06x01 - Yoga, Aerial Silks and Bo Staff

[bunniefuu]

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

[man] Ah!
[Dallas off-screen] Yes.

This is the show
where we put actual sense into

what's obviously
ridiculous nonsense.

We learn our lessons the fun why, whilst
others learn theirs the hard way.

Then, we reveal what went wrong and why,

with the help of such scientific
principles

as weightlessness, gravity.

And a little buoyancy.

In the battle between fools and physics,
there's only ever one winner.

Watch out, it's
the Science of Stupid.

[Dallas off-screen] In this show, we'll
be learning about Young's modulus,

gravitational
potential energy.

And static equilibrium.

Or lack thereof.
But first, this.

[Dallas] We now all know that lightning
is merely a giant electrical spark,

five times hotter than
the surface of the sun.

But for our ancestors, it was powerful
and mysterious, so they, quite sensibly,

attributed it to the gods.

[Dallas off-screen] A Viking might have
thought this cruise ship had done

something to anger Thor.

Perhaps this restaurant
served Zeus a cold burger.

And woe betide you if any god decides to
judge your talent show.

Yeah, I'm afraid it's
a no from me, too.

[Dallas] Lightning has an eternal
fascination for humans, as even today,

we can't quite believe that amount of
power exists in the clouds.

But, as ever, science
has an explanation.

[Dallas off-screen] As particles bounce
around in clouds, electrons

are knocked
off atoms, as they ascend.

Leaving them behind, at the bottom of
the cloud, giving it a negative charge.

Since opportunity charges attract,

a positive charge will develop at the
top of

tall objects, like this
tree via the cloud.

But air is a very strong insulator, and
the enormous electrical resistance

makes the discharging lightning bolt,
when it comes, incredibly hot.

It can instantly vaporize
water in anything it hits.

The superheating and expansion of air

then causes a blast wave that we call
thunder.

[Dallas] Did you know that a single
storm can discharge

enough energy to power the entire

continental United States for
twenty minutes?

So, to avoid becoming an unwitting
lightning rod during a thunder storm,

it really is best
to stay inside.

[man] There's a man out there.

[Dallas off-screen] During peak season,
Venezuela's Lake Maracaibo averages

a record 28 lightning
strikes a minute.

But this is Canada.

[man] Get back! Ah!
[man 2] Oh my God! Oh, [bleep]. No!

[Dallas off-screen] So, that
is a bit more of a novelty.

[man] Holy [bleep].
[man 2] Man.

[Dallas off-screen] As the lightning
hits the tree,

its intense heat vaporizes the water in
the living wood.

The liquid instantly
turns to gas and expands,

causing the bark to
explode off in large chunks.

[man 2] Damn.
[man] Holy [bleep] man.

[Dallas off-screen]
Ah, this looks romantic.

These lovebirds are going snorkeling in
a rainstorm,

and there's just enough time
for a quick selfie.

Perhaps a little flash?

Yeah, that's better.

The lightning strike
superheats gas in the air.

Causing it to expand,
and send out a shockwave.

So, if you find yourself holding
something

tall and conductive in a
storm.

It really is best to drop it, no matter
how unpatriotic you look.

[Dallas] Humans have been climbing
mountains

for almost as long as they've
been humans,

but only recently has it been done
solely for its fitness potential.

[Dallas off-screen] Mountain trekking is
a potent c*ck

of cardiovascular endurance
and adrenaline,

great for anyone who likes their
workouts with a view.

I think I may have
finally found my sport.

Yeah, actually, I've had a think about
it

and I'm probably just gonna stick
with the jazz boxercise.

[man] Umm...

[man] Yeah, you're not
gonna want to go that way!

[Dallas] Not knowing what you're doing
in mountain trekking kills

people each and every year.

So, if you fancy giving it a go,

you'll really want to pay attention to
the science.

[Dallas off-screen] Our
man's first issue is balance.

