Original subtitles

Please don't try anything you're about to see at home.

We're what you call experts.

Narrator: On this episode of "mythbusters"...

Oh! Nice.

Adam and Jamie have a "data" with destiny.

I am totally psyched about numbers!

They're testing the myth

that during an underwater explosion...

Boom.

Lying prone on the surface

will increase your chances of survival.

Whoa! Look how high that went!

Then... Cue the gong.

[ Gong resonates ]

Narrator: Kari, Grant, and Tory tackle an ancient armor saga.

[ Grunts ]

Ooh. I felt that one.

Is the farfetched theory that paper armor...

What? You couldn't find me a giant pair of scissors

to run with?

Protects as well as steel...

Now, that is one dangerous-looking machine.

Fact or Pulp Fiction?

[ Groans ]

Who are the mythbusters?

Adam savage. Come on! Let's go!

Here comes chaos.

And Jamie hyneman.

Relax. This won't hurt a bit.

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

Joining them...

Kari Byron...

This should be fun.

Tory belleci...

[ Laughing ] We survived!

And Grant imahara.

Start the car!

They don't just tell the myths.

They put them to the test.

Captions by vitac... www.Vitac.Com

captions paid for by discovery communications

check this out.

Navy divers who find themselves in the water

when an explosion, like a depth charge

or something, is supposed to go off underwater,

are instructed specifically

that the safest position for them to be in,

in the case of an underwater explosion

is flat on their back on the surface

and that that's significantly safer

even than treading water in an upright position.

Hmm. That's interesting.

You wouldn't think there'd be any difference at all.

You wouldn't.

And that's why i think it's something that we should test.

I'm up for it.

Navy seals... and walruses...

Are advised that if in danger of a depth-charged disaster,

their best chance of survival is to float on the surface

rather than treading water or diving down.

But would it really make a difference?

Adam, Jamie, and the bomb squad are prime to find out.

Ultimately, of course,

i foresee a large-scale quarry lake,

big explosions, very cool high-speed shots.

But where do we begin?

Well, let's say we start with some underwater shock-wave testing

here in the shop and see if we can collect some data,

see if there are any problems,

see if there's anything to the myth.

Sure. This shouldn't be that hard.

Okay.

We're gonna need three things... A tank full of water,

an explosion,

and a means of measuring the shock wave.

Narrator: It sounds deceptively simple,

but setting off and measuring underwater explosions

in the shop

is anything but simple.

What are you thinking?

I'm thinking this requires a brainstorming sequence...

Got a long, narrow tube.

With an inevitable tense discussion...

It would fail catastrophically.

Obligatory technical jargon...

15 p.S.I.

Equidistant from the sensors.

Blast pressure.

Seven p.S.I..

That could work.

And after a final audio crossfade or two...

And we create our shock wave.

So I'm just going to draw it.

And we got sensors.

There's a resolute conclusion signaling a solution.

I think that seems like a plan.

I think so.

This here is our tank... 15 feet tall.

It's gonna hold 1,300 pounds of water.

Inside that tank,

we will place four shock sensors.

I will detonate a pistol dead center in the tank.

That pistol will generate a shock wave

that will travel up and down through the tank.

If depth plays no role

in the propagation of a shock wave underwater,

we should see an identical reading

between sensors "b" and "c"

because they are each the same distance from

the source of the shock wave.

If depth does play a significant factor

in the force of a shock wave underwater,

then we should see a difference

in the force measured by these two sensors,

and that's where this story gets really interesting.

Narrator: But it gets interesting before that,

because Jamie has an ingenious plan of a tank.

We're gonna need a very tall, narrow tank for this test.

Now, we built one of these before

for firing bullets into water.

But let's just say there was a serious problem with that one.

Narrator: Ah-ha.

Water is heavy,

and keeping it contained is a tricky task.

[ Shouts ]

Oh, criminy.

Jamie: Now, with that in mind,

I've come up with an entirely new way

of building a tank that we've never tried before.

It uses very thick vinyl.

Well, that ought to do it.

You're off.

Another six inches? It's in.

Adam: In a few minutes,

we're about to fill that tube with 1,300 pounds of water.

Will it hold?

I can't detect any leaks.

I hope so.

Narrator: So does Jamie,

because nothing scares the hyneman more

than a mess in potentia.

It's terrifying.

Quit yanking on it.

With the tank holding, they're about to tempt fate

by introducing the explosive ingredient.

The role of our shock producer in the small-scale test

will be played by this... A .357 Magnum pistol,

to which I'm going to make some modifications

so we can fire it remotely and underwater.

