08x04 - Ski Backflip, Carbonisation and Hand Walking

[bunniefuu]

DALLAS (off-screen): This

is the Science of Stupid.

Yes, this is the show

that extracts the science from the stupid.

Watch as our researchers

confront the principles of

science and reap the rewards.

We'll witness the what and

expose the why with the help

of universal constants, like

elastic restoring force,

the law of gravity and

angular momentum

because you can question the

science, but you can't beat it.

Watch out, it's the

Science of Stupid.

In this episode we'll be

mastering linear momentum,

but our angular

momentum needs work.

We'll be looking at the

nucleation of CO2 bubbles.

Very closely and the elastic

potential energy of rubber

bands but first this.

Cars and water don't mix and

that's why we call them cars

and not boats.

Don't believe me,

well look at this.

DALLAS (off-screen): See and

they're the professionals.

The problem is to keep the car

on the road you need to keep

the car on the road but

sometimes water, i.e.

rain, can get in the way of

that very simple principle.

DALLAS (off-screen): A tire's

coefficient of friction with

the road reduces

when it gets wet,

problems can occur when

turning or changing lanes

as the centrifugal force

acting on the car wants to

pull it outwards and with

less friction the car can lose

traction and spin

out of control.

In really heavy rain the

grooves in the tires can't

channel the water away quickly

enough and a wedge of water

can build up

underneath the tires,

lifting it off the road

causing it to hydroplane.

You see, I told you that

cars and water don't mix.

The other problem we have is

that cars are really heavy and

really fast, so when it goes

wrong it goes really wrong.

DALLAS (off-screen): Our

driver here is aware of the

science, keeping his car

straight to avoid spinning out

due to the loss of traction.

It's a shame the pick-up

truck driver didn't study

the science too.

After almost crashing the

driver overcorrects and he

loses traction and our old

frenemy centrifugal force

takes over.

This Mustang driver appears to

be challenging the other black

car to a wet road race.

I bet he wishes he hadn't now.

As he swerves he

loses traction,

centrifugal force takes

control and then the lamp post

teaches him that this was an

extremely stupid thing to do.

Luckily heavy traffic stops

people losing control,

unluckily there wasn't

any in that lane.

Due to water on the road and

the speed he's traveling at

the tires can't channel the

water away quickly enough,

leaving him hydroplaning

out of his no claims bonus.

But if the water is just too

deep the sensible thing is to

just pull over

and not risk it.

The less sensible thing,

opening your window.

To understand the science we

normally end up concentrating

on the stupid but every now

and then we get the chance to

study at the feet, or

in this case the hands,

of a real expert.

DALLAS (off-screen): Meet

Kevin from Switzerland.

He's gonna try and set a

Guinness World Record title

for the fastest descent

of 50 stairs while walking on his hands.

Good luck, Kevin.

Wow, 14.58 seconds.

I couldn't run

it in that time.

Don't forget the problem

with walking on your hands is

there's nothing to catch you

when you fall and for most

people falling is

almost inevitable.

DALLAS (off-screen): If you

can get up in the first place.

Ah, that's much better.

MAN: Right, this is

going well so far.

DALLAS (off-screen):

Yeah, really well.

I would advise quite strongly

that you don't try this.

The thing is, Kevin knew

science and when you know

science it's just like

a walk in the park,

only upside down on your hands

and not necessarily in a park.

DALLAS (off-screen): First

he swings his legs upwards,

generating just enough angular

momentum to stay balanced

upside down.

His arms must be strong

enough to support his weight.

Being upside down can

be disorientating as the

vestibular system,

located in the inner ear,

sends signals to the brain

telling him he's inverted,

meaning he must concentrate

more to stay orientated.

Going downstairs he generates

more angular momentum,

which he balances out by going

down quickly and moving his

arms, his base of support,

under his center of mass.

So, to sum up Kevin

used his strength,

body control and speed to

break the record but now we

all know the secrets we can

all be record breakers but

just in case let's

start with the basics.

The launch.

DALLAS (off-screen):

Or the fall.

Her arms gave way almost

immediately but luckily the

hard wooden floor was

there to catch her.

Ah, carpet.

Very sensible.

It's a shame you didn't

carpet the wall really.

Too much angular momentum

meant it was more of a

cartwheel than a handstand.

Yeah, you might wanna

hand a picture over that.

Almost. One more try.

Oh, that's smashing.

On launching his left

leg is too far forwards,

moving his center of

mass outside of his base of support.