He can help himself by keeping
his center of mass low.

In other words, he needs
to squat, slightly.

But he has less control over his
terrain, earthy ground breaks

up easily beneath his feet.

But stones and rocks have a high Young's
modulus, and are incompressible

under his weight.

He still needs to be wary
of foot placement, though.

Friction between the rocks he's standing
on and those below can be low,

meaning the top rocks can
slip, giving him problems.

[Dallas] The Great Trail in Canada is
the longest hike in the world,

just under 15,000 miles.

But even if your treks are a, a little
bit more modest,

then success comes down to the
same three things,

balance, an understanding of friction,
and good foot placement.

[Dallas off-screen] Hugging the wall
will help with balance,

but not foot placement.

There's high friction between this
underdressed climber's shoes

and the rock, but low friction between
that rock and the one below it,

which leads me onto
one more bit of advice.

Don't get overconfident.

As a little skip down a
mountain trail can lead to.

[man] No, are you alright?
[man 2] Ah!

[man] No!
[Dallas off-screen] A much bigger step

than the one you intended.

This shirtless trekker lands on a
granite rock,

which has a high Young's
modulus,

so it will only compress
by an imperceptible amount.

But the earth its resting on is much
less resistant,

so it gives way, instead.

Oh, isn't
physics funny?

[man] That's it, nice and slow.

[Dallas off-screen]
There's a lesson here.

If you want to stay
safe, stay slow.

[man] Well done.

[Dallas off-screen] Running like this
guy is just asking for trouble.

[man] [bleep]. Are you okay?

[Dallas off-screen] And it
looks like he's found it.

The ground here is loose stones on top
of dry, compacted earth.

The low coefficient of friction between
them means he can't get enough dynamic

friction to stop.

Ah yes, he's managed it, now.

So, I suppose we could summarize the
whole thing like this.

Rocks, not quite as stable
as they get credit for.

Do you think he'll
clear the fence?

Of course he won't, this
is the Science of Stupid.

But which scientific principles will
combine, to ruin his day?

[Dallas off-screen] Did you spot the
scientific principles

that are about to conspire

against our teenage swinger?

Well, his take-off angle was pretty
good,

near to the 45 degrees required for
the optimal parabolic trajectory.

Sadly, his take-off
velocity was to low.

So, instead of clearing the
fence, his feet caught it,

but his momentum meant the rest of
his body just kept on going.

He's fine, but it's a valuable reminder
of why shouldn't try this yourself.

[Dallas] I am forever getting tangled up

in things like headphone cables, dog
leads,

romantic misunderstandings, but luckily,
I've found a hobby that turns this

affliction into an asset.

[Dallas off-screen] I'm talking, of
course, about aerial silks,

where the poetry of ballet meets the raw
power of circus performance.

But just like any art form, it
does take a bit of practice.

Yeah, someone
get the scissors.

[Dallas] Aerial silks are a type
of acrobatic dance,

performed while suspended by fabric.

Behind the undeniable poetry lies some
rather interesting physics.

[Dallas off-screen] As our acrobat
drops,

the controlled unwrapping of the
silks

allows gravity to accelerate him, as his
gravitational potential energy

is converted to kinetic energy.

As he reaches the bottom,
his momentum changes rapidly.

This increases
the load on the silk.

So, it needs the tensile strength not
just to support his static weight,

but this extra force, too.

So, now we know the secrets of the
silks, let's see who's been listening.

[screams]

[Dallas off-screen]
Yeah, definitely not her.

This lady's routine is going well,

until she decides to switch her weight
to one hand.

With it, she doesn't have the grip
strength

to counteract her static weight.

[screams]

[Dallas off-screen] And that gym mat is
gonna leave a nasty taste in her mouth.

This artist has sensibly
created a cradle,

the silk around her body that supports

her static weight is
a good safety feature.

[woman] Ah!

[Dallas off-screen]
That fails entirely.

