05x19 - Trail Blazers

[bunniefuu]

Narrator: on this episode
of "mythbusters,"

Adam and jamie put tinseltown
pyrotechnics to the test

With two flammable fables.

Time to burn
for science.

Will a burning trail of gas
actually reach your car

And blow up your gas tank?

Stay away from it.

Then, can you catch and stamp
out a lit fuse of gunpowder?

And will the powder keg
really go boom?

Come on, little buddy!
Don't burn out!

Go, go, go, go!

And kari, grant, and tory

Dip into two more
defibrillator myths.

Will a jump start for your heart
burn your bra?

Clear.

Or even cause
your piercing to spark?

Tory: oh.

Ow.

Narrator:
who are the mythbusters?

I'm so pumped!

Adam savage.

Time for science!

And jamie hyneman.

Was that beautiful
or what?

Between them, more than 30 years
of special-effects experience.

It bleeds!

Joining them,
grant imahara...

Don't give up on me now!

...tory belleci...

Say hello
to my little friend.

Narrator:
...and kari byron.

High expl*sives
and electricity -- whoo!

They don't just tell the myths.
They put them to the test.

We've got another
action-hero myth, huh?

We do, and it's really
only illustratable

By telling a story.

So, you are in a showdown
with the bad guy,

But as you're about
to sh**t him,

He jump into his car
and drives away,

But you're able to get off
one shot into his gas tank,

Which starts
leaking fuel.

Oh, I love this one.

'Cause I happen to have
a lighter in my pocket.

I light it, I drop it
into the trail of fuel,

And it catches up
with the car.

The car blows up.
Bad guy's dead.

Exactly that,
and we're gonna do it.

It's a cinematic cliché.

Our hero has to stop
the escaping bad guy.

Okay, so action heroes

Don't usually come
with a beret and mustache.

There's the single shot
into the gas tank,

The leaking trail
of gasoline,

The nonchalant flick of a light,

And finally the fleeing fugitive
feels the full force

Of hollywood-style justice.

But is this another example

Of the language of film
rewriting the laws of physics?

So, how are we
gonna do this one?

You gonna sh**t my car while I
drive away at high speeds?

We'll save that
for the finale.

We need to start small
and simple

And just test what
the different fuel types do --

You know, how quickly they burn,
break it down.

That sounds great.
Cool.

As always, jamie wants to take
the pragmatic approach.

But this look
into the future confirms

That the small and simple plan

Will quite literally
go up in flames.

Faster! Faster! Faster!
Everybody out!

And when the story ends
with full-scale mayhem,

Inevitably it began
with bench tests in the bunker.

The basic metric
for all of this

Is figuring out how fast
fuel burns from "a" to "b,"

So we're basically -- under
slightly safer conditions --

Gonna spray some fuel
on the ground, light it,

Time how fast it takes
to get from "a" to "b."

Narrator:
three fuels will make up the
samples for this first test,

And gasoline, diesel,
and jet fuel

Are the most likely culprits
to be found

Causing a conflagration
in an action movie.

Gasoline is first up,

And adam squirts a 7-foot trail
onto a smooth metal plate.

Adam: here we go.


That's fast.

And despite several tests
adding more and more gasoline,

That time of 1½ seconds
seems to be constant.



Yeah, 1½ seconds.

It's the same whether we use

A tiny amount of fuel
or a whole lot.

Well, this seems to be
a constant

In the timing of the gasoline --


It's really, really steady.




But we're getting
a very constant speed,

And it doesn't
seem to be related

To the amount of gasoline
we're putting down,

So I think we can extrapolate
this out to miles per hour

And start working with it
as a bona fide figure.

All right,
so it went 7 feet in...

That's 4.6 feet per second.

Equals 3.17 miles per hour.

That's actually, like,
a reasonable walk speed.

Narrator: but what about
the other fuels?

Diesel's next.

It's not lighting.

But despite liberally applying
the blowtorch,

It doesn't want to
go up in flames.

That's hard stuff
to light.

Jamie: it only lights
when it gets mistified.

Adam:
this is far out.

Diesel fuel does not light
like normal gasoline.

Apparently, it's formulated

To specifically ignite only
under certain circumstances,

And one of them is definitely
not laying it out on the ground

And lighting it with a match.

Next up is jet fuel.

Jet fuel in 3, 2, 1.

Narrator:
and just like the diesel,

Jet fuel does anything
but rocket along the track.

It's no burn.
It's no burn.

Very similar
to diesel fuel.

[ Sirens wail ]

The police are coming,
so let's get out of here.

While adam tries to explain away
his pyromania

To local
law-enforcement officers,

Jamie can give us the science.

The reason that diesel fuel
and jet fuel

Don't burn on the ground
is that they're not aerosolized.

They need to be mixed in with
the air in a vapor or a mist

For them to burn effectively.

Narrator: which leaves
just one conclusion.

It's pretty obvious that,
of all the things we tested,

Gasoline's the most volatile.

If you want to light
someone's gas trail on fire

And blow up their car,

You better hope they're driving
a gasoline-powered vehicle,

Not diesel or jet fuel.

Narrator: so, gasoline's
perfect trailblazing properties

Means it's the fuel of choice
going forward.

But where to next?

