07x11 - Car vs. Rain

[bunniefuu]

I know it looks like we have fun
on this show,

but we spend weeks
and sometimes months

planning how to do
our myths safely.

So, please,
don't try this at home.

NARRATOR: On this episode
of "Mythbusters"...

...there's real genius...

Today's forecast...


NARRATOR:
...lots of laughs...

[Laughter]

...and a whole heap
of explosions.

Like a wet-T-shirt contest,
really.

NARRATOR: First, Adam and Jamie
take on a classic urban myth.

This looks awful.

NARRATOR: With the top down,
can you stay dry

by putting
the pedal to the metal?

Whoa, look at that!

NARRATOR:
Then Kari, Grant, and Tory

have a two-part popcorn parable.

Let me have itl

NARRATOR:
First, they're asking,

can you cook corn
with explosions?

And then lasers?

ALL: Whoa!

Am I missing an eyebrow?

NARRATOR:
Who are the mythbusters?

Adam Savage...

- Am I missing an eyebrow?
- NARRATOR: And Jamie Hyneman.

You know, I usually
don't let people do that.

NARRATOR:
Between them, more than 30 years

of special-effects experience.

[Laughs]

NARRATOR:
Joining them... Kari Byron...

That was a rush!

NARRATOR:
...Grant lmahara...

Burn!

- NARRATOR: And Tory Belleci.
- Light it on fire

NARRATOR:
They don't just tell the myths.

They put them to the test.

So what's up with the umbrellas?

I'm planning to use them
to paint a metaphorical picture.

I want you to imagine that you
are having a midlife crisis,

and you run and spend
a bunch of your dough

on a really nice
convertible sports car.

Okay.

Further imagine you're
driving it down the street

and it starts to rain...
What do you do?

Pull over,
and you put the top up.

Aha! That's where
the fansite myth states

that you might be wrong.

That instead of wasting
your time putting the top up,

that you should floor it,
go as fast as you can,

because there is a speed
at which you can drive

that no rain will enter
the driver's compartment.

Sounds kind of unsafe to me.

Sounds really fun to test to me.

NARRATOR:
Aerodynamics...

Aahl

NARRATOR: Dangerous
wet-weather driving...

and a classic urban myth.

This is "Mythbuster" country.

Because viewers want to know,

if you've got the top down
when it starts raining,

will putting your foot down
keep you dry?

So, does this mean
we get to drive a fancy car

- really fast in the rain?
- We do.

But we are in sunny California,

and that presents
a little bit of a problem.

I think, just as we did
in running in the rain,

we're gonna have to manufacture
our own rain here.

It's a bit of a chore,
but I think we can handle that.

We still get to drive
a really fancy car

fast in the rain, though, right?

Yes, but slow down there,
cowboy.

I think perhaps we ought to take
this model car

and run some shop tests.

Sprinkle some water at it,
look at it on the high speed,

see if there is anything at all
to this myth.

Then we get to drive a really
fancy car fast in the rain.

We'll get some driving lessons,
we'll wet down some tarmac,

we'll go out next thing
and drive a fancy car.

- All right?
- All right.

NARRATOR: So, to keep
revhead Hyneman happy,

they shelve the shop tests
in favor of...

Well, the first thing on our
agenda is to get some training

in foul-weather driving
on wet roads.

And in lovely, sunny California,

there's nothing better for that
than a perfect sunny day.

NARRATOR: But being
the Boy Scouts that they are,

they came prepared
to make their own.

This is gonna be fun.

NARRATOR:
That's the bad weather.

So all we need now
is a convertible car.

JAMIE: If you've seen
"Mythbusters" before,

you know that generally when
we have cars, they explode.

But not that one, I don't think.

NARRATOR:
Guiding the guys

through their wet-weather
driving instruction

is Brian Frazer.

JAMIE: Brian's the guy
that trains anybody

that drives an emergency vehicle
how to do it right.

That means police, fire,
ambulances... Brian's the guy.

FRAZER:
There goes that understeer.

You let a little bit
of the steering out.

Right.

JAMIE:
If I had a car like that,

I wouldn't be letting Adam
drive it.

NARRATOR: Harsh,
but, given Adam's track record

and current
over-caffeinated mood...

- [Boing!]
- [Laughs]

NARRATOR: Fair.

[Boing!]

[Coughs]

[Man laughs]

Whoo!

I might have gotten

the microphone wet there
for a second.

NARRATOR:
Despite Adam's best efforts,

the microphone still works,
and they get down to business.

The surface is now wet.

We're gonna lose that cohesion

between the tires
and the concrete surface.

We're on a concrete pad
out here today.

[Adam laughs]

FRAZER: Hydroplaning
can also be a factor

- if we got standing water.
- [Tires screech]

Ways to deal with this...

we get off the gas,
slow our speed down.

