01x08 - Human Tower Disasters

[bunniefuu]

RICHARD:
It's the Science of Stupid.

- [electricity crackling]
- [glass shatters]

- [alarm blares]
- [reading]

It's the Science of Stupid.

Yes, this is the show
that finds science in stupidity.

[groans]

Over the next half hour,

we'll be dissecting the hard science
behind the hard knocks.

We'll reveal what went wrong and why

by exploring the scientific principles
behind all the lunacy.

Principles such as rotational inertia

and angular velocity

and we'll be examining

the consequences of dicing
with the elements,

like earth...

MAN: [bleep]!

RICHARD: ...wind...

and fire.

So don't just rely on blind luck,
trust in science,

the Science of Stupid.

[electricity crackling]

[glass shatters]

In this show, we'll be looking
at a real stick in the mud...

[cheers and applause]

MAN: Oh!

RICHARD: ...hydrodynamics...

- and equilibrium...
- [woman screams]

...or lack of.

But before all that, this.

[electricity crackles]

For me, cycling's all about
getting from A to B

at a nice, steady pace.

It turns out that not everyone
sees it the same way.

You won't see that in the Tour de France.

But is he cycling or pogoing?

On low slung bikes with tough frames,

urban bikers are doing
their crazy bunny hops.

But it seems not all bunnies can hop.

So if you want to perfect a bunny hop
and avoid the bunny flop,

check out the science.

A bunny hop is all about using body weight

to get the perfect trajectory in the air,

partly by controlling the way
a bike pivots on its wheels.

Shift your body weight back
to pivot on your back wheel

and lever your front wheel off the ground.

Scoop up the rear of the bike
with your feet

while shifting your weight forwards.

Shift your center of gravity
towards the middle,

to avoid pivoting forwards
on the front wheel.

And do wear a helmet,

it really can be dangerous.

Remember, it's about body weight, pivots,

and generally trying
to land on both wheels

without falling and hurting your head.

MAN: Yay!

RICHARD: Like that.

Then not that.

Yes, a trampoline
can increase your jump height,

but it's a bit unorthodox.

The real pros just use their legs.

This probably isn't a pro,
but let's give him a chance.

What do you get if you cross
a fire hydrant with a bike?

That.

A late takeoff means his wheel
hits the hydrant

before he can scoop the back up.

MAN: You all right, dude?

RICHARD: And remember
what I said about wearing a helmet.

Now, leaning back is correct,
but overdoing it is, uh...

- MAN: Ohh!
- RICHARD: ...nuts.

[winces] Ahh!

RICHARD: And he'd second that.

[winces] Ahh!

RICHARD: Getting it right once...

isn't always enough.

The first effort is textbook.

There's even a little grind in the middle.

On the second go,
he leaned back nicely,

but failure to move his weight forward

meant that he didn't get enough scoop
to lift that back wheel.

Oh, yeah, one more thing

for all the more expert bunnies out there.

Dropping from a greater height...

means greater damage.

He gets his rear wheel pivot spot-on,

scoops nicely, adds an impressive twist,

but here's the hard bit.

Falling from this height

equates to much greater
impact force on just one wheel.

Doubling your height
doubles the energy of impact,

and when you're going backwards,

that's sometimes asking
just a little too much.

- [electricity crackles]
- [creaks]

Bored of skiing and snowboarding?

Tired of waterskiing?

Well, why not combine the excitement
and injury potential of all three?

We're talking about the Slush Cup.

It may sound filthy,
but it's actually quite cleansing.

Look.

In this event,
skiers and snowboarders hurtle downhill

to gain enough momentum

to skim right across
a body of slushy water.

[cheers and applause]

More importantly for us,

it regularly goes horribly wrong.

[man laughs]

But if you prefer warm,
dry and retained dignity

to cold, wet, and humiliated,
here's the science.

The water forces the skis upwards
so they don't sink.

This is called hydrodynamic planing.

Double the surface area
in contact with the water

and you'll double the upwards force.

Doubling velocity quadruples
this hydrodynamic force.

With enough speed and contact area,

you plane across the surface of the water.

Without enough, you sink.

[man screams]

[gurgling]

I am told
it's a devilishly complicated equation

but, put simply, optimum speed
plus a large surface area

equals a perfect glide.

Nice.

But here's a few things
that won't help with speed...

sitting down...

wriggling around...

going backwards...

overdressing...

and, inevitably, showing off.

Generous scores, in my opinion.

Maybe they should have
just made the pool shorter?

MAN: Wow!

RICHARD: But with great speed
comes greater need for control.

Remember, I said optimum speed,
not maximum speed.

Mess this up,
and you'll not only be cold...

MAN: Ohh!

RICHARD: ...you'll be out cold.

MAN: Oh, [bleep].

RICHARD: He was fine... eventually.

Wet, but fine.

Of course, speed isn't everything.

For hydrodynamic planing,
you need a large surface area

in contact with the water.

It's about nailing that landing angle.

A nice flat angle
between board and water,

and you're away.