Well, the mythical action scene
in question

Involves a leaking gas tank
as a result of a g*nsh*t,

So to find out how fast
fuel falls from a b*llet hole,

Frank tabor has answered
the call

With a veritable
ballistic buffet.

Adam:
can I fire this one? Can i?

Do you mind?
Is it all right?

Sure. Go ahead.

Awesome.

With the gas tank in position

At the end
of their makeshift g*n range,

Adam and jamie are aiming
to find out...

[ g*nsh*t ]

...the size of
a .22-caliber b*llet hole...

[ g*nsh*t ]

...as well as a .44.

Jamie:
I'd round these off --

Say the .22 is a quarter-inch
and this is like a 5/8.

Absolutely.

sh**ting the hole was only
the first part of this test.

Now I want to know how fast

Fuel will leak out of the hole
that jamie shot.

So I've got
a one-liter bottle here.

I'm gonna let the fuel
fall into here,

Count how many seconds it takes
to get to exactly one liter.

Then I'll know how many liters
per minute this hole will leak.

It's just over
three liters a minute.

The results of this test
are pretty straightforward.

.22-caliber b*llet
leaves a 1/4-inch size hole

And leaks about 3½ liters
of fuel per minute.

A .44-caliber b*llet

Leaves a hole that's a little
over 1/2 an inch in diameter

And leaks more than double --
about 7½ liters per minute.

Narrator: so adam and jamie
know exactly how quickly

Fuel flows
from a g*n-shot gas tank

And the speed at which
a trail of gas burns.

And with that information,
it's full scale ahead.

But sh**ting the gas tank of a
car isn't exactly a safe option,

So adam builds a rig
for the back of an old pickup.

I'm gonna hang this gas tank
off the back of this truck

With a steel shield
between it and the pickup truck

So that I can experiment
with amounts of leaking fuel

Coming out of this,
igniting them,

And potentially blowing up
this gas tank

Without hurting the driver
of this truck while driving.

Narrator:
adam and jamie are all set,

So it's off to
the alameda naval base

To heat things up.

Ready, clear!

Is that your
defibrillator?

Yeah.

Hey, we've been here
before.

Yes, but the fans have
a couple more shocking myths

That they want
cleared up.

Get it?
"Shocking," "cleared."

Oh, we got it.
I'm pretty sure we got it.

Narrator:
last time the team said...

Everyone clear?

...grant built
his very own defibrillator

And then busted the myth that
medical nitroglycerine patches

Could give you a severe case
of blown up.

What do we got this time?

Bras and nipple rings.

You're a freak.

You might have to
explain this one.

Our unfortunate patient
in need of a jump start

Is either wearing
a metal underwire bra

Or has nipple piercings.

Oh, and the defibrillator
arcs to the metal,

And they get burned.

It's bad enough they're
having a heart attack.

Now they're gonna
get burned, too.

Well, we're gonna
find out.

Narrator:
so, the fans want to get

A pair of parables
off their chests,

And the first tale
the team is tackling is,

Will an emergency medical
procedure cause a bra burning,

Or is the brassiere
a benign bystander?

Using the same ballistic-gel
torso and homemade defibrillator

As last time,

Our intrepid trio
intend to find out.

Now, grant's heart-starter
may not look

Like the high-tech gizmo
you see on a medical drama,

But it is rigged to do
exactly the same job.

So, they have the equipment
and patient.

Now all they need is a 40aa bra.

Now, who'd wear a bra that size?

Apparently I am close to the
size of the ballistics dummy.

Therefore I have to go
and shop for a bra.

Once again,
making my family proud.

Narrator: a girl's got to do
what a girl's got to do.

Grant, however,
is there for fun.

I can't look.

I just don't know
if these express me.

I think I might want
another color.

Color is not really the issue
here, my friend. It's size.

We don't want it to cut into
the ballistics gel,

So may--

Maybe we'll get it
a little bit larger and, uh...

And go from there.

Is this as disturbing
as I think it is?

It's even more disturbing
than you think it is.

There's no doubt
it's disturbing.

There's also no doubt
we're going to show you more.

Yo, what up?

I can't get this thing on.

After a half an hour
of not-so wonderbras...

Need some help, big guy?

No, got it.
I'm becoming a pro.

...our odd couple
finally make a decision.

This is a fancy one.
Ooh!

I think that's our winner,
actually.

Fancy.

I think we got a winner.

Tory has liberated
his feminine side

And finally found
a bra that fits.

Wait a minute --
liberate, feminist, bra-burning?

So, speaking
of burning bras,

Have you ever heard the phrase
"bra burner"?

Actually, I have,

And the funny thing is
it's an urban legend.

The entire thing stems

From a story misreported
on a newscast.

Really?
Yeah.

In 1968 at the miss america
pageant, there was a protest.

The organizers wanted to burn
bras. Couldn't get a permit.

So, the whole thing
never happened

But everyone thinks
it did.

Hmm. Fascinating.

Well, let's get back
to the experiment.

Where's the bra?

Next, kari fits our patient
with the undergarment,

But despite her best attempt
to banish the thought,

She can't help wondering
what happened at the bra store.

You didn't take off
your shirt, did you?

No.
What are you, nuts?

