05x13 - Park Bench, Tandem Pole Dancing and Surfing

[bunniefuu]

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

Yes, this is the show
where smart and senseless

merge into an
assortment of anarchy.

Our crackpot team of testers
have laid themselves bare,

so we can dissect what
went wrong, and why.

With their expert
assistance we'll dig deep,

uncovering the science
behind stability,

Newton's second law of motion,

and ground reaction force.

So get comfortable to
watch the uncomfortable,

because this is the
Science of Stupid.

In this show we'll be looking
at coefficient of friction,

jaw strength,

and the center of percussion.

But first, this.

After I failed to medal
at the 1994 Winter Olympics

in Lillehammer I had to reconsider my
time as a professional figure skater.

A shame, because I
loved those sequins.

Fortunately, I have a new
sport that uses all my skills,

even if the outfits
aren't quite as fabulous.

GT sledding.

Now I definitely feature in one of these
clips, I just can't remember which.

Nice!

I imagine that was me.

Oh, there's more.

Yeah, no that does
feel familiar.

The GT sled sits on two skis and has a
third for steering with,

and if a broken arm and a squashed nose
taught me anything,

it was to listen to the science.

Our sledder builds up momentum
on the slope for his jump.

He must position his
center of mass perfectly.

If he leans too far forwards, torque
will rotate him over the handlebars.

Upon landing, his relatively high
center of mass

results in certain sections of the

skis flexing and taking the majority of
the impact force.

If this force is not dissipated, the
sled will stop as it sinks in.

But thanks to his
momentum, he will not.

So, momentum and torque are
the challenges on take-off,

while impact force and friction
will be the test on landings.

Can't see this being a problem.

Good buildup of momentum.

Nice straight line.

[man] Whoa!

[Dallas off-screen]
Yep, landing needs work.

His center of mass is well positioned,

and his GT sled well controlled for
launch,

but once in the air he gets out
of position and loses control.

And you really do need to
pay attention to gravity.

See what I mean?

The time the ramp is too steep,

which means he leans too far back after
take-off,

and the sled flies upwards out of his
hands, leading to a white out.

Right, shall we
look at landings?

Close, but not quite.

Points for a stylish spin, but he falls
short of the down slope,

so the force of impact is
not dissipated gradually,

much to the hilarity
of his friends.

Up, up and away!

Or down and out.

Your choice really.

This guy's steep trajectory means he
gets a larger force on impact,

and the result is the same.

Oh nice, he's gone
for a vintage model.

Which totally lets him down.

Because it's on skis and not a
solid bottom,

the combined mass is distributed
over a

much smaller surface area than a
normal sled,

meaning higher pressure on the snow,

and a halt in the
sled's momentum.

But not his.

It's not always the ground
that gets you though.

Sometimes a stray sled can
do all the damage needed.

[man off-screen] He had it!

[Dallas off-screen]
Not sure he did.

When it came to school sports lessons

some people felt at home in football
kit,

others the rugby strip, but I always
loved the look and feel of a leotard,

and my chosen discipline
the high bars.

But if I learned
anything, it was this.

Don't do it in the garden.

Don't do it in the playground.

The only safe place is in a gym, where
you know you can trust the equipment.

But just not this
particular one.

This is one of those sports where if you
get it wrong you can really get hurt.

But it's not the sports
coach who can help you out.

It's your science teacher.

Swinging around a bar, our man
experiences centripetal acceleration

as his body follows
a circular path.

Gravity and his own
momentum keeps him moving,

while grip strength optimizes the
friction

that allows our man to stay
attached to the bar.

If friction fails him, his inertia will
send him off in a straight line

until he's stopped
by something else.

Right, let's practice
our technique.

Remember, inertia, described by Newton's
first law,

tries to send you in a
straight line,

and centripetal acceleration
keeps you spinning.

Alright, let's see some
real-world examples.

Looks like it's one of Santa's elves
doing a little chimney jumping practice.

Back to the grotto with you.

[man] [Bleep].

[Dallas off-screen] Those toys
aren't gonna make themselves.

This is a classic
battle against inertia.

A successful hold would counteract it,
but with too loose a grip,

inertia is always going to win.

And then so is gravity.

Now this looks a bit
more professional.

Good channeling of inertia,
creating perfect swings.

Well, perfect-ish.

Ah, now he's color matched
his bars, shorts, and shoes.

Everything is red.
Including his face.

In the first trick he maintains
his centripetal acceleration

through the friction created
by gripping the bar.

But in the second trick he
loosens his grip too much,

and there's only one
way that can finish.

Painfully.

So, what is needed to pull off
a successful trick on the bars?

Well, you need to generate high spin
speed so that when you let go

you're carried far enough
away from the bar to clear it.

