okay.

The weight coming up,
read the pressure. Okay, let's see,
half of one-- Those are pounds
per square inch. Oh, half a pound,
one pound. Why would you want pressure
to build up inside here anyway? Do you know? -No.
-As the water has pressure put on it
its temperature goes up, it takes more energy to make it
boil, so you can get it hotter than 100 degrees Celsius
or 212 Fahrenheit, so that's why food
cooks faster.

What's it doing? It's climbing,
it's gone already to seven. Okay, 15 is supposed to be
the maximum according to the little diagram
here. That's when you cook
Swiss steaks. What'll happen at 15? In fact, you can see it already
here, see it--how we doing? Ah, we're at 13 and a half,
14, 14 and a quarter, half, three quarters-- Okay, you see it
coming out here? -Fifteen, yeah.
-See it coming out? -Yup.
-Okay.

I'll turn it down. There, now you can really
see it. So it automatically
comes out? Yes, because that's as
much pressure as you want. Whoa.

See why I wanted you to have
safety glasses on? Yeah. Okay, now I have a sort of
my own version of a pressure cooker,
but it's made out of glass, so come over here. We'll let that
cool down. Here is a blow torch
and here is a container that I'm gonna use
as a shield.

In the blow--flame of
the blow torch I'm gonna put this
little glass container. It's been sealed off,
see what's inside? -That looks like water.
-Water, yeah, so this is a little
pressure cooker. All we have
to do is heat it up and we'll change that
water to steam. What should happen? It should blow up.

You think it will? Yeah, 'cause it needs
to get out. Okay, that's why I have
this container here so if it does blow up
it won't shatter all over the place
and danger us. Okay. Are you ready? Not really,
but okay.

If I get it right down
there on that flame we should get it
to boil. Any minute--
any second. And you think
what'll happen to it? It's gonna explode. -Starting to bubble.
-Oh, it's starting to bubble, oh, no, yeah,
bubbles, bubbles.

That's going up. You thought it wasn't
gonna go, huh? Now you see why you
never heat something in a closed container? Yeah. Because what happens
to it? It has to get out. It has to get out,
and it could be a dangerous explosion, and you see
why I did it in this container so it wouldn't
get all over us.

You can see all
this glass and-- -Okay, that's a little water.
-Oh, it's water? Okay, well, thank you very much
for helping me with a very dangerous
experiment. You're looking at a fruit
within the mystery fruit. The one inside the ring
is undeveloped because in the flowering stage
it was not properly fertilized. Instead of developing
into a normal fruit with seeds it ended up inside
the ring looking something like a belly button.

That's why it's called
a navel orange. Chris, you and I may be starting
a couple of little fires, so just to be on the safe side
I have a bucket of water, which I'll put down
over here. -Well, that's pretty smart.
-Okay, now here is a glass lens,
there's the sun, and there's
a piece of paper, you ought to know what
to do, right? Oh, well, -kind of.
-You've done this before? -Yeah, a few times.
-What do you do? Okay, well, I think you've
got to take it like this and aim it so the sun's
going right through here and just concentrate it
into a little spot so it'll start burning
the paper. Okay, and it started
burning the paper.

Little hole. Now here's--here's another
glass one, but notice the thickness
of that. -Yeah, it's, well--
-Try concentrating the light with that one. Okay.

Gotta find
the sun. Well, it doesn't seem
to be burning much. 'Cause it's a certainly
a bigger spot, but notice it works in the same
way that the glass lens did, didn't it? Uh-huh, yeah. Okay, now try this one.

Here's one that's a flat
piece of plastic, see it? -That's pretty thin.
-Yeah. Okay, try burning a hole
where that one was. Hold it up and get it
so the light's concentrated on it like that. Wow.

Oh, it's on fire, jeez. Oh, that's a pretty
big mark. Yeah, it did it pretty
quickly, too, didn't it? Well, what I don't understand
is why this big th-- why did this big thick one
do it slower than this thin one? Well, I tell ya, that's because
this is a special kind of a lens called
a Fresnel lens. -Fresnel?
-Yeah, Fresnel, and I think I can explain it to
you better if we go inside, so come on.

Okay, whoops. I'll take this. Now, Chris, this is the lens
that you played with, right? Yes, the one that I used
in the backyard. Right, okay, but you've also
played with a lens like this that has a curved surface
on the front.

