06x07 - Planes, Fish and Chair Handstands

[bunniefuu]

[Dallas off-screen] This
is the Science of Stupid.

Yes, this is the show where science
bumps heads with stupidity.

[laughs]

Watch and learn...

[groaning]

As everyday folk attempt
acts of jaw-dropping lunacy.

[screams]

With eye-watering results.

[screams]

We'll find out
what went wrong.

And why.

With the help of scientific curiosities
such as flexural strength.

Hydrodynamic drag.

Or even kinetic energy.

So, don't try anything
you're about to see at home,

or anywhere else.

Watch out, it's the
Science Of Stupid.

In this show we'll explore
aquatic oscillations.

-The trouble with torque.
-[man off-screen] Whoa!

[Dallas off-screen] And learn
all about spatial memory.

But first this.

It's well over 100 years since
the Wright brothers took off

on the first powered
controlled airplane flight.

Now, that might
sound impressive,

but people don't
clap on take-off.

It's landing that's
the tricky bit.

[Dallas off-screen] So, three cheers for
the pilot of this plane.


stop in just 265 feet.

He knows how to land in style.

The pilot of this plane.

Well, it's... it's a style.

In the early 1800s, the
father of aeronautics,

Sir George Cayley, identified
the four key forces

involved in flight.

Lift, thrust, weight and drag.

And it's much the
same deal for landing.

[Dallas off-screen] To
descend, you steadily reduce

thrust, slowing
air flow over the

wings so that the plane's lift
becomes slightly less than the

force of its weight.

At the same time, the
plane's control surfaces use

aerodynamic forces to prevent
any unwanted rotation

and stay on course.

Drag force also helps
decelerate the plane before

wheel braking uses frictional resistance
to bring it to a stop.

Amelia Earhart, Charles
Lindbergh, Louis Blériot,

all etched upon the pages of
history for their ability to

handle Sir George's
four forces.

I wonder which of the
following pioneers will join

them on that
time-honored list.

[Dallas off-screen]
Here we are,

soaring over the
fields of Coulommiers,

just east of Paris.

The spirit of freedom, the
comforting hum of the engine.

[man] No engine! No engine!

[Dallas off-screen] Uh-oh.

Okay, bit of a thrust issue.

No problem.

Remember the science.

Use the control surfaces to
gently reduce lift and allow

weight to glide you in for
a smooth emergency landing.

Here we go.

Oops.

[man] Merde!

[Dallas off-screen]
Watch out for the trees!

[man] Merde, merde!

[Dallas off-screen]
Lift, lift, lift, lift!

Sacré bleu!

Zut alors!

Leveling the plane as weight
and gravity bring it down?

Mais oui.

[man] Merde!

[Dallas off-screen]
Clearing the treetops?

Ah, non.

Landing level and gracefully,
coming to a controlled stop?

Uh, no, no, no, no, no, no.

He recovered but has since sold the
plane and taken up boules.

This chap has
never flown before.

He just bought a plane and took himself
on a maiden flight.

[man] Dude, this dude's gonna
******* stall and die!

Come on buddy,
get it together.

[Dallas off-screen] This is
obviously a terrible idea,

and his first flight could
turn out to be his last one.

[man] Wow! He is
lucky to be alive.

[Dallas off-screen] Given his
zero lessons it's no surprise

that he was constantly
over-correcting with his

control surfaces.

Lift and drag sent him one
way and then the other.

But at least that meant
he had a slow descent,

if a less than elegant one.

There are all sorts of
ways to catch a fish.

[Dallas off-screen]
Angling takes real skill,

which he doesn't have.

Using a net is simple.

Usually.

But once you've got
that fish in your hands,

it's all worth it.

[Dallas off-screen] Providing
you can keep it in your hands.

Alas, fish aren't
just tricky to hook,

they're also hard to handle
thanks to some of the clever

evolutionary adaptations that make them
so adept in the water.

[Dallas off-screen]
As they swim,

fish contract muscles
on their sides,

generating oscillations in
their bodies which propel them

through the water.

Their skin is made from
overlapping textured scales,

which keeps the turbulence of
passing water to a minimum,

reducing their drag.

These slippery scales, plus
a layer of slimy mucous,

makes them hard to hold.