It's gonna multiply
any reaction we do,

so you want to not be jerky
in your steering movements.

Oh [bleep]

FRAZER: So, just
smoothing out your steering

and backing off speed can keep
you in control of the car.

Ohh!

[Laughs]

ADAM: The clearest difference
between driving on wet ground

versus the dry ground
is that it's a lot slipperier.

NARRATOR:
And that's the key.

By simply getting to grips
with the car on a wet surface,

they can be sure they won't lose
their heads at high speeds

on the real test...

...which means they're licensed
for wet-weather science.

I keep losing my hat.

NARRATOR: Now, in part one
of "Popcorn Pandemonium,"

is it possible to pop popcorn
with an expl*si*n?

[Woman screams]

[Laughs] I love this.
Watch this part.

Going to the movie theater is
one of my favorite things to do,

but what does this
have to do with the myth?

The fans love popcorn
as much as I do,

and they've sent in
a ton of myths

- about popcorn.
- Yeah, like what?

Can you pop popcorn
with expl*sives?

Now, how is that
supposed to work?

Explosions
generate a lot of heat,

and the fans think that is
just enough to pop popcorn.

Cool.

- It's delicious.
- So nutritious.

MAN:
It's a taste delight.

NARRATOR: Popcorn

and its distinctive
expl*sive expansion

is a ready-made recipe
for myth and disaster.

And the fans want to know,

can you put the pop in popcorn
with a bang?

Okay, so popcorn
with expl*sives?

How are we gonna test this?

Well this myth comes
in a whole variety of forms.

Everything from a torpedo

hitting a container ship
full of popcorn

to an industrial accident
at a popcorn-popping plant.

Whoa.
What are we gonna do?

I think we should take
our favorite explosions

from our favorite myths,
apply them to popcorn.

This is gonna be fun.

Oh, this is the part
where she dies.

NARRATOR: Despite
the various outlandish sources

for this fan request, the basic
premise for each is the same.

Heat and pressure
from an expl*si*n

causes raw popcorn kernels
to cook in an instant.

To test this one
central theory...

...the team is taking two
classic blasts from the past...

[Laughter]

...and reigniting them
at the b*mb range.

And first up...

GRANT: Now, we do have a myth
from James Bond

that is
the exploding propane tank.

If this doesn't pop the popcorn,
I don't know what will.

GRANT: Gonna strap some C-4
onto a propane tank,

put some popcorn kernels
on top,

and see if we get
this rain of cooked popcorn.

Now, we know that heat
is what causes popcorn kernels

to pop into popcorn.

You can do it on your stove.

And I think it's fairly likely

that the size of the fireball
that we'll get

will generate
the sufficient amount of heat

to make something pop.

NARRATOR: So, will the expl*sive
C-4-and-propane c*ck

cook the corn?

Or will it simply be
shaken, stirred,

and sprayed, shrapnel-like,
all over the b*mb range?

All right, here we go.
In 3, 2, 1.

[Cheers]

[Laughter]

TORY: Wow.

That was some heat.
You think we popped popcorn?

I don't know.

NARRATOR:
That's the burning question.

But up
at the corn-carnage epicenter,

the signs aren't good.

GRANT: I see a lot of unpopped
kernels on the ground.

TORY:
No popcorn.

- KARI: Nothing?
- TORY: Nope.

There's more foil over here.

NARRATOR: It seems the force
of the C-4 expl*si*n

and the rapidly expanding
propane fireball

distributed the raw kernels
far and wide,

without actually
cooking and popping any of them.

My propane-popcorn empire!

[Sobbing] Why?!

KARI: I don't think
there was quite enough heat,

and it wasn't sustained for long
enough for the popcorn to pop.

I think we just
kind of blew it out everywhere.

NARRATOR:
It's a popular fansite fable...

Can you keep the rain
out of your convertible

by putting the pedal
to the metal?

After taking
their luxury soft-top

for a wet-weather test spin...

[Tires screeching]

...Adam and Jamie
are back at the Batcave

for preliminary shop tests.

ADAM: This is our scale testing
rig for driving in the rain.

And since it's about two things,
wind and rain,

we're creating both
in a small scale.

I've got a leaf blower here
creating the wind over the car,

I've got Jamie perched up there
in the scissor lift.

He's gonna be the rain.

He's got a pressurized bottle
of some blue dye

so that we can actually see
the raindrops.

Oh, that's nice.

Hopefully, if there's
any validity to this myth,

that the rain,
somehow by the aerodynamics

of the car going fast, won't get
in the driver's compartment...

- Are you ready?
- I'm ready.