[ Woman screams ]

All right,
do underwire bras conduct?

You got the defibrillator.

Yeah, we got it.
We're ready to charge.

Narrator:
okay, this is the scene.
Your heart has stopped.

We gonna do maximum,


Let's do it.

Narrator:
the medics in a hurry

Place their homemade
barbecue-tong defibrillator

In the recommended position

And prepare to deliver
a lifesaving shock.

In 3, 2, 1.

Clear.

[ Thud ]

Nothing.

We may have saved her life,
but we didn't burn her bra.

Narrator: clearly, no underwear
went up in flames,

So is the burning-bra myth
busted?

To give it
the best chance possible,

Do you want to open up the bra
so that the wire's exposed

And we can see
what's happening?

Sure -- maybe it was
a slightly older bra.

And the wire
was peeking out.

Narrator: so it's take two

With an unlikely but conceivable
set of circumstances.

In 3, 2, 1.

Clear.

[ Electricity crackles ]

Ooh, a spark flew.

Oh!

We got a burn!

Narrator: yep, the sparks fly,

And our unlucky patient
takes a hot hit.

Grant: so what this means
for the myth is,

If they have the paddles
in the wrong position

And you've got
a slightly older bra

With some of the metal exposed,

You could be in for a few burns
in your tender regions.

The bra didn't
burst into flames

As some of the stories
I'd heard,

But there's an obvious burn
on the skin.

So I'd say this one
is pretty plausible.

Well, we've created
the worst-case scenario
for this myth,

And still it's not looking
very plausible.

True.
But we actually found

A story of a woman
that this has happened to.

Yeah, but that was
over 20 years ago,

And that's back
when defibrillators

Were twice the power
they are now, at 600 joules.

But it did happen
and her bra did catch on fire,

And that's why you have
a bare torso now when
they need to defib you.

Well, 600 joules
would pack a punch,

And bra technology has advanced
quite a bit over the years.

Yeah. They're actually
a lot easier to take off now.

[ Gasps ]
how did you do that?!

Narrator:
since around the time

Jamie started going to
the movies in the early 1900s,

A blazing trail
of flammable fuel

Has been a hollywood staple.

No action hero's cv
would be complete

Without a lit fuse of gasoline
blowing up the bad guys.

On the trail
of this flammable fable,

Jamie and his partner
in flame, adam,

Have found that gasoline burns
in a contiguous line.

[ Laughs ]

And they know how much
and how quickly

Fuel leaks from a b*llet hole.

Adam: it's just over
three liters a minute.

Narrator: so, on location
at the alameda naval base,

It's time to take things up
a notch.

Kind of dark in here.

Maybe we need
to light a fire.

[ Laughs ]
you like it?

We got a sealed floor,
total control, no wind.

It's the perfect
experimental space,

And the fire department
says -- provisionally --

We can light
some gasoline in here.

I love it.

Yep, the sealed floor
and contained environment

Is perfect for...this myth.

Oh, no.

[ Laughs ]

Okay, let's get started
with work.

And it just gets better
because the next step involves

A perfect piece of jamie style
invention.

At this point, we've learned
what gasoline does

When you lay it out in a stream
and light it,

But we have yet to see
what happens

When it's coming out
of something that's moving,

Like a vehicle.

So I figure,
like we normally do,

We like to start out small
to see what we're dealing with,

And, therefore,
I've invented this thing

Which I call the firebug.

Narrator:
which -- let's face it --

Is a remote-controlled
fire hazard on wheels.

That's absolutely perfect.

Well, you want to just
start him running around,

And I'll light the back end
as it goes?

Yeah.

With a full squeezy bottle
of gas on board,

The firebug is ready.

Fire extinguisher.
I'm totally ready.

Narrator:
and by turning the nozzle down
to simulate a leaking gas tank,

Jamie is all set.

Okay, ready?

Yep.

The firebug takes off,

Leaving a perfect trail
of gasoline in its wake,

Which adam happily sets ablaze.

Here we go.

[ Laughs ]

Jamie: this little thing

Is about the coolest rc toy
that I've ever seen,

But it's extremely dangerous.

You can't do this at home.

You may have an rc car, some
gasoline, but you could die.

You could burn your house down.

This is the coolest
remote-controlled car

I've ever seen!

[ Laughs ]

Jamie:
we've got fire extinguishers
and e.m.t.s and everything.

We're prepared.

You're not.
Don't try it at home.

Narrator: really --
leave this one to the experts.

After all, who needs to make
that call to your parents,

Explaining you
just burned the house down?

That was awesome.
Okay.

That was actually
a pretty good test.

It told us a lot
of what we needed to know.

We wanted to know if we
could lay down a line of fuel

Out of a moving vehicle
and it would remain contiguous.

The answer is yes.

And it doesn't seem like
we need that much fuel,

So I think we're ready
to go full-scale.

We've learned
what we wanted to know,

Although jamie still seems to be
enjoying setting stuff on fire.

Narrator: full-scale it is,

And for that they need
firebug's big brother...

Say hello to the firebeast.

Narrator: ...the firebeast,

A truck with
a leaking-gas-tank attachment.

Don't expect to see one of these
in a showroom near you.

This is the patented
"mythbusters" 10-minute solution

For controlling the fuel
from the driver's seat.