Okay, kari, what do you got for us?

I've got a historical myth, and i love this one.

Now, in ancient times, even up to the 1800s,

some armies in China

actually made armor out of paper.

Tory: Paper armor? That is cool.

Paper's the last thing you would think of to make armor.

I like this one.

And the cool thing is,

the paper was supposed to perform as well as steel.

Paper armor performing as well as steel armor?

I'd like to see that.

That's why i want to test it.

Narrator: Throughout history,

material science has been at the cutting edge

of advancements in armor.

But is it really possible

that the ancient Chinese manufactured paper armor

capable of performing as well

as its contemporary steel equivalent?

To find out, kari, Grant, and Tory

are arming themselves with the facts and then the armor.

Well, first up, I'd like to do some research,

talk to an expert,

find out how the paper armor was possibly made

and what the steel counterpart would be.

Yeah. I mean, when we think of steel,

we think of medieval armor like this.

But Chinese steel armor of the period

may not have been like this at all.

So, it sounds like we're gonna need

to get some steel armor of the period

and make ourselves some paper armor.

Then we'll run them through some tests

and see how the paper compares to the steel.

I'm looking forward to this.

For our paper-armor myth, I've come up to the napa valley

so that i can talk to Greg Martin.

Now, he's an antique arms and armor expert.

Hopefully he'll have a little insight for me.

Narrator: And his first interesting insight

is that the existence of paper armor

is no myth at all.

Historically, paper armor is traced back

to the tang dynasty in 600 b.C.

And, of course, the Chinese

were very big developers of paper.

So it would stand to reason

that paper armor would develop there.

Kari: So, how would paper armor likely have been constructed?

By using what we call lamellar paper

was laminated together into squares

and then attached piece by piece

and then would cover the entire body.

Narrator: So, lamellar paper armor

really was used in ancient China.

There are records

of multiple manufacturing methods and designs.

But the myth is

that it was as effective as the steel armor of its day...

An outrageous claim.

And the team is skeptical,

but there is some cause for hope.

Now, we know from historical sources

that they used a mulberry paper.

Look at this. You can see the fibers.

This is strong stuff.

What they would do is,

they would stack layers of it together,

and that was enough to stop arrows.

Now, one source told us

that they would take these layers of paper

and laminate it with resin or some kind of shellac

or even glue.

Another source says

that they would cover it with a cotton cloth

and sew around the edges.

What we're going to do is, we're gonna take all those techniques,

find out which works best.

Once we have that,

then we'll be able to put that up against steel

and see which one does better.

And to test our armor pieces, we're going to use this.

Ow.

This is a sharpened tip

on the end of a pneumatic cylinder.

Here we have a chunk of ballistics material.

Put each sample underneath,

and then we'll fire the cylinder like this...

And see how each sample performs as a result of the puncture.

And the best one will go on to make our final armor pieces.

Kari: This is folded paper with cotton.

Narrator: So, the goal is to compare the range

of historically accurate manufacturing methods.

One.

Wow, look at that. It actually stopped it.

Narrator: And decide which

will give the steel the best run for its money.

Each paper piece, regardless of its construction method,

is one-half-inch thick,

a dimension discovered in the research.

Lacquer made it more brittle,

and it actually went all the way through.

Narrator: And although the shellac, an organic resin,

may double up as an effective weapon...

[ Both laugh ]

Kari: That actually stuck!

Narrator: The result that emerges

is that hardened squares like lacquer

lack the penetrative protection of the winning sample.

Okay. And folded paper.

Whoa!

Oh, my god. Look at how well that worked.

This absolutely works the best.

Simplicity.

Now that we've found our winning paper construction,

which is simply folded-up paper,

it's time to put it up against steel.

So, we are gonna be putting both of these materials

against common weapons of the time.

We're gonna be doing blunt force,

some kind of a club or a mace,

a sword, and then finally, an arrow

and see which one performs the best.

Narrator: Later, in-depth-charge disaster.

Narrator: Adam and Jamie have a "data" with destiny.

But first...

Now, that is one dangerous-looking machine.

It's steel, paper, sword.

Narrator: Our trio of mythbusters

have a martial mystery from oriental history.

Supposedly, as a material for making armor,

paper matches steel.

Hah!

So far, the team has discovered

that of all the historically recorded

manufacturing techniques,

simple folded squares provide the most protection.

This absolutely works the best.

Narrator: But they're still skeptical

of paper's ability to match steel.

So, before they go all out

and build a full suit of paper armor,

paper will have to prove itself

in an, uh, authentic setting.

Greetings, friends.

