:00:03. > :00:08.On tonight's prorpblg. Dallas meets the team who are looking further
:00:08. > :00:12.into space than ever before. Believe it or not, galaxies
:00:12. > :00:17.themselves can act as lens, this may sound a little bit weird. I'm
:00:17. > :00:27.talking about a very real phenomenon, called gravitational
:00:27. > :00:34.lens. Liz comes into contact with a
:00:34. > :00:38.bedbug. I give you the bedbug, one of the
:00:38. > :00:44.greatest evolutionary bloodsucking bug.
:00:44. > :00:48.Stkpwr first up, the bed being, the papers are full of how we are
:00:48. > :00:53.facing a global epidemic of bedbug infestation. I thought it would be
:00:54. > :00:55.good to find out why these little citers are so good at invading our
:00:55. > :00:58.citers are so good at invading our space.
:00:58. > :01:03.We share our homes with millions of creepy crawlies, and if we don't
:01:03. > :01:11.think about it, they don't cause us any trouble. This little fella is a
:01:11. > :01:16.bit different. Ladies and gentlemen I give you the humble bedbug.
:01:16. > :01:21.One of nature's most perfectly evolved human bloodsucking machines.
:01:21. > :01:25.If a few of these get into our home, you will know all about it. I'm not
:01:25. > :01:31.taking any chances with this one, but I want to find out all about
:01:31. > :01:36.them. And there's no-one better to ask than Dr James Logan, he spends
:01:36. > :01:40.his days trying to work out how to combat the growing bedbug problem.
:01:40. > :01:46.His lab is host to thousands of little critters. And James knows
:01:46. > :01:52.all too well what it's like when the bedbugs bite. So, what does a
:01:52. > :01:59.bite feel like? I'm going to show you what a bite feels like, I will
:01:59. > :02:04.get a bedbug out and let it feed on my arm, when it starts to feed, I
:02:04. > :02:08.will lift off the pot. There it goes, it can't believe its luck.
:02:08. > :02:15.is having a wander around. How do you know, can you feel it? I can't
:02:15. > :02:21.feel a thing. It has gone really still. I felt a very, very slight
:02:21. > :02:28.nip there. Did it just go in for the kill? It is gone in. Will I see
:02:28. > :02:32.his little body fill up with your. Oh my goodness, it is going, it is
:02:32. > :02:37.sucking, moving as it is feeling. Bed begs have piercing mouth parts,
:02:37. > :02:40.it is like a needle, they inject it in to find a blood Kapilry, they
:02:40. > :02:45.start feeding from the blood. you have them you know you have
:02:45. > :02:51.them. Your arm will come up with a big red itchy lump. What your
:02:51. > :02:58.immune system is doing is react to go the chemicals injected into our
:02:58. > :03:06.body in their sallifva, it is a cocktail of chemical that is act as
:03:06. > :03:11.an anti-coagulate and anaesthetic. As it is biting the anti-coagulate
:03:11. > :03:15.gives you a nice stream of blood. How long will it feed for?
:03:15. > :03:21.should take a couple of minutes, you can see the body swelling up.
:03:21. > :03:26.God for bid, this one escape, do we have a situation here? We will have
:03:26. > :03:30.a situation. This one has probably mated, she has just had blood,
:03:30. > :03:34.which means she will produce viable eggs. She will lay her egg, they
:03:34. > :03:42.will hatch out and they will start reintroducing. They will leg three
:03:42. > :03:47.eggs in a day, and 300 eggs in their lifetime. How easy is it for
:03:47. > :03:52.this bedbug if she escapes to make it to my home? These beds are
:03:52. > :03:55.tremendous hitch hiker, they could get on your clothes and get into
:03:55. > :03:59.our home. This is why I hear because there are more
:03:59. > :04:02.international travellers there are more bedbugs in this country. They
:04:02. > :04:05.are getting into people's suitcases? That is how they are
:04:05. > :04:09.transported around the country and the world. The other reason is
:04:10. > :04:16.there has been a bit of an increase in secondhand furniture sale, they
:04:16. > :04:23.lay their eggs on the furniture, and the bedbugs themselves can even
:04:23. > :04:29.be transported. She's finished. She's moving. She just pooed,
:04:29. > :04:32.that's so rude. No only does she feed off you, she leaves a little
:04:32. > :04:41.calling card. Can you see she's struggling to walkings because
:04:41. > :04:45.she's so fat. I know - She's struggling to walk because she's so
:04:45. > :04:50.fat. They defacate on my arm as you say, that is the smell they use to
:04:50. > :04:55.get back home. Bedbugs do love a good square meal. In fact they can
:04:55. > :04:59.drink three times their own volume in one bite. A bit like me drinking
:04:59. > :05:06.180 litres of milk in one go. And it means these amazing creatures
:05:06. > :05:09.can live for up to a year inbetween meals.