ADAM: I would expect to see
these blue raindrops coming down

and the wind
coming over the car,

inhibiting them
from continuing their journey

onto the passengers
in the convertible.

NARRATOR: To simulate
driving through the rain,

they've got
a 15-mile-an-hour wind...

All right, go for it.

Oh, yeah.

[Laughs]

NARRATOR: Followed
by a small-scale hurricane,

with mini wind speeds
of 30 miles an hour...

I almost feel like
I'm driving it!

NARRATOR: After which Adam is
confident this myth holds water.

ADAM: I'm thinking
that our scale tests

are actually proving
pretty fruitful.

There may be something to this.

We've run three tests,
and they're showing me

what I would expect to see
if this myth were actually true,

i.e., we've run it
with no wind and some rain,

a slow-speed wind,


and a high-speed wind,


and I'm seeing
what looks like a bubble

forming over
the driver's compartment

with less rain
seems to want to get into.

Yeah, it does show the rain kind
of zipping over the c*ck,

but I'm not that sure

that the wind and the rain
scale that well.

We're gonna have to do it
full size.

[Laughs]

I knew you were gonna go there.

NARRATOR: But before said
dangerous wet-weather driving,

Adam has a couple of issues.

The first problem with this
as I see it

is that this was loaned to us

by a friend
and a fan of the show,

and it's worth over $100,000.

And we're mythbusters.

There's
an inherent danger factor

just letting us near something
of this value.

The second problem is that
we've got to figure out a way,

at some fairly extreme speeds,
to be able to know

whether water has gotten into
the driver's compartment.

JAMIE: We need to have a rain
detector for inside the car,

but because the amounts

that we're dealing with
are really quite small,

it's not like we can put
a funnel and a collector

or an electronic instrument
or something in there.

Like this.

I figured that if we put
something that would,

by virtue of getting wet,
show a dot,

that that would do the trick,

and so I thought
of tissue paper,

because when it's opaque,

you can't really see anything
through the other side of it.

But when it gets wet, like so,

all of a sudden, you've got
a very clear indication

that there's a drop of water
that hit.

Uh, it's like
a wet-T-shirt contest, really.

It shows you what's underneath,
don't it?

[Laughs]

NARRATOR: So far,
popping popcorn with expl*sives

is not looking good.

That didn't work very well.
Didn't work at all.

NARRATOR: The extreme expansion
of gases typical of an expl*si*n

is simply distributing
the kernels over the b*mb range

without cooking them.

[Cheers]

But our intrepid trio

have yet to light the fuse
on their final conflagration.

KARI: Of all the fireballs
that I've seen

from explosions that we've done,

creamer cannon has given us
the most slow fireball.

It goes into the air
and then [imitates expl*si*n]

[Laughter]

And we're gonna have the popcorn

kind of mixed in
with the creamer.

Yeah!
That's a recipe for disaster.

Hopefully kettle corn.

So, maybe the sticky creamer
will stick to the popcorn,

creating that heat
for long enough

that we'll get kettle corn.

GRANT:
I'm ever the optimist.

I think that this actually
has a chance of working.

- Lf you guys want to run...
- KARI: I do.

GRANT: What happens is,
you launch the cannon,

the creamer and the corn
goes up in the air,

the corn's surrounded by fire.

Somehow, it's going to make us
kettle corn.

- Right to go.
- All right.

In 3, 2, 1!

ALL: Whoa!

TORY:
I saw a bunch of burning...

Look at all those
burning kernels!

GRANT: I think
there's kernels out there!

TORY: Let's see
if we got some popcorn!

NARRATOR:
The fine-grained creamer

once again proves
extremely flammable...

...leading
to a satisfying fireball.

And there appears to be flaming
food falling to the ground.

[Cheers]

We popped popcorn!

It's kettle corn flambé!

It's burnt, but look!

TORY:
No, that's just burnt creamer.

KARI:
That's not popcorn?

No, but I saw it rain down!

Unfortunately, it was just
little bits of creamer.

But there was such hope there
for a minute.

I thought we actually did it.

My kettle-corn empire!

[Sobbing]
I'm wrong again!

NARRATOR: So, with the myth
looking pretty much busted,

it's back to the shop,

where Kari meets
a popcorn professor.

Now, we've been trying
to pop popcorn with expl*sives,

and I'm wondering

if we just don't have
enough heat generated.

Why do you think
that it's not working for us?

Popcorn pops best
at 450 degrees Fahrenheit.

When the popcorn is exposed
to that heat,

the moisture inside the kernels
expand and expand,

like your grandmother's
old-fashioned pressure cooker,

until finally,
there's enough pressure

to break open the kernel,

and what you're eating
is the starch

that has been condensed inside.

Yum, yum, yuml

NARRATOR:
That's the key.