Shall we have a go?

Nice and fast.

Perfect execution.

Well, full marks for effort.

Without the required spin speed
to take him further backwards,

he comes down too short and
gives the bar a whack instead.

[groaning]

So, just the dismount to go.

Yeah, maybe you're more
suited to something else.

I've always believed two wheels are
better than one, but can you guess

which key scientific law this renegade
rider is on her way to proving?

[Dallas off-screen] We asked you what
science this sunny cyclist

was about to show us.

[woman off-screen] Keep
going, keep going, Kalli!

[Dallas] Did you say
conservation of momentum?

Well done.

As Kalli pedals she builds up momentum,

and science tells us that any
momentum lost

by one object must equal the
momentum gained by the other.

And the lighter you are, the more you'll
be affected, so when Kalli collides,

the massive truck absorbs all
of her momentum, without moving.

I had a dream last night

that I'd been picked to represent Europe
in the Ryder Cup.

I was over the moon.

My partner wasn't as pleased when he
found out my handicap was 320.

But he did have
some good advice.

He suggested I stopped
combining it with other sports.

Like the high jump.

Or ballet.

Or even cricket.

[man] Ow!

[Dallas off-screen] Well
they shouldn't laugh.

Very, very unsportsmanlike.

But the one thing I wanted to do on the
golf course was the running trick shot.

Now, I might not have the golf skills,
but I do know the science.

A run-up generates extra speed,

giving the club more kinetic energy as
he swings.

Hitting the ball on the sweet spot,
known as the center of percussion,

allows the maximum amount of energy to
be transferred to the ball,

helping the shot to go long.

So, all you need is lots of kinetic
energy and lots of control.

And it is worth bearing in mind that the
run-up is likely to compromise control,

so in practice it doesn't necessarily
translate to extra distance.

Before your strike, good
preparation is essential.

[man off-screen] Just
limbering up is the man.

Just a practice stroke.

Here he goes!

And he misses!

[Dallas off-screen] Yeah, I don't think
those stretches

actually improved his technique.

The run-up gives the club extra kinetic
energy,

but without the required control
he fails

to connect with the ball, and instead
the only circular motion,

is the one taking him over.

Now, let's test some
brand-new clubs.

Back to the shop then.

There is a transfer of energy, but he's
so far from the center of percussion,

the transfer is not with the
ball, it's with the ground.

The energy reverberated back up the
shaft, snapping off the head,

and leaving him driverless.

If the run-up trick shot is too tough,
you could try the mid-air volley.

But because you have
to calculate two paths,

the circular motion of the club and the
parabolic trajectory of the ball,

you have even less chance of hitting the
center of percussion.

MANL Fore!

[Dallas off-screen] Five?

This budding Tiger Woods miscalculates
the parabolic trajectory,

missing the sweet spot.

By hitting the edge of the ball, he
spins it back, right into the camera.

Now, before we try
again, is everyone ready?

[man] Born ready!

[Dallas] Oh good.

[man] Oh no! No! [laughs].

[Dallas off-screen] I
thought you were born ready!

While he calculates the respective
trajectories perfectly,

and builds plenty of kinetic energy, his
swing is a bit too fast,

sending the ball off.

[man] Oh no!

[Dallas off-screen] But
snapping another club.

And with no clubs left.

[man off-screen] She's gone!

[Dallas off-screen] It's
time to take up another hobby.

Fire up the Bunsen burners and
get hold of your microscopes,

because it is time for
the science lesson.

This is the part of the show where we
examine the inner workings

of a scientific theory.

So, who can tell me what the
following have in common.

This rooftop dancer.

This troublesome table trasher.

And this futuristic fly swatter.

The answer is, of course, the different
properties of metals and non-metals.

All the elements in the periodic table

are roughly divided into these two
groups.

Let's see an example.

Metals tend to be denser,

and therefore have more mass for their
size than non-metals,

so they can exert a larger impact force
on anything they hit.

Their atomic structure makes them more
able to deform under compression,

making them malleable
rather than brittle.

And these metal wires
are electrically conductive,

so they easily transmit current
and spark

while this rubber insulator does
not.

Ok, time for a round of my new favorite
game, metal or non-metal.

Question one.

Which are usually more
malleable, metals or non-metals?

You know how we told you not
to try anything you might see.

[man] Ahh! Ooh!

[Dallas off-screen] Yeah, that's exactly
the sort of thing we're talking about.

This metal car is malleable,
allowing it to remain intact.

As for the non-metal
glass windscreen.

[man off-screen] Oh my
God, his windshield broke!

[Dallas off-screen] Well,
that's not so malleable.

Right, onto question two.

Which tends to be denser,
metals or non-metals?

Knees bent, arms stretched, and.