To resist the angular momentum

generated he tries to step in

with his hands

but it's too late,

which is bad luck for him

for the next seven years.

MAN (off-screen): Oh.

DALLAS: Okay, after mastering

the launch our wannabe record

breakers need to

start walking.

DALLAS (off-screen): Sometimes

even I'm impressed by our

dedicated scientists.

Other times less impressed.

Even upside down his

vestibular system served him

well and he wasn't

struggling with orientation,

but the angular momentum of

his right leg causes him to

twist and he tries to correct

this by lifting his left arm

and he loses his balance.

9.4 for the pipe dive though.

Okay, so our record breakers

aren't quite up to speed,

but Kevin shouldn't

rest on his laurels.

DALLAS (off-screen): As

they're all in the gym

training hard but by the

looks of it not hard enough.

Can you tell me what

scientific principle these

parked cars are testing?

DALLAS (off-screen):

Well, did you work it out?

What rule of science are

these cars experimenting with?

Yes, of course you did.

It was transfer of momentum.

Momentum is equal to an

object's mass multiplied by

its velocity, the large mass

of the truck is moving quickly

so it has a lot of momentum

and much of this momentum is

transferred to

the parked cars.

Well, at least clearing

up will be easy.

The thing about skiing is that

it can be a little repetitive,

first you go up the hill

then you come down the hill,

so people like to add a

little bit of flare to keep it interesting.

DALLAS (off-screen):

Like double backflips.

See, interesting.

Now, what our face planted

friend there has done is to

make the classic mistake of

failing to study the science

before attempting the jump.

DALLAS (off-screen): In order

to complete a double backflip

it helps to have

the perfect ramp,

too flat and he might

not go high enough.

Too steep and he could lose

too much linear velocity.

On take-off he leans backwards

to generate angular velocity,

which he increases by

tucking in to reduce his moment of inertia.

After two rotations he untucks

so that his feet are in the

right position to land.

Armed with the science we sent

our teams of researchers out

onto the slopes.

DALLAS (off-screen):

Perfect conditions.

MAN (off-screen):

Yes. Oh, no.

DALLAS (off-screen): Less

than perfect landing.

He needed to increase his

linear velocity to give him

more time in the air to

complete his second rotation,

maybe if he had a little bit

more height on take-off he

could have landed on his

feet rather than his head.

That is a steep ramp.

Maybe too steep.

The steepness of the ramp

decreases his linear velocity

and he tucks himself in too

late to minimize his moment of

inertia and once again fails

to complete the rotation but

we're getting closer.

Okay, not too steep and not

too flat, like this one.

Seriously?

The slope was right, but

his angular velocity wasn't,

and he didn't make

it all the way round.

Good velocity, tight tuck.

I taught him all the

science he knows,

apart from the landing.

Now, I know a lot of you think

I live in an ivory tower.

Well, I don't.

It's made of plastic

blocks, in fact.

DALLAS (off-screen): Like this

young architect's magnificent

structure before the

wrecking ball swung by.

A tower is definitively a

structure that is taller than

it is wide and if you know

anything about centers of mass

and bases of support then

you'll know that that can make

them a touch precarious.

DALLAS (off-screen): If the

force applied to these blocks

overcomes the friction

between them they'll slide out

resulting in demolition.

This is harder near the bottom

where more weight pushing down

means greater friction

but more potential for destruction.

You can add rigidity by

building it with interlocking

blocks, making the whole tower

act as one unit but if the

center of mass moves outside

the base of support even this

tower will fall.

So, keep within your base of

support and don't build it out

of anything that won't give

you a little extra rigidity.

Simple.

DALLAS (off-screen): Our first

researcher has built this

amazing tower without

a plan or thumbs,

but she wants to take

a close up look at the tower's rigidity.

Yeah, well spotted.

Inspector Whiskers quickly

identified the design flaws,

the blocks don't interlock and

there's an insufficient base

of support.

Although the tower has

a wide base of support,

the upright blocks in the

middle have a very small

base of support.

The friction between the up

rights and the rest of the

tower is not sufficient to

withstand even a simple nudge.

Well done, Whiskers.

So, let's work on

interlocking those blocks,

or in this case humans.

The tallest human

tower was 43.79 feet.

And that wasn't it.

Even though the research team

had followed the science and

interlocked spectacularly,

humans lack the rigidity of

human blocks and one of our

block's center of mass moved

outside their base of support.

Understanding towers can help

you out of tricky situations,

like when you've lost

your keys but have left a window open.