A popcorn kernel
is basically a pressure vessel

made up of three layers...

the tough outer shell,
the starch-filled middle layer,

and the small, central germ.

Add sustained heat,

and the moisture in the center
turns to steam.

This heat and pressure
gelatinizes the starch

until, finally,
the shell bursts.

As the steam is released,

the starch cools into the fluffy
white ball we know and love.

So let me get this straight.

The expl*sives didn't work

because we didn't have
any of the right circumstances.

You're saying we need


even heating over a period
of time, more like a minute,

before we can actually
get the popcorn to expand.

So, there's really no way
for us to flash-heat

and have expl*sives
make us popcorn.

That's my understanding.

Well, as exciting as that was,

we didn't really pop any popcorn
with expl*sives.

KARI: There's one more myth I
want to test that fans sent in,

and that's why I brought you
to the theater.

Which one's that?

Well, do you remember a little
movie called "Real Genius"?

Yeah, I patterned my life
off of it.

Do you remember the last scene
in the movie?

A laser pops an enormous amount
of popcorn in the house,

blows out the windows and doors
just from the power of popcorn.

And that's
what we're gonna test?

Yep. That's what we're
gonna test. Check it out.

NARRATOR:
A template for Grant's life,

a monument to geekhood...

Let me have itl

NARRATOR:
...and a source for this myth.

Can a 5-megawatt laser really
cook a gigantic ball of popcorn?

Ohl

NARRATOR: And can
the expansive power unleashed

really bring down the house?

All right,
well, first, we need to see

if you can even pop popcorn
with a laser.

And we need to characterize
the force of popping popcorn.

Let's start out
with some due diligence.

Before we unleash the power
of popcorn on an actual house,

how about you and I go check out
a military-spec laser,

see if it pops popcorn,

while you run some tests
on force and expansion.

- All right, let's go.
- We can't leave yet.

The credits are rolling.
People work hard on this.

- We didn't work on this, did we?
- No.

NARRATOR: Jamie and Adam
are on the runway at Alameda,

raising a rainmaker...

ADAM: It's a little
lwo Jima moment here.

NARRATOR:
...because to test the myth

that driving fast
keeps you dry...

ADAM:
Holy crapola.

NARRATOR:
...they need wet weather

at the flick of a switch.

[Echoing] Hello!

NARRATOR: And for that, they're
going back to their movie roots.

ADAM: Hollywood,
like mythbusters, doesn't wait

for ideal weather conditions.

They make their own weather,

and this device
is one of the ways they do it.

- This is a rain bar.
- Got it.

And it sprays water through
a set of spouts... these spouts.

There are six of them.

And if what you want
is torrential rain,

it can deliver


For us,
it's gonna be delivering

a linear swath of rain


Well, everything's
hooked up and in place,

and the next thing we're
gonna do is a dribble test.

We're just gonna pressurize
all the lines

to the point where water starts
dribbling out the rain heads

because of several things.

[Laughs]

This amount of rain
is perfect for our test.

It's just about


One, that's a lot of weight
of water...

about 600 pounds per bar...

and the weight distribution
could change,

and they could swing,
so we need to control them.

Two, there's a little bit
of a west-to-east breeze here.

We want to make sure
the rain falls

where the car's gonna drive.

So we might adjust
our final bar position

based on what we see here.

[Laughs]

That's perfect.

NARRATOR:
With the rain ready to fall

and the cameras ready to roll,

it's time to bring in
the star... the car.

ADAM: We've modified this car
in a couple of ways

to turn it into a data-
collection device for this test.

First, because it's a fancy car,

we've protected the whole
interior with absorbent fabric

so that no water
can damage the car.

Second, to measure what water
does get in the car,

we've got these two boards,

which is basically
a piece of plywood

faced with acrylic
and tissue paper.

Any water that hits this surface

is gonna create a nice dark spot

that's easy to see,
easy to count,

and should give us a really nice
comparative analysis

of how much water's getting into
the driver's compartment

under the different conditions
we're testing.

- Well, let's get to it.
- Okay.

NARRATOR:
And by "to it,"

they mean using
their driving instructor

as a human-crash-test
guinea pig.

The biggest danger posed by this
experiment is hydroplaning.

That's where the car floats up
on a cushion of water,

and you lose all control of it.

[Tires screech]

Okay, go rain and Brian.

[Engine revs]

So, Brian,
our safety trainer and driver,

is actually going to take
this run at 120 miles an hour

across the rainy tarmac

to make sure that it's safe
for Jamie and I to do.

NARRATOR:
Brian's about to hit

what's essentially
a sluiced-down skid pad

at 120 miles per hour.

This could be interesting.

ADAM: Okay.

NARRATOR: Out of control
through 450 degrees

is exactly why the expert
was behind the wheel

and not Adam or Jamie.

