03x15 - Air Flare, Trial Bikes and Fish Tails

[bunniefuu]

[Richard]
This is the Science of Stupid.

[electricity crackling]

[percussive music]

Yes, this is the show that combines
scientific endeavor

with baffling stupidity.

We'll see wannabe scholars
trying and failing

to make sense of their universe.

We'll learn what went wrong

and why

through key scientific principles, like

rotation,

compression,

and that little terror... gravity.

So think safe,

think science,

think...

The Science of Stupid.

[glass shatters]

[electricity crackling]

[Richard] In this show,

we'll explore the uncomfortable side
of elastic potential energy,

the co-efficient of friction,

and how to use force to conquer inertia,

and bushes.

But first, this.

[glass shatters]

[electricity crackling]

[Richard] At my local swimming pool,
there's no diving or running allowed,

which pretty much rules out any fun.

But there are people out there

with new and inventive ways
of entering the water,

people not afraid to bend the rules.

[upbeat music]

[Richard] Some are inspired.

[man, off-screen] Yeah!

[Richard] Some are clumsy.

[man laughs]

[Richard] That one's a bit random.

Yes, we're talking pool safety,

the act of entering a pool safely

is not governed
by the tightness of your trunks,

but by scientific principles
such as friction and momentum.

Here's the lowdown.

[electronic music]

You rely on friction
between your feet and the ground

to control your movement.

Water can act as a lubricating layer,
reducing the friction between them,

allowing momentum to take over.

Running tends to result
in a larger impact force

as your foot hits the ground,

which can generate
a larger frictional force.

But with increased momentum,

a little slip...

can have big consequences.

So enough water at the side of a pool

can effectively fill in
any grippy bits on the surface.

Clearly you want
to plant your feet carefully

and keep the momentum to a minimum.

Unless you want to do this.

[man screams]

[Richard] Oh, nice.

[man] Ah!

[Richard] Not so nice.

Lots of momentum and low friction,
which works if you want to go straight in,

but not if you try and slow down.

[man] Ah!

[Richard] Running is the conundrum here

because whilst it can increase
frictional force at your feet,

it also adds momentum,
which can be problematic.

So do you run or do you walk?

[soft rock music]

Yeah. Yeah, it's walk.

But at least he had a soft landing...

[laughter]

[Richard] ...eventually.

This bit is dry,
so more frictional force for running.

-That bit was wet.
-[man screams]

[Richard] One thing worse than
running on a wet surface...

jumping on it.

But there are times
when you really do want momentum.

[man screams]

[Richard] Like trying to jump
an 8-foot wide pool.

You'd want lots for that.

A dry poolside offered
plenty of frictional force on the run up.

[upbeat music]

And a touch more force on the landing.

[man, off-screen] Oh, [bleep].

[Richard] So best to
just stand and dive in,

well, for him. And yes, it is.

For him,

maybe not.

[man] Yippee!

[Richard] Make that definitely not.

Leaning forwards created
a sliding force,

overcoming the frictional force
between his feet and the wet roof.

[somber music]

He did make the pool though.

Bit by bit.

Don't worry, he was okay,...

[man] Yippee!

[Richard] ...eventually.

[electricity crackling]

My dad once took me fly fishing

to teach me that things taste better
when you catch them yourself.

It was the middle of winter,

all I caught was the flu,
and it tasted awful.

[lilting rock music]

But my dad was spot on
because when it comes to fish,

everyone likes
to catch their own dinner.

He certainly does.

Maybe wear a jumper next time.

She's at it too.

Look at her just waiting
for the fish to--

-[woman screams]
-[Richard] Ooh.

I'm not sure
who was catching who there.

Hand sandwich anyone? [chuckles]

Finally, a rod. Surely the best method
for catching your fish supper.

[man] Nice.

You son of a *****.

[Richard] Oh, no, actually, that's better.

But if you're not equipped
with humongous canines,

then the old rod and hook
is your best bet.

Using one relies on precise technique
and understanding a little science.

Stuff like
the law of the conservation of momentum.

[electronic music]

The further he whips the rod back,

the greater the distance
it will have to accelerate.