As she twists, she reduces her contact
with the material supporting her,

and starts to fall.

As she does, her gravitational potential
energy converts to kinetic energy,

as she accelerates
under gravity.

But when her leg slips, that cradle goes
from being a lifeline

to a liability.

And remember to check the tensile
strength of your equipment,

as even if you're quite slight, the
force of your body coming to a stop.

Won't be.

[Dallas] Okay, class,
pay attention.

Yes, it's time for today's science
lesson,

that part of the show where we
put one

scientific principle
under our microscopes.

So, who can tell me what's being
demonstrated by the following?

[Dallas off-screen]
A careless motorist.

A clumsy long boarder.

[man] Oh, [bleep].

[man 2] Oh, ah!

[Dallas off-screen] And an
extremely loud car stereo.

[Dallas] Did you guess
'driven oscillation'? No?

Well, if not, pay attention, because
there will be a test, afterwards.

[Dallas off-screen] When we hit the
tuning fork, it vibrates, or oscillates,

at its intrinsic
natural frequency.

All objects do,
when struck.

These oscillations are damped down by
external forces, like water resistance,

until it comes to rest.

But, if energy is added at just the
right frequency,

like the sound from
these speakers,

then the amplitude of
the vibrations will grow.

We call this a
driven oscillation.

The glass can't lose the kinetic energy,

or dampen the oscillations quickly
enough.

So, eventually.

It breaks.

[Dallas] Well, that all seems
fairly straightforward.

So, let's start
with the basics.

Question one, what
is an oscillation?

[man] Oh, yeah.

[Dallas off-screen] It's always
nice to see a brave researcher

ready to get their hands dirty

and help with a practical demonstration.
[man] Yeah!

[man 2] Ah!
[man] Oh, oh, oh, oh.

[Dallas off-screen] Even if it
then goes very badly wrong.

Oscillation is moving back
and forth rhythmically.

It happens when energy is added to
certain systems, like this.

And finishes when those
oscillations are damped.

Not usually by a head hitting a bank,
but there we are.

The bricks rotating inside this washing
machine cause it to oscillate,

but the vibrations are damped by the
trampoline, spoiling all the fun.

[Dallas] Okay, question two.

What happens if energy keeps being
added to a system

at a specific frequency?

[man] Oh.

[Dallas off-screen] Oh, that.

Here, the two chaps on the outside are
swinging the hammock,

and because they're adding energy
at just the right time,

the swings keep getting higher.

So, this is driven
oscillation.

And a good way to make
everything taste of sand.

[man 2] Ooh.

[Dallas] And the last question.

What happens if energy is added more
quickly than it can be damped?

[Dallas off-screen] That's right,

the oscillations will grow and grow like
that,

until they become
uncontrollable, like that.

[man] What the.

[Dallas off-screen] You can see how the
small side-to-side movements build up,

until they overcome the driver's ability
to control the car,

but not his ability to
make a massive mess.

Luckily, the driver here was fine, but
the same can't be said for his car.

So, that's driven
oscillations.

[man] Ah!
Ah! Oh my god, oh my god!

[Dallas off-screen] He's
right, it is exciting stuff.

Alright, class dismissed.

[man] Did you get it, did
you get it? Oh my god!

[Dallas] In India, yoga has a meditative
and spiritual core,

the ultimate goal being
moksha, or liberation.

But in the west, it's much more
associated with exercise

and very, very stretchy pants,

which feels like we might
be missing the point.

[Dallas off-screen] But when
you've mastered yoga on land,

why not take your
practice onto the water?

Impressive stuff.

Do it well, and you, too,
can find spiritual balance.

Although, I think all she's found is how
many leeches live in that lake.

[woman] That was awesome.

[Dallas off-screen] That's
what the leeches think, too.

[Dallas] Combining exercise with
spirituality,

stand-up paddleboard yoga is gaining
popularity with the millennial crowd.

