Episode 7 Richard Hammond's Miracles of Nature

'Animals are amazing.'

That's astonishing!

'And the more we find out about them,

'the more amazing they seem.'

That feels pretty harsh.

'That's why scientists all over the world

'are trying their best to copy them...'

This is the future.

'..making brand-new inventions...'

Tomato juice.

'..based on what animals can do.

'Some are astounding...'

We've just dived under the sea!

'..some bizarre...'

This is not at all pleasant!

Yes, it's gone!

'..but they're all inspired by the miracles of nature.'

Episode seven.

How your computer could be quieter

by taking a lesson from birds.

WAVES CRASH

This place is very special.

At about this time of year once, maybe twice, a week,

a unique phenomenon occurs, almost within touching distance.

And that's why, although this beach is far from easy to get to,

it draws fascinated onlookers from all over the world,

each hoping to see and hear something they'd be very unlikely

to encounter at such close quarters anywhere else.

And it's something that's going to happen any moment now.

All we can do is watch and wait.

This is it. Here it comes.

'Not a natural phenomenon at all,

'but the weekly arrival of flight 785 from Amsterdam.'

All here to see this. I know!

'Because here, on this very beach, you can get closer

'to a landing jumbo than practically anywhere else on the planet.

'And it's an ear-splitting experience.'

PLANE ENGINE GROWS LOUDER

Now, believe it or not, most of that noise comes not from

the plane's engines, just from the wind rushing around the aeroplane.

In other words, turbulence!

ENGINE ROARS

A lot of it!

I mean, a lot!

That turbulence is generated every time a plane pushes through the air.

But surely there has to be a quieter way to fly?

There is one creature which, despite having a top speed

well in excess of 30 mile an hour, is virtually silent.

Somewhere around here is one of those creatures

that's been specially trained to go into a hunting mode

when they hear this noise...

-MACHINE BEEPS

-..that's coming from that

beeper down there, being operated by this button in my hand.

So, here's the set-up. I'm going to lie down here,

with the beeper hidden next to my head,

and sound it.

My job is to try and take a photograph of the creature

as it attacks.

But to make that just an extra little bit tricky,

give me more of a challenge, I shall be blindfolded.

So, really all I can do is listen for my attacker.

Right.

Well, let's get started. I am now the prey.

MACHINE BEEPS

'Time to summon my trained attacker.'

It's surprisingly tense.

MACHINE BEEPS

If the creature appears, I've got nothing but my ears

to warn me of its approach.

MACHINE BEEPS

MACHINE BEEPS

And this is that creature -

a barn owl.

GRASS RUSTLES

CAMERA CLICKS

Wow, that was genuinely amazing.

When somebody tells you something like,

"A barn owl can fly silently,"

I generally take it with a pinch of salt, but trust me, they can.

I had no idea she was there until she hit the ground.

Totally silent.

It's a massive advantage for owls to be able to fly so quietly.

Firstly, so their wings operate silently enough

that they can still hear the sound of any possible prey.

And secondly, so that their prey can't hear them.

But to see what makes owl flight so special,

we need a little experiment.

Starting with this pigeon.

Just watch what happens when it flies across a bed of feathers.

That is turbulence in action.

Now here's an owl attempting the same thing.

There's almost no disturbance at all.

But how on earth is it doing it?

Well, it turns out that owl wings have three very special features.

These tiny knobbly teeth stop the front edge creating

one big whirlpool of air.

Then a layer of soft, velvety feathers keeps

that airflow close to the wing.

And finally, that tattered back edge reduces turbulence

as the air leaves the wing.

So I thought, what if I could make an airplane wing like an owl's wing?

I've had to improvise a bit, with materials and such,

but that's how it is with science.

And here it is. It's got everything.

The egg boxes give the leading edge that knobbly profile,

to break up the airflow into smaller vortices.

The carpet, the texture,

breaks up the huge bubble of disturbed air and reduces noise,

and the trailing edge is serrated,

and that cuts down on noise, as well.

So, why don't all aeroplane wings look like this?

Well, it turns out it's not that simple.

The problem is one of scale.

That amount of egg boxes and carpet

would just slow the plane down too much.

And the serrated lino would apparently

get in the way of the flaps they use for braking.

But all is not lost.

It turns out there are smaller wings that would benefit

from owl technology.

It's just that they're attached to fans.

And that might turn out to be even more important.

OK, so a silent fan might not sound as exciting as

a huge, furry aircraft wing, but bear with me,

because silent fans would make a bigger difference

than you might think.

FAN GOES SILENT

Imagine silent computers, silent hairdryers,

silent vacuum cleaners, silent wind farms, silent air conditioning.

Because all those fans suffer the same sort of problems

with turbulence that planes do.

So, the inventors of this fan have used owl tech to break up

that turbulence, by adding serrations to the back edge.

And the result is a fan that is very, very quiet indeed.

No matter how hard you listen.

So, this owl technology, copied directly from the way

a barn owl protects its super-sensitive hearing

from wind noise,

could end up making our noisy world just a little bit quieter.

At least until the next plane comes along.

PLANE ENGINE ROARS

A silent fan based on the way an owl flies.

One of the quietest miracles of nature!