ADAM:
What happened there, buddy?

That's what
we call hydroplaning.

Wow.
That seemed quite intense.

It was very intense
and a lot of fun.

[Both laugh]

JAMIE: I got to say, Brian gets
real props for that one.

Looking at the footage,

Brian's expression
didn't change at all.

He didn't flinch while
he's spinning out of control

around and around and around
at 120 miles an hour.

NARRATOR:
So, one thing's clear...

These tests will be dangerous.

Hitting a wet surface
at higher than highway speeds

has the potential
to put you into a spin cycle.

How do you feel about it, Jamie?

He did it.
I'll do it.

TORY: Whoa!

[Grant sobbing]

My kettle-corn empire!

Why?!

NARRATOR:
Our intrepid trio

are looking into unconventional
ways to pop popcorn.

Ohl

NARRATOR: And to test
this popcorn-themed scene

from the silver screen...

...Kari and Tory
go back to school

because they want to know
if there's any science at all

in this science-fiction-sounding
scenario.

Now, what we're trying to
find out here is,

can you pop popcorn
with a laser,

and, if so, could you do it
from a plane?

URBANEK:
I believe they're both possible.

Just a matter how much
laser power you have.

Now, how realistic do you think
the laser in the movie was?

URBANEK:


I'm not saying it's impossible,

but it's a stretch
even for chemical lasers,

which typically operate...

the highest power
is about 100 kilowatts.

I don't think
that a 5-megawatt laser

is around the corner just yet.

TORY:
Now, one serious question

that Grant
wanted me to ask you was,

how close are we
to lightsaber technology?

[Chuckles]

Oh, that's classified.

NARRATOR:
So, as unlikely as it sounds,

there's a "kernel" of truth
to this myth.

And for proof of concept...

Here is my popcorn kernel.

Here we go.

...they've got a 10-watt laser
pointed right at it.

[Lisping] We're popping
popcorn with lasers!

KARI: I'm looking
at the thermal camera.

I'm seeing heat at the top
and bottom of the kernel,

and they're expanding
very slowly.

I'm pretty sure this is
not how Mom used to make it.

KARI: Maybe this is how
Grant's mom used to make it.

[Cheers]

- It popped!
- TORY: Proof of concept!

[Cheers]

KARI: Well, now that
you can laser-pop popcorn,

let's just concentrate
on the power of popcorn.

That is cool.

Let's go.

Pretty good.

So, now all we need
is a 5-megawatt laser,

and then we can finally find out

if popcorn can break down
doors and windows.

Uh... no.

In fact, 100 kilowatt is the
most powerful you're gonna find,

and that's even
in military applications.

Yeah, so basically,
we're never gonna find

a laser big enough
to pop a houseful of popcorn.

GRANT:
If we can't get a laser,

we can substitute
another heat source.

Already on it.
Induction heating.

We just have to switch out
the tinfoil

for some sort of
steel container.

- Sounds reasonable to me.
- So, did you ask him

about that thing we were talking
about, the laser sword?

Actually, I did.

And guess what.
I got a prototype right here.

There you go, buddy.
Don't turn it on inside.

I said don't turn that on
inside!

You're gonna cut
somebody's head off!

NARRATOR: So out goes
the science-fiction-sized



and in comes
a giant steel frying pan,

heated by electromagnetism?

TORY:
So, we're trying to find out,

does popcorn have
the expansive power

to blow open doors and windows
of a house?

Now, we know, in theory,
that a laser can pop popcorn,

but there's no way we're
gonna be able to get a laser

powerful enough to pop
a whole houseful of popcorn.

So I'm gonna make a frying pan,

and not just any normal
frying pan,

but a giant steel,

electromagnetically heated
frying pan.

This is gonna be crazy.

[Clang!]

NARRATOR: It's a big pan,
but it's not house-sized.

And that's because the second
change to the movie scenario

is one of scale.

The team are starting small,
with just one window.

KARI: In the movie,
the weak point was the windows.

So, I'm constructing a window,
putting it in a wall,

making that
the lid for our pan.

Now, if this myth is true, the
popcorn should pop like crazy,

pop with mythical power,
bust through the windows,

and spill out everywhere.

NARRATOR:
That's the setup.

And inside,
Grant is using his...

Apply the Jedi mind force.

NARRATOR:
...uh, mind...

GRANT:
[Laughs]

NARRATOR:
...to crunch the crucial numbers

for the expansion potential
of popcorn.

Ah.

So, the popped kernel
has an increase in volume

of approximately 30 times,
which is pretty good.

NARRATOR: Next,
he uses the force... gauge

to measure the pressure
of that expansion...

[As Palpatine]
Rise, popcorn, rise.

Push on the plate with force.