This is not a good angle.

90 degrees results in

barely any of her skis'
surface area hitting the water.

Nice big splash, though.

OK, at the risk of stating the obvious,

you're after the surface area
on the bottom,

not the top of the skis.

- [electricity crackles]
- [metallic thud]

This unicyclist
is about to attempt a jump

into the unknown,

but what scientific insight
is he about to gain?

[glass shatters]

[electricity crackling]

This unicyclist is about to discover

that tempered glass
breaks explosively.

MAN: Whoo!

RICHARD: Its strength
comes from a heat treatment

that locks extreme pressure
into the glass,

as much as 10,000 PSI,

so when pushed beyond its limits,

its failure is total, like this.

[man laughs]

What's tall, heavy,

has humongous tires and goes
pretty much wherever it wants?

I'll just show you, shall I?

Monster trucks, and what's the problem?

All that height, weight and rubber
makes them an absolute beast to control,

but a little science can set you
on the right track.

Big tires make monster trucks very tall.

If they don't have a wide wheelbase
to compensate,

their center of gravity
will be too high for stability.

Double the height of a truck

and you halve the G-force
needed to topple it.

So that high center of gravity,

how big a deal is it?

What's the risk of tipping
when piling through

a load of speed-sapping mud?

Will the truck be OK?

Nah.

A little ditch is all it takes
to flip this top-heavy truck.

Don't worry, he's-- he's fine.

Uh-oh, here come
the autograph hunters.

[engine revving]

Now, here's some speed.

Careful. Remember, the higher the truck,
the less G-force needed to topple it.

Sometimes all it takes is a little speed,

a minor technical glitch and a tight turn.

Shedding a wheel is one way
of lowering center of gravity,

but he won't be getting very far.

Oh. Careful, sir.

Now, one thing you really need speed for,

and plenty of it, is a backflip.

Yep, I said backflip
and then I said it again.

In order to launch four and a half tons
of machinery into a somersault,

it needs to be traveling
at well over 30 miles an hour.

If you think this looks a bit slow...

you'd be right.

The greater the mass,
the greater the force needed

to spin the truck.

So, once this guy has pulled right back,

he needs to floor it.

Oh, what happened?

He throws away all that
lovely velocity here

and so winds up less monster truck

and more dying beetle.

The steeper the ramp,

the greater the rotation before takeoff,

but you'll need to get plenty of traction
on those back wheels.

And that is all the more reason
not to dawdle.

But if you are going a bit slow...

there's nothing like
a set of big, bouncy tires

to get you back on track.

Well, that worked out quite well.

Now do it again.

- [electricity crackles]
- [creaks]

Back at school, the best way
to fell a bigger lad

was always a swift kick
to the unmentionables.

Add a few years' training
and the power of a kick

becomes far more dangerous.

Roundhouse kicks, for example,

have been measured to generate
3,000 pounds of force.

But with great power...

comes great pain.

Same old schoolyard trick,

just applied in a less direct fashion.

Now you know how hard it can be.

You want to make sure
you've got your accuracy spot on,

and that's down to balance.

To stay balanced, all the forces
acting on the kicker's body

must be aligned and equal,
as in this sparring stance.

He uses force to accelerate his leg

and strike his opponent.

A faster kick has greater momentum

and delivers more force in the impact.

But all that momentum,
can unbalance him,

so when kicking he swings his arms
in the other direction

to counterbalance the kick's momentum

and keeps all the down force of his weight

passing through his support leg,

with his foot rooted firmly to the ground.

Remember, a roundhouse kick
can generate 3,000 pounds of force.

Most of us won't get near that,

but kicking is still a serious business
if you get it wrong.

WOMAN: Wait, stop, stop, stop.

[woman screams]

RICHARD: Leaning back
helps to kick higher,

but moving your center
of gravity backwards

makes it even more
difficult to balance.

Well, there's no need to be smug.
She did that to herself.

Remember, keep your center
of gravity over your feet.

Oh, try not to lose contact
with the ground.

Planting a foot
helps to keep you anchored.

- [laughter]
- I said a foot, not a toe.

[yelling]

Screaming doesn't help either.

- [yells]
- [laughter]

No.

Now for an aerial kick.

You have to balance
all the forces acting on you

when you land.

Tricky when your opponent
is making minor adjustments

with his hand.

Another thing that can
really affect your balance,

impact.

If you're going to
practice office karate,

it's one thing being light on your feet.

Just remember
the light above your head.

It's simple, get your balance right
and you'll nail your kick.

MAN: Ohh!

RICHARD: Just don't nail your friend.
That's not polite.

MAN:
You mulched him in the head.

[glass shatters]

[electricity crackling]

There are many big questions

on which the world's greatest thinkers
have pondered.

What was there before the big bang?

What's the meaning of life?

What's an airfoil?

I can't help with the first two,
they're just really difficult,

but I do know what an airfoil is.

Paragliders and hang gliders are airfoils.

They work like wings
and enable these daredevils

to soar through the sky.

