Dangerous game
Vincent Serventy, despite being a highly respected author on Australian conservation issues, has clearly failed to allow his own thinking on biological control of pests to evolve beyond a 1950s magic-bullet mentality (Letters, 9 December). Serventy, like many in the CSIRO, seems to think that science can do anything it likes and then seek public approval for its actions. What is wrong with the current Rabbit Calicivirus Disease (RCD) fiasco is that the CSIRO was allowed to carry out its subsequently botched tests at all.
The use of a virus to control the number of any mammalian species is fraught with danger, since there is always the possibility of mutation and of the virus crossing species barriers, with unintended consequences. With the rabbit calicivirus, such a possibility cannot be ruled out since, according to virologists, it shares “striking similarities” with human caliciviruses and feline calicivirus. We do not know what eftect RCD has on most native species, since only 13 have been tested.
Elementary evolutionary theory would suggest that organisms are more likely to mutate when placed in an alien environment, so although overseas observation is important in understanding RCD, it may not be applicable in the Australian context. Viruses are extremely adaptable organisms and demonstrate rapid evolutionary change. The virus in Australia is now subtly different from the rabbit calicivirus in Europe, just as the Australian wild rabbit is different from the European rabbit. With so much uncertainty it is unreasonable to suggest that the RCD programme in Australia represents good science and that we should embrace the spread of RCD with open arms. Ecological engineering, like genetic engineering, is a very risky business.
RCD has the potential to create a new round of extinctions of Australian native animals through predators switching to different prey as rabbit numbers crash. It could also mutate into a form that could seriously affect nontarget species, including humans. That we could deliberately import and then release such a virus, opening up these possibilities, does the CSIRO no credit and I am surprised that Serventy would wish to defend them.
Eurocentric?
Isn’t it about time that Lewis Wolpert was challenged to expand his narrow definition of what constitutes science? In his review of John Barrow’s book The Artful Universe (Review, 9 December) he arrogantly declares that “science flowered just once, in Greece, and all science as we know it comes from that remarkable group of thinkers”.
In making this statement, Wolpert ignores the work of the late Joseph Needham, who in the many volumes of Science and Civilisation in China, documented numerous “scientific” discoveries and observations made by the Chinese, in some cases many years before the theoretical speculations of the Greek philosophers and certainly in isolation from the West. These include examples of experimentation using controlled variables as well as the meticulously detailed results of their observational astronomy.
Wolpert has argued elsewhere that scientific thinking is an “unnatural” process and that what we now call “science” is a relatively recent phenomenon. But philosophers of science such as Paul Feyerabend have argued for a much more flexible definition of “scientific method”. Looking at science historically there are many examples where the rules are not completely adhered to, suggesting, for instance that Chinese observational, astronomy could be called “science” even though it wasn’t embedded in a geometrical cosmology.
In opposition to Wolpert’s “unnatural” assertion, Noam Chomsky has argued that all human beings possess a “science-forming capacity”, implying that scientific thinking is natural to all peoples, presumably since our modern brains evolved. As Jean Piaget demonstrated, most adults possess the cognitive machinery required for scientific thinking and we are all naturally capable of forming hypotheses.
Herd instinct
With reference to your article on hornless cows (Technology, 16 December), I would like to make two comments. First, the word used for removing calves’ horns should be disbudding, not dehorning. The latter suggest cutting away a long horn. Moreover, the word “painful” as used by your reporter is rather misleading. The only real pain involved in burning out the bud, which is the method commonly adopted, is in the injection of local anaesthetic. This causes as much pain as for humans given a local by their dentist.
Secondly, Joyce D’Silva’s remark that “there would be no need to dehorn animals if they were not herded together so closely” is as fatuous and nonsensical as you can get. Animals by nature are herd creatures. Not to herd them so closely would involve keeping them individually penned all their lives. She does not need me to tell her that that would contravene the Welfare Code.
Feel the vibes
I too have noticed the “vibration” effect described by David Tong (Letters, 2 December) but only when the chassis concerned was directly or capacitively connected to the live side of the electricity supply. In the same circumstances, a small neon bulb can be made to glow by touching one terminal on the live point while holding the glass envelope 鈥� the “electrician’s screwdriver” principle.