Though this looks like

an entirely authentic tang dynasty household,

it is, in fact, the best reproduction

we could come up with for under $10.

Cue the gong.

[ Gong resonates ]

Narrator: And here's how this proof of concept will work.

Paper will go up against steel in a series of weapons tests.

And if the damage to a Clay block beneath

is reasonably comparable,

only then will they move on to a full-scale testing

with full suits of armor.

Now, the way we're choosing our thickness of armor is,

we have done some research,

and lamellar armor was about 1/32 of an inch of steel.

As far as paper armor goes,

we found out that it was about a half-inch thick.

And the half-inch thick equals about 28 sheets of the paper.

Narrator: To get things rolling,

Grant wheels out a familiar robotic swinger.

Calibrated to human swinging speeds...

That's 125 miles per hour

for the data divas out there...

She's ready for weapon number one.

Grant: So, for our blunt-force-trauma test,

we're gonna use this.

This is a reproduction of an ancient Chinese weapon

called a chúi. [ Chewbacca growl sounds ]

That's gonna do some damage, isn't it?

Hopefully.

Narrator: First up for a taste of the mace

is the steel control,

the material the mythical paper armor has to match.

Trauma test in three, two, one.

Grant: Wow. That did really well.

Narrator: Yep, the Clay indentation is slight

and shallow.

But now for the all-important comparison.

Grant: All right.

Let's see how paper armor can do.

Okay. This is the trauma test.

Oh. That did not look good.

That looks like it would hurt.

Narrator: And a look at the side-by-side impressions

only enforces the impression

that this myth belongs in the waste-paper bin.

I'd rather be wearing steel at this point.

Right.

I think the steel wins in this situation.

Narrator: But there are two more chances

to find out if paper cuts it as armor.

I think i just cut my eyebrow.

First, the sword.

Now, that is one dangerous-looking machine.

And just for reference, let's first see

what the sword does to the unprotected Clay.

Ouch.

[ Laughs ]

All right.

So, it looks like it went in about an inch.

Narrator: Now for the cold, hard steel.

In three, two, one.

Oh! [ Laughs ]

Tory: All right.

Do you see here, the sword hit the steel armor,

and it put a dent in the Clay,

but it didn't actually cut through,

wounding the person.

So, now what we're gonna do

is we're gonna switch out the steel armor

for the paper armor

and see what kind of damage it does on the Clay.

Ooh.

Wow.

Narrator: The result is astonishing.

The damage is minimal.

It's similar to the steel at a vast improvement

on the inch-deep slice

experienced by the unprotected Clay.

It only cut, like. Maybe two or three layers.

Tory: That is crazy.

[ Laughs ]

Paper for armor?

It could work.

I'm impressed. It's looking great.

Narrator: Which brings us

to the third and final weapons test... the arrow.

Grant: Oh!

Kari: Oh, it bounced back.

Let's see how far it went in.

That's it. That's it.

That is less than a quarter of an inch.

Narrator: So, paper has one final chance

to prove its mettle against the metal.

In three, two, one.

Narrator: And hold on to your skeptic's hat,

because despite the arrow's penetration

into the paper,

the Clay beneath survived better than it did against the steel.

Kari: Huh.

Wow. Look at that.

Well, i think the arrow went deeper on the steel armor.

Narrator: Yep. It's concept proven.

The paper more or less matched the metal.

And this myth can move on.

To best avoid injury from an underwater depth charge,

would it really make a difference

lying supine on the surface?

Intent on investigating,

Adam and Jamie will set off an underwater shock wave

and measure it at various depths.

This is my finished shock wave-producing,

remote-firing pistol.

It will fire only blank rounds

because i have put a little shock-wave disperser in

so that it disperses the shock wave

both exactly up and exactly down.

I put a blank round in it, cock it,

and then from above the water,

i can fire it,

generating the shock wave we need for instrumentation.

Narrator: To measure the shock wave

from the handgun blank

is the final item on Jamie's list...

Four pressure sensors held in place by magnets.

Here we go.

Hey! It worked!

So, what's the water tube gonna tell us after this test?

Are we gonna get a much higher blast pressure here than here?

It's an interesting question

because the pressure here

is already at 4.2 pounds per square inch.

Up here, it's only two pounds per square inch.

And that's just from the weight of the water.

It feels like a bank heist.

So, that combined with the explosion, i think,

is gonna inherently give us a higher blast pressure down there.

But will that equate to death while treading water

while life while lying flat on your back?

I don't think so.

Okay, we're hot.

Jamie: The question we're trying to answer here

is whether there's some feature to do with depth underwater

and the associated pressures.