So, fix up your manbun,
put away your healing crystals,

and get ready for
some proper science.

[Dallas off-screen] Doing a
typical headstand,

our man needs
to create static equilibrium.

He does this by maintaining body
tension, and keeping his center of mass

within his base of support.

This is much harder on water,

where the board's ability to
move means he has to deal with

an ever-shifting
center of mass.

If our man's dry, he'll have plenty of
friction between his body and the board,

but there's no friction between the
board and the water.

So, if he applies any horizontal forces,
it will slide away from him.

It sounds hard to stay dry with this
one, so let's start slowly.

Step one, be wary of applying horizontal
forces, or you will look a lot less zen

and a lot more.

Stupid.

As this lady launches herself forward,
her moving the center of mass,

combined with the lack of friction
between board and water,

means it moves backwards while she
learns to move more slowly.

Like these two, unhurried,
deliberate movements,

so as to not push their boards in the

opposite direction,
barely a ripple.

These two have that mastered.

But, they still need
to work on everything else.

When these yogis lift a leg, their
centers of mass

are no longer directly
over their bases of support.

So, their boards
slide out from under them.

And I wonder if this
would work with a surfboard.

Let's see.

No. No, it wouldn't.

A surfboard is less buoyant than a
paddleboard,

and pushing it underwater
is like loading a spring.

But as he leans, he applies a
horizontal force to the board.

So, he falls one way, and it fires out
the other, quite painfully.

So, that's water yoga,
a quick way.

[man] Oh, ah.

[Dallas off-screen]
To realign your chakras.

[man] Oh my God.

[Dallas] If, like, me, you know your
ancient Japanese weapons,

then you'll know all
about bo staffs, or bojutsu.

[Dallas off-screen] Technically
difficult, visually impressive.

They're a firm favorite
in action movies.

[man] Go.
[man 2] Ready?

[man] Yeah.
[man 2] Action.

[Dallas off-screen] No
matter what the budget.

[screams]

[Dallas off-screen] Even
very, very cheap ones.

[man 3] Ah!

[Dallas] The bo staff gained popularity
in fifteenth century Japan,

when weapons were banned
under the Sho Dynasty.

But, people were allowed staffs to
help them carry water.

The history is interesting, but not as
interesting as the science.

[Dallas off-screen] As our martial
artist spins his bo,

its constant angular velocity
translates into different

linear velocities at
different parts of the stick.

The very ends of the staff have to
travel the furthest,

so they travel fastest, giving them lots
of momentum and kinetic energy.

You do need to have an awareness of the
staff's plane of rotation,

and quickly changing it by moving his
hands across his body

is especially tricky.

That sounds hard, which is why I'm gonna
leave this one

to our amateur scientists.

[man] This is a workout, jeez!

[Dallas off-screen] Yeah,
you're gonna feel that tomorrow,

although mainly in the jaw.

[man 2] I got that on video.

[Dallas off-screen] When his shoulder
gets tired, his arm drops slightly,

and the staff's new
plane of rotation.

[man 2] Ooh.

[Dallas off-screen] Passes
right through where his face is.

[man 2] Alrighty.

[Dallas off-screen]
Now, she's got it mastered.

Maybe this is a bit
simpler than it seems.

Yeah, maybe not.

Very quick rotations means that the end
of her bo staff was traveling

at around 50 miles an hour.

That's as fast as a bolting gazelle,

and about as damaging to have in your
lounge.

Still, she looks more
professional than this guy.

[woman] Watch the wine!

[Dallas off-screen] Who seems to be
using half of his mum's mop.

That's bo staffs.

They take years to master.

Really doesn't seem
worth it, does it?

Galileo Galilei apparently once said,
'You cannot teach a man anything,

you can only help him find it within
himself.'

Well, this lot are still
looking.

♪ ♪

[screaming]

[man] But I think that's
a wrap on that, at least.