05x20 - Trampoline, Trick Shots and Nose Slides

[bunniefuu]

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

Yes, this is the show where
absurdity and astuteness

merge in a carnival of chaos.

As our ridiculous researchers scrutinize
key scientific principles

so you don't have to.

With their extreme expertise,

we'll examine the science behind,
kinetic chains.

Inelastic collisions
and unstable osculation.

So, open your minds and prepare for a
large serving of knowledge,

because this is the
Science of Stupid.

In this show we'll
be looking at torque,

traction, and friction.

But, first this.

There's nothing better than a
peaceful moment on a park bench

for some quiet contemplation.

But when some people go to the park they
struggle to sit still,

which is a shame, as it leads them to do
dangerous things

on something designed for relaxation.

Like this hopeless hurdler.

This parkour park wrecker.

And this concrete step smasher.

For some people, benches offer
an opportunity

to illustrate impressive athleticism,

and incredible stupidity, by say
attempting an unwise bench flip.

His run up generates
linear momentum.

By planting a foot on the bench,

he receives a reaction force and creates
a pivot point over which to rotate.

His linear momentum is then converted to
angular momentum for his flip.

So, let's see how our brave
researchers are coping

with putting theory into
practice in the real world.

That looks painful.

When the bench jumpers foot slips, he no
longer has control of the jump

and he can't achieve the height required
to stop his crotch

colliding with the art.

A run up is a good start.

Now he just needs to hit
the ideal pivot point.

[screaming]

That wasn't it.

His plan is to push off from
the seat and hurdle a bench.

But his foot slips and his maneuver
becomes a little uncontrolled.

That's more like it.

Well, he's just showing off.

And he's showing himself up.

This bench jumper's plan falls apart
when his foot misses the seat.

And whilst all his linear momentum is
converted to angular momentum,

it's quickly absorbed
by the bench.

If jumping over a park bench
doesn't seem idiotic enough,

flipping off one is always
an option for the foolhardy.

This looks fun.

But not much fun for him.

[man off-screen] You good bro?

[Dallas off-screen] I
imagine he's had better days.

He needs to generate a
reaction force from the bench

to achieve enough height
and angular momentum.

But, he overcomes its material strength

and he feels the full force of his own
stupidity.

[man off-screen] Damn!

[Dallas off-screen] Yes, this bench
jumping is a lot harder than it looks.

[man off-screen]
This guy's got it.

[Dallas off-screen]
Are you sure?

It really doesn't
look like he has.

You see he hasn't.

[man] Ooh.

[Dallas off-screen] But
that is an amazing noise.

If I've learnt one thing from my many,
many, many years of celebrating

in the back of pickup trucks,
it's that it's dangerous

to get carried away when the vehicle
you're in is pulling away.

So, these football fans
need to be careful.

You see what I mean?

That is gonna smart
in the morning.

Somebody call the emergency services,
because those moves are on fire.

Lovely dancing.

Terrible balance.

When it comes to pulling away in a
vehicle,

it can either be a case of wind
in your hair or face full of gravel,

and the difference can be as simple as
understanding the science.

Newton's first law tells us that as the
vehicle accelerates our man's inertia

will resist any change
in speed or direction.

To stay on, he needs to anchor his
center of mass to the vehicle

so that they become a single
system and the vehicle

can apply a force to overcome his
inertia and take him with it.

Otherwise, a sudden force from the
vehicle

could overcome the inertia of his feet,

but not the rest of
him and he'll rotate.

Right, so it's all about
knowing your inertia,

anchoring your center of mass
and controlling your rotation.

And, of course, that's easiest if you
stay aware of your surroundings

so that you can anticipate any upcoming
changes in speed or direction,

which is hard as a passenger.

Especially if you're
a little distracted.

Still, these two special friends

have opted for a pickup truck with
raised edges,

so that should help
them stay aboard.

But it didn't.

While he's standing up, the edge
is aligned with his lower legs.

So when the vehicle starts
moving it rotates him backwards.

Amazingly, he seems fine.

But I wonder if a
motorbike would be safer?

Yeah, perhaps not.

Without any back support, the
passenger had no easy way

of anchoring his center
of mass to the bike.

And so he doesn't.

I wonder what would happen if you had
the bike on the back of a truck.

Yeah, that's even worse.

The lady on the bike forgot that inertia
also applies to direction.

So, when the truck turned sharply, she
and her bike don't turn sharply.

Still, it's better
than taking the bus.

It seems that you're only really safe on
a vehicle when it's stationary.