The greater the depth, the more intense the shock wave.

That is perfect.

The shallower the depth,

the less intense the shock wave and the safer you'll be.

What do i think?

I don't think there's gonna be much of a difference.

Narrator: So, both mythbusters are skeptical,

but science is an evidence-based discipline.

This is depth-charge disaster... Small-scale test.

Hopefully not making me too wet.

In three, two, one.

[ Gunshot ]

Nice.

Narrator: Well, the sensors did register a result,

and the tank didn't spring a leak,

but a close look reveals the numbers aren't ideal.

So, what did we get?

Well, it's looking awfully noisy,

but we're getting some interesting numbers.

Jamie: Unfortunately, the close proximity

of the walls of the tank to the explosion

is affecting those pressure waves

and creating noise,

which is obscuring the measurements

that we're looking for.

Narrator: That noise, the reflected shock waves

bouncing around in the narrow tank...

Is it still noisy?

Means the peak pressure wave for each individual sensor

is difficult to determine.

Let's run it again.

But three bangs later,

and they have enough data points for a pattern to emerge.

Adam: All right, kids.

Put down your juice boxes and pay attention.

It's time for the moment you've been waiting for.

It's time to interpret the numbers.

Remember that if there was anything to this story at all,

if depth did play a factor

in increasing the force of a shock wave,

we should see that the deeper sensors

would give us a higher reading than the shallower sensors

at the same distance.

And that is what we're seeing.

In every one of our tests,

the sensor-three readings are higher

than the sensor-two readings.

The sensor-four readings are higher

than the sensor-one readings.

That tells me at least that in small scale,

there might just be something to this story.

So, paper armor has potential.

I think it might be time for us to go full scale.

Let's make armor out of paper

and put it up against steel in a series of challenges.

I love it. We'll put each of the armor on

and then run through a series of tests.

Maybe we'll test speed, agility, and endurance.

And we'll have to have some kind of ultimate battle

between the two suits.

Not wearing them, of course.

Pick a number.

Narrator: So, cue the full-scale monumental mission...

You're a dork.

Narrator: To make a full suit of paper armor...

Only 850 to go.

Narrator: And the less taxing task

of having a real steel one delivered.

Grant: So, to put our paper armor to the test,

we're going to pit it against a metal suit of armor

from the same period.

Now, because this is hard to make,

we ordered it from a modern armory company

in the Ukraine.

And it's battle ready.

Hah! Who wants some?

I also do parties.

Narrator: Uh, meanwhile,

Tory gets busy pulling the paper-armor design together,

a design based on these ancient drawings

and Grant's period-accurate steel replica.

Now, if you look at the steel armor,

the scales have holes drilled into them,

and they're tied together with leather straps.

Plus, they are overlapping.

That way there are no gaps in the armor.

I think we need to do the exact same thing...

Take our paper scales, drill some holes into them,

overlap them, and tie them together with cotton cord.

Narrator: Producing this season's hot, new paper armor is a huge job.

So the mythbusters' sweatshop is open for business.

And after a week's hard work,

hundreds of lamellar plates have been sewn together

to form a full suit of armor

that, after some minor tailoring,

will be ready to go into battle.

[ As Tim gunn] Oh, kari, i just don't know about this paper motif.

I don't know if the judges are really gonna like it or not.

Oh, well. Make it work.

Narrator: The question is, will it work as well as steel?

To find out,

the team is signing up for basic battle training.

Aah! Hang tough!

Now that we have our full suits of armor made,

it's time to put them to the test.

We're gonna put our suits head to head

in the types of things that you would find in battle...

Namely speed, agility..

[ Laughs ] And endurance.

[ Crack ]

Oh, my back.

Narrator: First event in the armor Olympics

is the 50-yard sprint with sword.

What? You couldn't find me a giant pair of scissors

to run with?

Well, you will be wearing a suit of armor,

this season's must-have safety gear.

Here on "mythbusters," we are making science...

Hah!

Cool?

Hah!

So, I'm about to take my speed run in the paper armor.

All right. This is sprinting in paper armor.

Are you ready?

And i have to say, i do think that the paper armor

is gonna encumber me a little bit

just because I've got the armor

right down here where my legs are.

Here we go.

On your mark, get set...

We'll see how i do.

[ Gunshot ]

Aah!

[ Beep ]

Narrator: So, eight seconds is the benchmark.

And although the paper is undoubtedly bulkier,

the steel is twice as heavy.

Meanwhile, Tory,

looking for revenge for past transgressions...

Ooh!

Narrator: Fails to dent Grant's defenses.