Rather than a complex
solenoid-driven valve
or something like that,

It's a rope.

Pull on the rope...

Nozzle lifts above the level
of the fuel.

Let it go and it starts
to run out.

It's just that simple.

Narrator:
mythbuster ingenuity --

Also useful for time-saving
home inventions.

I use one of those
when I go to the bathroom.

I'm done.

So on this test,

Adam and jamie will get
a good feel for this movie myth.

They already know
a gas trail burns

Like it does in the movies.

They've got .44- and
.22-caliber-sized b*llet holes

In their gas tank,

And they've seen in small scale

A continuous gas trail
laid by a moving vehicle.

Hyah! I am the fire ninja.

Narrator: and you could say
adam is excited.

Ow.

Narrator: and sore.

Adam: so, our goal here
is just to find out

If the .22-caliber-size hole
or the .44-caliber hole

Leaves enough fuel
behind the truck

For the fire to follow,
right?

And at what speed it'll
sort of keep up with it.

So I'm just gonna listen
for your cues on the radio,

And you tell me to speed up
or slow down.

That's what I'll do.

Okay, start with a baseline
of five miles an hour,

A good, brisk run.

'Cause that seems to be
what we've been seeing --


For the fuel.

In this action-movie scenario,

Jamie's playing the part
of the escaping bad guy

With a .22-caliber b*llet hole
in his gas tank.

It's time to burn
for science.

Let's go.

And adam is standing in
for the hero

Who's going to light up
the gas trail

Jamie's leaving behind.

Jamie,
whenever you're ready,

Lower down the fuel
and start driving.

Jamie the villain
makes a run for it.

I'm lighting the fuel now.

You can slow down,
jamie.

It's moving quite slowly.

But there's no need to hurry.

[ Laughs ]

That's moving
really slowly.

Not exactly the high-speed
blazing trail of fire

We're used to seeing
on the silver screen.

Okay, yeah,
you can stop it.

Jamie:
I had to put my brakes on.

I wasn't giving it any fuel
to get it to go that slow.

I was just, like, idling
with my brakes half on.

You could pretty much
push a car

Faster
than gasoline burns.

Kind of sort of.

So does that put the brakes
on this myth?

Or will the .44-caliber-sized
hole make a difference?

Adam: my prediction is,

From what I saw
in the bunker test,

Volume didn't affect speed
that much.

Now, this is a much bigger test

Than we were able to do
in the bunker,

So this will be
pretty definitive,

But I don't think it's gonna
prove anything different

Narrator: jamie moves off,

Gently idling along
at less than five miles an hour,

Easily staying ahead
of the lit trail...

Adam:
it's looking good, jamie.

It's keeping pace with you
about 10 feet back.

Narrator:
...until adam has a lapse in
concentration on radio duties

And fails to warn jamie
the flames are gaining on him.

Faster! Faster! Faster!

Lift it up.

Jamie:
it was going along fine

Until it started to catch up
a little bit,

And all of a sudden,
adam's saying, "g*n it."

And I took off,
but it was too late.

It actually stayed with me,

And it caught up with the tank
and could have set it off.

Narrator: traveling at the
lower limit of the speedometer,

Jamie is unsure of his speed,

But it seems as though

The fresher the trail,
the faster it burns.

However, another run
to test that hypothesis

Is brought to an abrupt end
when jamie gets hemmed in.

Jamie:
guys, I'm gonna stop.

We're gonna start
to have crossover.

Narrator: as another band
of 'busters once said,

It's a bad idea
to cross the streams.

Pew, it stinks in here!

We're waiting for the smoke
to clear in there,

But provisionally, I'll say
the .44-caliber hole test

Was really educational,

Specifically noticing that

The closer the line of gas
got to the source,

I.e. The gas tank,

The faster the flame traveled.

And remember, it is not
the liquid gas that's burning.

It's the vapor gas
above the liquid,

So if it's had a long time to
settle, that vapor spreads out,

And it's got a lot of wind
resistance like a weather front.

But the closer it gets,
the faster it travels.

There may actually be
something to this.

That was pretty good
for a best-case scenario.

Yeah. You know,
expoxy-sealed floor,

No wind,
perfectly flat and smooth.

I think
we got to go outside next.

I think we do.
Let's come back tonight.

Okay.



Narrator: kari, grant,
and tory have burned their bra

And proved it's plausible

That underwired underwear
can be too hot to handle.

But the team have their eye
on another defibrillator myth.

So, this myth is about

Defibrillating somebody
who has nipple piercings.

They're metal, and
there's a possibility that,

When the paddles go to the skin
and they discharge,

That it could actually arc
to the metal in the piercing.

Narrator:
our ballistics-media torso

Is going through
a rebellious phase

And wants to upset his mom.

I'm pretty sure
this isn't how they do it.

A barbell in each nipple
should do it.

Kari:
this looks really weird.

You think?

Let's just -- yeah,
let's just do this one.

Like a well-oiled machine, our
trio of highly untrained medics

Prep the patient
and administer the shock.

Clear.

And just like the bra test,

With the paddles
in the recommended position,

There's no sign
of that mythical sparking.

But this time, they know exactly
how to replicate the results.