A small flick of the handle
accelerates the far end even more.

The tapered tip allows
conservation of momentum

to give it an extra burst of speed.

And the rods flexibility helps
by damping the turning force

as his catch pulls on the line.

You see, it's about making the most
of the rod's shape and flexibility.

That starts with that whipping motion.

Slowly back and whipped forwards.

Slowly back...

and whip forwards.

[man] Aah!

[Richard] I said forwards.

Plenty of force,
but if you're pushed for space,...

[man] Aah!

[Richard] ...best not to cast sideways.

Can you get fishing helmets?

[playful music]

What happened?

[man, off-screen] Oh ****! He just hooked
himself in the neck.

[Richard] Oh, well, that was silly.

Remember, that little hand movement
causes a big acceleration,

so fling it over your head,
not around your neck.

[man] Can you just get it out?

-[man 2] I'm so sorry, Jim.
-[Richard] I hope so.

Nothing worse than
getting a fly stuck in your throat.

-[both laughing]
-[man 1] I'm so sorry.

If you remember,
that rod's flexible design

isn't just about whipping,

it's also about taking the force
of a fleeing fish.

[upbeat music]

That bendy rod is soaking up
some of the force of his catch.

[man] Get on there! Get on there!

Go on!

Oh, God. Ah!

[Richard] But not all of it.

The bigger the fish...

[man] Oh, God. Ah!

[Richard] ...the greater the force
on the rod.

Maybe go for something smaller.

I don't know. Maybe stickleback?

Little fish, yeah.

[man] Wow, It's a big tail!

[Richard] He's got a lovely flexible rod,
so that fish isn't going anywhere.

-[man] Get the net.
-[Richard] Unfortunately, he is.

-[man] Ah!
-[man 2] Here you go.

[Richard] The rod bent, storing energy.
He stepped back and released it.

-[man] Ah!
-[man 1] Here you go.

[Richard] And his fish.

Dinner for two then.

[electricity crackling]

[country music]

Can you guess which scientific principle
this man is about to hammer home?

See if you can have a bash.

[glass shatters]

[electricity crackling]

[country music]

So what science
is this man about to hit on?

[crowd gasps]

[Richard] That's right. Impact explosions.

Hitting the beam caused the chemicals
placed beneath it to react.

Lots of energy was released
very quickly.

And the shock wave knocked him sideways.

Yes, you hit a b*mb.
What'd you expect to happen?

[cheers and applause]

[electricity crackling]

[Richard] If you love motor biking
as much as I do,

but you find it a touch too clean
and perhaps a tad too safe,

well, not to worry,
look no further than this.

[rock music]

Dirt biking.

All the thrill of biking on the road
with added mud,

obstacles...

[man screams]

[Richard] ...and, of course, jumps.

-[man laughing]
-[dog barks]

[Richard] Okay, not so much that,

more this.

[man screams]

[man laughs]

[man, off-screen] You all right?

[Richard] Unlikely.

Yes with their beefy suspension
and rugged tires,

dirt bikes are pretty much made
for jumps.

People with their soft skin
and relatively brittle bones are not.

Reason aplenty to get
a firm grasp of this science.

[electronic music]

A ramp determines launch angle,
which if set at 45 degrees

will result in the furthest
horizontal distance.

Velocity is also key because
the slower the bike leaves the ramp

the more time gravity has
to rotate it towards the ground.

Finally, a landing ramp that matches
the bike's parabolic trajectory

will help minimize impact force.

One that doesn't,

won't.

Okay, got that?
Then let's start with the take-off.

Remember you need just the right velocity
and a ramp at just the right angle.

[polka music]

Good velocity.

What did he forget?

Oh, yeah, the ramp.

That was more of a ditch.

He's got velocity and a ramp.

Him?

Just the ramp.

At least you'll clean the muck off.

Shiny.

Look, velocity isn't just
for clearing that distance.

Remember, too slow and gravity
will tilt that bike front wheel down,

and if you had to choose
a wheel to land on,

it wouldn't be the front one.

[electronic music]

[man, off-screen] Oh!

[Richard] See what I mean?

