05x01 - Big Wheel Trike, Motorbikes and Balancing

[bunniefuu]

[Dallas] This
is the Science of Stupid.

[Dallas] Yes, this is the show
that squeezes some sense out

of preposterous nonsense.

Our trusty team of testers learn their
science the hard way

so you don't have to.

Then we scrutinize what went
wrong and why,

with the help of such
scientific principles

such as centrifugal force,

angular momentum

and of course torque.

So don't try any
of this at home.

Actually don't try it at all.

Watch out.

It's the Science of Stupid.

[Dallas] In this show we'll
tackle turning force,

the impulse momentum theorem
and inelastic collisions.

But first this.

Nature is amazing.

The breathtaking majesty of
the Grand Canyon,

the soaring heights of the Himalayas,

the way penguins always look as if they're
on their way to the Oscars.

But one thing nature doesn't do that well
are compact ramps made of snow.

[Dallas] In fact most ramps are best
man-made and done right they allow you

to avoid things like
synchronized flops,

unexpected face plants
and unwanted snow angels.

Learning how to jump a snow ramp can
take years to perfect,

but luckily for us science has some tips
on how to master this art.

[Dallas] As our man
gains speed he needs to know

that the longer the ramp the
more velocity he'll lose due to

friction and by traveling
uphill, against gravity.

So, the shorter the ramp
the faster he'll launch.

The steeper the ramp the
higher he'll jump that the

more air time he'll
have for tricks.

A smoother ramp means a lower coefficient
of friction between the board and snow,

allowing him to
go even faster.

Just be careful
not to go too fast.

So it's all about
velocity, angle and friction.

Get those right and the only other thing
you need is snow, lots of snow.

[man] Alright.

[man] We've got this
little like pile...

...of ice rink snow.

[man] Sean thinks
you can backflip it.

[man] The jump's like
a foot and a half tall.

[Dallas] See that
doesn't look like enough snow.

Not enough for a
soft landing anyway.

This ramp's smooth so has a
low coefficient of friction

allowing Sean to maintain lots
of his velocity for launch,

but a short run up meant he didn't have
much velocity to begin with.

[man] Are you OK?

[man 2] ****!

[Dallas]
I don't think so.

Deeper snow this time and
a longer run up means this

guy can build
speed for his jump.

However, his teeny tiny ramp
isn't steep enough so he can't

get any height for
his rubbish trick.

Luckily he's got supportive friends to
help him through this tough time.

[man] ****!

[Dallas] I know what you're
thinking, has this guy got it?

Well no, unless you were
talking about concussion.

Pulled along by a snow mobile
he had plenty of velocity

but he missed the middle of

the ramp and the angle wasn't steep
enough to get him over that bar.

But at least he got
ice on it straight away.

This looks better.

No buildings to hit.

This jump should be perfect.

Shame about the landing.

With so much velocity this guy got a lot
of air, more than he expected,

which lead to...

A less than elegant landing.

[man] Are you all right?

[Dallas] And some dented pride.

I love a wedding and I always
promise myself the same thing,

this time I won't cry.

But I barely make it to the 'I dos' before
I'm a big snotty mess.

It's one of the reasons I'm no longer
allowed to officiate nuptials.

Apparently I've been accused of being
distracting and unprofessional.

Yet for some people weddings can be the
best day of their lives.

[Dallas]
Ah, falling in love.

Or just falling.

Making a grand entrance.

They'll remember him.

And that
passionate first kiss.

Hang on, save
something for the honeymoon.

But for me the best part of a wedding is
of course the first dance,

and what better chance to show off your
well rehearsed dance dip.

If you don't want to mess up your big day
you better listen to the science.

Our man needs to achieve a balanced
position by creating a large,

stable base of support.

He signals to his partner that he will be
dipping her

by placing his hand on her back.

Our man then moves his partner's center
of mass backwards,

using their weight to
create a turning force.

But to stay balanced he needs to make
sure that their combined center of mass is

within their combined base
of support or they'll have

an inelegant
rotation to the floor.

So, it's all about having a strong
combined base

of support and using turning

force to elegantly rotate
your partner backwards.

Right.
I think I've got it.

Now all I need is a partner.

Ladies?

Men dressed as ladies?
Anyone? No?

Oh well, let's see if this lot have my
natural grace and winning charm.

Many couples spend months going to
lessons so they'll nail that first dance.

If these guys had maybe it
would have gone a bit better.

A nice rotation into the dip provides
sufficient turning force from her weight.

But her turning force overcomes his
ability to resist it.

Still there's nothing like starting
married life off with a bang,

to the head.

[Dallas] Ah, here comes a dance
teacher and partner.

These two should
be well rehearsed.

