MythBusters

Narrator: On this episode of Mythbusters,

Adam and Jamie make alternate history as they go back in time

to recreate an attempt to assassinate Hitler.

I wouldn't want to be in that room.

Narrator: Was a room change the reason this bomb in a briefcase failed?

In the meantime,

Kari, Tory and Grant

all take one for the team

as they test out the myth

that you really can slap sense into someone.

This myth sucks.

Narrator: Who are the "Mythbusters"?

Adam Savage,

Jamie Hyneman,

between them,

more than 30 years of special effects experience.

Joining them,

Tory Belleci,

Grant Imahara

and Kari Byron.

Science gets more fun when I get a bigger gun.

Narrator: They don't just tell the myths,

they put them to the test.

In 1944,

a plot was hatched to kill Hitler and the operation was successful enough

to get a briefcase full of explosives into the room

with Hitler and detonate it.

But the operation was a failure because Hitler did not die in that blast.

What went wrong?

The meeting was supposed to happen in a closed,

underground bunker,

but at the last minute,

the meeting was switched to an aboveground room with open windows.

Conventional wisdom holds that the same blast

would have killed Hitler if it had happened in a closed bunker room.

Nice. A little blast from the past, so to speak.

Narrator: The venue was Hitler's East Prussia headquarters.

Wolf's Lair.

The would-be assassin was Colonel Claus von Stauffenberg.

His weapon of choice was a bomb and a briefcase.

But late in the day,

the meeting was moved from a fortified bunker

to a conference room aboveground with conventional doors and windows.

Four people were killed in the blast,

but Hitler survived with just minor injuries.

There are dozens of theories about what went wrong,

but the biggest is that it was the change of venue

that turned the bomb from lethal

to survivable.

So this myth is a tale of two roofs.

The question boils down whether or not an explosion in a enclosed space

is more deadly than one in an open space, right?

Exactly.

Where do you think we should begin?

Let's do some research,

start small and work our way up.

Perfect.

Narrator: History books are helpful,

but Jamie's gone the extra mile and sourced actual photos from the blast.

What these photos tell me is that the blast was quite severe.

Given the fact that Hitler was standing here when the bomb was right nearby

and four people actually did die from the blast,

Hitler really narrowly escaped death.

Narrator: While Jamie pours over the details,

Adam pours paint in a tub full of water.

A simple experiment that would show what happens

when shock waves are contained or released.

All he needs now is two model rooms.

Why is the conventional wisdom that the explosion that did not kill Hitler

in the room with windows, would have killed him in the bunker?

I'm hoping to tease out the reasons for that thinking with this visualization.

Before me, the four walls of the bunker.

I'm going to drop this little weight into the center.

Let's see what happens.

Let's look at the high speed.

Narrator: The idea is that the ripples or waves of water behave

much like a blast through air.

Awesome.

My visualization of waves in a closed room worked just like I hoped.

You can see them hitting the walls and then bouncing back.

They've got nowhere to go.

Narrator: Now, to see if throwing open a few windows

makes much of a difference.

This is my situation room.

Each of these spaces is an open window.

Here is my bomb.

Let's see what happens.

Perfect.

Narrator: The high speed confirms what Adam suspected.

That's so cool.

Narrator: Give a wave half a chance to escape and it takes it.

The waves are contained.

They cannot escape.

In the open room with windows,

the waves get out.

Narrator: So, it looks like there's some science to back up the myth.

Back at headquarters,

Jamie's now gotten his hands on the official report of the bombing.

Upper pressure would have destroyed the situation room to a larger extent

and exited through windows and doors as well as through partition walls.

Points of impact of metal fragments not detectable,

but splinters of wood and leather fragments are embedded into the woods.

The Fuhrer suffered only slight injuries

although in the immediate vicinity of the center of the explosion.

Narrator: So, the facts and photos are duly noted for future comparison.

You have to agree that it's high time they blew something up.

This is going to hurt me more than it hurts you.

You're right, that did hurt.

What was that for?

I'm preparing you for the next myth,

which is that you can slap sense into someone.

Oh no!

Oh yes.

The idea if that is someone in a state of confusion or shock,

by slapping them,

you can get them to focus,

hone in their senses and perform better.

Narrator: It's a familiar scene from old school Hollywood.

Someone flips out, a good, sharp slap brings them back around.

It kind of makes sense what with the shock and the sting,

but does it work?

When I think about this saying,

I think about someone who's hysterical,

on the edge of panic.

How are we going to induce panic in each other?

I'm not sure we have to.

I'd like to talk to a trauma expert.

Find if there is a way to inhibit the brain

something similar to panic

but a lot easier to achieve.

As far as the testing goes,

the pre-slap and the post-slap test,

they have to be a decision making test.

We're not testing IQ here.

We're testing how you make decisions under pressure.

Exactly. Totally agree.

Narrator: First up,

Kari takes council to learn how the body responds to a slap in the chops.

What do you think of the myth that you can slap sense into someone?

Multiple things happen simultaneously, with intense stimulation.

You have a signal going from your face to the brain

which then sends a signal to the adrenal gland

which secretes epinephrine.

This triggers the flight-or-fight reflex.

You get an immediate blood flow increase to those vital organs.

Your eyes widely dilate so you get clear and increased vision.

So you're ready to make a decision. You can think clearer.

You can fight or flee.

Narrator: Is old fight or flight response isn't exactly unknown.

When in terror, I will use one of my co-workers as a human shield.

Narrator: But how can the guys induce something akin

to a sense of panic in order to test out the myth?

There could be a variety of tests,

so if someone is compromised in some way,

and people can be compromised from a variety of sources,

but to test that,

you'd want to find some fine psycho motor skill.

Narrator: Back at the shop,

Grant and Tory are welding up a storm.

They're determined to take the human factor out of the equation

by scratch-building a faceslapping robot.

We have a bungee cord that's attached here.

It'll wrap around this rod.

We'll wound around the arm and release it.

Don't want to use motors or pistons

because we're going to be putting our faces in the way of this slapping hand.

We want slaps, not broken jars.

Narrator: All this mechanical marvel is missing is a hand to hit with,

so they'll fashion a surrogate forearm from Kari.

Deceivingly hairy arms. They're not hairy!

It's like baby dow.

Narrator: It's a process Tory's almost perfected.

The limb gets shaved,

greased and plastered with dental alginate

which eventually sets to make a mold.

In this case,

the mold is filled with silicon and when that sets,

they can arm the robot.

Oh, goodness.

Here, Tory.

Before we do that,

need to find out how hard we slap.

That's where this guy comes in.

We're going slap the plate,

record the data and use that to calibrate our machine.

Narrator: Grant strikes first.

It's going to hurt you more than it hurts me.

Narrator: Then Tory.

That looks more like a spank.

Narrator: Then Kari steps up to the plate.

Remember, how ever hard you slap that thing

is how hard you're gonna get slapped.

This myth sucks, all right.

Oh, maybe that was too hard.

Narrator: Maybe it was, but Grant's in no mood for a do over.

Kari, you hit with 94,

I hit with 114,

and Tory, you hit with 116.

Our average is 108 pounds. That's our target.

It's no comfort to Kari to know that the hand set to strike is more or less hers.