Gripping with more force can
help by increasing friction,

but if the force isn't applied
perpendicular to the surface,

a component of it will push
the fish sideways rather than

hold it steady.

Those scales make a fish act a
bit like this bar of wet soap.

Squeeze it with a force that's
not perpendicular to its

surface and, well,
you get the picture.

But before you get to grips
with a slippery surface,

you've gotta wrestle
with those oscillations.

[Dallas off-screen]
At, oh, around 180 pounds,

this chap should be able to take on the
grouper he's hooked.

But its powerful oscillations
give it a lot more force.

I think he's got it, though.

[man] Whoa!

[laughs]

[Dallas off-screen] Right,
that'll be just the chips

for dinner, then.

Carp can swim at up to three miles an
hour, which doesn't sound that fast.

[man] Ohh.

[Dallas off-screen] But they
can slap you in the face

at ten miles an hour, which
definitely feels fast.

His complete lack of grip
force allowed his carp to

oscillate freely.

And if there's one thing
we all know about carp...

[man] Ohh.

[Dallas off-screen] They
will hit a man with glasses.

[man off-screen] Well, like I said, we
weren't going home empty-handed.

Oh-h*, oh-h*, oh-h*! On video.

[Dallas off-screen]
I think he might be.

He had a firm grip initially,
but one big oscillation from

the fish meant some of
his force was no longer

perpendicular and his supper
slipped out of his hand like

a bar of scaly soap.

Okay, how about a
different approach?

This lady is going to show you
a very ill-advised way to trap

a fish with your feet.

[speaking native language]

[Dallas off-screen] Yeah,
right, that's not working.

[speaking native language]

[Dallas off-screen] Her
rubber soles have a relatively

high coefficient of friction.

But the aquatic dodger's
powerful oscillations bounce

it out of reach.

And if you can't beat them,
just go for a swim instead.

[laughs]

Let's get radical.

But can you guess what science this
skateboarder is about to demonstrate?

[man off-screen] Whoa!

[Dallas off-screen] Did you
work out the science this

skater is about to show us?

[man off-screen] Woo!

[Dallas off-screen]
Yes, well done.

It's impact time.

[man off-screen]
Zarek, come here, man.

[Dallas off-screen] As he
lands, he bends his knees,

increasing the time over
which the impact occurs to

reduce the force.

[man off-screen]
Zarek, come here, man.

[Dallas off-screen] So, it's
just a shame this runaway car

doesn't have any knees.

[man off-screen] Whoa!

[Dallas off-screen]
Or any driver.

[man off-screen] There's
nobody in the car!

[Dallas off-screen] Both
skateboarder and car fell at


thanks to its greater mass,

the car hit the deck with


[man off-screen] There's
nobody in the car.

[Dallas off-screen] Yes,
we've been through that.

Whenever I'm feeling
a little bit blue,

I like to make a list of the
things that I'm better at

doing than apex predators.

For example, I'm better at staying awake
all day than a lion.

I'm better at texting
than a k*ller whale.

And I'm pretty sure that
I'd be better at chair

handstands than a T-rex.

[Dallas off-screen] For a
start, the heavier you are,

the harder it is.

That massive tail would
make it hard to balance.

This lady's making it look
hard even without a tail.

[grunts]

And of course, they went
extinct 65 million years

before the chair was invented.

[grunts]

Even for us humans, handstands on top of
anything are hard to master.

And that's particularly true
of chair handstands as they

require a tricky balance
of strength and skill.

So, best not to
try this yourself,

even if you do
understand the science.

[Dallas off-screen] As
our man raises himself,

he's also raising the combined center of
mass of him and the chair.

The higher that gets,
the more unstable it is.

Then it's just a question
of holding himself in static

equilibrium, ensuring that his
center of mass remains over

the base of support.

Well, it's simple
if you get it right,

but if you're off-center
or over-rotate,

then you need to be able to
provide a large enough torque

with your muscles to correct
it, and that is hard.

So, this is best left to
the experts, and even then,

they'll need a
very stable chair.

[man off-screen] Whoa!

[Dallas off-screen] Yeah, much more
stable than that one.

This guy raises the
combined center of

mass of him and the
chair quite high,

and when he starts to
rotate it's hard to correct.

This would've been easier
on something a bit more,

what's the word, solid.

