Episode 5 Bang Goes the Theory

On tonight's prorpblg. Dallas meets the team who are looking further

into space than ever before. Believe it or not, galaxies

themselves can act as lens, this may sound a little bit weird. I'm

talking about a very real phenomenon, called gravitational

lens. Liz comes into contact with a

bedbug. I give you the bedbug, one of the

greatest evolutionary bloodsucking bug.

Stkpwr first up, the bed being, the papers are full of how we are

facing a global epidemic of bedbug infestation. I thought it would be

good to find out why these little citers are so good at invading our

citers are so good at invading our space.

We share our homes with millions of creepy crawlies, and if we don't

think about it, they don't cause us any trouble. This little fella is a

bit different. Ladies and gentlemen I give you the humble bedbug.

One of nature's most perfectly evolved human bloodsucking machines.

If a few of these get into our home, you will know all about it. I'm not

taking any chances with this one, but I want to find out all about

them. And there's no-one better to ask than Dr James Logan, he spends

his days trying to work out how to combat the growing bedbug problem.

His lab is host to thousands of little critters. And James knows

all too well what it's like when the bedbugs bite. So, what does a

bite feel like? I'm going to show you what a bite feels like, I will

get a bedbug out and let it feed on my arm, when it starts to feed, I

will lift off the pot. There it goes, it can't believe its luck.

is having a wander around. How do you know, can you feel it? I can't

feel a thing. It has gone really still. I felt a very, very slight

nip there. Did it just go in for the kill? It is gone in. Will I see

his little body fill up with your. Oh my goodness, it is going, it is

sucking, moving as it is feeling. Bed begs have piercing mouth parts,

it is like a needle, they inject it in to find a blood Kapilry, they

start feeding from the blood. you have them you know you have

them. Your arm will come up with a big red itchy lump. What your

immune system is doing is react to go the chemicals injected into our

body in their sallifva, it is a cocktail of chemical that is act as

an anti-coagulate and anaesthetic. As it is biting the anti-coagulate

gives you a nice stream of blood. How long will it feed for?

should take a couple of minutes, you can see the body swelling up.

God for bid, this one escape, do we have a situation here? We will have

a situation. This one has probably mated, she has just had blood,

which means she will produce viable eggs. She will lay her egg, they

will hatch out and they will start reintroducing. They will leg three

eggs in a day, and 300 eggs in their lifetime. How easy is it for

this bedbug if she escapes to make it to my home? These beds are

tremendous hitch hiker, they could get on your clothes and get into

our home. This is why I hear because there are more

international travellers there are more bedbugs in this country. They

are getting into people's suitcases? That is how they are

transported around the country and the world. The other reason is

there has been a bit of an increase in secondhand furniture sale, they

lay their eggs on the furniture, and the bedbugs themselves can even

be transported. She's finished. She's moving. She just pooed,

that's so rude. No only does she feed off you, she leaves a little

calling card. Can you see she's struggling to walkings because

she's so fat. I know - She's struggling to walk because she's so

fat. They defacate on my arm as you say, that is the smell they use to

get back home. Bedbugs do love a good square meal. In fact they can

drink three times their own volume in one bite. A bit like me drinking

180 litres of milk in one go. And it means these amazing creatures

can live for up to a year inbetween meals.

Even when they are full they can slip into the tiniest nooks and

cranies in our homes. It is only at night they emerge to sniff out

their prey, then they sniff their way back home. James's plan is to

develop traps to catch bedbugs before they bite you. But to do

that he needs to understand their amazing sense of smell. Which

requires a very complex chemistry kit.

What exactly is this massive box, what's going on in these tubes?

OK, so this is a gaschromatigraph, we are separating out gases. What

we have is a sample of human Oder, it is my Oder that I have collected.

You are going to fire that sweat, your sweat, at the antenna? That's

right. I'm going to use the syringe. I can't believe you have collected

your own BO in a glass vial, that is little bit dark! We will put it

in the hole and inject it in, this machine is a big oven. It heats up,

as it heats up, low molecular weight compound also travel much

quicker around a column to a flame, that then tells what you the

chemicals might be. Inside here is a spliter, half of the chemical

gets split to the flame to tell us what the chemical S the other half

of the chemical gets blown out, this transfer line here, into

another air stream, that then gets blown over the an then that of the

insect. How is the antenna still reacting

to smells? Even though the bedbug is dead, the receptor cells on the

antenna stay alive, for about 30 minutes. Like moths their antenna

will stay alive for hours, we can actually use it, even though it is

dead, because the receptor also fire and respond to chemicals. They

are picked up by protein that is carry the chemical across a space

to the receptor cell, that illicits an electrical response in the

nervous system, and that make behavesor, the insects are

attracted and come towards us. That is how they find us. We haven't

done a lot about bedbugs and human oweders so we don't know a lot

about it in this way. They have it made, I actually went to an all-

you-can-eat buffet in Vegas once and I couldn't eat for a year.