You call that a kick?

Let's do this.

Now, to make sure that Grant is testing these armors fairly,

we're gonna let him rest in between tests,

so that way he has full energy for each of the runs.

Kind of reminds me of "raiders of the lost ark."

[ Gunshot ]

[ Screams ]

On your marks, get set...

[ Gunshot ]

Grant: I have to say, I'm really surprised

at how little a difference there is

between the paper and the steel armor.

I can't believe there's only a second difference.

Narrator: Yep, the bulkier, more restrictive paper armor

performed fractionally better.

But with so little in it,

conclusions can't be drawn just yet.

Cue test two.

Tory: Now, for the endurance part of this test,

i will be running a mile through these hills

and then ending up on that side of the moat

at which point I'll try to jump up onto the rope...

[ Groans ]

and cross over.

Narrator: So, that's the course.

Yes! Go!

Narrator: Now for the time trial in paper.

I don't know if I'm gonna have the energy to fight when i get there.

Narrator: With the armor weighing in at close to 30 pounds,

it's tough going.

Tory: Now, the running wasn't so bad in the paper armor.

I mean, it is awkward. You have all this bulk on you.

I even tore part of the paper.

But climbing over the rope...

I'm getting too old for this.

I thought i had it.

But about midway there,

my legs fell off the rope.

Once i lost my legs...

Kari: Can you pull yourself back up?

Oh!

I knew that was it, i was going in.

Grant: [ Laughs ]

Oh [Bleep]

[ Laughs ]

Narrator: Bleep, indeed,

because paper and water don't necessarily mix.

But luckily, it has a chance to dry out overnight.

Whether it will retain its structural integrity

for the test to come is another matter.

And speaking of tests to come,

Tory's time to beat tomorrow while wearing steel

is just short of 12 minutes.

Boom.

Coming up on "mythbusters,"

we replace this cardboard boom with the real McCoy.

Please don't try what you're about to see at home.

We're what you call experts.

Yeah!

Whoo!

So, where do we stand?

Well, our data's a little noisy,

but it does seem to be supporting

the central tenet of this myth,

which is that depth does seem to be a factor

in increasing shock wave strength.

Yeah, but the data's just too noisy.

I don't trust it.

I think we need to go full scale.

To a quarry lake?

Could be. Done.

Oh, look at you.

Aren't you Mr. television?

Come on. Let's get to work.

[ Laughs ]

Jamie: To test this story,

we're gonna set off a series of explosions

15 feet underwater and measure them with sensors

placed at different depths nearby.

Ha-ha!

I claim this shore in the name of "mythbusters"

and science in general.

Now, for all this to be accurate,

we need to be able to locate the explosives

and the sensors in a precise orientation to each other.

Oh!

Oh! Oh!

What'd you let it go for?

[ Chuckles ]

I didn't realize it would pull so hard.

To pull that off,

we're gonna use a variety of ropes and anchors.

All right. That's our sensor-array buoy.

Narrator: The sensor array with its pcb sensors

at five different depths

will be positioned at three distances

from the site of the explosion.

And that spread of 15 data points

is designed to answer the question

how best to survive a depth-charge disaster.

And with the lake rigged

with all the relevant anchors and buoys,

the bomb boys arrive.

Now, whenever we use explosives, we bring in the professionals,

retired FBI special agent frank Doyle

and the calaveras county bomb squad.

Narrator: Sporting a look available

at www.Shadesanduniforms.Bomb,

these are the guys

that will make sure all three big booms happen safely.

Meanwhile, Adam, with his sensitive mast,

is focusing on data acquisition.

This is my sensor mast.

These five devices are my sensors.

In a few minutes, I'm gonna join them all together

and put them in the water to make the largest piece

of data-gathering scientific equipment

we have yet built and used in the history of the show.

Narrator: That's no exaggeration.

Attached to a floating rig

will be five high-tech pressure transducers

at five different depths

all linked to a central command center.

Let's talk about the constants and variables

in this experiment.

As far as the constants go, we're always gonna be using tnt.

We're gonna be using 10 pounds, which is five of these things,

and they're gonna be hanging

at 15 feet below the surface of the water

where the explosion will occur.

Boom.

Also a constant are the sensors.

They're gonna be placed at five different depths

both above and below water,

and they'll be the same for every blast.

I feel safer already.

As far as variables, there's only one,

and that's the distance of the sensor array

from the explosion.

Now, we're gonna start at 150 feet away

and move progressively closer,

recording the readings that we get off the sensors

at each stage.

Hey, look, that's working beautifully.

