02x10 - Surfing on Sand and Walking in Heels

[bunniefuu]

[Richard, off-screen]
Welcome to the Science of Stupid.

Yes, this is the show that
links stupidity with science.

We shine a light on brave,

but clueless researchers conducting
ill-advised experiments.

By analyzing their errors,

we'll clarify such scientific
rules as form drag,

accelerants.

And angular momentum.

Never argue with science,

as it's a battle
you can only lose.

So with that in mind,
do not try any of this yourself.

Sit tight.

It's the Science of Stupid.

On today's show,
we'll study axis of rotation.

[man] Owww that hurt!

[Richard, off-screen] How generating
lift will enable you to ride

on water,

or not.

And see why drag and
momentum are vital

when it comes to surfing.

But first, this.

Hurtling down a mountain
is a skill in itself

but add tricks
like a 360 spin

and to be honest you are just
making life harder for yourself.

It is impressive though.

Okay, so an imperfect 360
can be a painful experience.

To grasp it, you need to
master angular momentum,

but this time around
two different axes.

The vertical axis runs
from your head to your feet

so you rotate
around this sideways.

The horizontal axis runs through your
waist so you rotate around

this forwards or backwards.

On take-off, the skier spins
around their vertical axis,

but with a 360, he must
also rotate forward

around his horizontal axis.

Fail to do this and he'll
land at the same angle

he took off at.

If this is too far
back, it's all over.

So what science
is telling us is to make sure

you spin correctly and watch
your take-off and landing, easy.

Let's start with rotation
around that vertical axis.

Good skiing.

[man] Ah!

[Richard, off-screen] Bad jumping.

He begins rotating around his
vertical axis too early causing

him to clip the ramp and rotate
around his horizontal axis.

[man] Ah!

[man] Oh!

[Richard, off-screen] Ooh, let's look at
that from another angle,

not enough rotation
around the vertical axis.

Although, he does rotate
around his horizontal axis.

Shame it's the wrong way.

[Richard, off-screen] Hmm,
the problem here is the ramp.

And everything else.

A caught ski plus
too much rotation

around the horizontal axis

equals an impromptu somersault
and a face full of snow.

[man] Owww that hurt!

[Richard, off-screen] A lot better
rotation around the vertical axis

but let's look at that landing.

Not enough concentration
on his horizontal.

Funny how people keep
filming in a crisis.

[man] Unlucky!

[Richard, off-screen]
Unlucky, no such thing.

He's just forgotten to rotate
around his horizontal axis.

I can't stress enough
the importance of the axis.

[screams]

[Richard, off-screen] You need to work
on your horizontal son.

So remember people,
it's a two axis equation.

But don't over analyze.

Or you'll end up snowed under.

[laughing]

Water skipping.

No, I'm not talking about
throwing a stone into the sea

and counting the bounces.

This is the skill
of driving a vehicle

on top of a body of water.

[man] That was ******* insane!

[Richard, off-screen]
Yeah, that is one word for it.

[man, off-screen]
Just give it.

[man] That did not work.

I generally favor the boat when
buoyancy is required.

But if you want
to buck the trend and travel

on water using a
car or motorbike,

you might want to take
heed of the science.

You'll probably still end up
sinking but here it is anyway.

A horizontal
entry is vital.

Too steep and
you'll simply dive in.

To stay on top of the water
you must generate lift.

This is done by pushing enough
water downwards to balance

the weight of the vehicle.

The rate of water
pushed downwards increases

with velocity

and wider wheels have greater
contact area with the water,

which also helps to push
it down and create lift.

Being a bit of a rev head,
I do like this one.

But will our researchers
adhere to the science needed?

I certainly hope so.

Let's start with
angle of entry.

Right, a motorbike, thin wheels but it
is light and powerful.

His exit from the first
pond causes him to jump

and ruin his angle of
entry into the second.

So close and yet
so very, very far.

Ah, a quad bike.

Four fat wheels,
this could work.

[man, off-screen] Oh!

[man] I told you he was
going to get thrown off of it!

[Richard, off-screen] Well it might have
worked had he not jumped in.

[man, off-screen] Oh!

[Richard, off-screen]
At least he remains triumphant.

[cheering]

[Richard, off-screen]
A push bike. Are you sure?

No, you're probably not.

