05x15 - Ricochets, Vehicles and Ski Racing

[bunniefuu]

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

[man] Ooh.

[Dallas off-screen] Yes this
is the show where idiocy and

intelligence fuse in a
festival of foolhardiness.

[man] Oh.

[Dallas off-screen] As
our impulsive investigators

inspect, key
scientific principles,

so you don't have to.

With their heroic help we'll
examine the science behind

torque,

isometric contraction
and mechanical work.

So get your brains in gear for
some extreme learning because

this is the Science of Stupid .

In this show we'll be
looking at reflexes,

inverted pendulums,
and cantor torque.

But first this...

I love traveling.

I get to discover the
specialties of a region and

learn more about
the local culture.

In Germany there's a brewing tradition
that dates back centuries.

And as a result they've become
experts on all things beer.

[Dallas off-screen] Like
this Bavarian football

fan who is demonstrating
how to tap a keg.

I'd have thought he would
be a bit better at that.

[man] ****is there a
leak in it, or what?

[Dallas off-screen]
Oh he's American.

He might not have been German,
but these guys really are,

and they seemed to have
successfully tapped their keg.

I don't think that
was supposed to happen.

Perhaps they should try again?

Yeah that's just
made things worse.

Evidently tapping a keg
is a tricky business.

So in an effort to prevent
global beer wastage,

we've done some research,
so you don't have to.

[Dallas off-screen] There
are four parts that interact in

a pressurized beer
keg; the liquid beer,

carbon dioxide that
dissolves in the beer,

carbon dioxide in the head
space above the beer and the

keg itself, which resist
the pressure from the carbon

dioxide and the
liquid combination.

If agitated the pressure will
build up as carbon dioxide

bubbles nucleate in the
liquid, for example,

by repeatedly tapping the keg without
breaking through the key stone.

But should it break
through a little bit,

then an unplugged opening is
created and the pressure from

the liquid and gas will
force the beer out.

So much like my tips
for a happy marriage,

it's all about avoiding any
unnecessary agitation and to

achieve that, it's important
to have the right tool.

[Dallas off-screen] This guy
has opted for a plank of wood.

Let's see if that
does the job.

This is not going well.

And it appears to be
getting progressively worse.

The wood plank is too light
to deliver sufficient force,

so he gives the tap multiple
hits and each hit agitates the

beer a little bit more,
causing a buildup of CO2,

and pressure.

This lady has opted for
a mallet and a big crowd.

[woman] I have no
depth perception.

[woman] That's okay.

[Dallas off-screen] Well
she's correct about one thing.

Never mind have another go.

If anything, that's worse.

This party starter misses
first time and hits the keg

which agitates the
pressurized beer.

A few more taps dislodge the
key stone and the thirsty

audience gets an early
drink, slash bath.

It's best to avoid wearing
all white especially if it's

a multi brown ale.

[man] On three!
One, two, three!

[Dallas off-screen]
Yeah, that's definitely a

multi brown ale!

His first strike with the
mallet delivers enough force

to dislodge the key stone but
the tap is pushed back out by

the pressure of the beer,
meaning he looks like the

victim of a very
messy accident!

I love the snow!

It makes everything
look wintry and nice,

but it isn't always such a
pleasure to travel through.

[Dallas off-screen] Especially
if you're not wrapped up warm.

But at least they're wearing
boots, unlike this lady.

I don't think high heels are the best
choice of footwear here!

That's better!

He looks ready for anything
the winter weather can throw

at him, except maybe
winter weather!

Walking through snow
can be complicated but,

pay attention to the science and it
could be significantly easier.

[Dallas off-screen] Snow can
have a low co-efficient to

friction, especially when
it's compressed and not fresh.

So when our man walks on it,
the frictional force between

the snow and shoe can be very
low and he's likely to slip.

In deeper snow,
he'll sink further,

and the drag force is likely
to be greater tripping him up.

It can also obscure obstacles and steep
drops in the landscape.

Personally I find the best
way to cope with snow is by

staying indoors!

But for some the lure of a winter
wonderland is just too great!

[Dallas off-screen]
If you must go out,

make sure you have
your wits about you,

and some grippy boots.

The snow has a very low
co-efficient to friction so as

he walks, the frictional force
between it and his shoes

is also low.

Which leads to a
bruised behind.

If the walking is tricky,
then adding a kick into the

equation isn't a good idea.

His run up means he's applying
greater horizontal forces

against the ground and thus
needs a larger co-efficient to

friction to avoid slipping.

But the snowy surface
is unforgiving,

and he pays a high price
for smashing the snowman.

[man] That was a lot harder
than I thought it would be.