NARRATOR: Which turns out
to be .22 PSI.

TORY: So, we're about to heat up
the pan to cook the popcorn.

The way we're gonna do that

is we're using
an induction heating system.

How that works
is there are copper coils

underneath the steel plate,

and they send out
a high-frequency A.C. Current.

Now, that current
creates a magnetic field

which will move the molecules
around in the steel.

As those molecules are moving,
it creates friction,

which creates heat.

And that's how we're gonna
cook our popcorn.

In essence,
we're making a giant skillet.

[Lmitates sizzling]

Aaah!

GRANT: So, now we're gonna coat
the bottom of the pan

with coconut oil
to spread the heat evenly...

Mm. Smells like popcorn.

GRANT: And then fill it
with 3/4 of an inch

of popcorn kernels.

NARRATOR: According
to Grant's earlier calculations,


should expand to over 20 inches.

And with the window a mere 6
inches above the uncooked corn,

we're all set to find out

if popcorn has the power
to break out.

GRANT: So what we're looking for
in this experiment

is whether the force
of the popping popcorn

will actually break the window.

MAN:
Okay, it's on.

GRANT:
Now, in my earlier experiment,

I found that the popcorn
generated .22 PSI...

They're popping!


- TORY: Yeah!
- GRANT: Yeah!

...which doesn't sound like
a whole lot,

but consider this is
a relatively large surface area,

and the window's
over 1,000 square inches,

which means, potentially,


NARRATOR: But despite
a sterling, stirring effort...

Rake it, Grant!
Now's your chance.

Show us what you got, boy.

NARRATOR: The popcorn fails
to make an impression

on the window,
and it never will,

because confining the popcorn
while it's cooking

prevents it from popping.

So it looks like
most of our kernels popped,

and you might be thinking,
"If they didn't bust the window,

why don't they just add
more popcorn?"

But there's actually a maximum
amount of kernels you can use

before not only does
the compression

start making them pop smaller,
but everything just burns.

This is the most popcorn

that's going to pop
in these circumstances.

NARRATOR:
So, it's a catch-22.

Putting pressure on the popcorn
means it doesn't pop

and can't exert
that expansive pressure.

But the guys
aren't giving up yet.

KARI:
We do know from your experiment

the pressures
that the popcorn should exert.

So what if we took
the cooking out of the equation,

used pre-popped popcorn,
and applied our own force?

Yeah. Then we could see
if the popcorn is strong enough

to break out of a house.

Or whether the kernels

would simply crush
under those conditions.

- So, back to the drawing board?
- Yeah.

NARRATOR: Adam and Jamie
are lifting the lid on a myth

that to stay dry,
you don't put the top up,

you put your foot down.

ADAM:
First up is the control.

See, the myth states
that if it starts to rain

and you're driving your
convertible with the top down,

you shouldn't waste
your time putting it up.

You should g*n it, floor it,
go as fast as you can.

So of course we're
gonna g*n it, floor it,

and go as fast as we can.

But what do we compare that to?

We compare it to the control,

which is driving
into a rainstorm,

stopping, putting the top up,

and seeing how much rain
we gather that way.

NARRATOR: With a direct line
to the weather gods...

All right,
stand by for pressure.

NARRATOR: Or at least John,
the rain-bar operator,

Adam commences the rain.

Today's forecast...


Go ahead and pressure it up.

Jamie, come on in.

[Engine revs]

NARRATOR:
Remember, this is a control

for comparative purposes.

ADAM: All right,
now stop and put the top up.

[Laughing]
Oh, this looks awful.

NARRATOR: If you're foolish
enough to be driving

with the roof down while
there's a rainstorm approaching,

we want to know
how wet you'll get

in the time it takes
to pop the top back on.

Now go ahead and drive off.

NARRATOR: And it's pretty clear,
because that's one wet Hyneman.

[Laughs]

How was that?
Looks like you got soaked!

JAMIE: I think so.

ADAM: [Laughing]
Oh, look at our test boards!

There's no drops to count.
They're just 100% soaked.

I don't know whether there's
gonna turn out to be something

to driving really fast to keep
rain out of your convertible,

but it's pretty clear
that stopping at all,

even to put the top up,

is gonna get you saturated
with rain pretty quickly.

All right,
now stop and put the top up.

Now that we've got
a good control,

it's time for some real testing.

If there's any merit
to this myth,

we should see a lot less rain

on our rain-collection panels
than last time.

NARRATOR: But the weather gods,
the real ones,

otherwise known as the physical
forces of meteorology,

decide to rain on Adam
and Jamie's scientific parade.

The tissue-paper rig is not
gonna work in these conditions.

Well, why don't we do
some runs anyway,

and sh**t it on high speed,
look at it closely,

and see if we can detect
any kind of pattern from it?