Adam: All right. How are we gonna use our sensors

to represent a body lying flat on its back

versus a body treading water?

Here's what we're thinking.

We determined that the torso

of a person lying flat on their back on the surface

has an average depth of about six inches.

We also determined

that the torso of a person treading water

has an average depth of about two feet.

Why the torso?

Well, 'cause that's where the air pockets are.

Thus, that's where our sensors are going.

Narrator: Yep, it's a gruesome but important detail.

Injuries from underwater explosions

are primarily caused

when shock waves pass through internal air cavities,

such as the lungs and intestines,

hence the focus on the depth of the torso.

10 pounds of underwater fun.

Adam: Well, everything's prepped.

Yep. Nothing left but an explosion.

Unfortunately, you're gonna have to wait for that explosion

for these commercial messages

and perhaps some other mythbusters.

Narrator: Tory is rested, ready, and looking not so hot.

You know what?

This thing will protect me from arrows and getting dates.

Kari: Come on, Tory! You can do it!

Grant: Go!

Narrator: The question is, how will Tory's time in steel

compare to the 12-minute paper run?

And will he even survive?

Kari: You know, there's actually a little jeopardy to this test

because first of all, the run is gonna be really hard.

It's gonna be slow. That thing is heavy.

[ Breathlessly ] This sucks big time.

Kari: But climbing this rope over this water,

he's wearing 60 pounds of steel.

He goes into the drink, that's six feet deep.

Grant: Pick up the legs.

[ Groans ]

There's no way you're making it across that rope.

I don't think I'm gonna make it.

Somebody stick a spear in me.

I'm done.

Narrator: The weight of the steel was the killer.

Tory took an additional five minutes to complete the run

and then couldn't climb the rope.

So an army traveling any kind of distance on foot

would be at a distinct disadvantage

in the heavier steel,

which means paper wins that round.

For the final event in the armor Olympics, agility,

courtesy of some time-bending editing,

kari will simultaneously tackle the assault course

in steel and paper.

After drying out overnight,

the paper doesn't appear to have suffered any damage.

But it's still just as awkward.

It's definitely not as heavy as the steel armor.

Not a lot of give here.

Okay. Here we go.

In three, two, one.

[ Whistles ]

[ Clock ticking ]

Grant: Go, go, go! Pick up those feet!

Pick up those feet!

Narrator: On the first obstacle,

the paper already has an advantage.

Wow!

Narrator: The weight difference is clearly the key factor.

Halfway into the course

and paper-clad kari has already opened up a big lead.

Come on, Byron!

Go, go, go, go, go, go!

And while crawling,

the paper may well be slowing kari down.

Uh-oh, she's having a little trouble

with the sand pit.

But the steel almost brings her to a halt.

[ Grunts ]

The paper's in the way!

Narrator: Which pretty much sums it up

for the rest of the agility course.

The paper may be awkward,

but the weight of the steel seals the deal.

[ Bleep ] Good work.

Narrator: So with the first three events in the armor Olympics complete,

the conclusion is clear.

Paper is outperforming steel.

But now is the real test... The battle test.

We're going to use weapons from the period

and see if it can still stand up to metal.

Adam: Welcome back.

Let me walk you through our setup.

Out there in the middle of the lake tied to a buoy,

we've got 10 pounds of explosives

floating 15 feet below the surface.

Oh, it does nicely. Great.

150 feet away from our explosives,

we have our sensor mast

with five sensors that detect shock waves mounted to it,

one above the water

and four below at the following depths.

One at six inches below the water...

This simulates someone lying flat on their back

at the surface of the water,

one two feet under the water...

This simulates our person who is treading water,

one 15 feet below the surface

at the exact level of the explosives,

and one deeper than the explosives

mounted all the way down 25 feet below the water's surface.

Each explosion will cause movement in the sensors,

which will be translated into electrical energy

which will be sent as data through these wires.

That data will find its final resting place

here in the equipment manned by David Harding,

who will crunch our numbers.

After three blasts, we'll end up with 15 data points

and hopefully the answer to our question.

Now, normally we would do something like

set off a blast, look at the data,

set off another blast, look at the data.

I think we're good to go, huh?

In this case, we're not gonna do that.

We're gonna set off all three of our blasts

in as short a period of time as possible.

Fire in the hole!

We're doing this for two reasons...

One, so that the condition the explosions happen under

is really, really similar.

That makes our data much more consistent.

Fire in the hole!

The second reason is,

the numbers we're gonna be looking at

might be quite subtle,

and only by correlating across all three blasts

are we gonna be sure

that we're telling a proper story.

Narrator: Here we go for data acquisition stage one...