:05:09. > :05:16.Even when they are full they can slip into the tiniest nooks and
:05:16. > :05:20.cranies in our homes. It is only at night they emerge to sniff out
:05:20. > :05:23.their prey, then they sniff their way back home. James's plan is to
:05:23. > :05:27.develop traps to catch bedbugs before they bite you. But to do
:05:27. > :05:30.that he needs to understand their amazing sense of smell. Which
:05:30. > :05:35.requires a very complex chemistry kit.
:05:35. > :05:43.What exactly is this massive box, what's going on in these tubes?
:05:43. > :05:47.OK, so this is a gaschromatigraph, we are separating out gases. What
:05:47. > :05:52.we have is a sample of human Oder, it is my Oder that I have collected.
:05:52. > :05:56.You are going to fire that sweat, your sweat, at the antenna? That's
:05:56. > :06:02.right. I'm going to use the syringe. I can't believe you have collected
:06:02. > :06:06.your own BO in a glass vial, that is little bit dark! We will put it
:06:06. > :06:11.in the hole and inject it in, this machine is a big oven. It heats up,
:06:11. > :06:15.as it heats up, low molecular weight compound also travel much
:06:15. > :06:19.quicker around a column to a flame, that then tells what you the
:06:19. > :06:23.chemicals might be. Inside here is a spliter, half of the chemical
:06:23. > :06:26.gets split to the flame to tell us what the chemical S the other half
:06:26. > :06:29.of the chemical gets blown out, this transfer line here, into
:06:29. > :06:34.another air stream, that then gets blown over the an then that of the
:06:34. > :06:40.insect. How is the antenna still reacting
:06:40. > :06:44.to smells? Even though the bedbug is dead, the receptor cells on the
:06:44. > :06:48.antenna stay alive, for about 30 minutes. Like moths their antenna
:06:48. > :06:54.will stay alive for hours, we can actually use it, even though it is
:06:54. > :06:59.dead, because the receptor also fire and respond to chemicals. They
:06:59. > :07:04.are picked up by protein that is carry the chemical across a space
:07:04. > :07:08.to the receptor cell, that illicits an electrical response in the
:07:08. > :07:12.nervous system, and that make behavesor, the insects are
:07:12. > :07:17.attracted and come towards us. That is how they find us. We haven't
:07:18. > :07:26.done a lot about bedbugs and human oweders so we don't know a lot
:07:26. > :07:30.about it in this way. They have it made, I actually went to an all-
:07:30. > :07:36.you-can-eat buffet in Vegas once and I couldn't eat for a year.
:07:36. > :07:39.In case you were thinking I was not being a wuss by being not bitten,
:07:39. > :07:43.can I show you his arm the day after, and the day after, he said
:07:43. > :07:47.it was so sore and nasty. I rest my case.
:07:47. > :07:50.What happens now if you're at home and you have bites like that, what
:07:50. > :07:54.should you do? Even though bedbugs are on the rise,
:07:54. > :07:59.the chances are you are not going to get them. If you get bites and
:07:59. > :08:06.you suspect bedbugs, there are tell tale sign, as you saw, they do a
:08:06. > :08:12.little poo after they feed. So in your bed you find some bround
:08:12. > :08:16.blotchy grainy bits of bedbug deafcation in your bed. There is a
:08:16. > :08:22.sweet, musty smell in the environment, they like to he can
:08:22. > :08:32.sudden that smell to follow it home - he can sued that smell to follow
:08:32. > :08:34.
:08:34. > :08:36.it home. The best thing about James's work is it is going on.
:08:37. > :08:42.feel paranoid, you think I have bedbugs. Nothing fires the
:08:42. > :08:45.imagination like looking up into a star-filled night. I went to
:08:45. > :08:55.Caltech in Pasadena, to look into deep space with a telescope that is
:08:55. > :08:58.
