Ben -   That’s a very nice idea and I can see how it would work but I can also see a couple of problems because if we start to rely on these, if you have the vision-impaired community relying on these, in order to avoid being hit by very quiet electric cars, then what happens when it goes wrong one day?  And I really think that we need to find ways where we don’t rely entirely on technology to get around this.  I’ve wondered what they must do in Holland because I’ve been to Holland a few times and they have trams there that are virtually silent as well.  With the amount of cyclists around, crossing the road in Amsterdam, really can be quite a hazard because there’ll be cyclists coming from one way, a tram coming from the other and if you’re not looking out carefully, they might well hit you.  So, I think we’ll probably find a way around it that doesn’t involve this sort of technology but it’s a really nice suggestion.  Thanks very much. 

Chris -   Indeed, this was the nodulisporium fungus which is an environmental fungus but it produces nodulisporic acid which the paper we reported on last week is scientists making a version of that called nodulisporamide which targets an ion channel which is only present in insects.  It’s not present in people and it’s therefore neurotoxic to insects but because we don’t have their ion channel, it’s harmless to us.  I suppose it’s possible that we could do the same thing for other flying insects.  The problem is of course, you’d have to dose enormous numbers of people.  If you’re going to dose enormous numbers of people or something, you might as well give them an anti-malaria drug in the first place.  So, I guess that that’s one of the criticisms.  Isn’t it?  That if you’re going to do something like that, well, might as well treat the disease that’s mostly the problem, but it’s a good idea and it may be that that’s one way to tackle this.

Ben -   That’s very true.  If we already had the facility to dose that many people with any medication then, yes, we’d be using anti-malarials, wouldn’t we?

Chris -   What he’s getting at, is that radio waves do not propagate very well through water.  Part of the reason is a radio wave is an electromagnetic wave and as water contains lots of dissolved salts and ions, you can’t get the signal to go very far.  That’s why submarines, when they're underwater, they can’t communicate very easily.  They have to surface or they can only communicate with limited range and they tend to use sonar because sound travels very, very easily underwater but radio waves are soaked up by the fact that they are a moving electromagnetic wave and this makes the ions in the water go backwards and forwards and so, you lose all your energy in your radio wave very quickly underwater.

Ben -   Right  So, I wonder, should you happen to be trapped in a car underwater at the bottom of a river, how on earth do you get somebody to come and help you?

Chris -   I think you have to get out.  I don’t think that your mobile phone signal is going to spread very far, unfortunately.

Chris -   I think this is probably a legacy of our pre-LCD era.  We take for granted having these flat screen, very light screens now, but in the old days, not so long ago actually, we relied on cathode ray tubes, these big old giant television-like things that we had in our living rooms and that technology could be condensed down to something fairly compact but still quite bulky which was the way of making an image on a screen.  Green is a good choice for two reasons.  One is that the phosphors, the things that glow and make the colour are relatively easy to make it green.  And because the eye is more sensitive to green light than virtually any other wavelength, it means that you can make your display dimmer than any other wavelength and your eye will be sensitive to it.  And it means therefore, you can run your thing with less power than you would otherwise need to make another colour visible so green’s a good choice.  And I think also when you’re looking with night vision goggles, you’re actually seeing monochrome anyway, it’s a black and white picture anyway.  There’s no colour information that can be conveyed so it doesn’t matter that it’s only just in one colour.

Ron -   And the dragon fish that live in the deep sea that are as mentioned just now that see red light.  They actually see the red light using chlorophyll and the laboratory in the states have now started putting chlorophyll into the eyes of mammals, things like rats and mice and have been able to make them super sensitive to red and there’s even been the suggestion that you could do this with humans so that you can make them almost infrared sensitive and you wouldn’t need goggles at all.

Chris -   So this would be a sort of military application.  You could give your pilots or your armed personnel super red vision so that they could see the enemy on the battlefield glowing because they’re putting out heat.

Ron -   Absolutely, theoretically as you would say.

Chris -   That’s wonderful.  Thank you Ron.

We put this question to Professor Ron Douglas:

Ron -   That’s almost a philosophical question.  The first thing to say is that what’s happening in the eye in all of us is the same.  We have the same chemicals.  We have the same responses to the light but its what our brain makes with this information that’s different.  So for instance, if you take, you know, if you were I, you’ll probably be appalled to hear we’re fairly similar.  If you have all chips of all different colours and you put them into different piles, we would make a pile for green, a pile for blue, a pile for yellow, a pile for red.  But if you ask people for instance some African tribes who’ve had very little contact with the Western world, they will put them into different piles that they will put yellows and reds together and swear blind that they’re the same colour and they will put blues into different piles and closer to home.  Even in Welsh, there is a word called glas which encompasses what you and I would call blue but it also encompasses some things that we call green.

Chris -   Wow!  But if you look in the retina, the thing that’s doing the seeing and converting light waves into brain waves, is there a dramatic difference between the way the African tribes who do what you’ve just described are doing that and us.

Ron -   No!  There’s absolutely no difference at all in what the eye is doing but it’s a difference in the brain, it’s where culture comes in to play and interacts with the visual stimulus.

Chris -   No.  People did think but it happens too quickly.  The photic sneeze reflex to recap is when you go out on a sunny day, bright light comes to you and you suddenly feel this irresistible urge to sneeze often multiple times.  About one person in five is affected, tends to run in families, and it seems to be a neurological phenomenon.  It’s not a tear tickling your nose phenomenon because you tend to sneeze quicker than your eyes water so people have sort of written off that theory unfortunately.  So we think it’s more the same thing that makes your pupil get smaller and you blink in response to bright light, probably the same bit of the brain that’s doing that is also crossing over into the sneezing center a little bit and triggering both reflexes.

Ben -   So it’s wiring rather than plumbing?

Chris -   Absolutely!