Episode 3 The Secrets of Everything

Humans are an incredible species.

We've found ways to talk to each other

on opposite sides of the world.

We've discovered cures for terrible diseases,

and some of us have even left this planet to explore space.

But there's still so much left to find out.

I'm Greg Foot. Ever since I was a kid, I've been into science.

I've always been asking questions and taking things apart

to understand how they work.

I was the kid trawling through the rock pools

and the one that tried to turn his bike into an aeroplane.

I even went on to do a science degree.

And I'm still asking questions.

-This is going to hurt, right?

-Yeah.

And I reckon a lot of you are too.

And that's what this series is all about,

getting to the bottom of all those questions

that never get properly answered, to reveal the secrets of everything.

This time on The Secrets Of Everything...

Can a loud noise kill you?

I want to see the effect of sound on these massive pig lungs.

The Doc and I launch our own space probe

to find out why the sky is blue...

Pick up the pace a bit, Doc, or we'll lose it.

We're up to 33mph now.

Come on, Harold. Come on, Harold.

And I find out if it's ever OK

to drink your own bodily fluids.

Bottoms up!

But first -

the secrets of survival.

You're walking down a dark alley, and you're set upon

by a group of thugs. If you were in a film,

you'd heroically finish them all off.

But this is real life.

Could you survive an unfair fight?

The first guy, I'd distract him

by showing him a picture of something incredibly ugly.

I'd probably run around screaming a lot

and just dodge them through speed.

And then the other two guys that are standing next to the first guy,

I'd slam their heads together.

I would make sure I'm fighting with my hands and my legs.

You can't just fight with hands.

Try and beat them all up. And I reckon I'd do quite a good job.

Now, in the absence of a bunch of Hollywood stuntmen,

I've settled for a group of cage fighters from Liverpool.

Leader of the gang is current mixed martial arts champion Rosi Sexton.

She's hard as nails.

That looked impressive.

Just a bit of fun, really.

Before Rosi has "a bit of fun" with me,

I'd like to get some idea of just how unfair

this fight is going to turn out.

You're going to need these.

Er, great. Cheers, thanks.

So, go and get changed and we'll see you back here in a minute.

Now, I've not done a lot of punching before,

but how hard can it be?

So what we got?

Got over eight there, so we've got 80G.

80G. All right. Happy with that.

'G is a way to look at force.

'100Gs is what you'd experience in a 60-mile-per-hour car crash,

'so 80's not a bad punch.

'Beat that, Rosi.'

Good. That's a 12G there, Rosi, so 120.

Wow! 120G.

And I'm going to be on the receiving end of that.

'This is looking less and less like fun to me,

'but those Hollywood heroes never back out,

'and as it happens, I've got a secret weapon.'

We all do. Adrenaline.

It's the same thing that makes your heart race in extreme situations.

'The scene is set,

'the camera's rolling,

'cue the adrenaline.'

I reckon the adrenaline's shooting up already.

I don't think I need to go in.

'Adrenaline increases your breathing and your heart rate.

'But it also triggers a sudden release of stored sugar...

'..your body's source of instant energy.

'It's all part of the body's fight or flight response,

'because in situations like this,

'you're either going to need to fight your best fight ever

'or run the fastest you possibly can.

'To be honest, I've felt on better form.'

Ahhhh!

It's like being in a food processor.

'I might feel utterly rubbish,

'but in theory, the adrenaline surge means I should be meaner,

'faster and stronger than normal.'

Let's check out the power while this adrenaline's going through.

Yes, so that's, what, 110?

-110G?

-Yeah.

So there you go. That test shows that I went up from 80G before

to 110G after the fight,

with all that adrenaline racing through my body,

so my response to that fear was

to release all that adrenaline, make you stronger.

'It's starting to look like the movies

'aren't quite as daft as they seem.

'Adrenaline has turned me into a superman after all.

'Taking on mere humans, even two at a time,

'is beginning to look a whole lot easier.'

In the films, the hero's always being attacked

by opponents from all sides.

So what happens if I punch both of these at the same time? You ready?

It's weak.

2G. That's rubbish.

If you're punching two directions at once,

you've only got the strength of your arms,

and, relatively speaking, that's not very much.

You can't put any of your large core muscles

or the strength of your legs and your hips into it.

You're just like that. It's just...

-it's rubbish.

-Yep.

You're right.

'So unless you're in a movie, or you can persuade

'your attackers to take it in turns,

'you're going to get hit, and that really is rubbish.'

Now, it's not the punch but the shock wave that's going to get you.