[Dallas off-screen] When walking in deep
snow caution is key as the snow can

easily obscure obstacles,
like holes for example.

This chap seems to have mastered
the art of walking on snow,

but even when you're
in control of yourself,

you can't ever fully
control your surroundings!

Sometimes life is
inherently unfair.

Can you guess what
key scientific

principle this batty bar
fly is about to demonstrate?

[man] That's so beautiful.

[Dallas off-screen] We
asked you what key scientific

principle was being demonstrated
by this imprudent punter.

[man] Put it in there and chug.

Don't touch the glass!

[Dallas off-screen] If you
said Newton's first law,

give yourself a gold star.

The tower is tall with a
narrow base of support,

so it's not very stable.

When he leans
forward to drink,

he applies an accidental
sudden force to the base which

combines with the inertia
of its center of mass,

to rotate the tower
and destabilize it.

And he gets a
face full of fire.

Despite his stupidity, his
only injuries were singed

eyebrows, a bruised ego
and a hefty bar bill!

Ever since I laid eyes on
the glistening torso

of Schwarzenegger
in Pumping Iron ,

I've been an aficionado
of body building.

Sadly I'm not very good at it.

[Dallas off-screen]
Unlike these two,

who's love of heavy lifting
is matched only by their love

for each other!

h*. h*.

This guy really knows how
to show a girl a good time!

[woman] One hand.
One hand. Go faster!

[Dallas off-screen] She's
seems to be enjoying it!

Who wouldn't?

But the problem
with human weights,

is that they're unreliable.

The ability to lift
people in the gym might seem

incredibly glamorous, but
before you go changing

careers, it's best
to be informed.

So, here are the basics
of the human bench press.

[Dallas off-screen] Our man
needs to be strong enough to

provide a force that's
sufficient to accelerate his

partner's mass upwards.

His partner has to maintain
muscle tension to keep his

body rigid, otherwise
he'll crumple downwards.

His partner resting
on his arms,

forms an inverted pendulum,
so to stay stable,

he needs to make continuous
fine adjustments to keep his

partner's center of
gravity directly above him,

or his friend will be sorry
he ever agreed to help with

his work out.

Now that all seemed
fairly straight forward,

so without further ado, let's
pop to the gym to put this

theory into practice.

[Dallas off-screen] I'm
always inspired by the

dedication of honed
athletes training.

But it's more fun
scrutinizing the stupid.

[man] Is it safe?

[Dallas off-screen] A stable position is
compromised when the bench

presser lacks the
strength to lower the bar,

this destabilizes
the hand stander,

resulting in a loss
of body tension.

And chuckles galore.

They say the couple that works
out together stays together,

so these two are my
relationship heroes.

Her center of mass
is too far forwards,

so a sudden force from the bar
combines with the force of her

weight resulting in a loss
of stability in a frankly

unfortunate face plant.

Of course, once you've
mastered the bench press,

you can move on to
greater challenges.

Right you lot settle down and Morley
stop flicking ink on Jenkins!

Yes it's time for
today's Science Lesson.

That part of the show where
we dig deep and really explore

one particular
scientific principle.

So do you know what the
following have in common?

[Dallas off-screen]
This startled spectator,

this spice girl and these
foolish fence fiddlers?

If you said
reflexes, well done!

As a treat, there will be
no homework for you tonight!

The rest of you need to pay
attention to this science.

There will be a
test to follow.

[Dallas off-screen] The
approaching object activates

sight receptors, sending a sensory nerve
signal to the brain.

A motor nerve signal is sent
straight to the muscles of the

face and body producing an
involuntary startle response

that provides initial defense
against sudden threats.

And that's even more useful
when the threat is real.

Hopefully that's all been
absorbed by your sponge like

craniums and even
more impressively,

some reflexes are controlled
directly by the spinal cord,

bypassing the
brain altogether.

So, question one, what reflex helps you
escape a sudden threat?

[Dallas off-screen] One of
our researchers is going

to find out.

The unexpected intrusion
generates a sensory nerve

signal that instigates
the startle reflex.

And the thing about a startle
reflex is that even when the

perceived threat isn't real,
like this plastic snake,

it'll still kick in, if you're
not expecting to see it.

[woman] What is that?

[Dallas off-screen] Well it's
all a little embarrassing but

at least he runs
like a live gazelle.

Question two.

What reflex can come into play
when we get an electric shock?

[man] So you just plug it
right into the electrical...

[Dallas off-screen] That's
right it's the pain reflex and

a good reason not to
do your own electrics!

[man] Well.

[Dallas off-screen] When he attempts to
put the plug in the poorly wired

socket, he receives a shock
and the pain generates a motor

nerve signal that causes him
to move away very quickly.