Yeah, well that
answers the question.

This cast iron weight has a density of
around 490 pounds per cubic foot,

which is deceptively heavy.

The weights would be much lighter if
they were filled with air,

but no-one ever got ripped,

by pumping gas.

My third and final question
of metal or non-metal.

Which is a better conductor?

Now how on earth
did you manage that?

[man off-screen] Come on Paul, get your
bike off that electric fence.

[Dallas off-screen]
Easier said than done.

[woman off-screen] You won't
get a bolt through here...

[Dallas off-screen] Yes, the answer is
metals are better conductors.

[man off-screen] How can you get a bolt
through a rubber tire?

[Dallas off-screen] You didn't!
You touched the spokes!


the average electric fence,

which travels through the bike frame, to
the spokes, and into your hand.

So, what's the solution?

Exactly, a non-metal
with lower conductivity.

Yeah, this might take a while.

Alright, class dismissed.

[Dallas] Me and my brothers were
a nightmare to feed growing up.

My brother Houston would only eat
burgers, Austin lived on chocolate,

and I insisted on
oysters and caviar.

Mind you, we weren't the only
picky eaters in the house.

Our cat, San Antonio, wouldn't start the
day without a bloody Mary.

And our dog, Barry, insisted
on doing his own food shopping.

How I miss Barry.

For all animals with jaws it is possible
to measure their jaw strength,

which my mother knew,

and always took into consideration
when meal planning.

Here's the science.

The force of a bite is measured
in a unit called the Newton.

The bite of an adult great white shark
is predicted to be about 18,000 Newtons.

For humans it's less than 1,000.

The vicious bite of a carnivore

is often the result of a combination of
sharp teeth

and strong mandible muscles,

which give many deadly creatures their
large bite force.

The key to jaw strength
isn't necessarily size.

It's sturdy teeth
and strong muscles.

Shall we see what's on the menu?

I've always said there's nothing more
relaxing than catching your own food.

Except when that happens.

This Goliath grouper's sharp teeth and
fast snap means its bite is very strong,

leaving the diver with a long swim home
and a takeaway for dinner.

Fetch, Fido! Fetch!
Come on boy!

You might want a smaller stick.

Dogs evolved to hunt in packs and have
relatively strong mandible muscles for

a dangerous bite, which is
perfect for a game of fetch.

If only he had better
spatial awareness.

This cat had the best birthday ever,

but even after the cake he's still a bit
peckish.

The domestic cat has canines sharp
enough to easily pierce skin,

so the balloon was no problem.

It's an adaptation that's
useful for catching prey,

unless of course that target
is part of your own anatomy.

I once asked my late grandmother why it
is that we paint Easter eggs.

She said it was because it was easier
than trying to wallpaper them.

But that was my gran for you.

Looking for Easter eggs is difficult,
because whether you're hunting high,

or low, inside,

or outside,
they can be dangerous.

I think mum is more keen
on this than you are.

There are lots of ways to
get Easter egg hunts wrong,

but luckily science is here
to show us the correct way.

Our man wants to get to the egg before
anyone else, so he builds up momentum.

To simultaneously run and grab the egg,
he must use coordination,

performing several
movements in the right order,

using visual information
to guide and adjust.

As he reaches down for the egg, his
center of mass shifts,

creating a turning force,

converting linear momentum
into angular momentum.

Children need time to develop more
complex motor skills

and are less coordinated than

adults, so they're more susceptible to
hazards, ensuring more eggs for me.

But that doesn't stop
them from trying.

[woman off-screen]
On your marks...

...get set...

...go!

[girl] Whoa!

[laughter].

[Dallas off-screen] I don't think she's
gonna find any eggs in there.

It doesn't matter how fast you are, if
your cat destabilizes you,

your linear momentum will become angular
momentum,

and you're straight in the wet
stuff.

Ten out of ten.

Perfect technique.

Good control of momentum.

And another egg in his sights.

He's on a roll.

And now he's on the floor.

With a last-minute change of direction,
his forwards momentum is disrupted.

One bad foot placement, and he's created
a turning force that trips him up.

This guy lives by one rule.

Slow and steady wins the race.

[girl] Go, go, go! Whoa!

[Dallas off-screen] Just a shame his
sister wasn't listening.

She appears to lack the
coordination to ensure her legs

can keep up with her
body's momentum.

And with a little help from gravity,
she's heading straight for the ground.

But it doesn't stop
her laser-like focus.

[girl] Don't let
anybody get them.

[woman] Ok honey, it's ok.

[Dallas off-screen] On
beating her brother.

All of scientific knowledge is built on
a foundation of uncertainty,

and only moved forward
by experimentation,

so we should look on the people in this
program

not as buffoons, but as
pioneers.

[music plays through credits]