MythBusters

On this episode of "MythBusters"...

The current is really strong.

It's bubble, bubble, toil and trouble...

Like riding a bucking bronco.

...as the guys test a fizzy fable

that it's impossible to stay afloat in bubbly water.

You're just not trying hard enough.

That's more like it! Yeah, baby!

But, will it be a case of sink or swim?

Swim harder.

Meantime, Kari, Tory and Grant take aim at a myth

that's got them quiver with anticipation.

Okay, it's lit!

Can an exploding arrow

cleave a mighty pine tree in two?

With precision explosives

and the mother of all pine trees,

it's time to split.

I'm so ready!

Here we go.

Three, two, one!

Who are the MythBusters?

Adam Savage...

That's the spirit, soldiers!

...and Jamie Hyneman.

I'll be darned.

Between them, more than 30 years

of special effects experience.

Joining them, Kari Byron...

That is messed up!...

...Grant Imahara...

Start the car!

...and Tory Belleci.

This time is car up!

They don't just tell the myths...

...they put them to the test!

MythBusters 09x04 - Bubble Trouble Original air date April 27, 2011

Hangover?

No.

I'm setting up a demo for our next story.

Which is?

There is a myth going around

that it is impossible to swim in bubbly water.

Whether it's antacid tablets, or carbonated,

as long as there's bubbles in the water, you won't be able to swim.

Really?

Yeah, the conventional wisdom is that the bubbles

make the water overall less dense,

and so, while you would float in the non-bubbly water,

when you get to the bubble part,

you would sink like a stone.

Sound like we're going for a swim.

I think so.

According to the myth,

when water is filled with fizz,

you supposedly sink without trace.

But, does the density difference of bubbly water

really mean that swimming in it is impossible?

Well, since we used up all our antacid breaking out of jail...

...what say we start with something small, like a fish tank,

and make a bunch of bubbles in it, see what happens.

Sounds good. Let's do it.

The myth is that it is impossible to swim in bubbly water

because the aerated water is supposed to be

less dense than regular water.

Are you ready for some experimenting?

I don't think so.

So I'm about to conduct some scale experiments

to see if there is a change in density of water

when I run a crackload of bubbles through it.

All right, let's try that again.

It's a great place to start.

Adam and his 2-D "mini me"

will test the science at the heart of this myth.

Do bubbles make a difference to the density of water?

What I've made here is a crude hydrometer.

It's actually floating at a very specific depth,

depending on the density of the water.

If I increase the density of this fish tank

with, say, salt, he would float a little higher.

If I decrease the density

with, let's say, air bubbles, he'd float a little lower.

Now, if this myth is is true,

and I put a whole bunch of air bubbles underneath this guy,

little Adam there is gonna drown.

So, now that 2-D "mini me" is neutrally bouyant,

it's time to see if he'll sink like the myth suggests.

Three, two, one.

Someone is happy.

But aside from putting a smile

on Adam's dial, what are the results?

I'm seeing almost no change at all

in the hydrometer's level.

If anything, it's actually rising a little bit.

And I must admit, I had a little bias going into this.

I thought that as soon as I turned on the bubbles,

that hydrometer was gonna drop below the surface.

I'm fully in camp of "the bubbles lower the density",

but there's something else going on here.

At any rate, in a small scale test,

it is not looking very good for this myth.

A conviction only confirmed after Jamie gets a demo.

So I see you're fixing to dump water all over my floor.

No, no, I'm containing it in this lovely tank.

So, what do you think is gonna happen?

I think it's gonna sink.

Check this out.

It's not sinking.

Not at all, not even a little bit.

If anything, it rises up a fraction of an inch.

You would think that the increased amount of air in the water

would make it less dense, so it would sink,

but that seems to be counteracted, and then some,

by the upwelling current of the movement of those bubbles.

Not looking very good for the story at this point.

No.

Far from sinking, the hydrometer rose slightly,

but it's too early to call this myth yet.

After all, you can't test a swimming saga without getting wet.

Next up, a myth that's going to blow you away.

All right., so this myth comes from a viewer.

A guy in Iowa wrote in and said that his uncle used to take

a bow and arrow, strap a stick of dynamite to it,

light it, fire into a tree,

and when it would explode, it would split the tree up the middle.

Okay, are you sure this is a viewer myth

and not like a Tori Belleci family history?

No, I'm serious! He wrote it in!

Wery well, I'm willing to try it.

Sounds like we need a stick of dynamite, an arrow, and a tree.

As any William Tell fan will, err, "Tell" you, the trick

of splitting an apple with an arrow is a blast.

But according to this myth, an arrow, coupled with dynamite,

can split a much bigger apple.

But is this fan fable bubble baloney?

Okay, for this experiment I think we need to just go for it.

Get the biggest log we can find and just anchor it

to the ground at the bomb range.

Remember, we're trying to split this tree down the middle with explosives.

We don't wanna just blow it into pieces.

Right.

Full scale testing means finding the right tree.

We're here at the bomb range to find out

if our dynamite arrows can split a tree.

These are our trees.

They're pine trees from a recycler.

Now, they're 20 feet long and almost 6,000 pounds.

So the first step, dig a hole.

The pine trees tech specs match the viewer myth almost to the letter.

All right, how's about right here?

While Kari gets on with step one...

So much better than a shovel.

...getting to grips with the pines' parameters is Grant.

Now, we've chosen the pine tree

because it's one of the most common trees in America.

In fact, there are over 35 varieties in North America alone.

But there are two reasons that might make it easier to split down the middle.

One, they have vascular bundles that run the entire length of the tree.

These are tiny tubes that carry water and nutrients to the top.

And two, it's got a spiral grain which goes parallel to the axis of the tree.

Those things together might just help us get a split.

That's the theory.

And, with the target tree now standing tall...

That's what I call a real stick in the mud.

...the guys turn their attention to the weapon,

setting up a remote bow and arrow firing mechanism.

So we need to fire a lit stick of dynamite from a bow and arrow into a tree.

Now, that is way too dangerous for us to do.

So, we brought out our remote arrow firing mechanism.

With the bow ready to go, that just leaves the payload.

We're not gonna use dynamite,

cause, actually, it's a fairly unstable substance.

Instead, our experts Frank Doyle and J.D. Nelson have given us... this.

It's a binary explosive.

It's a lot more stable, which means it will go off when and where we want it to.

And it has exactly the same amount of energy as a stick of dynamite.

After a quick test fire to make sure the remote bow and arrow is on the money,

it's time to take aim at this myth.

It's time to load up our arrow firing machine, shoot it into the tree,

and see if it gets split down the middle.

Do I think that's gonna happen?

Sure. Absolutely.

If we lived in a cartoon.

"Wile E. Coyote" Kari has her doubts. But there's only one way to find out.

All right. So the dynamite's lit.

Let's see if we can cleave this tree.

Okay, this is dynamite arrow, take it!

Here we go, in three, two, one...

The arrow gets triggered.

The fuse burns through.

And then...

And the tree still stands.

That was a good blast.

It sure was a hefty blast.

But when the smoke clears, it's clear it wasn't hefty enough.

The tree appears to be pretty well undamaged.

All right,

well, the tree is still in one piece.

Yeah, I don't even see a crack.

Well, maybe we need more explosives.