05x19 - Backflips, Bikes and Burpees

[bunniefuu]

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

[man] Ooh!

[Dallas off-screen] Yes, this is the
show

where we focus the microscope of
truth

on the petri dish of stupid.

Prepare to see people feel a whole world
of pain of their own making.

We'll explain what
went wrong and why,

with the help of such
scientific principles

as Newton's
Third Law of Motion.

Coefficient of Friction.

And the Center of Percussion.

So strap yourself in
and keep your eyes peeled,

it's the Science of Stupid.

In this show we'll tackle
angular momentum,

oscillation,

and kinesthetic awareness.

But first this.

There are many reasons why people cycle,
it's healthy, it's cheap and it's green.

In fact it's now so popular there are
over a billion bicycles on the planet,

but only a few brave few
souls decide to ride a tandem.

If you want to join them,
make sure your bike's solid.

Make sure you're both
steering the same way.

And if you want to be good,
make sure you start young.

Sharing your wheels with someone else
presents a cornucopia of conundrums.

So if you don't want to be tripped up by
a trip on a tandem,

then you're best to
listen to the science.

The two cyclists on a tandem are
known as a stoker and captain.

While the long wheelbase gives them less
chance of flipping forward when braking,

side to side stability
is more difficult,

since the two riders must both be
balanced over a narrow base of support.

And if they overcompensate by steering,

the bike can oscillate and become
difficult to control.

So like any good relationship this is
all about communication and stability.

Now who's up for a ride?

These two appear to be
poor communicators,

and as a result their
relationship lacks stability.

Perhaps they should work on themselves
before getting mixed up with each other.

Their side to side stability gets worse
as they both overcompensate.

The stoker's movements become out of
synch with the oscillation of the bike,

causing the movements to grow to a point
where their only destination

is the ground.

That's a funny looking tandem.

And he needs a hand.

It looks like his friend
is going to help him,

to fall over.

The jumping stoker causes the
tandem to lean,

and the high center of mass starts a
topple.

But by then it's too late for corrective
action and down they go.

Throwing a jump into the mix is
not a good idea,

because with more mass at each end the
bike has a higher moment of inertia,

making it harder to rotate
front to back over the jump.

And when you add into the equation the
need for equal weight distribution

and a safe landing, it sounds like a
recipe for bad things happening.

But that hasn't stopped
these two from trying.

Better luck next time.

With a large moment of inertia,

their bike is more resistant
to the front to back rotation

required to travel
the ramp, which leads

to a less than
awesome landing.

Maybe these lovebirds
will fare better?

If anything, that's worse.

Although I have had more
painful first dates.

There are a lot of things that people do
for fun that I think are a bit strange:

elephant polo, river dancing,
extreme dog grooming.

I long for a simpler time

when you could have all the fun you
needed in your local playground.

Everyone loves the
climbing frame.

The roundabout is
always a good laugh.

But I was never a fan of this.

For reasons like that.

Of course if you're silly, playgrounds
can be dangerous places,

which is why I always steered
clear of the high carousel.

It injected a level of jeopardy that I
was never comfortable with,

and this science
should explain why.

As our man starts to move,

Newton's first law tells us that his
body's inertia

wants it to continue
in a straight line.

To allow the carousel to spin him, he
must use friction between his hands

and the carousel to grip on.

But centrifugal force
pulls him to the outside.

This can overcome the friction from his
grip and send him flying.

It's well known that Isaac Newton came
up with his first law

whilst spinning on a carousel.

At least that's what I heard.

But for most of us, the
challenge is just staying on.

This looks like a
really bad idea.

Why am I always right?

The high rotation speed creates a large
centrifugal force,

once his feet are loose,

his inertia drags his
body further out,

until he decides it's time
for a bit of a sit down.

If that was bad, this is worse.

Yeah, he's not going
to be doing that again.

His initial grip is sufficient to keep
him clamped to the carousel,

but as he accelerates,

the centrifugal force
increases overpowering his grip,

and sending him face
first into the sandpit.

[man off-screen] Got it?

[Dallas off-screen] It's always
nice to have a helpful husband.

WOMANL Like, go slow!

MAN [off-screen] Aargh!

[kid off-screen] Duck, daddy!

Duck, daddy!

[Dallas off-screen] You really
should listen to your children.

She has a good enough grip
to hold onto the carousel.

[woman] Like, go slow!

[Dallas off-screen] But the centrifugal
force pulls her lower body

out to a horizontal position, and it's a
clip round the ear for her husband,

and a bruised
coccyx for her.