In case you were thinking I was not being a wuss by being not bitten,

can I show you his arm the day after, and the day after, he said

it was so sore and nasty. I rest my case.

What happens now if you're at home and you have bites like that, what

should you do? Even though bedbugs are on the rise,

the chances are you are not going to get them. If you get bites and

you suspect bedbugs, there are tell tale sign, as you saw, they do a

little poo after they feed. So in your bed you find some bround

blotchy grainy bits of bedbug deafcation in your bed. There is a

sweet, musty smell in the environment, they like to he can

sudden that smell to follow it home - he can sued that smell to follow

it home. The best thing about James's work is it is going on.

feel paranoid, you think I have bedbugs. Nothing fires the

imagination like looking up into a star-filled night. I went to

Caltech in Pasadena, to look into deep space with a telescope that is

We have had telescopes now for about 400 years, although people

credit Galileo with inventing them, he was not the first, he did play

with the I arrangement of lens inside a tube, that increases

magnification, let us see further, and in the process, revolutionised

science. Since then, astronomers' telescopes

have grown ever-larger and more powerful. Now they even launch

giant ones into space, in their attempts to see further and further

away. OK, so if size matters, just imagine what you would see if you

had a lens the size of a galaxy. Believe it or not, galaxies

themselves can act as lens. This may sound a little bit weird, but

I'm talking about a very real phenomenon, called gravitational

Lening. Using the effect - lensing, using

the effect astronomers can create lens so big they span the universe.

Gravitational lensing was first suggested by Einstien in his

general theory of relativity. You don't need to be Einstien to

understand the principle of it. I want you to imagine this is a

galaxy far, far away. Light from the orange tree galaxy is making

its way towards earth. I want you to imagine inbetween us is a huge

cosmic body right here, another giant galaxy or cluster of galaxy,

billions of stars. You would think by having it here, it would block

the light heading towards the earth. But because it is so massive, light

is actually bent around it. Even though our orange galaxy is

obscured, we can still see it. A giant galaxy is so heavy with

such a strong gravitational field, it warps the space around it, which

makes light bend on the way through. So the galaxy acts like a lens,

revealing and magnifying distant objects, or indeed, oranges, far

beyond. This monstrous gravitational field

is acting just like a lens. Gathering, distorting, and

managefying light from distant galaxies, the whole thing is just

like one big cosmic telescope. The trouble is, these lensing galaxies

are incredibly difficult to spot. Some have been identified by a

project partly based here at CalTech.

Come on in. This man is part of a team hunting

for them. That is a foreground lensing galaxy, we are looking at

the blue as a disturn galaxy. The blue bits are not off to the side,

they are directly behind the blob. They are. That is how we see it.

The blob in the centre is the lensing galaxy, it is showing a

galaxy further away, creating a ring of blue light. That is not

their real shape, it is the distorted shape? Yes, because of

gravitational lensing, this galaxy is magnified by about 10/30.

can see how the ring of light is produced by shining a torch through

the base of a wine glass a tiny light in the distance is distorted

into bright spots and a tell tale ring. It is such a simple principle,

a lens bends light, and now we have light bending because of gravity.

How rare is it to find these lensed galaxy? It is very rare, maybe one

or two out of 100,000 galaxies. We have now this telescope that

operates on the infrared wave length, we have managed to find a

large sample of lensed galaxies. This is a new orbiting telescope

launched in 2009, peering further into dark corners of the universe

than ever before, it has discovered very distant young galaxies,

bursting with new stars, its secret is infrared.

We couldn't see them using optical light, because places where there

is lots of star formation has lots of dust. Optical light cannot

penetrate through this dust. So with Hirshal we are finding these

new galaxies that we didn't know existed.