If you imagine that this bucket is your skull,

and the water inside is your brain,

if I hit there,

you get waves.

The impact spreads out from the point that I hit it,

and waves travel across.

They're called compression waves.

Now, the real problem comes when those waves

bounce off your skull, and when they collide

it causes a massive decrease in pressure.

Now, that might only be for a couple of milliseconds,

but it is enough to boil your blood

and to cause the tiny blood vessels to rupture

that carry oxygen to your brain.

'From your brain's point of view

'it doesn't really matter if it's damaged in a fair or unfair fight,

'it's just that if there are more of them than you,

'the chance of brain damage goes up.'

So, the best way to win an unfair fight?

Well, predictably, it's to avoid getting in it in the first place.

I'm really into my music, whether that's listening in the car

or at a club or ideally at a gig or a festival,

where the music is so loud,

it gets your ears ringing for a couple of days.

But if sound can cause long-term damage to your hearing,

can it hurt the rest of me as well?

And can a sound actually kill you?

Sound is essentially a type of energy made by vibrations.

When an object vibrates, it makes the air molecules around it vibrate,

and it's similar to what happens when a water drop hits a puddle.

It makes the water molecules around it vibrate

and the ones next to them also move, and the ones next to them,

and that makes the wave.

'And the bigger the wave, the louder the sound.

'Which is something stereo junkie Matt Sprigg knows all about.'

God, this is really going to have some welly, isn't it?

-Can we have a look indoors?

-This is where the magic happens.

Some daddy speakers. Look at them!

Eight massive sub-woofers.

-Can we have this thing on full blast?

-Full whack, definitely.

'I want to what 24 speakers' worth of bass sound can do

'in a confined space, and I've invited a friend along for the ride.

-RATTLING

-'Matt is playing the frequency so low

'that you can't hear it on TV speakers,

'but it's the sound that's messing up our dummy's hair,

'and the noise you can hear

'is the car rattling as the sound waves rip through it.'

Wow. That has got some kick to it!

That is just massive speakers moving huge amounts of air,

and it just shows that all sound is is the movement of air.

'Without protection,

'the wave of air will tear right through your eardrums,

'damaging your hearing forever.'

But your ears aren't the only organ vulnerable to sound,

and to show you that,

I need something even more powerful than Matt's 24 speaker beast.

'These speakers, usually used at festivals,

'are capable of knocking out more than 150 decibels.

'That's the kind of levels you'd get from a jumbo jet taking off.'

I want to see the effects of sound on these massive pig lungs.

We're going to blast them with low frequency, high intensity sounds,

so that proper drum and bass kick,

hopefully 150 decibels,

which is even louder than you'd get at a music festival.

'Pigs are often used for research

'as their basic physiology is so similar to our own,

'and because this level of noise is so extreme,

'we've even had to have the building checked for structural safety.'

Right, let's do this.

'We're going to blast 128 hertz of low frequency sound at these lungs.'

OK, everyone.

Three, two, one,

go.

SOUND WAVE PLAYS

All objects have a natural frequency that causes them to vibrate.

It's known as their resonant frequency.

For lungs, it's right down there.

It's the sort of frequencies you get in bass music,

about 128 hertz, to be precise.

'If your lung vibrates like this,

'it could collapse like a popped balloon,

'which might be fatal.

'And it's not just the lungs.

'Look what happens when the stomach gets the 128 hertz treatment.'

As sound travels through the air, it compresses and decompresses it,

and it does exactly the same thing

when it travels through the air in your stomach. You can only imagine

what that would do to your bowel movements.

So, loud music can have some pretty gory side effects,

from bleeding ears to collapsed lungs.

It probably won't kill you instantly,

but it could be the start of a slow and painful death.

But at the right volume, it's all good,

so hopefully at my next gig, I won't lose control of my bowels.

'Protect your ears.'

'If you look at space from a spaceship,

'it's black. But if you look at space from down here on earth

'it's blue when it's not cloudy, and we call it the sky.'

But why is it blue here but black right out there?

Well, to find out, we need to take a journey into space.

'To help me build a spaceship,

'who better than a man who's a chemist, a practical engineer,

'meteorologist, and...

'Polish musician?

'He is Doctor Zbigniew Szydlo.

'I just call him Doc.'

# I see a bad moon rising... #

'Doc and I are on the way to see Steve Randall.

'His weather balloons travel to the edge of space,

'so we're hitching a ride to find exactly why

'the sky changes from blue to black.'

We'll send up a couple of these cameras in the payload

and then we're going to analyse the footage that comes back.

'As well as filming the colour of the sky,

'we'll be taking other readings too.