Okay, that sounds good.

- Let's do 25 miles an hour.
- Okay.

NARRATOR: For this
stately 25-mile-an-hour test,

out go
the rain-detection boards,

and in comes
the high-speed camera.

Then, after a quick reset,

Jamie ups the speed
to a healthy 55 miles an hour,

before heading back
to compare the two runs.

JAMIE:
At 25 miles an hour,

I don't see any plume coming off
the windshield at all.

You will. It's coming up
in just a minute. There, see?

JAMIE:
Yeah, it's pretty small.

ADAM: But still,
you can see the effect.

Looks like a lot of it is
going into the c*ck, though.

Yes.

Here's 55, though.

The difference
is actually pretty marked.

So, no plume.
Look at how the plume appears.

JAMIE:
Oh, yeah.

- ADAM: Isn't that nifty?
- JAMIE: Yeah.

Just totally clear.

NARRATOR:
Totally clear?

Well, there seems to be more
of a plume at the faster speed,

but is the c*ck
actually staying drier?

There's no way of knowing
for sure

until the real rain lets up.

I'm not gonna say this too loud,

but it looks like it
might actually be clearing up.

We might get a window
for testing soon!

NARRATOR: Kari, Grant, and Tory
are asking,

can popping popcorn
blow out your house?

It's kind of tinkling
against the window.

I thought they'd be
more aggressive.

NARRATOR: Large-scale cooking
didn't work,

so they're taking heat
out of the equation

to focus on the expansion
potential.

Now, what we do know is that
if you can pop popcorn,

it does exert a certain amount
of force.

So, PSI .22.

So, we're gonna try
this experiment again

but in a different way.

TORY: We're gonna take
a bunch of pre-popped popcorn,

fill a house that we build,
add our own pressure,

and see if the popcorn is enough
to destroy the house.

Ow!

That kettle's hot!

Am I missing an eyebrow?

KARI:
We've done the calculations.

To fill a house
that is 6x6x6 feet,

we're going to need 30


So we've got
six popcorn poppers,

all popping at the same time,

and we're working around the
clock so we can fill the house.

NARRATOR:
After the corn mountain peaks,

Kari's four-legged
vacuum cleaners move in,

and the team can move on.

And with a house built to code
in fast-forward,

Grant steps up with
a larger-than-necessary piston

to apply the popcorn power.

Ta-da!

I'm not compensating
for anything.

[Both laugh]

So, I'm standing
underneath what would be

the floor of our house.

We're gonna fill up
the entire house with popcorn,

and then this cylinder
is going to push up.

[Laughing] Oh, yeah!
It fits.

Now, initially it's going to be
just the popcorn force,

just to see if,
under ideal conditions,

if we popped every kernel,
what would happen to the house?

Would it push up
and blow out the windows,

or would it do nothing?

Here we go.
Pump's on!

- All right, you guys ready?
- TORY: Yep.

GRANT: Okay, so, this is
regular-popcorn popping force.



TORY:
It's moving.

- KARI: Yeah. Slowly moving.
- [Creaking]

You hear the creaking?

TORY: Yeah.
Something's gonna give.

Is it the popcorn?
Is it the house?

NARRATOR:
As it turns out, neither.

Popcorn power, which, according
to Grant's calculations,

is 0.22 PSI and exactly the
pressure exerted by the piston,

just isn't enough
to do any damage at all.

So basically the expansive
pressure popcorn exerts

doesn't come close to denting
the door or windows.

That means...

This part of the myth
is looking busted.

- Yep, busted.
- Yep, busted.

But you know what?

We still have
a houseful of popcorn.

I say we max it out,
see what happens.

I want to see
what's gonna go first,

the house or the popcorn.

Do it!

All right,
let's wreck this house!

NARRATOR: With Grant's piston
cranked to the max...



NARRATOR:
...this "test"

is a transparent excuse
to destroy stuff.

The only question is, will
the popcorn crush into dust,

or will the house
come tumbling down?

[Cheers]

NARRATOR: And as it turns out,
the popcorn wins out...

Raise the roof!

It blew the roof off!

NARRATOR: Or at least
Grant's giant piston did.

KARI:
It wasn't really popcorn power.

That was how many tons of force?



So it was really just popcorn
as a spacer.

Yeah.

So popcorn power didn't
really destroy the house.

- No.
- But that was cool!

[Laughter]

NARRATOR: Adam and Jamie
have already seen hints

of the aerodynamic basis
for this myth.

- JAMIE: Oh, yeah.
- Isn't that nifty?

NARRATOR: On the next


they're looking
for physical evidence

on the tissue-paper
rain detectors.

Jamie, you may start
your run now.

This is 70 miles per hour,
gunning it.