Or the first big boom of the day.

150 feet.

In three, two, one.

Oh, yeah.

Jamie: Wow!

That was a hell of a thud.

I felt that.

That blast was really unexpectedly cool.

It had three distinct kind of "whomps" to it.

Like a "whomp! Whomp! Whomp!"

Very cool.

Oh, look at that. That is just lovely.

And I'm always astonished by how fast the shock wave moves.

Jamie: Yeah, it's done and gone

before you actually see anything happen.

You think this is all the explosion.

That's way after. That's the aftermath.

Blast one went off perfectly,

and David says we got good data from all the sensors.

We are going to withhold looking at them for now.

We're gonna go right into blast two from 70 feet.

Okay. That ought to do it.

Firing in three, two, one.

Oh!

Whoa! Look how high that went!

Wow! Jamie: All right.

Well, let's go look at the high-speed.

Jamie: So, what actually happens during an underwater explosion?

Well, the explosion creates a rapidly expanding gas bubble

that pushes water in front of it,

and that creates a pressure wave.

It's that pressure wave that we're looking at

because that is what could potentially hurt a human.

Narrator: But the question is,

does that hurt potential and your very survival

depend on a difference in depth?

This is truly awesome.

It's pretty.

To answer that,

the race is on for numbers

and the third and final data point.

David says we've got good data from the first two blasts.

Shall we prep for the last one?

Great. I'll set it up.

All right.

Want to know why we did what we did

and didn't do what we didn't do?

Check out the after show.

Log on to discovery. Com/ mythbustersaftershow.

Narrator: As incredible as it sounds,

paper armor is holding up

against its contemporary steel equivalent.

But the team has yet to put

paper in front of the firing squad.

Good work.

Tory: So, now that both steel and paper armor

have passed through the agility test,

it is time to see how well they protect

under a full-scale attack.

What we are gonna do is set up some mannequins...

Grim up.

This is gonna get dangerous.

Cover those mannequins with both armors,

and then attack them on a full scale

with swords, arrows, and even an ancient gun.

Then we'll be able to find out once and for all,

is paper armor as good as steel armor?

Narrator: But perhaps paper's biggest test

will come not from our trio of weapon-wielding barbarians

but a second soaking,

this time from the heavens.

Or more accurately,

the condensation of atmospheric water vapor.

The rain may indeed weaken the paper and favor the steel,

but it's a real-world problem.

If paper is to prove itself as protective armor,

it'll have to cope with a light shower.

Kari: We're all set.

Now we're gonna start with the arrow test

and just throw a barrage of arrows at them.

Remember the hwacha?

Hwacha!

We're gonna hwacha them.

So "hwacha" this.

Narrator: And so, the barrage begins.

Kari, Tory, and Grant let loose from 20 feet

at both sets of armor.

And despite being soaked, softened, and sodden,

the paper protects our male-model mannequins

as well as the steel does.

Grant: [ Laughs ]

Tory: Totally worked!

That is phenomenal!

That totally worked!

Tory: The paper armor is stopping the arrows.

We have not gotten one arrow to penetrate through.

I mean, it doesn't look as good as the steel armor,

but the important thing is, it's working.

Next up, the sword test...

Slicing, dicing, jabbing, stabbing.

I'm just gonna go and try to maim those guys.

Kari, just swing wildly.

Narrator: Using both an edge-slicing stroke...

[ Grunts ]

and a stabbing action...

Ooh, i felt that one.

Kari finds the dial marked "crazy" and turns it up to 11.

Kari: I'll tell you one thing.

It's interesting the sounds you make when you're attacking.

I didn't actually mean to verbalize all the "aah!"

[ Grunting ]

[ Laughs ]

Working out some issues there?

I'm gonna get myself a stabbing mannequin for home

'cause it's really a good way to work out aggression.

Narrator: And speaking of aggression,

where does that leave the mannequins and the myth?

It looks like it's separated through,

but it's stopping

before it even gets halfway through the tile.

That's great. Wow.

Narrator: Yes, the paper armor is working.

On any individual stab, slice, or arrow shot,

a previously undamaged scale clearly matches the metal.

But Tory sees a key armor attribute

where steel trumps paper.

Now, right now, the paper armor is stopping the sword attacks

just like the steel armor.

However, after multiple attacks,

the paper armor starts to break down.

It's looking like the steel armor

is a lot more durable.

Next weapon.

Narrator: And this is where we surely draw the line on paper,

because gunpowder has just been invented.

Grant: Okay, Greg.

So, for our experiment, we need a firearm

that would have been of the era of paper armor.