A steep hill will add
some much needed momentum,

but push bikes are not designed for
water skipping, fact.

Ah, a snow mobile,

lots of surface area
but also very heavy.

Yes, yes, yes.

No. Once the heavy back end starts to
sink, the only way is down.

[man, off-screen]
That was cold.

[Richard, off-screen] They do say a good
captain always goes down

with his vessel.

Here's a little fact for you.

A 440 pound quad bike would need
to shift around 53 US gallons

of water a second, downwards at


But you know what,
it can be done.

At last, a professional outfit.

Wide wheels,
tread like a steamboat paddle,

and what's more,
we are gonna film the lot.

Oh. Why do I tempt fate?

Sorry.

What force does
our researcher experience

during this
air bag extravaganza?

[man] Hey! Hey!

[man] Hey! Hey!

[Richard, off-screen] The air bag has a
fixed volume of air in it.

When his mates jump on the back,
their kinetic energy

is transferred through the
gas and out the other side.

He receives the kinetic energy
of his six friends causing him

to be launched into air
two and a half times faster

than they land.

Perhaps a second air bag for the landing
might have been useful.

I remember my first
ever trike, I loved it.

Tearing round the garden,
pretending to be in the Moto GP

and then my wife pointed out
I should be doing something

more constructive
with my time so I stopped.

But seriously, there are
trikes for grown-ups, standard,

un-powered three wheelers,
but with rear wheels that have

intentionally little grip
to drift round corners.

Sounds like a recipe
for disaster, well it is.

Yep, drift triking on an
open road is dangerous,

but you can get into trouble
even without oncoming traffic.

Getting round those corners

will require a firm
grip of the science.

When turning a corner,
you need centripetal force,

which is normally provided by
the friction between the tires

and the road,

but a drift trike's
rear tires are designed

to have very little grip.

This means that on a corner,

the back wheels will
often slide out into a drift.

You can take this to the extreme by
doing a 360 degree spin

with your handle
bars at 90 degrees.

Science here is telling
us that it's essential

to have slippy back wheels
with limited friction.

It's also quite important to
steer, but what if you don't?

[Richard, off-screen] By
not even attempting to steer,

this guy gets no drift.

And a face full of fence.

Ooh, synchronized
drifting, I like it.

Are they part of some
national display team?

No.

He needs to turn that front
wheel to the right angle.

His drifting partner's not
gonna be happy with that.

Being towed by a car with
no helmet, brave or stupid?

[man, off-screen] Stoplight!

[man] Hey, he's off!

[Richard, off-screen]
Yep, stupid.

The car turns
a tight corner,

but his tires can't create enough
friction to follow.

[man] Hey, he's off!

[Richard, off-screen]
Yep, to hospital.

[screams]

[Richard, off-screen] Spinning at around
one and a half turns a second,

his head is
experiencing 4G.

About the same
as a drag racer.

[screams]

[Richard, off-screen]
He tries to exit too soon.

With his wheel
pointing across the hill,

there's suddenly
a load of friction.

just when
he didn't want it.

This looks more like it.

Nice controlled drifting.

[screams]

[Richard, off-screen] But even science
can't help with potholes.

I love cranes,
huge lifting things

that can move stuff from
like here to say there,

but the bigger they are
the harder they, well,

see for yourself.

You can probably see why I love them so
much, but why do cranes

have a tendency
to fall over?

Well there's only one
thing that can tell us

and that thing is science.

Most cranes can
carry enormous weight,

providing they're
lifting it vertically,

but they aren't
built to withstand

large horizontal forces, which
is why drivers do everything

slowly to avoid the swing.

Another problem is that
the further the perpendicular

distance between the
load and the crane's base,

the greater the turning effect
of the weight it's lifting,

and the more likely it
is to topple over.

It's why cranes
use counterweights.

When two cranes
are involved,

one small movement from one can have a
huge effect on the other.

Who would have thought
that so much goes into

lifting a really heavy object?

Clearly not this lot.

Standard crane,
looks pretty sturdy to me.

But that is an armored
vehicle it's lifting.

Oops, he's tanked it.

As the crane rotates,
the perpendicular distance

to the edge of
the base increases

and the inevitable happens.

Personally, I'd just
have driven the tank round,

it's kind of
what they're for.

A sub-perfect outcome.