'This is a thermometer and this bit measures atmospheric pressure,

'or, in other words, how much air is left above our craft.'

And this, this is the crucial bit. This is the GPS.

If we didn't have this, we wouldn't be able to find it again.

and that is going to be our payload.

A beauty.

# Spaceman, I always wanted you to go... #

'I've always wanted to launch a spaceship,

'but I never thought it would look like this.'

Brilliant.

Follow that balloon.

'Although we've now lost visual with Spaceship One...'

It's just got to 5,200 metres.

'..here at mission control, Steve's in constant contact.'

It's currently just over 10,000 metres.

'At 10,000 metres,

'Spaceship One is over a kilometre higher than Mount Everest,

'and when it gets to 20,000 metres, higher than any airliner flies,

'the blueness that what we see from the ground as sky

'is now just a thin line on the earth's horizon.

'Up here, there's almost no atmosphere at all.

'The helium in the balloon expands as it tries to fill the void of space.

'Now the race is on, to recover Spaceship One's re-entry module

'and harvest its data.'

Pick up the pace a bit, Doc, or we'll lose it.

Up to 33mph now. How quick's that?!

Go on, Harold!

So we've got to go to its kind of last known position,

roughly, and then try to track it locally?

Oh, hang on a minute...

Brilliant.

Success.

OK, let's get it open. We need to look at the footage.

'Doc and Steve now analyse Spaceship One's data

'at mission control's research centre,

'to find out why the sky gets blacker the further you go into space.

'Straightaway, our video shows how the colour blue drains away

'the higher the balloon gets.

'But what about the other measurements? What about temperature

'and atmospheric pressure?'

Now, if we have a look at the precise colour measurements

from those pictures, what we find is

that the colour changes a lot

as you go higher and higher and higher,

until you're a lot higher and it doesn't change as fast.

Temperature also changes as you go higher,

but it kind of changes at a similar sort of rate

until you get to the top and it doesn't change that much.

Now, the air pressure, the thickness of the air,

also changes as you go up,

and it does so...

..in a very similar way to the colour.

And that's what it's all about,

As the air gets thinner, our blue sky fades to black.

So the sky is blue

because of the thickness of the atmosphere above us

and the light bouncing off all the air molecules and dust particles.

Take away the atmosphere and the sky would be black,

just like it is in space.

Here's Professor Logic.

How do you do, Professor?

Professor Logic is a busy man.

So much to see, so much to learn,

so much to measure.

Professor Logic loves measuring.

What are you going to measure today, Professor?

You want to know how big infinity is, so you're going to measure it?

Professor Logic has tried to count to infinity,

but every time he thinks he might have got there,

he finds he can make it bigger by one.

So he's left the Earth to see if he can see

if space is infinitely big.

There's a problem?

If space really was infinite,

it would contain an infinite number of Professor Logics,

and you've never seen any.

Professor, are these your animals?

You're using them to see if it's true

that an infinite number of monkeys

actually could write the complete works of Shakespeare.

Oh, dear.

So near and yet so far.

Professor, does it really matter that you can't measure infinity?

I mean, it seems to me that infinity is a rather beautiful thing.

A symbol perhaps of eternity, or maybe eternal love.

Perhaps like a carousel that's turning,

running rings around the moon.

Like a clock whose hands are sweeping

past the minutes on its face,

and the world is like an apple whirling silently in space,

like the circles that you find in the windmills of your mind.

The trouble is, Professor,

infinity isn't a number at all,

more an idea that you can't measure.

It certainly makes you think, doesn't it? Goodbye.

ALARM BLARES

BURGER BURPS

Ah! You've been feeling really rubbish for days.

You've got a stinking cold,

Every time you sneeze, your whole body shakes

and you just can't keep your eyes open.

Does that mean the urban legend you heard as a kid is true?

If you sneeze with your eyes open, will your eyes really pop out?

'To find out I've asked my friend and serial sneezer Ella to help.'

-All right, you up for this?

-Yes.

'First up, though, we've got to make ourselves sneeze.'

I've read some stuff about this.

-What is it?

-This is ground white pepper.

-Yeah, I'm ready for it.

'Pepper contains something called piperine,

'a chemical which really irritates your nostrils.'

SHE COUGHS

Oh...

-Yes?

-No.

-No?

Aaargh!

I'm crying, but I'm not sneezing.

'Clearly my sneeze threshold is quite high.

'Time to try something different.'

-This time, take the tissue...

-Yep.

..and twist it and shove it up and tickle the top of your nose.

OK.

OK.

-I've got one coming.

-Me too.