Too slow on approach
and gravity tipped his bike...

...into a nosedive.

So, is it better
to land on the back wheel?

Well, better than
the back wheel landing on you.

Followed by the front wheel.

Yeah, that didn't work out.

[man groans]

[Richard] Don't forget. Aside from speed,
another way of perfecting that landing

is to have a landing ramp
at the same angle as your trajectory.

Let's see if he's got one.

Oh.

Doesn't look like it.

[country rock music]

Not sure what that is,

but you probably wouldn't want
to be landing in it.

[man groaning]

[Richard] Has he got one?

[engine buzzing]

-[man groans]
-[Richard] Yes, he has.

But that ideal landing angle
is on the other side of it.

A touch more speed next time.

[rock music]

That looks a bit too fast.

-[air whistling]
-[Richard] Yep

This large ramp had a slope
that matched his angle of descent,

but that one didn't.

[man] Ah!

[bell rings]

[Richard] You can probably tell
from my no-nonsense hat

that it's time
for today's serious science lesson,

the part of the show
where we take the analytical scalpel

to one of science's
fundamental principles.

See if you can guess today's principle
from the following clues.

[slow circus music]

Any ideas?

[grunts, gasps]

[Richard] No?

[man]
Ow, ******* it, that ******* hurt.

[Richard]
Here's another one.

No?

How about this?

Bit abstract.

Weirdly hypnotic though.

Maybe he thinks there's a nut in it.

All right, the principle uniting
all of these amateur scientists,

apart from a slight lack of common sense,
is elasticity.

Here's what you need to know.

[electronic music]

Elastic object deform
when stress is applied,

storing elastic potential energy.

When the stress is removed,

the object will return
to its original dimensions

and the elastic potential energy...

will be converted into kinetic energy.

[soft piano music]

But if the tensile strength
is exceeded while stretching,

the object will snap.

Got all that? Time for a quiz.

Question one: What happens
when an elastic object

is stretched and then released?

[overlapping chatter]

[Richard] Let's see if these kids know.

[boy] Malcolm, stop.

[boy 1] My face!

[Richard] Well, they do now.

Remember, the elastic object
wants to return to its resting state,

so if the kid doesn't release it...

-[boy 1] My face!
-[Richard] You get the picture.

-[man] Okay, line drive.
-[Richard] And the more

a material stretches...

[man] Pull!

[both] Ah!

[Richard] ...the greater the velocity
of the rebound.

-[both] Ah!
-[Richard] That was quick.

[man groaning]

Question two: Elastic potential energy
is converted into kinetic energy,

but do you know
what kind of energy that is?

[dramatic piano music]

That's right.
It's the energy of motion.

Elastic stretches, stores energy,
transfers it into kinetic energy.

Result, motion.

And not a good one.

[soft dramatic music]

So what if you stretch it more?

Yeah, you get more energy and pain.

Increasing the amount
of elastic energy he stored...

increased the kinetic energy
he got out.

Well, there are better activities
out there.

Right question three
of our science lesson,

what happens when the tensile strength
of a stretchy object is exceeded?

[indistinct shouting]

That's right. It snaps.

[indistinct shouting]

[Richard] Even a pole vaulters pole.

It was elastic... up to a point.

So elasticity,

in theory, it's easy.

In practice...

[upbeat music]

...it's a bit of a stretch.

-[man] Ah!
-[laughter]

[glass shatters]

[electricity crackling]

[Richard] If there's one thing
any ski instructor knows,

it's that nothing beats
weaving your way down a mountain

in your salopettes
and managing to stay upright.

And it's hardly surprising,

because when a ski instructor does it,
it looks like this.

[lively fiddle music]

Nice salopettes.

But for the rest of us, there are times
when it looks a bit more...

[playful music]

[both yell]

[Richard] Yeah, that.

Or this.

[both shouting]

Or even that.

[laughter]

[Richard] Ah, aren't kids sweet.

[laughter continues]

[Richard] Never happened to me,
but that's because I know

that there's more
to a stylish turn on the slopes

than merely popping on
an attractive bobble hat.

There's also science, and here it is.