:08:58. > :09:03.We have had telescopes now for about 400 years, although people
:09:03. > :09:08.credit Galileo with inventing them, he was not the first, he did play
:09:08. > :09:11.with the I arrangement of lens inside a tube, that increases
:09:11. > :09:16.magnification, let us see further, and in the process, revolutionised
:09:16. > :09:20.science. Since then, astronomers' telescopes
:09:20. > :09:23.have grown ever-larger and more powerful. Now they even launch
:09:24. > :09:29.giant ones into space, in their attempts to see further and further
:09:29. > :09:35.away. OK, so if size matters, just imagine what you would see if you
:09:35. > :09:39.had a lens the size of a galaxy. Believe it or not, galaxies
:09:39. > :09:44.themselves can act as lens. This may sound a little bit weird, but
:09:44. > :09:49.I'm talking about a very real phenomenon, called gravitational
:09:49. > :09:55.Lening. Using the effect - lensing, using
:09:55. > :09:59.the effect astronomers can create lens so big they span the universe.
:09:59. > :10:05.Gravitational lensing was first suggested by Einstien in his
:10:05. > :10:08.general theory of relativity. You don't need to be Einstien to
:10:09. > :10:17.understand the principle of it. I want you to imagine this is a
:10:17. > :10:21.galaxy far, far away. Light from the orange tree galaxy is making
:10:21. > :10:27.its way towards earth. I want you to imagine inbetween us is a huge
:10:27. > :10:30.cosmic body right here, another giant galaxy or cluster of galaxy,
:10:30. > :10:35.billions of stars. You would think by having it here, it would block
:10:35. > :10:40.the light heading towards the earth. But because it is so massive, light
:10:40. > :10:49.is actually bent around it. Even though our orange galaxy is
:10:49. > :10:53.obscured, we can still see it. A giant galaxy is so heavy with
:10:53. > :10:59.such a strong gravitational field, it warps the space around it, which
:10:59. > :11:01.makes light bend on the way through. So the galaxy acts like a lens,
:11:01. > :11:07.revealing and magnifying distant objects, or indeed, oranges, far
:11:07. > :11:11.beyond. This monstrous gravitational field
:11:11. > :11:16.is acting just like a lens. Gathering, distorting, and
:11:16. > :11:22.managefying light from distant galaxies, the whole thing is just
:11:23. > :11:31.like one big cosmic telescope. The trouble is, these lensing galaxies
:11:31. > :11:36.are incredibly difficult to spot. Some have been identified by a
:11:36. > :11:39.project partly based here at CalTech.
:11:39. > :11:49.Come on in. This man is part of a team hunting
:11:49. > :11:53.for them. That is a foreground lensing galaxy, we are looking at
:11:53. > :11:59.the blue as a disturn galaxy. The blue bits are not off to the side,
:11:59. > :12:05.they are directly behind the blob. They are. That is how we see it.
:12:05. > :12:11.The blob in the centre is the lensing galaxy, it is showing a
:12:11. > :12:17.galaxy further away, creating a ring of blue light. That is not
:12:17. > :12:22.their real shape, it is the distorted shape? Yes, because of
:12:22. > :12:27.gravitational lensing, this galaxy is magnified by about 10/30.
:12:27. > :12:33.can see how the ring of light is produced by shining a torch through
:12:33. > :12:40.the base of a wine glass a tiny light in the distance is distorted
:12:40. > :12:43.into bright spots and a tell tale ring. It is such a simple principle,
:12:43. > :12:51.a lens bends light, and now we have light bending because of gravity.
:12:51. > :12:56.How rare is it to find these lensed galaxy? It is very rare, maybe one
:12:56. > :13:00.or two out of 100,000 galaxies. We have now this telescope that
:13:00. > :13:07.operates on the infrared wave length, we have managed to find a
:13:07. > :13:11.large sample of lensed galaxies. This is a new orbiting telescope
:13:11. > :13:17.launched in 2009, peering further into dark corners of the universe
:13:17. > :13:23.than ever before, it has discovered very distant young galaxies,
:13:23. > :13:26.bursting with new stars, its secret is infrared.
:13:26. > :13:32.We couldn't see them using optical light, because places where there
:13:32. > :13:36.is lots of star formation has lots of dust. Optical light cannot
:13:36. > :13:43.penetrate through this dust. So with Hirshal we are finding these
:13:43. > :13:49.new galaxies that we didn't know existed.