And sometimes not even then.

In this case, the force that
accelerated the ladies bumper car

came from behind, so,

she can't really be blamed
for not anticipating it.

Which I'm sure is a
huge comfort to her now.

[woman off-screen] Hey honey, be careful
walking around in those things.

It can be kind of dangerous.

[Dallas off-screen] Can you guess what
key scientific principle

this flipper footed fool
is about to demonstrate?

[Dallas off-screen] We asked you what
science was being demonstrated

by this silly snorkeler.

[woman off-screen] That's
how accidents happen.

You know you're supposed to wait
until you get in the water...

...to put those things on.

[Dallas off-screen] If you said human
gait, give yourself a gold star.

While wearing flippers

he needs to adjust his gait to allow for
the extra length of his feet.

But he doesn't do that and his
flipper catches on the floor

generating friction that stops

and rotates his foot, which means he
gets a dunk in the drink.

My late grandmother once told me that
there are a million ways to surf,

but I can only think of three.

When I tried to question
her, all she said was,

"As long as you're smiling
you're doing it right."

I'm not convinced
that's true.

But my uncle Johnny always
has a grin on his face.

And so does Auntie Doreen, so he
must be doing something right.

If you want to smile
like Johnny and Doreen,

you're gonna have to learn
the basics of tandem surfing.

So, here's some science.

Our man and his partner need to maintain
their combined stability

by keeping the base of support wide and
the center of gravity low.

But a surfboard floating on waves

provides a relatively unstable base of
support.

In a lifting move they're more likely to
have a higher combined center of gravity

and so will be even less stable.

And, because of the water, there's also
a reduced coefficient to friction,

meaning they could slip or drop
each other and this can lead to

an unbalanced weight distribution, which
can flip the board.

That all seems fairly
straight forward.

So, let's see how our trusty
team of testers are getting on.

This pair are operating in unison as
they ride the waves of Hawaii.

They really are in sync

and are maintaining their combined
stability with ease.

[man] Woo-hoo.

[Dallas off-screen] If only all
relationships could be this harmonious.

The perfect partners are coping with the
unstable base of support.

But, a change of position moves their
combined center of gravity,

disrupting their stability
and they take a tumble.

These two are right at the beginning of
their tandem surfing adventure,

but they seem more focused
on selfies than surfing.

Water provides an unstable surface, and
as her center of gravity strays away

from her base of support, she
can't maintain her balance.

Still, I bet you
get a lot of likes.

This couple looks ready for business,
and judging by their routine,

for them tandem
surfing is serious.

But, for us, it's
seriously stupid.

A lack of friction means the girl slips
his hold, which unbalances the weight

distribution and they're unable to
maintain their combined stability.

Oh, cheeky.

Okay, everyone calm down.

Corathus, stop making
ridiculous faces.

It's time for the
science lesson.

That part of the show where we
use the microscope of physics

to examine one
particular principle.

So, get your thinking caps on
and tell me

what these following
foolish fellows have in common.

This magnify glass menace.

[man] What the **** are
you doing, you ********!

[Dallas off-screen] This
unconventional chef.

And this senseless shopper.

If you said the
electromagnetic spectrum,

give yourself a pat on the back.

Now, pay attention to this science
because there'll be a test afterwards.

The electromagnetic spectrum is the name
for the continuous range of wavelengths

adopted by waves of
electromagnetic radiation.

The sun outputs energy
across much of the spectrum.

It feels hot because it emits
lots of infrared radiation.

While it causes sunburn due
to ultraviolet radiation.

And visible light

describes the wavelength that our eyes
are sensitive to.

Colors are representations of different
wavelengths within visible light

and can be split into a rainbow.

Right, did any of
that make sense?

Let's see.

Question one. How can we harness
infrared radiation to cook food?

One way is to reflect it.

[man] The sunlight...

...is being concentrated through the
glass straight into the food.

[Dallas off-screen]
Watch out though.

It can get a little warm.

The food is cooking because
all the reflected radiation

is concentrated on a point
in the center of the dish.

But there's too much radiation and the
glass absorbs enough heat to shatter.

This festive genius has
opted to barbecue his turkey.

But, infrared radiation.

[man off-screen] You're on
fire, dude, you're on fire.

[Dallas off-screen] Is
also emitted by fire.

As the fire starts, there's a big
upsurge in emitted infrared radiation,

which he detects as heat.

[man off-screen] Stop, drop
and roll! Stop, drop and roll!