Well, this is my diagram
of that. And let's trace the rays
of light like scientists do. You start, trace with your
finger, trace the center beam. Okay, it just goes along there
and hits the lens and just goes
right through.

Right straight through
and comes out over here. Now trace the top one. Okay, it does the same thing and
comes along and hits the lens. But stop right there.

'Cause notice what
happens to it? -It curves. Yes, it's bent
right there, isn't it? Because of the curve
of the glass, okay. Then it continues on
over to here. Now trace the next
to the bottom one.

Okay, it does the same
thing as the other one and it hits the lens,
and because of the angle it'll bend again
and hits the final point. So notice that all the bending
of the light takes place only on the outside here
where the glass is curved. And none of this part in
the center here is necessary 'cause the light's going
straight there. -Okay, I could see your point.
-So, remember that now 'cause we're gonna make
a plastic lens.

Here's my plastic lens,
see it? Okay. That looks just like
this one, right? -It's a little bigger, though.
-A little bigger, yeah. Now I'll take
the outside out. There's the outside.

Now here's the next
inner section and I've cut it
into two pieces. Which piece
do you want? Uh, this one
because of the curve? 'Cause it's got the curve
on the top, sure. Okay, so I just put
it in here? All right, here
are two more pieces. Which one
do you want? The top one
because of the curve again.

Okay, here's the last piece. Okay, well, I'll take
the top piece again because it's got more of
a curve than the bottom one. In fact, the bottom one
doesn't have any curve at all. You see, here's all the glass
that we got rid of.

And we now have it all
piled up like that and look. Hey, it looks just like this one
except it doesn't have as many ridges
as this one, curved ridges. This has more of
them, right? -Yeah.
-Yeah, because I made
this one myself. But that's the idea
of Fresnel lens.

-Fresnel lens?
-Yeah, Fresnel lens. It's called that because
a scientist had the problem posed to him of how to get
a great, big magnifying glass in front of
a search light and he realized that if he
made it as big as he wanted to it would be too heavy,
so he got rid of the glass and just made these
rings like that. And today they use 'em
all over the place. They use 'em in a variation
in car headlights, and spotlights,
and all over the place.

Magnifying glasses and
telescopes and stuff like that? Well, no, they wouldn't use that
in a telescope 'cause they would use
another system. Here, for example,
is the other piece that we used. Remember it was real thin,
burned real fast? Yeah, but it doesn't have any
ridges or anything. No it doesn't, well, here, rub
your hands over it.

With your fingernail
especially. Okay. I can--yeah, I can see
some little, uh-- feel some little curved
ridges on it except there's more
than this one. Right, lots of 'em,
thousands of them, probably.

And because it is such--
it's such a big piece it'll magnify, too,
watch, look at this, what do you see? I see a big red,
big, big, red fork. Right, because this is
a magnifier even though you can't
see the curve and because it is such
a big one we concentrated all the light
from all this whole area down into a spot and that's why
you were able to burn that hole so much more quickly. Okay. So--and sometimes they put
these on the back of cars so they can see down to
the back, so when you see one you'll know it's called
a Fresnel lens.

Boy, you have a big face. And so do you. Okay, now, what's gonna
happen when you let go? Well, it's gonna go flyin'
all over the place. You've done this
before, right? -Yeah.
-Okay, let 'er go, watch it.

Now let's take a look
at this one. Why did it go flying
like that? Well, there's air in there
and the air is coming through and it's--since it can't
go this way it's gotta go out
the hole. All right. That's a sorta--
think of it this way, there's air inside, right,
and under pressure the balloon is squeezing it,
but the pressure is equal and opposite
in all directions, -so nothing happens.
-Okay.

Okay, now when you release
this end of it this part can go out,
but there's nothing counteracting this pressure
up here, so that's what makes
the balloon go forward. Okay. Okay. This time, though,
instead of just letting it fly all over
I have a string stretched between two
trees, see? -I see.
-And here is a plastic straw on the string
and we're going to tape the balloon here,
but before we do I wanna let the air out
slowly so you can see how the balloon deforms
as the air goes out, watch.

Okay. Well, it's coming out
of that end first. See, it's coming out
of the front end, so put the tape sort of
back in here, okay? Okay, got it? Yup. Put it right there.