Hirshal scans vast areas of the sky, picking out the tiny signs of

distant galaxies that other telescopes miss. What are we seeing

here? We are looking at the infrared universe. Each speck or a

dot here is a galaxy. But you can pick out this bright things, one

here, there is one right here and they actually are priter, because

they are being gravitationally lensed. These are the lensed

galaxies discovered with Hirshal. It is truly as ifing, undiscovered

galaxies billions of light years away, discovered by gravitational

lensing. Why is it so important to see the galaxies hiding behind the

other galaxies? We want to understand how stars form in the

distant universe. We don't understand the physics associated

with star formation, how the galaxies came to be, how did the

first galaxy formed, this is one way for us to get handle on that.

love things that only noticable on scales so vast that they are beyond

common experience. Who would have thought that if you get a massive

enough object, it will actually bend the light going past it and

focus in somewhere else. That is a very beautiful ING this. I want to

know is when did we first become aware of gravitational lensing out

there in the universe. We have known g it for a while, since 1979,

but the idea of what gravitational lensing could do, we are talking

about the late 1930, as a concept in physic, back to Einstein, the

theory of relativity, that space could be warped by gravity and

therefore warped. Historically it is an interesting story, it shows

how science works, science as a process from big idea through to

practical application. It is lovely. Nature composes some of her

loveliest poems for the microscope and the telescope. Follow the links

to the Open University to learn more about life, the universe and

everything, including me and astro physicist Frank Drake talking about

the search for alien life. Doesn't it seem like every week

there is another headline that this or that will vastly increase your

risk of this and that, but as Dr Yan explains, statistics and gut

reactions aren't necessarily a good reaction.

When you read medical stories in the press, it is hard to interpret

what they are telling you, especially where statistics are

involved, the figures seemed designed to bamboozle us. I will

show you what I mean, using bacon sandwiches. A few years ago it was

all over the news that eating processed meat like bacon or

sasauges every day could increase your chances of getting bowel

cancer by about 20%. So let's see how people react to that. And see

what they make of my cancerous bacon butties.

Free bacon sandwiches? Always like that. Increase your risk of bowel

cancer by 20%, they are literally free, I don't know if you want them.

I'm less hungry now I have seen that. Increase your risk of getting

bowel cancer! There has been some research that shows regular eating

of bacon increases your chances of bowel cancer by 20%. One other

thing, let me give you a choice, these bacon sandwiches, only

increase your bowel cancer of 5%-6%. Which one takes better. Help

yourself to either plate, but prefer these ones? I prefer the

percentage. I think I will take the risk.

Either way I'm having bacon. don't like bacon any way.

We're not trying to trick you, I have eaten these. Can I ask why

this one, why does it increase rather than this one. The ones that

are really nice that are not good for you, like all food. Can I let

you into a secret, it is no different at all. These two are

exactly the same. Those risks are exactly the same as well. The

difference is, just in the way that you present statistics. Do you want

me to explain, I will show you. So, normally, your chance of getting

bowel cancer is about 5%, OK, that means out of 100 people, some time

in their lives, five of them will probably get bowel cancer any way.

That is five out of 100. What this scientific research showed, was

that if you eat about 50 grams of processed meat every day, those

risks are not 5% but 6%. In statistics that is known as the

absolute risk, that is what this is telling you, that isen increase of

But that's not to say the 20% is wrong, it is just another way of

expressing the same figure. And this is called the relative risk.

Relative to the people who would have got it any way, one extra

person, that's one, compared to five, one fifth increase. Which is

20%. Exactly. So this figure is right as well, just a different way

of putting it. Of course 20% sounds a lot worse, doesn't it. Actually,

most of you, choose the sandwiches from the plate that was labelled 5-

6%, that shows you how persuasive statistics can be, it is important

to look behind the headline figures to find out what is really going on.

I think I will have a bacon sandwich now.

I have got a bit of a bug bear when it comes to banner headlines and

statistic, we have to understand the basics, like Dr Yan showed us.

We have to realise a lot of the statistics are "cherrypick"ed for

effect without being in proper context, we have to remember that.

Enough about the bug bears and the bedbug, let's talk about the cake.

Because, I think you two both have a birthday this week. 31. 29.5.

Statistics I'm unsure of. The lovely Dr Yan has sent this cake,

it comes as catch, you can't have any until you figure how to split

it into eight equal pieces with only three cuts.