:13:49. > :13:52.Hirshal scans vast areas of the sky, picking out the tiny signs of
:13:52. > :13:57.distant galaxies that other telescopes miss. What are we seeing
:13:58. > :14:03.here? We are looking at the infrared universe. Each speck or a
:14:03. > :14:08.dot here is a galaxy. But you can pick out this bright things, one
:14:08. > :14:14.here, there is one right here and they actually are priter, because
:14:14. > :14:23.they are being gravitationally lensed. These are the lensed
:14:23. > :14:29.galaxies discovered with Hirshal. It is truly as ifing, undiscovered
:14:29. > :14:34.galaxies billions of light years away, discovered by gravitational
:14:34. > :14:39.lensing. Why is it so important to see the galaxies hiding behind the
:14:39. > :14:41.other galaxies? We want to understand how stars form in the
:14:41. > :14:45.distant universe. We don't understand the physics associated
:14:46. > :14:53.with star formation, how the galaxies came to be, how did the
:14:53. > :14:58.first galaxy formed, this is one way for us to get handle on that.
:14:58. > :15:01.love things that only noticable on scales so vast that they are beyond
:15:01. > :15:04.common experience. Who would have thought that if you get a massive
:15:04. > :15:09.enough object, it will actually bend the light going past it and
:15:09. > :15:13.focus in somewhere else. That is a very beautiful ING this. I want to
:15:13. > :15:18.know is when did we first become aware of gravitational lensing out
:15:18. > :15:23.there in the universe. We have known g it for a while, since 1979,
:15:23. > :15:28.but the idea of what gravitational lensing could do, we are talking
:15:28. > :15:35.about the late 1930, as a concept in physic, back to Einstein, the
:15:35. > :15:37.theory of relativity, that space could be warped by gravity and
:15:37. > :15:42.therefore warped. Historically it is an interesting story, it shows
:15:43. > :15:47.how science works, science as a process from big idea through to
:15:47. > :15:51.practical application. It is lovely. Nature composes some of her
:15:51. > :15:56.loveliest poems for the microscope and the telescope. Follow the links
:15:56. > :16:01.to the Open University to learn more about life, the universe and
:16:01. > :16:06.everything, including me and astro physicist Frank Drake talking about
:16:06. > :16:10.the search for alien life. Doesn't it seem like every week
:16:10. > :16:15.there is another headline that this or that will vastly increase your
:16:16. > :16:18.risk of this and that, but as Dr Yan explains, statistics and gut
:16:18. > :16:21.reactions aren't necessarily a good reaction.
:16:21. > :16:25.When you read medical stories in the press, it is hard to interpret
:16:25. > :16:29.what they are telling you, especially where statistics are
:16:29. > :16:34.involved, the figures seemed designed to bamboozle us. I will
:16:34. > :16:39.show you what I mean, using bacon sandwiches. A few years ago it was
:16:39. > :16:42.all over the news that eating processed meat like bacon or
:16:42. > :16:47.sasauges every day could increase your chances of getting bowel
:16:48. > :16:56.cancer by about 20%. So let's see how people react to that. And see
:16:56. > :17:02.what they make of my cancerous bacon butties.
:17:02. > :17:07.Free bacon sandwiches? Always like that. Increase your risk of bowel
:17:07. > :17:13.cancer by 20%, they are literally free, I don't know if you want them.
:17:13. > :17:21.I'm less hungry now I have seen that. Increase your risk of getting
:17:21. > :17:25.bowel cancer! There has been some research that shows regular eating
:17:25. > :17:30.of bacon increases your chances of bowel cancer by 20%. One other
:17:31. > :17:36.thing, let me give you a choice, these bacon sandwiches, only
:17:36. > :17:41.increase your bowel cancer of 5%-6%. Which one takes better. Help
:17:41. > :17:50.yourself to either plate, but prefer these ones? I prefer the
:17:50. > :17:57.percentage. I think I will take the risk.
:17:57. > :18:02.Either way I'm having bacon. don't like bacon any way.
:18:02. > :18:06.We're not trying to trick you, I have eaten these. Can I ask why
:18:06. > :18:10.this one, why does it increase rather than this one. The ones that
:18:10. > :18:13.are really nice that are not good for you, like all food. Can I let
:18:13. > :18:17.you into a secret, it is no different at all. These two are
:18:17. > :18:21.exactly the same. Those risks are exactly the same as well. The
:18:21. > :18:26.difference is, just in the way that you present statistics. Do you want
:18:26. > :18:31.me to explain, I will show you. So, normally, your chance of getting
:18:31. > :18:36.bowel cancer is about 5%, OK, that means out of 100 people, some time
:18:36. > :18:41.in their lives, five of them will probably get bowel cancer any way.