Maybe next time leave

a key with a neighbor.

A decent wide base of

support but having wheels on the upper block's bins,

maybe not

the brightest idea.

MAN: I'm okay!

DALLAS: Now then most of us

like a cool refreshing soda or

carbonated drink on a hot

day, what's not to like?

MAN: This stuff is just so good.

DALLAS (off-screen):

Apart from that.

But have you ever thought

about the science that goes

into getting that bubbly

goodness into, well, you?

It all starts

with carbonation,

dissolving CO2 in water.

DALLAS (off-screen): Dissolved

CO2 molecules can more readily

escape a liquid if there's

somewhere for them to form a

bubble, like a rough surface

or even another CO2 bubble.

This is called 'nucleation'.

Shaking a container of fizzy

drink disrupts the surface of

the liquid, introducing

bubbles and creating lots of

areas for nucleation, which

in turn creates even more

bubbles, all of which are

looking for a way out.

What is it about those

delicious CO2 bubbles that

keep us coming back for more?

First up, do they

improve taste?

DALLAS (off-screen): Well, not

according to our researcher.

He's spotted that after

nucleation the dissolved CO2

is released as carbon dioxide

bubbles and that a chemical

reaction on the tongue

converts this bubbles into

carbonic acid, giving

his drink a sharp bite.

On the positive side

he's learnt early not to trust his parents.

So, if the bubbles

don't improve the taste,

what are they there for?

Ah, propulsion.

Smashing the soda bottle onto

the floor introduces bubbles

into the liquid creating

hot spots for nucleation.

These resulting bubbles are

then propelled out of the top

of the bottle and conservation

of momentum means that it

becomes an

uncontrolled rocket.

Hilarious and also

incredibly dangerous.

MAN: This is Matt here, and

he's about to go into space.

DALLAS (off-screen): And

Matt's fuel of choice,

soda power, aided by candy's

microscopically coarse coating

which will generate lots of

bubbles that in turn become

hot spots for even

more nucleation,

building so much pressure

in his soda rockets that he launches.

MAN: 3-2-1. Go. Yeah.

DALLAS (off-screen): Oh and

that's why NASA didn't use

fizzy soda to get to the moon.

MAN: We have simply stuck

DALLAS (off-screen): But

as long as you remember the

science and the dangers.

You too can enjoy

carbonated drinks in safety.

No, not you toucan,

you too can.

To get a body like mine you

could sign up at the gym,

spend a small fortune and

never go or you could try a

resistance band because they

are perfect for exercise.

DALLAS (off-screen): Even

ones you've made up yourself.

There are only a few

of us who can do that.

What our sideways friend was

taking advantage of was a

resistance band's

effectiveness when it comes to

toning, honing and strengthening

our lower body muscles.

It's all about the

elastic potential energy.

DALLAS (off-screen): When you

stretch a resistance band you

give the band elastic

potential energy.

When the band is released that

elastic potential energy is

quickly converted into

kinetic energy as the elastic

restoring force acts to push

the band back to its original

shape and length.

As the band is light it's

accelerated very quickly with

a lot of kinetic energy.

The band adds resistance to

simple movements making it a

fitness tool that's flexible

in more than one sense of the

word, so as long as you're

careful with all that stored

up energy you'll be just fine.

DALLAS (off-screen):

Unless it snaps.

When it breaks the elastic

restoring force pulls the band

back into its original shape,

creating a lot of kinetic

energy that has

to go somewhere.

Like her face.

Now, this band is made of

sturdier stuff and is not

going to give way,

unlike her hands.

The up and coming gymnast

loses her grip on the band and

the elastic restoring

force reminds her she shouldn't have.

Now, this researcher is

not falling for that.

She's taken her hands out

of the equation completely.

Just not her head.

Her back foot can't cope with

the restoring force and bends,

allowing the band to slide

over her socks and reform to

its original shape via

the side of her head.

Maybe the socks

were the problem.

Grippy shoes, will that help?

Well, not in this case.

The shoes did add

grippy friction,

but he couldn't resist the

restoring force of the band,

which changed the

angle of his foot.

This time though the

band didn't hit the face.

Alright, don't take

it out on the snacks.

So, after studying the science

our researchers suggest you

take extreme precautions,

maybe not that extreme.

And that's all the

pain, I mean science,

we have time for and as

political thinker and avid

viewer, Leon

Trotsky, once said,

'Everyone has the right

to be stupid on occasion,'

and these guys have

obviously taken that to heart.

Well done comrades.

(music plays through credits).