HE SNEEZES

-Were my eyes open or shut?

-Definitely shut.

-Definitely shut?

'Just before you sneeze, you breathe in and your chest inflates.

'When you finally let rip, it all comes rushing out at over 100mph.

'That explains why your mouth moves so much in a sneeze,

'but it's still not clear why your eyes shut.'

Right. There's only one way we're going to do this.

You're going to have to hold them open,

I'll have to tickle. I'll have to see what happens.

I really hope they don't pop out.

I need them.

HE SNEEZES

Come on!

That was open.

'My eye only stayed open because it was forced to,

'but there's a good reason why it didn't pop out.'

Lucky for me, you've got muscles in your eyes that allow you to look up,

down, those ones there, left, right,

and also ones that keep it in place, so when I sneezed,

-my eyes weren't going to go anywhere.

-That's good.

'Urban legend - rubbish.

'There's nothing like a cool refreshing drink on a warm day.'

But if I was stranded, alone,

far from the comforts of civilisation,

how long could I exist without drinking?

'Imagine you're marooned on a desert island.

'The only water you've got is what you can personally provide.

'Would you, could you survive on your own bodily fluids?'

I think it would be pretty disgusting, to be honest with you,

but, erm, can't knock it until you try it, I suppose.

-Might as well.

-Pretty much.

-I probably would, yeah.

Yeah, I'd do it, because in my head I'd be like,

"If I'm thirsty..."

HE LAUGHS

-I'd rather die.

-No, I would actually do it.

-No. I'd rather die.

No, I'd rather die, thank you.

'The BBC refused to pay for a desert island,

'so I've come to the next best thing,

'a lab in Wales...'

-Hiya, how are you doing?

-Hello.

-I'm Greg.

'..where Sam Oliver will make me thirsty enough to...

'well, we'll see.'

First thing we need to do is establish how much you weigh.

'Sam's got a plan to extract as much fluid from me as possible,

'and regular weigh-ins will tell him

'exactly how much he's getting.'

79.8 kilograms.

'Now, I've not been to the loo for 12 hours.'

I'm sure I can squeeze one out for you.

'Time to open the floodgates.'

It's nice and warm.

I'm proud of that, Sam, that's a lot.

That's exactly 800ml.

'According to Sam, it's possible to pee out

'up to two litres of urine every day,

'so this lot would be worth its weight in gold on a desert island.

'The trouble is, peeing isn't

'the only way we lose fluid

'so Sam's recreated my island paradise in a sealed chamber

'heated to 30 degrees.'

I'd like to be able to monitor your core temperature, and the...

Thermometer, yeah?

No...it's best to measure it rectally, actually.

This is the probe I'd like you to insert.

I feel violated.

'The plan is to dehydrate me even more.'

Keep going, that's really good.

'We sweat from glands all over the body,

'and the humidity in this Welsh desert island

'is sending them into overdrive.

'Worse still, as my breathing gets faster, I'm going to lose

'even more moisture from my lungs.'

2...1...and stop.

It's about 77.7.

OK, Sam, so how much sweat did I lose?

You actually lost just over a litre in sweat.

So today, with urine, sweat and breath, I've lost

just over two litres, am I now classified as dehydrated?

Yeah. You're going to be around two and a half per cent dehydrated.

'If I was on my desert island, I'd be in trouble,

'and if I didn't drink anything for another four days,

'I'd be dead.

'So seeing as my pee is the only bodily fluid

'I'd stand any chance of collecting,

'it's time for a swig of the amber nectar.'

So, erm, could I survive off it?

I guess if it was your only fluid. It is sterile.

It would be your choice, really, I think, Greg.

Well, you know what, Sam? I've come this far.

I may as well see this journey to the end.

Bottoms up.

Ahhh. Eurghh.

How was that, Greg?

GREG LAUGHS

If my life depended on it, I could probably just about do that.

'And then, at the eleventh hour,

'Sam drops a bombshell.'

Unfortunately, on a desert island, though, Greg,

your urine's likely to be a lot more concentrated,

and therefore might even make you vomit or cause diarrhoea.

So, erm, you probably wouldn't drink your urine on a desert island.

Thanks! You've just told me that after I drunk it.

Cheers(!)

3, 2, 1...

'There are still loads of secrets out there.

'Next time - can body armour really save your life?'

Did it stop the bullet?

'Why boomerangs come back...

'usually...'

It may not look like it,

but there's a lot of physics going on in this bent bit of wood.

'..and surviving being buried alive -

'all you need to know.'

I just feel weak.

Subtitles by Red Bee Media Ltd