They're using 40 times the
voltage of a household socket

Real close
to a conductive metal object

In the left nipple
of the patient.

As electric six once said,
"danger, danger, high voltage."

Nipple piercing
defibrillation test

With the paddles
ridiculously close together

Touching the piercing.



Clear.

Tory: oh!

Ow!

That was a good one.
That was good.

The end of the piercing
is black,

Surrounded
by an indention

That took the coating
off of the piercing.

Whoa.

That seems like
it'd be enough to burn you.

Yeah, I think
the kind of heat

That would melt
the coating

Would definitely burn
your skin.

Narrator:
so, are the fans right?

Is this another
plausible result?

Okay, guys, what are we
calling this one?

That's a good question.

Well, we did get
some scorching

From arcing between
the defibrillator paddles.

But that's when the paddles
were practically touching.

During defibrillation,

There's no way
they would be that close.

And the metal of the underwire
bra would have to be exposed.

And medics are trained
to remove anything

That's gonna impede
that procedure anyway.

So we're calling this one
plausible?

Yeah,
but totally unlikely.

Almost impossible.

Narrator:
adam and jamie are no strangers

To testing tales
about blazing trails.

When they put hollywood
on trial,

They stubbed out the myth

That you can light up fuel
on the floor with a cigarette.

Adam: I'm rolling it
in the gasoline.

Nothing's happening.

But this time,

They're testing whether
the trail lit by g.i. Jamie

Will blow up
an escaping car's gas tank.

And for a definitive answer,

They've returned to the runway
at alameda.

This is perfect.

The sun is setting.
The wind's dying.

We got ideal
real-world conditions here.

And just as importantly,
it'll be dark soon,

Meaning they'll be able
to clearly see the flame.

First thing we're gonna do
is sort of a control.

We're gonna put
a .44-caliber-sized hole

In the tank.

Gasoline's gonna
come running out of the tank

As the truck is moving.

Narrator: remember,
the previous tests took place

On a sealed floor
out of the elements.

So this first test
is a control

To see if the lit trail
burns continuously

Just like it did indoors.

Adam, I can't see a thing
back there.

So I'm
totally in your hands

As far as what I'm doing
with this truck.

The first thing
I am gonna do

If I see the fire getting
too close to you

Is tell you to pull up
the nozzle.

Okay.

Okay?
Okay. Got it.

[ Engine turns over ]

Jamie at the start position
lowers the hose,

Letting the fuel spill out.

Adam: and go!

And adam, once again fanning
the flames of his pyromania,

Lights her up.

More, more, more.

More, more.

Good. Good speed.
Good speed.

And that's pretty much
all she wrote.

Adam:
for a real-world control,

That test went about as good
as I could have hoped.

Jamie drove
at a reasonable speed.

The fuel line he laid down
burned totally continuously.

What I'm looking for here

Is not whether or not the fuel
line would catch up to jamie.

It's really, actually,

Just whether or not
it'll burn in a single line.

And for a control,
couldn't have gone better.

Narrator:
a good control, but really,
it's a case of so far, so slow.

Jamie:
in the testing so far,

I've been driving so slowly

That it's not even registering
on the speedometer.

This next test, I'm gonna get
up to 20 miles an hour

Before I hit the starting line.

Right at the starting line,
I'll be dropping the hose,

Starting to leak fuel out,

And my guess is that
it's gonna be such a thin stream

That actually contacts
the pavement

That it's not gonna light
more than a few inches.

It is still
moving towards him.

Oh, but it's petering out.

Narrator: which means
the fleeing fugitive

Is free and clear.

That was interesting.

You did that perfectly.

The gas started
before the first two cones

And ended
after the second.

When I set it on fire,

It burned longer
than I thought it would --

Almost 100 feet --

And then
it just couldn't continue

And it petered out there.

You know, the gas
had already evaporated.

The line was too thin.
It wasn't gonna go.

And 20 miles an hour
isn't that fast.

No, not like
an action-movie car chase.

It would be a lot faster.

So it would only get worse
for this myth

At any speed above 20.

Not looking too good.
No, it's not.

Yep, if our villain takes off
at any kind of reasonable speed,

The trail simply burns out.

And although the fat lady
is preparing her tonsils,

Adam and jamie aren't ready
to call it.

After all,
there's two parts to this myth.

Even though we proved

That it is extremely unlikely
under most circumstances

For the line of burning gasoline
to get to the tank,

Now it's time to find out what
happens if it actually does.

We're removing the rubber hose.

We've got just a hole
sticking out of the gas tank.

We're gonna let the fire get
all the way to it.

And jamie will actually only be
crawling forward

To keep any fuel or fire

From getting to his truck side
of the metal shield.

Narrator:
adam, in full safety gear,
lights up the pool of fuel,

And jamie crawls forward,
letting the flame catch up.

Adam:
okay, it's reached the tank.

It's reached the tank.

It's burning up the line,
but it's not exploding yet.

Stay away from it.

It's just running out
and burning.

It's not in any danger
of getting under your tires.

Don't let
your guard down yet.

Don't worry.

Adam: that was not what I
expected out of that test.

You know, in every movie,

Every b*llet or cigarette
equals an exploding gas tank.