I think the best thing is to
stay seated, just don't get off.

I told you.

Sweet moves, but what
scientific principle

is this backroom break-dancer
about to demonstrate?

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

was about to show us.

If you said transfer of momentum, go to
the top of the class.

His leg had a lot of momentum because it
was moving around at high speed.

When it collided with the bottom of the
desk support,

his leg transferred momentum to it,

making the bottom rotate outwards

and bringing his freestyle to an early
finish.

Oh, that's why they
call it breakdancing.

I love nothing more than simply
throwing myself into water.

Done right, the pool back flip

is one of the most elegant examples of
the strength and

poise of the human body.

But done wrong, and it can
all get very uncomfortable.

I bet that hurt.

I know that did.

Maybe it's easier in the wild?

Or maybe not.

Personally I prefer a full body bathing
suit and some form of inflatable.

But if you insist on back
flipping into the pool,

then we at the Science of Stupid are
only too happy to help.

Standing on the edge of the board,

she jumps to generate vertical and
horizontal

velocity, and throws her arms backwards
to generate angular momentum.

Once in the air, she reduces her moment
of inertia by tucking her legs in tight

to increase her rotation speed, before
stretching out again to slow her

rotation and form a streamlined
shape as she enters the water.

Of course you're limited in how much
angular momentum you can get,

since your body isn't made
for bending backwards.

But basically it's a case of, close your
eyes, fling yourself up and back,

and hope for the best.

Shall we start with a small one?

Oh right, straight
in at the top.

Yeah, I thought that
was a bit ambitious.

This brave diver doesn't tuck in very
tight,

meaning he doesn't increase his
rotation speed

enough to get him all the way round, and
he's heading straight for a back flop.

Ooh a bit of bounce,
this looks professional.

Well not that bit.

Great upward velocity and enough angular
momentum for a full spin,

but stretching his arms
out slows him too quickly,

leaving him a quarter turn away from a
dive, and thoroughly humiliated.

It seems the pros can't
do it, so can anyone else?

I don't think he
was even trying.

It's always nice to have an audience
when you wanna show off.

But he probably wishes that
people weren't watching that.

He has the vertical
velocity and back spin,

but he totally forgot about the
horizontal velocity

needed to get to the pool.

And misses it completely.

Settle down at the back, Jones.

You're not going to learn anything by
doing wrestling moves.

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

the part of the show where we test you
on a key scientific principle.

So who can tell me what the
following have in common?

These sliding siblings.

This slipping scooter.

And this skating sedan.

Need more time,
well it's too late.

Pens down, today's lesson is on active
and passive forces,

and how one responds to the other.

Bring on the science.

She applies active grip
to the ball handles

which produces the passive force of
friction to keep them in her hands.

As she swings the poy, the weights put
the rope under tension,

also a passive force.

The trailing veils experience
passive air resistance,

which makes them lag behind the poy.

And when they
impact the ground,

they experience a ground reaction force
that stops them in their tracks.

And Newton's third law tells us
that active and passive forces

come in equal and
opposite pairs.

So passive forces usually
balance out active forces.

Right, lets see whose
been paying attention.

Question 1, what usually
accompanies an active force?

This is the Science Lesson,
not ice hockey training.

That'll teach you to skip class.

That's right, forces always come
in equal and opposite pairs.

He applies an active force
to the chair when he hits it.

Newton's third law ensures he
experiences an

opposing passive impact force

leading to a smack in the face.

[man off-screen] Oh man!

[Dallas] Question 2.

Who can give me an example of a passive
force we rely on every day?

Here's a clue, it's a great
way to impress a lady.

You see that seems to
have got her attention.

Yes of course it's friction,
which can be a bit of an issue.

Because of the ice there's a reduction
in the passive frictional force,

the wheels of the car spin but they're
unable to grip the road,

causing a slide.

Against all the odds, he's
parked up without crashing.

It's always nice
to get home safely.

Ooh, nasty.

[woman off-screen]
Are you all right?

[Dallas] I'd get
some ice on that.

[man off-screen] No!

[Dallas] So we know what
active and passive forces are.

But question 3, what happens if the two
forces are perfectly balanced?

Ready?

That is deeply unimpressive.

The passive force, in this case,
friction,

overcomes the active force of
his weight

on the dry slide, before
balancing it exactly.

Meaning he isn't
going anywhere fast.