Clearly somebody wasn't paying
attention in class that day.

Balancing on one leg shouldn't be a
problem, if you maintain a stable

combined base of support with your
combined center of mass within it.

But they didn't
do those things.

And don't feel you have to save your
dips just for weddings.

In the wider world you
can even practice en masse.

But those two might wish
they hadn't had an audience.

Her turning force becomes too much for
her partner to resist,

throwing him off balance.

It's alright, you just carry on.
I don't think anyone saw.

Here we have a kind uncle
teaching his niece to dance.

[woman] Oh my God,
it's so creepy!

[Dallas]
People can be so judgy.

It's never weird when I
slow dance with my uncle.

Luckily help is at hand to
save the world's largest TV.

[man] You guys got that right?

[Dallas] Oh yes we did.

These days every young man dreams of
owning a tractor, but can you guess what

science this keen mower
is about to show us?

[Dallas] This young chap is doing
a spot of mowing but what

scientific principal is he
about to demonstrate?

[man] Holy ****!

[man] ****!

[Dallas] It's torque.

With his rev to get up the hill the engine
exerts a torque on the rear wheels

which in turn exerts a
reaction torque on the body,

usually resisted
by its weight.

However, because his weight
is at the rear of the tractor,

the torque
causes the front to

rotate up and back into
an accidental wheelie.

[man] ****!

[Dallas] Don't worry, he was fine.

I think that one of the true marvels of
Roman engineering are

arched stone bridges, many of
which are still standing today.

But even 2000 years later some people
still haven't got the hang of them,

which is weird because you'd think that
using any bridge would be pretty simple.

[Dallas] He's
not got the hang of them.

Yeah, neither of they.

And he's definitely
not doing it right.

Going under a bridge is a bit more
complicated that it first appears,

and science tells us why.

[Dallas] When
our man approaches a bridge

it's important for him to
remember that no two solid

objects can occupy the
same space at the same time.

And humans tend to over-estimate the
height of vertical structures,

so our man could misjudge the clearance,
resulting in a collision.

This is likely to be an inelastic
collision which will dissipate some of the

truck's kinetic energy and slow him down,
causing damage in the process.

The greater the truck's velocity the more
kinetic energy it has and the more

damage there's likely to be.

Ah, so that's why
people get stuck under bridges,

by over-estimating the height
of surrounding structures

and thinking
that they have more

space than they do, which I suppose is why
they often have nice clear signs on them.

[Dallas] Like that.

Hard to miss.

But not impossible.

Looks like this guy forgot that two solid
objects can't occupy the same

space at the same time.

In this case those
boards and that bridge.

I'd offer to lend a hand but I've got
places to go, people to see.

Like this maverick.

[man] Oh here's a big one.

[man] ****!

[man] What a ******* idiot!

[Dallas] He's forgotten that structures
tend to appear taller than they are

and has over-estimated
the bridge's height.

Luckily for him the has little kinetic
energy and the load nearly fits,

so the suspension and boom have enough
give to squeeze through.

The world's longest bridge
is 102 miles from end to end.

Fortunately for these
guys this isn't it.

The driver of this snow covered truck
seems pretty optimistic about

getting under that bridge.

Fortunately the snow is weakly attached so
the collision disperses it while

the truck remains undamaged.

Not so lucky for
the driver behind.

Now where'd that truck go?

Remember people, there's always a
tendency to over-estimate height,

so be careful out there.

[Dallas] Yeah,
a bit more careful than that.

The collision rotates the truck and
dissipates enough kinetic energy to

entirely destroy it's load.

I don't think
he's noticed though.

It isn't the end of the day until I say
it's the end of the day.

Yes, it's time for today's science lesson,
that part of the show where we probe the

inner workings of a particular
scientific principle.

So who can tell me
what links the following?

[Dallas]
These topless tumblers,

this outside acrobat,

and this gym
ball joker?

Do I really need to
tell you not to do that?

Yes, the answer is of course the impulse
momentum theorem.

In other words the amount of force you
absorb over a specific amount of time

in a collision which
changes your momentum.

As two objects accelerate towards the
ground they build momentum.

But when they slow they experience a
change in momentum or impulse.

In a sudden collision the object
experiences the

same impulse over a
shorter period,

resulting in a much
larger impact force.

But in a gradual collision the
object experiences

an impulse over a long
period of time,

resulting in a
small impact force.

Got that?

Well let's see.

Question 1, if the momentum of an object
is transferred quickly

does it have a large
or small impact force?

[Dallas] That's
right, a large impact force.

Humans are rigid, so they don't absorb
momentum gradually.

[man] Get out the way ref!

[Dallas] That probably would have
been a good idea yes.