:18:41. > :18:46.That is five out of 100. What this scientific research showed, was
:18:46. > :18:51.that if you eat about 50 grams of processed meat every day, those
:18:51. > :18:55.risks are not 5% but 6%. In statistics that is known as the
:18:55. > :19:00.absolute risk, that is what this is telling you, that isen increase of
:19:00. > :19:04.But that's not to say the 20% is wrong, it is just another way of
:19:04. > :19:09.expressing the same figure. And this is called the relative risk.
:19:09. > :19:16.Relative to the people who would have got it any way, one extra
:19:16. > :19:23.person, that's one, compared to five, one fifth increase. Which is
:19:23. > :19:27.20%. Exactly. So this figure is right as well, just a different way
:19:27. > :19:33.of putting it. Of course 20% sounds a lot worse, doesn't it. Actually,
:19:33. > :19:37.most of you, choose the sandwiches from the plate that was labelled 5-
:19:37. > :19:40.6%, that shows you how persuasive statistics can be, it is important
:19:40. > :19:44.to look behind the headline figures to find out what is really going on.
:19:44. > :19:50.I think I will have a bacon sandwich now.
:19:50. > :19:53.I have got a bit of a bug bear when it comes to banner headlines and
:19:53. > :19:57.statistic, we have to understand the basics, like Dr Yan showed us.
:19:57. > :20:00.We have to realise a lot of the statistics are "cherrypick"ed for
:20:00. > :20:05.effect without being in proper context, we have to remember that.
:20:05. > :20:12.Enough about the bug bears and the bedbug, let's talk about the cake.
:20:12. > :20:17.Because, I think you two both have a birthday this week. 31. 29.5.
:20:17. > :20:23.Statistics I'm unsure of. The lovely Dr Yan has sent this cake,
:20:23. > :20:30.it comes as catch, you can't have any until you figure how to split
:20:30. > :20:37.it into eight equal pieces with only three cuts.
:20:37. > :20:41.That's not possible. Is it: Very easy. If you think you know the
:20:41. > :20:46.answer is on the website. Before I get too distracted by the chocolate,
:20:46. > :20:50.I will get back to the bedbug investigation. We have heard that
:20:50. > :20:57.bedbugs have an incredible sense of smell, time for an e permanent to
:20:57. > :21:06.show us how they use it. - - experiment to show us how they use
:21:06. > :21:09.I have two specimens to show what things are attracted to our little
:21:09. > :21:18.bugs. These are two of the smelliest
:21:18. > :21:23.people I know. Dallas and Yan. James have - has set up an
:21:23. > :21:28.experiment to see which of the two has the most attractive smell to
:21:28. > :21:34.the bedbugs. Yan and Dallas haven't washed for 24 hours, they are a bit
:21:34. > :21:41.smelly. James is making them stew in their own juices for another how,
:21:41. > :21:46.in hot, sweat, foil bags. There is something deeply wrong with with
:21:46. > :21:51.this picture. What's happening? have them in the thermal bags which
:21:51. > :21:56.is used to collect body Oders. You can probably smell it. There is a
:21:56. > :22:03.pierce pong in here, it smells of boys' bedroom. We are pumping the
:22:03. > :22:10.body Oder from the bag, up the tiny tubes here, leading to this
:22:10. > :22:16.apparatus here into this arena, the behavioral arena, to find out if
:22:16. > :22:25.Dallas is more attractive than Yan to bedbugs. I think I'm going to be
:22:25. > :22:30.more attractive to bugs. The bedbug is released, what
:22:30. > :22:34.happens now? We will turn the pumps on and vacate the room. The one
:22:34. > :22:41.thing about bedbugs is they only feed at night, it will have to be
:22:41. > :22:45.done in the pitch dark. No hanky pangy, we are doing the lights -
:22:45. > :22:48.hanky pangy, we are turning the lights off. They can't bite them,
:22:48. > :22:54.they are perfectly safe in there, I have given them a night vision
:22:54. > :22:59.camera to stop them getting board. This is Yan, in his sweating bag.
:22:59. > :23:05.Outside we watch on a monitor as the monitor sniffs its way around.
:23:05. > :23:10.So there's our friend in his little choosing area, he's going to choose,
:23:10. > :23:14.up there, choice arena there is a camera, you can see him do his
:23:14. > :23:21.thing. There is infrared lights on there as well. That is the sound of
:23:21. > :23:24.the Oder being sucked down the tubes. That is the sound of science.