[electronic music]

As a skier takes a fast curve,
he leans

carving the edges of his skis
into the snow

increasing the frictional resistance
to a sideways skid.

Pushing down with his feet
bends the skis in the middle

so that they form the arc of a circle.

And centripetal force guides
the skis in a curved path

making him turn,

as long as he keeps those edges dug in.

All complicated stuff
when you're weaving your way

down those slopes at breakneck speeds.

So let's break it down

starting by leaning those skis in.

[rock music]

He's got it.

Digging the edges in,
increasing sideways friction.

Oh. Never mind.

A loss of friction and he ended up
digging more than just his skis in.

Here we go. Lots of friction,
tight turns,

loose ski.

[woman, off-screen] Whoa!

Oh ****!

[Richard] Going from two skis to one
upset his balance

and the sudden friction
of a foot on the ground did the rest.

[laughter]

[Richard] Lucky he has
such supportive friends.

[laughter continues]

[Richard] Mmm, not doing too well
on the leaning,

so let's have a look
at how bending those skis

can help you around a turn.

Just bear in mind, the tighter the turn,
the more bend you need.

Ah, look,
smooth turn up ahead.

Not much bend needed.

[crowd gasps]

[Richard] But perhaps more than that.

That applies to both of you.

[upbeat music]

Can she make a controlled turn?

Well, no.

But turning 180 degrees keeps her upright
for long enough to--

-[woman groans]
-[Richard] Oh, dear.

That's more like it.

Edges in, controlled curves,

even a jump.

[man, off-screen] Oh!

Oh, oh!

[man] Look at the******* tree!

[Richard] Yeah, good advice.
Bit late though.

[electricity crackling]

When it comes
to pulling heavy objects,

the bar was set pretty high
with the building of the pyramids.

four and a half thousand years later,

I can just about get
the shopping out of my car.

But we h*m* sapiens
do have a proud history

of testing our strength
against all sorts of things.

[upbeat music]

Things like cars.

Impressive.

Animals.

Optimistic.

And even each other.

[both grunt]

[Richard] Bit pointless really.

Not to mention dangerous.

-[both grunt]
-[laughter]

[Richard] Now if people are going to make
a habit of pulling heavy objects along

then it's worth drawing
on our old friend, science.

To move an object depends
largely on force, friction and inertia.

[electronic music]

All objects have inertia,

the tendency
to resist acceleration.

This one also has friction
pegging it to the ground.

The bigger the mass,
the more force is needed to accelerate it.

If he applies enough force,
inertia and friction will be overcome

and the object will gain momentum.

But without enough friction
between the feet and the ground,

he'll lose traction
and momentum will be lost.

Simply put, you're after good friction
to help you stay on your feet

so you can apply plenty of force.

How do you do that?

[woman, off-screen] Pull! Pull!

[Richard] That's right.

But you do have to keep it up.

[mellow music]

This man is applying extra force to a bush
with the help of a car.

Will it work?

[woman, off-screen]
Here it goes.

[Richard] Yes. Yes, it will.

When the lightweight bush
became uprooted,

he easily overcame its inertia.

And the extra force
helped him accelerate too.

[woman, off-screen]
Are you OK?

[Richard]
He's fine. Just a bit bushed.

It's family tug-of-w*r

and the sides are well-balanced
in terms of friction and force.

[indistinct shouting]

-[all scream]
-[laughter]

[Richard]
Well, they were.

With the pulling force
and frictional force

relatively equal on either side,

all the stress was
on the middle of the rope.

-[all scream]
-[laughter]

[Richard] It is funny what passes
for family entertainment these days.

[laughter continues]

With all that inertia
and friction to overcome,

maybe it's safer to just push things.

-[man groans]
-[Richard] Then again, maybe not.

[glass shatters]

[electricity crackling]

That's all the acts of physics-based
humiliation we have time for.

Obviously, we'd much rather
you didn't try these stunts at home

because we'd like
to see you again next time

for the Science of Stupid.

[lively fiddle music]

[man groans]

[man screams]

[all groaning and shouting]

[man] Yippee!

[man] Oh, God. Ah!

[indistinct shouting]

[woman screams]