Okay. Now let's put it way down
at the other end so we can get a nice,
long run. Okay. Okay, Darren,
let 'er go.

-Wow, great!
-Oh, good one! Okay, send it back. 'Kay. Okay. -Are you ready?
-Ready.

Whoops. That happens to me sometimes
because, you know, why does it get
twisted up like that? Well, sometimes
the straw can come off -or the tape.
-Yes, and sometimes the pressure coming out of
the balloon might make it go sideways this way, so it'll push
with various signs of pressure. -And push the straw.
-So if you're going to do that when you loosen the tape
I'll blow up another balloon, we'll make
one more try. There we go.

Okay, there it is,
it's all yours. Okay. Put it right there. Okay, now I'll take
it back.

-Okay, here we go.
-Here we go. -Wow, great.
-All right. That was a good one. Hmm, hmm,
a-ha! How many North Poles
are there? The imaginary north/south
lines on a map all meet at a point called
the geographic North Pole, North Pole number one.

A compass points to
the magnetic North Pole that at the present time is in
the Queen Elizabeth Islands. That's North Pole
number two. To the east is
an imaginary point where the magnetic pole
would be if the Earth had a giant bar magnet
running through it. Satellites out in space
respond to this so-called geo-magnetic pole,
and scientists use it in their orbiting
and space calculations.

So there are three
different North Poles, and, of course,
for the same reasons, three different
South Poles for a total of six poles
all together. Okay, I've got our names
typed in, and I couldn't fit yours,
so I just typed Mr. Wiz. Okay, second player
is Jason, so what are we
doing now? Well, we're--I just started
the game of 3-K Trivia.

Okay, 3-K--
three--what was that? 3-K Trivia. Oh, okay, well,
what are we gonna do now? Well, I'll get
the game started. Question one. And you get to
go first.

Okay, it looks like
a slot machine. -What's goin' on there?
-Well, actually these are the-- these are actually
just the, uh-- -Various categories?
-Yeah, the categories, and there is, uh-- Right now is sports. A bonus will give
you extra points, so what you've got to do,
you can choose between sports and general. And general and...

And I have to select
a category and I see I have
a number up there and that's gonna
keep score, right? Now besides these there's
other categories like sports and science
and nature and... Well, there's sports
right up there. Okay, so there's science
and nature and stuff? And what is the one over
in the right there, general? I'll take general. M-kay, that's about...

Pretty well anything. Okay. Okay. Oh, what's this 15
up there? That's your time limit.

Oh, you mean I have
to answer? What is the capital
of Vermont? Uh, Montpelier. -How do you spell that?
-M-O-N-T-P-L-I-E-R. Couldn't be, right--sorry,
Mr. Wiz, you ran out of time, the correct answer
was Montpelier, okay.

That's all right, I got zero,
so it's your turn now, okay. -Different categories this time.
-I got history and geography, yeah, and sports
and show biz, ooh. I guess I'll go
for history. You have-- Jason, ooh,
you got 15 seconds, too.

Who shot Lincoln, oh? I know-- Oops. Eight, seven, six, five-- Can't remember
his last name, oh. Four, three,
two, one, I'm sorry, Jason,
John Wilkes Booth, right. Well, what's the whole
point of this thing? Well, you see
what happens is, uh, you're trying
to get points.

I see. How many questions are
there all together? We're playing
a five question game. Oh, in other words,
at the end of five questions it automatically adds
up your score? -Yeah.
-How 'bout the total number of questions
that are available? I think it's 3,000, plus,
you can add 100 of your own to each category. Why would you wanna do this
rather than play the board game? Well, this one is, you know,
it's easier, you don't have cards
and boards and little pegs sittin' around,
and you can play it yourself, yeah.
-Yeah.

General, history,
and true trivia. True trivia? What is the--
the--uh, general. General, okay, that's
sort of like, uh, mi-- mixed up and sometimes
they're hard, sometimes they're
easy, so... What city is the
business capital of the South? Atlanta.

Atlanta, enter,
he got it! Oh, no, you're ahead
of me now. Okay, I'm gonna have to
get a good science one 'cause I'm good at those. Okay. C'mon, science, oh,
bonus, that might give me extra points--
whoa.