That's not possible. Is it: Very easy. If you think you know the

answer is on the website. Before I get too distracted by the chocolate,

I will get back to the bedbug investigation. We have heard that

bedbugs have an incredible sense of smell, time for an e permanent to

show us how they use it. - - experiment to show us how they use

I have two specimens to show what things are attracted to our little

bugs. These are two of the smelliest

people I know. Dallas and Yan. James have - has set up an

experiment to see which of the two has the most attractive smell to

the bedbugs. Yan and Dallas haven't washed for 24 hours, they are a bit

smelly. James is making them stew in their own juices for another how,

in hot, sweat, foil bags. There is something deeply wrong with with

this picture. What's happening? have them in the thermal bags which

is used to collect body Oders. You can probably smell it. There is a

pierce pong in here, it smells of boys' bedroom. We are pumping the

body Oder from the bag, up the tiny tubes here, leading to this

apparatus here into this arena, the behavioral arena, to find out if

Dallas is more attractive than Yan to bedbugs. I think I'm going to be

more attractive to bugs. The bedbug is released, what

happens now? We will turn the pumps on and vacate the room. The one

thing about bedbugs is they only feed at night, it will have to be

done in the pitch dark. No hanky pangy, we are doing the lights -

hanky pangy, we are turning the lights off. They can't bite them,

they are perfectly safe in there, I have given them a night vision

camera to stop them getting board. This is Yan, in his sweating bag.

Outside we watch on a monitor as the monitor sniffs its way around.

So there's our friend in his little choosing area, he's going to choose,

up there, choice arena there is a camera, you can see him do his

thing. There is infrared lights on there as well. That is the sound of

the Oder being sucked down the tubes. That is the sound of science.

Oders coming from the bags are being pumped through the pots. It

is sussing out which side it prefers, which one will be the best

blood meal? It is favouring this side more. It is definitely

favouring that side now. This is quick it exciting. Having a whiff

of the two boys when - quite exciting, having a whiff of the two

boys, who would your money be on? Yan, I would escape out of the hole,

if I was the bedbug, the smell There is some serious science going

on here. Because James wants to find out which chemicals bedbugs

respond to. Once you discern whether it is attracted to a

particular individual's body Oder, do you take apart the body Oder to

see what chemicals might be attractive? If somebody is more

attractive than someone else, it possible they might produce for

attractants than the other. It might be the person not attractive

might be producing natural repellant, that their body has a

natural defence system against bedbugs. I thought it was always

about something in your body Oder that is attractive to insects, I

never realise you had had repellants. If we can find out what

it is we can sell it as a repellant. It is definitely spending more time

on one side than the other. looks like a clear result, but to

be sure we run the same experiment again and again. After several

hours there is no doubt. They look bored now. A game of I Spy. I do

feel for them, there has been in the bags them, it gets hot and

sweaty and it is not pleasant. There is about a quarter of an inch

of water in the bottom of this bag. Do you reckon we have a good

result? I'm confident we have an answer. Let's let them out of the

cave. How are you. Oh my gosh the pong in here is something else.

is a bit ripe. Do you want to who is more attractive to bedbugs. Who

do you reckon it is? I reckon it's Dallas. Why do you reckon it is

Dallas? I reckon it is Yan, he's a little gamey. Dallas didn't have a

shower this morning and the shame T-shirt for two days. James has his

money on Yan? I did. After he got a whiff of you, he said it is

definitely going to be Yan. We have a categorical, all-out winner, I

can announce to you that the person in the room who attracts the

bedbugs most s a certain Mr Dallas Campbell. Get in. Bet bug of taste.

Clearly has - bedbug of taste. traictive, it is scientifically

approved I'm attractive. Draw a line and move swiftly on. I say

that, I think I'm attractive to all insect life on earth, because every

time I go on holiday I get bitten to shred, whoever I'm with are

absolutely fine. Exactly the same experience, I went travelling with

mate, we would share a room, I wake up with bites, and he never got

bitten. I never could figure out if I was attractive or he was

repulsive. Depending on the insect you are giving out an traictant or

repellant, we don't know what it is for bedbug, he finds out it was a

repellant that Yan wask sueding we can make a - was exuding we can

make a spray. Can you imagine, essence of Yan. If you want to see

more boy dorm action, if you are in the mood, get on to the website,

check it all out. I haven't seen it yet, I can't tell you what it is

like. That is it for this week, next week I'm doing something

really stupid. In the name of science I will not clean my teeth

to see what will happen. I have a smell thing goingen in the series.

I'm looking into something we take for granted. Artificial light, only

in recent history have we had the ability to flick a switch. But new

research suggests that it may also be having an unexpected biological

effect on our bodies. Dr Yan will be coming over all health and