[man off-screen] Whoa!

[Dallas off-screen] But what if you
don't have a stable chair?

I think that probably
answers that.

This guy's handstand is good,
nice body tension and classic

center of mass over base.

But the chair swivels
as he raises himself.

He tries to generate torque
to pull himself back round,

but that shifts
his center of mass,

which turns the chair more,
creating a bit more torque.

And some soggy joggers.

This looks better.

The sun lounger is
quite low and stable.

If he remembers to rotate
slowly and keeps his body in

static equilibrium,
this should be perfect.

Oh, looks like for once we
may be getting the deposit

back on the sun bed.

I'll get my wallet.

Alright, class, settle down,
sit up straight and pay

attention because it is time
for today's science lesson,

where we focus on one particular
scientific principle.

So, what are the
following examples of?

[Dallas off-screen]
This dune-flipper.

This volcano-surfer.

Or this out of
season-snowboarder?

[grunts]

No, they aren't all examples
of mankind's seemingly

inexhaustible
reservoir of stupidity.

It's actually that they all
feature granular materials.

These are loose collections of
independent particles that act

as solids individually but
collectively they can act like

a solid, a liquid
or even a gas.

Confused?

Well, let's take
a closer look.

[Dallas off-screen] A single
grain or rice is a solid,

but a whole sack of rice acts
like a liquid as it's poured

out, flowing freely.

But when this tennis
ball is dropped,

the rice deforms on impact,
acting like a non-Newtonian

fluid, spreading the force
over a greater area and

reducing the momentum more
slowly for a gentler landing.

But what makes granular
materials tricky is that you

never know what's going
on under the surface.

Two can seemingly be identical
but have radically different

support strengths depending on
their packing configurations.

But let's start easy.

Question one, what is
a granular material?

[man off-screen] Go.

[Dallas off-screen]
That's right,

it's a group of solids that
can in the right circumstances

act a bit like a liquid.

[laughs]

A grain of sand is an
incompressible solid,

but a dune of sand has
very different properties.

I love physics.

[laughs]

Question two,
given the choice,

why might you want to land on
a pile of granular material

rather than a solid surface?

[screams]

[boy off-screen] Oh [bleep]!

[Dallas off-screen]
Luckily for him,

they help to reduce
impact force,

deforming when impacted and
providing a softer landing.

[boy off-screen] Yes!

[Dallas off-screen]
Here's another example.

A jump from 30 feet up on to a
solid usually means a trip to

the emergency room.

[screams]

But here it just means
you get to spend

the rest of the day getting
sand out of your ears.

[man] Oh, my God.

[Dallas] Now, you see, that is
a very dangerous thing to do,

so don't be tempted to try
it yourself even if you can

answer question three, which
is in what way are granular

materials unreliable?

[laughs]

[Dallas off-screen] Remember,
they only act as liquids in

specific circumstances.

So, while sand might
sometimes act as a liquid,

it can also...

[laughs]

Feel really quite solid.

And that has a lot to do
with packing configuration.

Because while different bits of Mount
Fuji may look identical...

[woman] Look how fast I'm going!

[Dallas off-screen] That
doesn't mean they are.

So, that's granular materials.

Complicated but amusing.

[boy] Ah, ohh.

[Dallas] Sometimes when
it's a bit wet outside,

an umbrella and a brisk
pace is all you need to

keep yourself dry.

Other times, you'd be
better off with a boat.

[Dallas off-screen]
Or a wakeboard.

Yes, for some, one of the
world's deadliest natural

disasters, floods, are just
an excuse to engage in

some extreme sports.

Like puddle jumping,
for example.

[laughs]

[man] Oh, yeah!

[Dallas] But floods are
not to be toyed with.

Not only can they
run deceptively deep,

but worse still, they can be
surprisingly powerful and fast.

And here's why.

[Dallas off-screen] A common
cause of flooding is when land

is inundated with rainfall.

If water can't percolate into
the ground quickly enough,

or if it's an impermeable
urban landscape,

surface runoff will flow
and settle in the lowest

point it can find.

The greater the
volume of this flow,

the greater the momentum and
the more force it can impart.

Water is surprisingly heavy.

Just one-inch depth over
an acre weighs 113 tons,

which means even a shallow
flood can move with an

extraordinary amount of force when it's
trying to find its level.