[man] Damn!

[Dallas off-screen]
And collapse.

[man] Well, I guess we won't plug
it into the electrical outlet.

[Dallas] Time for our
third and final question.

Who can name a reflex
used to expel irritants?

[man] We good?

[man] Cheers!

[Dallas off-screen] Spooning
cinnamon into your own

mouth shouldn't be done
and here's why.

The cough is one of several
reflexes that we use to expel

irritants and as much as
the guy in the cap tries to

suppress it, when you got
to cough, you got to cough!

[man] You guys look
ridiculous right now.

[Dallas off-screen] So that's
the end of our lesson on

reflexes, class dismissed.

[screams]

[Dallas] Did you know that there is a
species of antelope capable of

jumping higher than
the average house?

Apparently it's due to their
powerful hind legs and the

fact that the average
house can't jump!

[Dallas off-screen] This
guys is more spring flop

than spring box.

It's best not to
be over ambitious!

That guy was rubbish, perhaps
he can pick up some pointers

from this penguin.

Piece of cake!

For some animals a good
horizontal leap could be the

difference between
life and death.

Impala can leap 30 feet in a
single stride and this ability

helps them to survive
the threat of predators.

But whatever type of animal
you may be it always help to

understand the science.

[Dallas off-screen] A
horizontal leap is a case of

projectile motion in which the
maximum horizontal distance is

achieved by maximizing
horizontal velocity and

vertical velocity at
the point of takeoff.

From stationary, this is achieved by
launching at 45 degrees.

The surfaces chosen for
launching and landing are also

important, friction and
stability need to be taken

into account.

Animals with larger jumping
muscles and longer hind limbs

tend to be better jumpers.

One of the best jumpers in the
world is the humble flea which

can jump 200 times its
length in a single leap.

But some members of the
animal kingdom could do with

refining their technique!

[Dallas off-screen] This
little p*ssy cat is still

learning the basics, well
you got to start somewhere.

As she jumps, her feet slide
on the low grip surface,

so she lacks horizontal and
vertical velocity and lands

lower than where she took off.

This cat looks like he
has more experience,

so should know better.

His leap has
excellent trajectory,

but it doesn't matter how good
the jump is if the landing

surface is unstable.

Now dogs can be excellent
at jumping once they've

learned to jump!

[woman off-screen] Poor baby.

[Dallas off-screen] The pathetic puppy's
poor horizontal velocity results

in a face first
grounding in gravity,

back to puppy school for you.

This dog is fully grown but,
he still needs more practice.

The dog converts some of
his horizontal velocity into

vertical velocity in
order to clear the fence,

but he misjudges the distance
and starts to descend too soon

and the collision with the
fence eliminates his front

feet from the equation
and his face becomes the

primary landing tool!

Flying a helicopter is amazing
and it provides a view of the

world that only Gods and CEO's get to
share on a regular basis.

For the rest of
us mere mortals,

the closest we'll come to flying one is
with remote control.

[Dallas off-screen] This is great if you
want to scare the dog.

But it's probably
safer done outside.

Ah, that's more appropriate.

The bride and groom
look gorgeous!

Ready for your close up?

That's a little too close!

So flying a remote control
helicopter is clearly complex

and if you want to avoid
aviation accidents,

you should pay
attention to this.

[Dallas off-screen]
Helicopter's rotor blades are

shaped like wings so that as
they spin they generate an

upwards force called lift
but as the rotor spins,

the body of the craft
experiences a torque that

tries to rotate it in
the opposite direction.

This torque can be resisted by the force
from the sideways pointing tail rotor,

which can also help
with nifty tricks.

That reminds me of one of my
grandmother's old sayings,

keep that in mind when
controlling your chopper and

you won't come a-cropper!

Mm, so wise.

Let's see if anyone else had
a grandmother who offered them

similar aviation advice.

[Dallas off-screen] It
doesn't look like he did,

by launching it with his hand,
he starts it moving forward

before achieving stability which makes
it harder to control.

Resulting in that!

Now this is a truly impressive
display of aerial gymnastics

and illustrates one of
the major advantages radio

controlled helicopters have
over normal ones because

they're incredibly agile,
which means he can do this,

but only once!

As it somersaults in the air,
it gets closer to the ground,

and when the rotors
touch the turf,

they shatter and can no
longer generate lift.

This looks like an
expensive hobby!

Whatever else you do,
make sure you have an

appropriate launch pad.

OK, that's all for now, but
I'll leave you with this

thought apparently from George
Bernard Shaw: science never

solves a problem without
creating ten more.

So let's see some people
attempting science and

creating a few
problems of their own.

[music plays through credits]