Episode 5 Bang Goes the Theory

Episode 5

Science series. Liz investigates a common and unwelcome guest - the bedbug. Meanwhile, Yan explains why statistics are not to be trusted, and Dallas goes stargazing in California.

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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


Liz investigates an increasingly common and unwelcome guest - the bedbug. Meanwhile, Yan explains why statistics are not to be trusted, and Dallas goes stargazing in California.

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