[man] What the hell is she doing?

[Dallas off-screen] In fact,
just six inches of flood water

can be enough to knock
a person off their feet.

That's about two inches
deep, but she's on a slope.

So... there she goes.

[screams]

And keeps on going.

Well, let's just hope she
doesn't get hit by any, oh,

I don't know, floating
debris like that stop sign.

So, floods are certainly
a hazard for waders,

but nearly half of all flood
casualties occur in vehicles.

Just two feet of water can
deliver enough force to wash

a car away.

[man off-screen] Woo!

[man off-screen] Oh my god!

[Dallas off-screen] Well, that is more
than two feet of water.

[man off-screen]
Turn back this way. This way.

[Dallas off-screen] But they're in a
specially adapted truck.

[man off-screen]
Turn back this way.

[Dallas off-screen] That water doesn't
appear to be flowing.

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

[Dallas off-screen]
It's a hobby, I suppose,

but I prefer personally a
more traditional activity.

[laughs]

Like an exhilarating
hiking trip in Hawaii.

Yes, I bet the view
would be better up there.

Ah, see.

Right, time to get
back to the trail.

Is it me or is that
water flowing a bit fast?

Yes. Yes, it is.

Flash floods can happen when
an obstruction holds back

floodwater, allowing it to
build up before giving way and

releasing it as a sudden wave.

[screams]

Like that.

Don't worry, he was okay.

[screams]

Look, there he is.

But you don't need
to fly to Hawaii.

If the water level's high
enough outside your window...

[man] Whoa!

[Dallas off-screen] You can
make you very own flash flood.

But I wouldn't recommend it.

Jump hooks, fadeaways,
floaters, slam dunks, sure,

I've mastered most of the
coolest basketball shots,

but even I can only dream of nailing a
backwards overhead three-pointer.

[Dallas off-screen] sh**ting from
outside the arc gets you three points.

Doing it backwards
makes you a legend.

[cheering]

And a little bit lucky.

But we all have to
start somewhere.

[man] Oof!

[Dallas] Any shot is going to depend on
power and trajectory.

But if you're sh**ting blind,
you're also relying more on

something called
spatial memory.

As you move around, cells
fire in your brain telling you

where you are in relation
to other objects,

leaving a kind of imprint that
helps build a memory model of

your environments.

Here's how that
works for the shot.

[Dallas off-screen] This
basketballer's brain has

created a spatial
memory of the court,

helping to estimate the
parabolic trajectory he'll

need to sink the ball.

For a greater launch velocity,
he follows through with his

arm as he throws, increasing
the time over which

he can apply force.

And he judges his launch angle
so that the ball's trajectory

takes it perfectly
through the hoop.

Scientists have calculated
the optimum launch angle for a

three-pointer to be 45 degrees with two
revolutions per second of backspin.

Now, that's a lot to get
your spatial memory around,

so let's start simple with
some practice at home.

[Dallas off-screen] If
there was a prize for blindly

hurling household objects into
receptacles, and there isn't,

I've checked, then
he would win it.

[man] Noah, do you like your
water warm or chilled?

[Noah] Er, chilled.

[Dallas off-screen] Cool.

And if you're serious
about spatial memory,

then check this guy out.

[boy] Oh!

[Dallas off-screen]
Because he hasn't got any.

I've no idea what he
was trying to achieve,

but I do know that the acute
angle of launch and excessive

amount of force took the bottle on a
very high velocity,

shallow trajectory...

[boy] Oh!

[Dallas off-screen] And he probably
didn't want to do that.

[boy off-screen] [Bleep].

[Dallas off-screen] Right, I think we're
ready for the court.

Remember, launch angle,


[girl] Ow.

[Dallas off-screen] Yeah,
that was closer to 90.

This selfie shot means he's not
technically doing it blind.

But he might as well be.

The trajectory was fine, but
by throwing it with too much

force, he gives his friend a
face full of basketball and

invents a really fun new game.

The historian Daniel
J. Boorsten said,

'The greatest
enemy of knowledge is not

ignorance, it's the
illusion of knowledge.'

So, let's watch people get wiser as
their illusions are shattered.

[man] Oh!

[man off-screen] Wow,
he is lucky to be alive.