[Dallas off-screen] It's good advice,

but not as good as don't do it in the
first place.

Question number two.

Which part of the electromagnetic
spectrum

do humans detect with their
eyes?

The answer, of course,
is visible light.

Something these unsuspecting diners in
the dark are sorely lacking.

So, they can't see as their
friend on stilts sneaks up.

The night vision on the camera shines a
light on these midnight munchers,

and because there's very little visible
light

to reflect off objects and into
their eyes,

they're all shocked when
their friend drops in.

Time for our third
and final question.

Can an electromagnetic wave
go through a solid object?

Certain wavelengths, such as visible
light, can be transmitted

through solid objects, such as glass,
because they're transparent.

Humans can't.

The glass doesn't reflect or absorb
visible light, so it's almost invisible.

And that's the end of our lesson
on the electromagnetic spectrum.

Class dismissed.

[Dallas] When I was younger, I used to
have the nickname Traction Man,

because I always seemed to
end up sticking to the floor.

I was pleased, because traction is very
important

and a lack of it can make you
look very

stupid, which is why we've got
some tips on what effects it.

Water can be problematic.

As can paws on a
polished surface.

But a bit of carpet on belly action

provides perfect traction for doing
this.

For animals, understanding
traction is very important,

especially if they don't want
to suffer hurt or humiliation.

So, let's hope they're paying
attention to the science.

When not moving, normal force prevents

the foot and ground from penetrating
each other.

Traction comes into play
when an animal wants to move.

The larger than normal force, the more
traction the animal will have.

Traction also increases with
the coefficient of friction,

which depends on the nature of the foot
and the surface it is on.

There you have it.

Now, let's put theory to the test with
the help of some cats and a dog.

I'm not convinced that that pug belongs
on that slippery staircase.

I hate being always right.

The combination of polished pine and pug
paws produces low traction

and the slope formed by the stairs
corners reduces it further still.

This cat burglar is on a heist.

Foiled again.

Thanks to the rug, there's too
little traction for the leap

and then the poor pussycat can't get any
traction with his paws onto the table.

[meow]

Ah, this cat looks comfy.

And not so much.

This cat's claws hook into the surface

and generate traction to push itself
along.

But once on the slope, gravity is trying
to pull him down and the low friction

between his body and the surface, means
his cat nap is off to a shaky start.

Remember, a lack of
traction isn't always bad.

Nice parking.

I don't like to talk
about my charity work,

but until recently I volunteered
at my local fire station.

It all went very well until they caught
me on the pole in my Lycra leotard.

I tried to tell them about the
full body workout you can get,

but they weren't listening.

Which is a shame as to pull it off
gracefully requires many skills,

none of which I possess.

Such as gymnastic flair.

[man off-screen] What!

[Dallas off-screen] I
said gymnastic flair.

[man off-screen] [Bleep].

[Dallas off-screen] And I suppose you'd
call it enthusiasm.

[woman off-screen]
Are you all right?

[Dallas] Ooh, I think
he's bruised his coccyx.

Yes, poles can be a dangerous business,
so, it's always good to have a partner,

and thus tandem pole
fitness was born.

But two people on one pole
is a recipe for disaster,

unless you know your science.

After these gymnasts
leave the ground,

their grip must withstand
the force of their weight.

As they rotate, their angular
acceleration applies torque on the pole,

which the pole anchors
must be able to resist.

But as long as they're on opposite
sides, their torques cancel out.

Now, it's worth remembering that double
the mass means double the weight,

and potentially
double the torque.

So, a strong grip and a steady
pole are absolutely vital.

These two are obviously
professionals.

Just not in this.

In such an awkward position,

it only took a slight foot adjustment
for the force

of their combined weight to overcome her
grip, causing a nasty slip.

Gravity can be unforgiving.

These guys have a more
energetic approach.

It'd be a lot safer if you
are on opposite sides, guys.

Especially if that pole isn't actually
screwed into the ceiling.

By being on the same side, their
combined angular acceleration

became too great for
the pole's supports.

Or I'd imagine any
watching females to resist.

These best friends are
always on the same side.

Which isn't necessarily
a good thing.

They've forgotten to
cancel out their torques.

You need to be on opposite
sides of the pole.

Alright, so what have we learnt?

Well, you either need to know the
basics,

or be prepared to take it on the
chin.

Well, that's all
we have time for.

But I will leave you with a
little something to ponder.

Science is neither good nor bad,
but it can be used both ways,

as these guys know
only too well.

[music plays through credits]