They seem to be
on hair triggers,

And in this case, we had gas
pouring out of a tank on fire

For about a good
six or seven minutes.

The wind started to whip up
the gasoline and the flames.

The flames got under the tank,
which heated it up,

And once they heated it up,
the air inside started expanding

And I started watching the gas
spewing out of the hole.

At that point,
the flames got so vigorous,

They engulfed
one of our cameras,

And I decided to pull the plug
and extinguish everything.

Move! Camera!
Let's put it out!

Despite being cooked to within
an inch of its digital life,

The camera came through
and got the shot.

[ Laughs ]

Jamie: well,
there's your problem.

Oh, that's awesome!

So, what do we do now?

Well, I think we're back to
our old friend and nemesis,

Air/fuel mixture.

I think we need to know

Exactly when we're
at the correct expl*sive limit.

And I think we do
whatever it takes to get that.

Let's pop off
those ports on top,

Let's get some air moving around
in there, put some gas in --

Do the same thing we did before
but we don't light it

Until we have a meter
that tells us

We're at the right
expl*sive limit.

And this time, let's take
the camera away from it.

I think so.

Narrator: in an attempt to get
that hollywood-style big boom,

Adam and jamie open up
several ports on the tank.

But why are they even necessary?

Gasoline or gasoline vapor
by itself is not exploding.

It needs a source of ignition,
and it needs air.

In fact, it needs
a very specific amount of air

For it to blow up.

That range
is above 1.4% vapor to air

Or below 7.6% vapor to air.

If it's outside that range,
it's not exploding.

If it's within that range
and it has a source of ignition,

It can blow up.

Now, we're gonna use
this meter here

To determine
what we've got in the tank

And whether we can get it
to the butter zone or not.

Narrator: so, the mix of air
and fuel vapor in the gas tank

Has to be just right.

In a vapor-rich environment,

There has to be
the right amount of air

To be in what's known
as the flammability band.

And in a contained environment
with an ignition source,

You're in prime territory
for an expl*si*n.

And to detect
that crucial air-to-fuel ratio,

The guys are using
a portable gas monitor.

It's going back and forth
between 4 and 4.5.

That's fantastic.

And so we're
right in the butter zone.

Awesome. Let's go.
Let's do it.

With the added throughflow,
the air/fuel mixture is perfect.

And we're about to find out...

Go ahead!

...if those spectacular
cinematic explosions

Are based on
real-world physics...

Careful, you guys.
Not too close.

...or simply movie magic.

Good. Stop.

It's burning in the tank.

But it's stubbornly
refusing to detonate.

Adam: the facts here
are pretty simple.

We were at 5%.

That is exactly the butter zone
we were looking for.

We got perfect ignition.

The test went really well, and
we did not get an expl*si*n.

Don't get me wrong --

If my car's on fire, I'm going
to be running away from it.

All I'm saying is,

The way movies look at gas tanks
and explosions is just wrong.

Hey, adam?

Yeah?

Should I just lay down some fire
and we call it a day?

Jamie: this is actually
really frustrating to look at,

Because if the tank is enclosed,

It very quickly goes above
the expl*sive limit.

If it's open like we had it,
then it's just burning.

It's just flame.
It's not an expl*si*n.

No expl*si*n!
That's a result.

How do you want to wrap up
vapor trail?

The flame did follow right
along that trail of gasoline

As it was laid down.

It went all the way up
to the tank.

But it went so slowly,
man.

Man, it would never catch up
to any car.

You could push a car faster
than that gasoline trail burned.

And once it got to the tank,
it no blow up!

I guess we got to
call it busted.

Busted it is.

Narrator: jamie and adam
have busted

The movie myth
that a blazing trail of gasoline

Will catch a car
and explode the gas tank,

But this fiery fable
is still alight.

I know it's a bit
of a segue,

But I don't feel like
we're all the way done

With hollywood pyrotechnics
just yet.

Why is that?

Because I've got another one
I want to try,

And it is an old cowboy myth
that involves gunpowder.

You mean where the bad guy
lays down the trail of gunpowder

That goes to the keg --

He lights it,
but the good guy rushes in

And puts out the flame
right before it reaches the keg?

It's like you're a mind reader
on something.

That's exactly it.

So it's trail blazers, part two.

But this movie myth
comes from way back yonder

When your average action scene
involved cowboys and gunpowder,

Not cars and gasoline.

[ Screaming ]

A lit trail of gunpowder
is heading for a powder keg,

And if it can't be stopped,
disaster.

But our hero saves the day

By leaping ahead
of the sparking fuse

And kicking out the trail.

Back in the bunker,
the team begin testing

To find out what would happen
in real life.

Adam: I don't think
this is gonna work.

The whole premise we're testing,

Which is, can a cowboy lay out
a line of black powder,

And if I saw it and
tried to kick out that powder

Before it got to something
it was gonna blow up,

Would I have enough time?

I don't think I would.

I think the black powder
is gonna burn too fast.

Every time we've ever noodled
with it on the show,

Its defining characteristic
is that it's superfast.

Narrator:
so, like the vapor trail,

Adam thinks this movie myth
is just another special effect.

My guess is,
it's gonna be less a "shh"

Than a "shaboom" kind of moment.

We'll see -- without the boom.