What do you have?

Well, if paper armor was used up to the 19th century,

let's try something from the 18th century,

which is this French flintlock pistol

from about 1750.

Okay. Let's do it.

And first up facing the flintlock is the metal.

Kari: Whoa!

Tory: Nice shot!

Followed by its fibrous friend.

Now, to assess the results.

Ouch. Did it go through?

It didn't go through.

Martin: Hey!

The paper armor stopped the bullet!

Tory: It looks like the steel stopped the bullet, as well.

Both these armors are effective against this weapon.

Narrator: With paper once again in the same league as steel,

this myth requires a further fast forward in time.

So, now we're gonna try our 19th century gun, the Colt .45,

1,200 foot-pounds of muzzle energy.

This should put our paper armor to the test.

This is 19th century gun versus steel and paper armor.

[ Gun cocks ]

Here we go. In three, two, one.

Narrator: And neither stood a chance.

Tory: Well, it's obvious it punctured the steel,

and it looks like it went through the paper, as well.

Narrator: With both sets of armor

succumbing to the souped-up firepower,

it's time to conclude this ancient Chinese conundrum.

Okay. The paper armor performed the same as steel

with every test we've done,

and it failed in the same place, as well.

Yeah, it just seems

that the guns got too powerful for the armor.

I've really been wanting to do this story for a long time

because it seems so outlandish,

but it's super impressive.

Paper armor is actually a viable option in warfare.

Narrator: Viable, but there is one notable drawback.

As you can see,

it doesn't have the same durability

as the steel.

But it still works.

So this one is plausible.

Plausible.

Plausible it is.

Unbelievable.

Adam: Welcome back.

Jamie and i have been spending this episode exploring the idea

that if you're in the water during an underwater explosion,

you are far safer lying flat on your back at the surface

than you are even treading water.

We've done some small-scale experiments.

We've done some large-scale blasts in this here quarry lake.

We have not yet looked at our data.

We have one more data point to get, one more blast,

and then we're going to look

and see if it actually correlates

to what this myth purports to say.

Jamie: Okay. 30-feeter. You good to go?

I'm good to go. Let's do it.

In three, two, one.

Ooh.

Whoa!

[ Laughs ]

For those of you keeping score,

10 pounds of explosives, 15 feet under the water,

130 feet from where you're standing on land

feels exactly like an earthquake.

Jamie: Well, it all comes down to this.

David's crunching our last set of numbers,

and that's the final piece of the puzzle that we need

to answer our question.

Narrator: Remember, the question is,

during an underwater explosion,

does it really make a difference

lying on your back compared to treading water?

And the threshold number to keep in mind is...

What our research has uncovered

is that people exposed to a pressure of 87 p.S.I.

Or higher have a greater than 50% chance of dying.

That's our threshold, then.

Anything below 87 p.S.I. Milliseconds is alive.

Anything above it equals dead.

Narrator: And hot off the portable printer,

the figures make for a pair of happy mythbusters.

Remember, Jamie smiles on the inside.

Dude! Check that out!

[ Laughs ] Nicely done!

Doesn't get any clearer than that.

It totally does not.

I have to admit, we have rarely gotten data this lovely.

We had five sensors,

three blasts for 15 separate data points.

And this whole story comes down to two data points...

The sensor we had at six inches

versus the sensor we had at two feet

for the blast from 30 feet away.

That blast would have killed you if you were treading water,

and you would have lived through it

if you were lying flat on your back.

That's the story we came to tell,

and that's the story the data tells.

It's lovely.

Narrator: It's a definitive set of data, all right.

But to really put this myth to bed,

Jamie reads you the story called "why?"

Jamie: All this data is great,

but what it doesn't tell us is why.

Now, i did a bunch of digging around,

and this is what i found.

Energy doesn't like to transition from one material

to another if they're different.

The more different they are, the more it doesn't like it.

So, in the case of an explosion underwater,

as that pressure wave travels towards the surface,

it bounces off because it can't pass through it.

And what it does is it transitions

from a pressure wave to a tensile wave.

And therefore, it's able to neutralize a lot of the energy,

especially in that surface zone, and that's why it's safer there.

So, soldiers in the military are told

that in the case of an underwater explosion,

they are far safer

if they are lying on the surface of the water flat on their back

than if they're treading water.

What is our answer to that?

That's exactly what we found.

They got it right.

It's confirmed.

Totally confirmed. Let's go.

I'll tell you, even though that last blast

would have been survivable if i was lying on the surface,

i wouldn't want to try it.

Yeah, that was like being in an earthquake.

[ Laughs ]