NARRATOR:
g*n it, Jamie does...

...hitting his mark and holding
steady at the target speed

for the length of the course.

And cut the rain.

NARRATOR:
And with no hydroplaning

or dangerous spinout, it's time
to take in the results.

Whoa, look at that!

Wow, that's far out.

It looks like no rain at all
hit the middle here,

but we've got wetness
up top here

and on the left-hand side here.

JAMIE:
It's important to note

that whatever little water
came in here

on the 70-mile-an-hour run

was a tiny, tiny fraction
of what came in on the control.

ADAM: Totally.

I predicted there'd be less rain
in the car on this run...

not nearly this little.

There really seems to be
something to this myth.

NARRATOR:
A conviction only confirmed

by the high-speed camera.

ADAM: That's really clear.
It's like there's a line.

It's a really visible bubble,
isn't it?

JAMIE: Yes. That's what
the windshield's for.

[Adam laughs]

So it would seem.

NARRATOR:
But the guys aren't done yet.

Adam, who will observe
from a safe, dry distance,

feels the need for more speed.

ADAM:
Well, as far as I'm concerned,

we should go
for 100 miles an hour

and see if we can get
those boards to stay bone-dry.

I'd go ahead and leave
the traction control on.

NARRATOR:
But Brian, our safety driver,

is concerned about
the additional soaking

the surface took
from the real rain,

so he suggests sticking
to 90 miles per hour.

Try to countersteer it,

- but if you can't, let it go.
- Got it.

ADAM:
Let's go to full pressure.

JAMIE:
I am set and ready to go.

Awesome. Jamie, you may start
your 90-mile-an-hour run now!

Let it rip.

And cut the rain!
Nice work, Jamie!

It didn't hydroplane.
Awesome!

Let's open this top
and see how we did.

h* h* h* h*! Dude!

Look at that!

JAMIE:
We wanted to find out

whether driving fast
when it's raining

will actually keep you dry,
and it turns out it does.

Around 25 miles an hour or so,
it's not so effective,

but as you go faster,

it actually does deflect
most of the rain.

Now, it's not that hard
to understand, really,

because the rain's coming down
like this.

If you're going this way and
got something in front of you,

then it's gonna catch
all the rain

and send it up over the top
of you, and you stay dry.

ADAM:
So it does make sense to g*n it.

The faster, the better, in fact.

Yeah, you might die
in the process, but...

- You'll be dry.
...you'll be dry.

ADAM: Your honor, ladies
and gentlemen of the jury,

for my closing argument,

I'd like to call your attention
to exhibit 24, which is footage

from the "Tailgate Up or Down?"
Fuel-efficiency myth

that "Mythbusters" filmed.

If you'll notice here
at the water-oatmeal test,

there's a bubble formed in
the back of the pickup truck

that allows air to flow over
the back of the pickup truck.

The self-same aerodynamics

that the engineers
put into this sports car

that allow it to be aerodynamic,
even with the top down,

create the same kind of bubble
over the passenger compartment,

and I contend that that's
what keeps the passenger dry

at high speed.

This is a conundrum, because
I don't feel like it's right

to call this one confirmed.

Yeah, driving really fast in
the rain can be very dangerous.

How about plausible,
but not recommended?

I'll buy that.

NARRATOR: It's been
a long and winding road

for this popcorn parable.

Kari, Grant, and Tory
have discovered

explosions won't pop your corn.

That didn't work very well.
It didn't work at all.

- NARRATOR: But lasers will.
- [Cheers]

NARRATOR:
However, a giant ball of corn

popped by a 5-megawatt laser

leading to a house expl*si*n
is pure fiction.

- KARI: Busted.
- Yep, busted.

[Horn honks]

TORY: Now, our house
hasn't exploded yet,

and this myth calls
for an exploding house.

So we're out here at the b*mb
range, and this is the plan.

We're gonna load it with C-4
at the top and the bottom,

and when this day is over,

we should see splinters
and popcorn, and that's all.

I don't think they taught me
this in b*mb school.

KARI:
Well, we started with a bang,

we're ending with a bang.

So, basically, we've got
a boom-popcorn sandwich.

TORY:
All right, you guys ready?

- Ready.
- In 3, 2, 1.

ALL: Whoa!

Look at the rain
of popcorn coming down!

Ohh!

The rain of house, too.
Whoa!

Now, that is exploding
a house with popcorn.

Well, not really popcorn.
With C-4 surrounded by popcorn.

GRANT:
To get this result,

we had to go very far away
from popcorn power.

It didn't really push up
on the house.

It didn't blow the windows open.

It didn't really do a whole lot.

KARI: Popcorn power turned out
to be science fiction.

This expl*si*n... real genius.

[Chuckles]