We're not adding in any boom
just yet.

This is all about the "shh."

Narrator: on site supervising,
it's pyrotechnician rob clot,

And he's got
the shaboom-making materials.

Adam:
this is black powder.

You can buy this
in most g*n shops,

And it's actually
the closest thing we have

To what would be period-correct
for a cowboy move.

It's what we've used when we
fired our civil w*r era musket,

When we fired
our period ammunition.

This is perfect for these tests.

Narrator: yep -- black powder
and the mythbusters go way back.

It's been particularly useful
for period realism

In a number of ballistic myths.

And as an added bonus,
it does this.

Man: fire!

Firing!


And seeing it's an integral part
of the show,

Let's find out some more.

We use black powder
in a lot of our experiments.

Yeah, black powder engine,
k*ller cigarette butts,

And salami rocket.

Do you know
who invented it?

The chinese, right?

Yeah, the chinese
were searching

For the secret
of eternal life.

And they somehow came up
with black powder.

Eternal life?
I did not know that.

Well, obviously they didn't
achieve eternal life,

And in fact,
they didn't even realize

That they'd created
a weapon.

They were using
black powder

On things like skin irritations,
like fungus.

[ Laughs ]

Now, that is
one skin treatment

I would not want to have
on my skin,

Standing close
to an open flame.

Regardless, I think we found
some uses for it.

Narrator: first up,
they're starting small --

A trail just a few feet long.

Adam:
I think that's great.

This is just to see
what it does.

Just to see how it feels.
Okay.

Narrator: to light it safely,

Adam has pulled out
all the stops to impress rob.

This is a standard industry
remote lighter.

This is your butane torch

On the end
of a couple tie straps

On some structural aluminum,

Providing some distance
between me and the flame

So I can light while I'm safely
away from the expl*si*n.

All right.

Everybody ready?

Here we go.

[ Laughs ]

That's a little too fast.

Narrator:
yep, and the myth that you could
run ahead of the burning fuse

Looks like it's
gone up in smoke already.

Jamie: gunpowder, by design,
burns very quickly.

When you have it inside a g*n,
it burns explosively quickly.

When we lay it out in a line,
it just burns fast.

Well, it behaved exactly the way
I thought it would behave.

In fact, you'll see that
the rating for this is "ffffg,"

Which is pretty much the sound
it made when we lit it,

And that's what it's based on.

What do you think
we do now?

I think we need
to come up

With a more controlled way
of laying down the powder --

Something very consistent --

And maybe
a little less of it.

Narrator:
jamie, basing his design on
an old-fashioned powder horn,

Soon has a solution,

And they're ready to see
how quickly

A 3-foot line of powder burns.

Wow, look at that.

That was really nice.
That was much slower.

It was like --
[ hissing ]

That was like
a really slow walk.

We found out that there is
no experiment too small

For us to be wrong about what
the results are gonna be.

I thought that,
if we laid out a line here

And it was fairly visible
black powder,

That it would go --
[ imitates expl*si*n ]

And just go really fast,

But in fact, it seems to burn
at a rate not unreasonably close

To what I'm used to remembering
in cowboy movies.

I'm starting to think

That if we laid out
a line of powder like this,

Maybe 20 feet long

With a, you know, keg at the end
that might blow up,

And I had a few seconds
to run over and kick this line

So it would stop igniting,

I might actually be able
to do that.

I figure I could outrun that
pretty easily.

If you want to try, I say
we get out to the b*mb range

And do it for real.

Okay.
Let's get out of here.

Narrator: alameda county
b*mb-disposal range,

Adam and jamie's second home.

Another day
at the b*mb range.

Narrator: and, as usual,
their hospitable host

Keeping them out of hospital
is sergeant j.d. Nelson.

The b*mb range
is the perfect location for us,

'Cause we can blow stuff up,

But it's a little bit rocky,
and it's dirt.

We want to be able to see
the black powder.

We're gonna lay out, basically,

A dance floor for dancing
with the black powder.

It's about 20-some-odd sheets
of plywood or chip board

That we're gonna lay out
in a line

Approximately


It should be plenty of a run
for our black-powder tests.

[ Whirring ]

Well, there you go.
Dance floor.

My dance card is empty.
Let's go!

Adam's job is to kick out
the line of burning powder

Before it reaches this.

Now, for safety reasons,

We're not gonna put any powder
in this.

We're not quite ready
for adam to blow up just yet.

Narrator: what jamie means is,

For safety reasons,
the keg will be empty.

But at the end of an 80-foot
trail of black powder,

Adam can't resist adding
a cupful of extra motivation.

I really would like to try it
first. Is that all right?

Yeah.
Okay, cool.

[ English accent ]
my motivation for this
is really, like, you know,

Humanity is going down
the wrong path.

That's the gunpowder line,

And I'm the only one
who can see that it's burning,

And I've got to kick it out
before it explodes.

Adam:
[ normal voice ] oh.



Here we go.

It's not that hard
to outrun it.

Here it comes!

[ Chuckles ]

I stopped it!

Look at that.

Here, light this one.

It's like a really brisk walk,
really.

Here it comes to the thing!
Boom!

[ Laughing ]

This is a fun job.

Well, I don't know about you,
but it seems to me

It doesn't move
as fast as I thought.