All right. So now the bonus is I'm forced
to take show biz. Oh, what insect was the movie
Them about? Ants, I saw that movie. All right,
I'm ahead of you, 500 points.

Ordinarily, you leave the beach
when night falls, but this night stay
to see an amazing sight. You have to wait
for complete darkness because even the flame
of a match will frighten off
the visitor from the sea. There it is,
a sea turtle. Once out of the water
lights no longer dissuade her as she works
her way up the beach.

She has to stop frequently
to rest. Moving across the sand
is more difficult for her than swimming
in the ocean, which she does
with ease. She continues up the beach
until she gets above the high tide line. With her back flippers
she begins to dig a hole in the sand, just
the right size for her eggs.

She will lay up
to 120 of them, each about the size
of a ping pong ball. When she's finished
she covers the nest by pushing sand with
her front flippers toward her rear flippers,
which shove the sand into the nest. She moves her body back
and forth to conceal the location. Finally, she lumbers back
to the safety of the water.

During the two months
of incubation the eggs are vulnerable
to predators. After emerging
from the eggs the baby turtles dig
themselves out of the sand and scurry toward
the sea. Out the hundred or so
in the nest only a handful will
survive to lay their own eggs. Some will be eaten
by sea birds, others by live fish.

Their survival is
further threatened by houses built on
the beaches where the turtles come to lay their eggs. Commercial fishermen
are another hazard. They inadvertently catch
the turtles in their nets. They're cooperating
with wild life officials by releasing the turtles
and by designing nets that catch shrimp,
but not sea turtles.

To help the endangered
animals survive the state of Georgia
has set aside sanctuaries on islands
off the coast. Here biologists observe
the egg laying and tag females to see if they
return to the same beaches year after year. They also dig up the eggs
and transfer them to the areas of the beach
that are safe from predators. Learning more about
their life cycle and continuing such
hatchery projects may bring back from
the edge of extinction the ocean reptiles
called sea turtles.

Jackie, have you ever
been a detective? No, I haven't. Well, you're gonna be one today
because someone in this room touched that piece of paper
there on my desk, and it's up to you
to determine who did it. Okay. Komal, did you do it? No, I didn't
touch that paper.

It's pretty obvious,
Christian, did you do it? Nope. Now both of your suspects
have denied -touching the paper.
-Yeah. -May I give you a clue?
-Okay. Come over here
and put on these glasses.

Did you notice that
both of your suspects were wearing glasses? No, I didn't. That doesn't give you
a clue to solve the problem? No, not really. Here's another clue. Invisible tracing powder? Yes, invisible tracing powder.

See, this is the kind
of powder that when you shine invisible light on it
it turns the invisible light into a light
that you can see. -Oh, okay.
-And... Here is the light
that you shine on it. It's sort of, uh--
see how it's sort of purple-ish? Yeah, and sort
of violet, well, there's also
ultra violet in this, which is light
that you can't see, but it's converted into
light that you can see when you shine it on
that powder.

Now--so it looks better,
here, hold it near the edge of the paper
like that and I'll go turn
out the lights. See how it's sort of
blue-ish purple? Okay, now put it over
near the center of the paper. It's orange. Yes, that's the color
of the powder when you shine
an ultra-violet light on it.

So does that give you a clue as
to how you can solve the problem? That means that if I shine it
on their hands if their hands are orange
that means that -they was--yeah.
-They touched it, right. And, by the way, the reason
they're wearing glasses is because ultra-violet light
is not too healthy. You shouldn't be looking
at it with your eyes, so these are glasses that are sort of
safety glasses for ultra-violet. Okay, go ahead and try it,
see if you can solve-- solve the mystery.

Okay, Komal,
put out your hands. No, okay,
turn them over. Nope, okay,
it's pretty obvious, Christian,
put our your hands. Turn them over.

What'd you find? It's just normal,
there's no orange. Yeah, well, someone in
this room touched the paper, so now what do
you do? You did it. How you gonna
prove it? Put out your hands. Turn it over.

Put out your
other hand, and turn it over. There, nice
and orange, yes. Orange, you did it. You solved the mystery
of who touched the paper by using invisible
ultra-violet light and changing it
to visible light with that special powder.

Congratulations,
you solved the problem. Thanks..