:23:24. > :23:29.Oders coming from the bags are being pumped through the pots. It
:23:29. > :23:33.is sussing out which side it prefers, which one will be the best
:23:33. > :23:40.blood meal? It is favouring this side more. It is definitely
:23:40. > :23:45.favouring that side now. This is quick it exciting. Having a whiff
:23:45. > :23:50.of the two boys when - quite exciting, having a whiff of the two
:23:50. > :24:00.boys, who would your money be on? Yan, I would escape out of the hole,
:24:00. > :24:02.
:24:02. > :24:07.if I was the bedbug, the smell There is some serious science going
:24:07. > :24:13.on here. Because James wants to find out which chemicals bedbugs
:24:13. > :24:17.respond to. Once you discern whether it is attracted to a
:24:17. > :24:21.particular individual's body Oder, do you take apart the body Oder to
:24:21. > :24:26.see what chemicals might be attractive? If somebody is more
:24:26. > :24:30.attractive than someone else, it possible they might produce for
:24:31. > :24:34.attractants than the other. It might be the person not attractive
:24:34. > :24:39.might be producing natural repellant, that their body has a
:24:39. > :24:45.natural defence system against bedbugs. I thought it was always
:24:45. > :24:55.about something in your body Oder that is attractive to insects, I
:24:55. > :24:59.
:24:59. > :25:09.never realise you had had repellants. If we can find out what
:25:09. > :25:10.
:25:10. > :25:15.it is we can sell it as a repellant. It is definitely spending more time
:25:15. > :25:25.on one side than the other. looks like a clear result, but to
:25:25. > :25:27.
:25:27. > :25:37.be sure we run the same experiment again and again. After several
:25:37. > :25:41.
:25:41. > :25:47.hours there is no doubt. They look bored now. A game of I Spy. I do
:25:47. > :25:56.feel for them, there has been in the bags them, it gets hot and
:25:56. > :26:01.sweaty and it is not pleasant. There is about a quarter of an inch
:26:01. > :26:08.of water in the bottom of this bag. Do you reckon we have a good
:26:08. > :26:12.result? I'm confident we have an answer. Let's let them out of the
:26:12. > :26:16.cave. How are you. Oh my gosh the pong in here is something else.
:26:16. > :26:23.is a bit ripe. Do you want to who is more attractive to bedbugs. Who
:26:23. > :26:28.do you reckon it is? I reckon it's Dallas. Why do you reckon it is
:26:28. > :26:34.Dallas? I reckon it is Yan, he's a little gamey. Dallas didn't have a
:26:34. > :26:39.shower this morning and the shame T-shirt for two days. James has his
:26:39. > :26:44.money on Yan? I did. After he got a whiff of you, he said it is
:26:44. > :26:48.definitely going to be Yan. We have a categorical, all-out winner, I
:26:48. > :26:55.can announce to you that the person in the room who attracts the
:26:55. > :27:01.bedbugs most s a certain Mr Dallas Campbell. Get in. Bet bug of taste.
:27:01. > :27:05.Clearly has - bedbug of taste. traictive, it is scientifically
:27:05. > :27:09.approved I'm attractive. Draw a line and move swiftly on. I say
:27:09. > :27:14.that, I think I'm attractive to all insect life on earth, because every
:27:14. > :27:18.time I go on holiday I get bitten to shred, whoever I'm with are
:27:18. > :27:25.absolutely fine. Exactly the same experience, I went travelling with
:27:25. > :27:29.mate, we would share a room, I wake up with bites, and he never got
:27:29. > :27:34.bitten. I never could figure out if I was attractive or he was
:27:34. > :27:40.repulsive. Depending on the insect you are giving out an traictant or
:27:40. > :27:46.repellant, we don't know what it is for bedbug, he finds out it was a
:27:46. > :27:51.repellant that Yan wask sueding we can make a - was exuding we can
:27:51. > :27:56.make a spray. Can you imagine, essence of Yan. If you want to see
:27:56. > :28:01.more boy dorm action, if you are in the mood, get on to the website,
:28:01. > :28:05.check it all out. I haven't seen it yet, I can't tell you what it is
:28:05. > :28:09.like. That is it for this week, next week I'm doing something
:28:09. > :28:13.really stupid. In the name of science I will not clean my teeth
:28:13. > :28:17.to see what will happen. I have a smell thing goingen in the series.
:28:17. > :28:21.I'm looking into something we take for granted. Artificial light, only
:28:21. > :28:25.in recent history have we had the ability to flick a switch. But new
:28:25. > :28:30.research suggests that it may also be having an unexpected biological
:28:30. > :28:33.effect on our bodies. Dr Yan will be coming over all health and