It's pretty easy to run down
a line of gunpowder

And kick it out
to stop it from blowing up.

You want
to give it a shot?

I'll give it a shot.
But you know what?

I want to wait till it gets
really far down there

And then see if I can catch up
with it and kick it out.

Okay, done.

Adam: put them on,
little feet.

The reason jamie's feet
are so small

Is that he escaped from
communist china in the '40s

Dressed as a woman
with bound feet.

They've never
gotten bigger again.

Ready to race some powder.

Adam, would you mind
laying the powder?

I'm just gonna
sort of relax.

And you can light it.
I got a good view.

Narrator: jamie's idea of racing
is pretty laid-back.

Powder-keg test
number two.

Grandpa hyneman
presiding.

Go!

Jamie, cool as a cucumber, gives
the fuse a good head start.

Of course, he's thinking
his only obstacle

Will be covering the ground
in time.

[ Laughs ]

Oh, it's still going!

Yeah, you --

[ Laughs ]

He pushed me
out of the way.

What the hell was that?

I was giving you
more of a challenge.

[ Both laugh ]

Jamie: we wanted to find out
whether it is possible

To outrun
a burning line of powder,

Break the line, and stop it
before it reaches the barrel

And blows up the barrel.

It turns out it is.

We did it.
It's not that hard, really.

Narrator: so the movie myth

That you can outrun a lit trail
of gunpowder is confirmed.

But the fun doesn't end there.

The fuse is still burning
on this fable.

Jamie,
despite unforeseen obstacles,

Is confident
that you can outrun and kick out

A burning fuse of gunpowder.

But the guys haven't quite
satisfied their big-boom quota.

Jamie: the next thing
we need to know is,

What would happen
if you were not successful?

Maybe somebody got in your way
or pushed you, you know,

Before you were able
to do your job.

Does the barrel blow up?

Will it run up the stream of
powder coming out of the barrel?

Are we gonna see
a big expl*si*n?

Narrator: it's a cartoon
caper classic.

The lit fuse of gunpowder
leads right to the powder keg,

And kablooey.

But would the barrel
really blow,

Or would the fuse
just fizzle out

When it reaches
the end of the line?

Go ahead and plug it in.

And to find out, they'll need
to light the powder remotely,

And our bright sparks
have just the thing.

Adam: it's a 20,000-volt
neon transformer.

I know that the electrical
resistance of air

Is roughly 10,000 volts
per centimeter,

Which means I only need to get
the two ends of this transformer

Within two centimeters
of each other

For that arc
to travel across them,

And it is the most ideal thing
to light the gunpowder.

[ Electricity crackles ]

Perfect.

Narrator:
next, with adam and jamie

Displaying
all the characteristics

Of kids who know
the ice-cream man is coming...

Yet another thing
to not try at home.

Narrator:
...fill the keg with powder

And lay down
the road to explode.

As soon as the line
gets here, shaboom!

At least in theory.

Narrator: it's a theory they
can't wait to put into practice.

Plus, there's a breeze

And a danger the black powder

Will soon be blowing
in the wind.

All right,
let's do this thing.

So it's double-time
down to the bunker.

I'm gonna count it down.
Tell me when you're set.

I am totally set now.

Okay,
going in 3, 2, 1.

[ Electricity crackles ]

There it goes.

Look at it go.

The trail is ablaze,
and just like in the movies,

It races
towards its destination.

Come on, little buddy.
Don't burn out!

Go, go, go, go!

A barrelful of big boom.

Go, go, go.

And...

[ Laughing ]

Yeah!

That was awesome!

That was the best expl*si*n
we've ever done!

I swear.

That was a serious bang.
Yeah.

Yeah, it took all its time
to get there.

It was like -- that's the way
I always expected it should be.

[ Laughs ]

Awesome.

Let's get an all-clear
and go inspect.

This is one cinematic
and cartoon cliché

That does exactly what it says
on the label.

Jamie: what happens when
a burning line of gunpowder

Reaches a keg
full of gunpowder?

Exactly what you think.

It's gonna blow up,
and that's what it did.

Each one of these expanded
a little bit.

And look at all the burn stripes
on the inside.

It's quite clear
what it did.

It blew out both ends.
It blew out the weakest part.

If you watch the show at all,
you know I like to live my life

Halfway like
an action-movie hero

And halfway like
a cartoon character,

And this expl*si*n satisfied

Both of those halves
of my personality.

I proclaim it my favorite-ever
"mythbusters" expl*si*n.

How are we gonna
call this one?

Let's go down the list
one by one.

The myth that you can light
a line of black powder,

And yet still someone
can outrun that line

As it's on fire
and kick it

And break its stream before
it gets to an expl*sive thing.

Perfectly plausible.

And that line
of black powder,

If it got all the way
to a powder keg full of powder,

Would it explode
that keg?

Absolutely...plausible.

I totally agree.
I think it's plausible.

I think we've done some
very good work here today.

Let's get out of here.
All right.

Guess what.

We've got another viewer special
coming up.

So if you've got an idea

For a myth
you'd like to see us test,

Log on
to discovery.com/mythbusters

And post it.

We want to hear
what you've got to say,

And it just might
make it on the air.