And that's the end of our Science Lesson
on active and passive forces.

Class dismissed.

[Dallas] For some people the idea
of a day in the gym is heaven.

They love pumping iron, getting sweaty,
and flexing in the mirror.

I hate those people,
and I hate the gym.

You can never get
on the machines.

There's always some
guy showing off.

And the ball pit is too small.

But if you insist on going to the gym,

you'll probably want to have a go at a
burpee,

it's an exhausting exercise consisting
of a squat and a thrust,

followed by a jump.

And if you do, we've
got the science to help.

He starts the burpee by flexing his
knees and explosively kicking backwards,

generating momentum to get
him into a plank position.

He then uses arm and shoulder
strength to perform a push up.

Mobility and strength in his
hip joint

allows him to pull his
legs back underneath his torso.

Finally he pushes his feet into
the ground with enough force

to propel himself from the ground.

Doing this repeatedly requires good
coordination and kinesthetic awareness,

as well as strength and stamina.

It all sounds too much
like hard work to me,

but some people insist on adding an
extra element to their burpee workout.

He's adding in a ball throw,
making it more complex.

Which in retrospect
wasn't the best idea.

Racing against the ball
challenges his coordination

and he gets himself into
an unbalanced position.

It's too late to readjust, and
soon he's feeling the burn.

Ah, the classic swing burpee.

That's a bit of an
unorthodox technique.

The force she puts on the swing

affects how long it'll take to go back
and forth.

Coordinated perfectly, and it keeps the
pace of the burpees up.

Timed badly and it can
lead to a serious headache.

The good thing about working out
at home is

no one can watch except your best
friend.

Don't worry he won't
tell, because he's a dog.

He combines excellent
coordination

and expl*sive movements
to complete the burpee.

But the added pull up puts
too much pressure on the bar,

and the only expl*sive movement
is the one down to the floor.

Time to kick it up a notch.

I've decided to call this one, the
Dallas Burpee,

because of how cool it looks

and the ease with which I
can reel off a 100 of them.

Anyone else wanna try?

Yeah, we might need to
work on technique here.

Adding a back flip makes
the burpee more difficult.

Without the strength to jump hard and
tuck tight, the rotation fails,

and it's less
burpee, more hurtee.

The only problem with having pets is
just how much attention they need.

Fortunately I've
been lucky with mine.

They take themselves out.

Make their own entertainment.

[boy off-screen] Go, go, go!

[Dallas off-screen] And even
sort their own dinner time.

And that's because teamwork is
vital in the animal kingdom,

as the science will
no doubt explain.

Teamwork is cooperation is cooperation
in animals for beneficial purposes.

By working together, groups
like red ants can achieve tasks

they wouldn't be able
to individually.

It's a survival instinct that
enables complex

hunting patterns in order to eat.

One of the keys to good teamwork
is excellent communication,

as well as a clear sense of
everyone's role in the group.

Great communication and working with
others has always been my weak points.

So it's a good job I don't
have to live in the wild.

Ah, the dog, man's
obedient best friend.

[man off-screen] Bath time.

Daisy!

Bath time.

Daisy!

Bath time!

[Dallas] They're
more shower dogs.

Dogs are experts at team work,
having evolved to hunt in packs.

With a common goal of avoiding
bath time,

the skills of one dog allow both
to stay dry,

and leave their owner.

[man off-screen] Bath time.

Daisy!

Bath time!

[Dallas off-screen] Stranded
and bewildered on the patio.

And when it comes to playtime
they'll go the extra mile,

especially for something
as fun as a tire.

It's too complex a job for an
individual, but by splitting the task,

and reacting to each other's
approach, they get the job done.

It's a bit big for a
game of fetch though.

[man off-screen] Did you
make this mess, Dakota?

[Dallas off-screen] There's
nothing worse than getting home

to realize the kids
have had a party.

[man off-screen]
Was it Phoenix?

[Dallas off-screen] I'm not sure you can
trust anyone named after a place.

[man off-screen]
Who made this mess?

[Dallas off-screen] Huskies are
known for working in groups,

and these two are pros.

[man off-screen]
Was it Phoenix?

Was it you?

[Dallas off-screen] Yeah,
they've got each other's backs.

Not that that is
gonna tidy the house.

[man off-screen] Wait?

[Dallas] Well that's all for now,

but I shall leave you
with this little nugget,

often attributed
to Albert Einstein.

If we knew what it was we were doing, it
wouldn't be called research, would it?

[music plays through credits]