As it swings around,
the horizontal forces

are too much for the crane
and two of its legs are lifted

right off the ground.

For sale, one crane in
need of modernization.

Remember what we
said about two cranes?

[clanking]

Ooh, that
didn't sound good.

[clanking]

Oh, at least it
didn't fall in the hole.

Oh, that one did.

Where do you book a
crane to lift a crane?

Another two-craned operation.

[clanking]

[Richard, off-screen] A small movement
and there you go.

Well, that's one
way to launch a boat.

Anyone got a
bottle of champagne?

Right, dudes, surfing.

Harder than it looks, course I
can do it because I'm so cool,

but not everyone
is as wicked as me.

Mmm.

[screaming]

See, I told you.

One of the most difficult
parts of surfing is balance,

but once you're up,
you need to stay up.

Hang ten and check out the
science behind riding a wave.

A low wide stance
will help to keep

your center of
gravity over your base.

Keeping the nose of the
board above water reduces drag,

but if it dips below,

drag increases and the
board's momentum is reduced.

And with little friction between
the wet board and your feet,

there is only one outcome.

So, center of gravity,
momentum, drag,

of course looking fly,

not a lot to think about when
you are effectively trying

to stand on water.

He's up.

No he's down.

Initially his low-wide stance
works, but as he stands taller,

his high center of
gravity is his downfall.

Ooh, on board camera, gnarly.

As his center of gravity
moves away from his base,

it's a splashdown.

Right, so let's assume
you've mastered

your center of gravity, next
you have momentum to deal with.

That's a huge wave
and a bigger fall.

On a really big wave,
extra momentum is gained

as he drops down
the wave itself.

As the board's nose digs in,
the increased drag reduces

its momentum, but not his.

Surely we've got it now.

But maybe not.

His increased momentum meant
more drag when the nose dug in

at the bottom of the wave.

Okay, I think we're
ready to put it all together.

but then there is the added
problem of thousands of gallons

of falling water.

You might be
thinking it's impossible.

But here's someone
with low center of mass,

minimal drag, and the
added bonus of four legs.

Yeah, it's what nature
intended you know.

[dog] Woof woof!

Woof!

I love autumn.

One thing does
get to me, though,

the falling leaves,
but it's okay.

I saved up and
bought a leaf blower.

I keep it under lock and key
though because you can't trust

just everyone and anyone
with a leaf blower.

To be honest, in my book,

using a leaf blower to
spin on an office chair is.

Well, it's stupid isn't it?

But even I have to admit that
this light-hearted activity

is a weighty example of
the use of propulsion.

In much the same way as
a g*n recoils when it's fired,

it's down to
Newton's Third Law.

To spin on an office chair,
he holds the leaf blower

to the side so the force has
a turning effect or moment.

By keeping his
legs tucked in,

he keeps his center of mass
close to the axis of rotation,

which prevents
the centrifugal force

from throwing him
off the chair.

Okay, it still sounds
slightly on the stupid side,

but I guess that is the name
of the game and our mission

is to find science in
the silliest of scenarios.

Let's push on with
some fettle research.

Blimey, look at
the size of that.

[man] OK, fire it up!

[Richard, off-screen] Okay.

Legs tucked in
for maximum spin.

Textbook.

But once those legs
start to stick out,

his center of mass moves
away from the axis of rotation.

[man] We are a bunch of morons!

[Richard, off-screen] Oi, there's
nothing moronic about science, chum.

[man] Oh, boy.

[woman] And he's
spilt the gas...

...on his crotch.

[Richard, off-screen]
Yeah, he did that.

[man] Alright, go for it.

[man] I'm probably
a bit big for this!

[Richard, off-screen]
Your words, not mine.

Fire extinguishers work much
the same as a leaf blower.

He angles them and
drives in a straight line.

Well, for a while.

Ooh, at last,
someone's cracked it.

Remember what we said about
keeping those legs tucked in

to keep the center of mass
close to the axis of rotation?

And a word of advice,
spinning on an office chair

will make
you very dizzy.

That's it,
I'm dizzy and sore all over

and I've just been
sat here watching.

If you feel inclined
to water skim,

perform a 360, or try your
hand at big wave surfing,

heed the warnings
from science.

It could just save you
from the emergency room.

And I can tell you,

you won't find science queuing
behind you with a broken arm.

♪ ♪

♪ ♪