But this is not our natural environment.

If God had meant us to fly,
he'd have given us wings.

And you can see why he didn't.

You don't have to be a rocket scientist
to fly an airfoil,

but a little understanding
of aeronautical science

will go a long way.

Here's one explanation
of how airfoils create lift.

The shape of an airfoil forces air to move
faster over it than under it.

This increases pressure below the airfoil,
creating lift.

To steer, pull down
on one side of the airfoil,

which brakes and makes you turn,

but your drop speed increases.

To land, you lower the back of the airfoil

to increase wind resistance and brake.

Get this wrong and you could crash.

So first things first.

If you want to make a turn,
pull on the sides of the airfoil to steer.

He looks confident.

He'll need to make tiny adjustments

by pulling to either side
to land between the trees,

or do nothing

and end up like a fairy
on a Christmas tree.

This is more promising.

He's spotted a nice snowy clearing
over there,

which is perfect for a soft landing.

He needs to decrease air pressure
on the appropriate side to...

hit a tree.

Oh.

Better. No trees or bushes
to get in your way,

just acres of sky.

The Statue of Liberty.

Doesn't she look great from up here?

MAN: Oh! Oh, [bleep], [bleep]!

RICHARD: Although, on closer inspection,
rather less appealing.

MAN: Whoa!

Once you've mastered steering,

it's time to perfect a controlled landing.

Oh, that's looking
anything but controlled.

WOMAN: Oh, [bleep].

RICHARD: A low level turn
increases his descent speed,

and as he comes into land,
it's too late to pull back on the chute,

so his only means of braking
is a marquee.

- WOMAN 1: Get out!
- WOMAN 2: Oh, [bleep].

In summary,
carefully control the air pressure

on the sides of your airfoil to turn

and maximize the wind resistance

as you land for a graceful touchdown.

Am I inviting trouble by suggesting
this looks pretty good?

- [horn honking]
- MAN: Oh, you!

RICHARD: Yes, yes, I am.

Even in the middle of nowhere,

you can't escape the curse
of the white van.

Amazingly, he sustained only bruising.

Not the driver, the paraglider.

But they were both shocked.

- [electricity crackles]
- [creaks]

For most people, the basic idea with a car

is to use the engine
to provide drive to the wheels

and actually go somewhere.

Turns out some people aren't so bothered
about the moving bit.

Welcome to the world of the burnout.

A burnout is when you apply the brakes

to one set of wheels and spin the others.

You can do it in a car.

You can do it on a bike.

Just don't do it on your tummy.

[screams] God, that [bleep]!

[bleep] that! [bleep]!

God, it sucks so bad!

RICHARD: No, it's not suction.
We're talking friction.

They're different.

If you've little else
going on in your life

and you feel inclined to try
a burnout yourself, don't.

It'll cost you a fortune in garage bills,
even if you do it right.

To get a burnout right,
the driving force of the driven wheels

cannot exceed the friction
provided by the non-driven wheels.

If the force on the driven wheels
is greater

than the friction
between the tires and the road,

they'll fail to gain traction
and spin instead.

Time to get some new tires.

Here's someone after
plenty of driving force

but minimal friction.

[crowd gasps]

- MAN 1: Whoo!
- MAN 2: Whoo!

RICHARD: A helping hand from his friends

enabled that rear wheel to gain traction
and off he went.

If you're keen to see
more friction in action,

pop round the next time
he sees his mates.

It doesn't take much
extra friction, you know.

Just one friend will do.

- [laughter]
- And what a friend.

If you're going to up
the friction anywhere,

it should be on the stationery wheel,

so the big lad at the front
is doing him a favor.

There you go, success.

Yeah!

- [cheers and applause]
- [expl*si*n]

Although it's not great for the bike.

Here's an unplanned burnout
that can ruin your day.

And your gearbox.

That soft mud is so slippery
that the wheels just spin like crazy,

but it's also deep enough
to prevent the truck

from moving forwards.

As the wheels fail
to make any purchase,

something under the bonnet
is causing a major meltdown.

[cheers and applause]

MAN: Ohh!

RICHARD: Not a definitive burnout,

but I can smell the burning from here.

MAN 1: Fire extinguisher!
Fire extinguishers!

MAN 2:
Get out of there, Harold, now!

RICHARD: You can actually
move forwards slowly

whilst performing a burnout

by allowing the driving force
to just overcome the friction.

MAN: Ohh!

RICHARD: But not by that much.

Quit while you're ahead.

It's not scientific,
it's just common sense.

[glass shatters]

[electricity crackling]

[glass shatters]

That's enough stalling,
singeing, slapping,

slushing, smashing, and smacking.

I'm having myself
taken into protective custody

in case one of our hapless heroes
asks me out for a spin.

But I won't ignore the safety warnings.

This is as close as I'm getting
to the Science of Stupid.

[woman screams]

MAN: Ohh!

WOMAN: Oh, [bleep].

WOMAN: Oh!

[cheering]

[man groans]

MAN: Ohh!