It looks like these guys may have solved
that particular problem.

A valiant effort.

Our man in yellow builds enough
momentum

to overcome that of his
opponent.

Luckily bubble ba*ls deform on impact,
giving you a soft landing.

Question 2, What are the best ways to
reduce your impact force in a collision?

[Dallas] This mum
seems to have sussed it out.

She's surrounded by items that will absorb
momentum gradually,

luckily.

When mum jumps onto the ball it absorbs
her momentum then redirects it,

rebounding her into her
compliant surroundings.

[man] You didn't make it.

[Dallas] It's good hear someone's
paying attention.

Two friends
sandboarding together.

That's nice.

That's less nice.

As sand is granular it can absorb

momentum more gradually
than solid ground,

creating a lower impact force.

But that's no
comfort to her now.

Finally Question 3, is a collision with a
large volume of water sudden or gradual?

[man] Three, two, one, go!

[Dallas]
Well that was sudden.

Of course it all depends
how you enter the water.

She belly flopped and lost her momentum
quickly so received a large impact force.

What a send off though.
Class dismissed.

When I wake up in the morning I'm
quite often frightened

by my own reflection.

But then I put on my glasses and I realize
it's just my teddy.

But for these guys
there is no teddy.

This cranky c*ck,

this cute Siamese kitten,

and this confused pooch.

So, what do a flappy bird, a crouching cat
and a bewildered dog all have in common?

No, they're not my favorite yoga
positions,

it's that they're all animals that

aren't believed to possess what's known
as theory of mind,

which determines how
self-aware a species is.

One camp believes that we can assess to
some extent that a species is self-aware

by whether it can recognize
itself in its own reflection.

Humans can only do this
from around 18 months old.

However, some species do not have this

ability and instead might
be threatened by,

compete with or try to
attack their own reflections.

So far we know that some apes, dolphins,

elephants and humans can recognize
themselves in

their reflections
but can Labradors?

[Dallas] There's
only one way to find out.

Just like myself, this dog's a stickler
for manners and wants to avoid conflict

with what he thinks
is another dog.

This lunch could take a while.

OK, but what about fish?

Not known for their intelligence, it's no
surprise that she can't recognize

herself in the mirror so she flares her
fins to scare off the intruder.

Looks like it worked.

Good job.

Now cats are known to be bright and Gary
here was a bit lonely.

Luckily he found
someone to play with.

I won't tell them if you wont.

[Dallas] We share 99% of our
DNA which chimps and,

just like us, some of
them love the mirror.

Look at these ladies
checking themselves out.

Yeah, still got it.

Now you might
not know this about me

but when I was younger I was
the master of a few tricks;

around the world with a yo-yo, the
hula-hoop shoulder pop and of course the

Rubik's cube challenge.

Sadly my childhood just missed
the internet

by a couple of decades but
these talented

people have the world on tenterhooks,
watching their stunts.

Get it right and it
can be quite exciting.

[girl] Oh my God!

[Dallas] It's
something of a phenomenon.

Yes, very good.

And you can do it anywhere.

Actually that is quite clever.

Yes we're talking of
course about the bottle flip.

It doesn't seem so
exciting but the kids love it.

The challenge is to flip a partly filled
water bottle and make it land upright.

But of course, as always, there's a
scientific method behind this madness.

Holding the bottle by it's neck creates

a pendulum so that
when he moves his hand in

an arc the bottle gains angular and upward
velocity and centrifugal force keeps

the water near its bottom.

The bottle spins around an axis of
rotation near its center of mass but this

reduces centrifugal force which makes the
water spread out,

slowing the bottle's rotation just in time
for a stable landing.

Too little water and it's too light to
slow its rotation enough.

Too much water and its center of mass is
too high so it will be unstable

for an upright landing.

But, get it right and you
will be a schoolyard legend.

[Dallas] And that's not right.

That's a full bottle with a high center of
mass, but that doesn't matter

anyway because his throw missed his
target on top of the sign.

And sadly his catching is
just as bad as his throwing.

Yes, to get this right takes concentration
and a bit of skill.

[boy] No! What the actual
hell just happened there?

[Dallas] Fear not my young friend,
science can explain all.

The water dissipates the bottle's angular
momentum and it slows it down,

but it lands at an
angle and dents.

Luckily it's only one third full so has
a low center of mass,

keeping it balanced
and securely in place.

[boy] What just
happened there, then?

[Dallas] All that stuff I just said.

Just remember the basics and you too
can be internet famous.

[boy] Yes!

Well that concludes our
misadventures for this time.

Einstein apparently once said

that imagination is more important than
knowledge,

which is probably
good news for this lot.

[music plays through credits]

♪ ♪