I first noticed the effect in the late 1950s at a time when I was very interested in amateur radio, and would surprise my friends by using it to detect faulty earthed radio equipment, although merely reversing a two-pin plug was often sufficient to make the effect disappear.
It has since become integrated into a way of life; when you first meet a new item of electronic equipment, approach it with one hand in your pocket and stroke the front panel lightly with the other. Only if no warning “vibration” is detected proceed further.
This may have saved my life on more than one occasion. Most recently, on moving into our new house I noticed that the screws on the plastic light switch plates were live. A wiring check revealed that the earth line and wiring conduit had become disconnected from the true earth. When reconnected, the fuses immediately blew; a short in the loft ensured that the so-called earth had in fact been at 240 volts AC. I hate to imagine that the previous owner might have disconnected the earth in order to “cure” the fault.
It is even possible to notice the effect when standing under high-voltage power lines where they run closer than usual to the ground. Stroking the palm of a partner’s hand is sufficient to reveal the effect, although its strength seems to vary, possibly with the humidity. However, stroke the smooth but sensitive skin on the back of your partner’s neck with caution: the effect is much more detectable here, a minute spark jumps and can feel like a sharp pinprick to your disconcerted partner.
A good place to observe this effect is in a nature reserve on the Test marshes near Southampton, under some 275 000-volt power lines (the approximate grid reference is SU363146). But mind where you tread: the rare Celery-leafed buttercup Ranunculus sceleratus grows by the footpath at this point.
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A vibration can be detected when a finger is gently rubbed up and down the VHF aerial of a radio powered by the AC mains. A friend said he felt a tingling effect when he moved his hand across a switched-on electric blanket.
While walking close to pylons I got a tingling feeling (physical, not mental) when I moved my hand along my wife’s arm.
These effects were discussed in 1977 in Queries in Physics, a publication for physics teachers which has since been discontinued. No clear explanation was given, but it was suggested that it might be due to a small leakage current or a capacitively induced charge.
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In the 1960s, I sometimes repaired televisions in a rather damp garden shed. Mains-driven televisions used a cheap and nasty way of deriving DC supplies from the AC mains which resulted in a 50 per cent chance of the metal chassis being at full mains potential. I found that a quick way to determine whether a television chassis was “live” was to gently brush it with the back of my hand to feel the characteristic vibration.
Sometimes there would also be a gentle humming noise from the point of contact. I had assumed this effect was due to stimulation of subcutaneous muscle by the 50-hertz current, but Tong’s observation that the effect vanished when his finger stopped moving casts doubt on this idea. Unlike Tong, I did not find the sensation particularly nice.
With sufficient, suitably modulated, current it might be possible to stimulate an area of skin to act as a sort of “living loudspeaker”.
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I noticed the effect in a cassette radio which my father gave me about ten years ago. This is a mains/battery National Panasonic FM/AM model RQ434S, number AG219284. I suppose it’s twenty to twenty-five years old.
You don’t have to get inside to find the effect because it occurs on the metal parts of the case. It’s particularly noticeable on the speaker grill, which is an aluminium sheet covered with small holes. You can’t feel the holes when the power is off, so I don’t think the phenomenon is being enhanced mechanically.
I’ve got other radios and cassette radios with metal cases 鈥� JVC, Bush, Grundig 鈥� but they don’t display the effect.
Weak spells
You seem to have invented a new disease called amniotrophic lateral sclerosis (Technology, 16 December). It should, of course, be amyotrophic lateral sclerosis, better known motor neurone disease. I wonder what our most famous sufferer (Stephen Hawking) would have to say about it.
Do not disturb
In reply to Tony Waldron on opening Shakespeare’s tomb (Letters, 25 November), I wish to point out that the famous bard must have had a premonition about this. In the church where Shakespeare lies buried one can read an inscription below his effigy stating that his bones are not to be disturbed. Respect for the dead?
Correction: Observant readers will have noticed that the research described in the article “Neutrinos blown by winds of change” (Science, 16 December) had earlier featured in the story “The riddle of the solar wind” (Science, 12 August). We apologise for this inadvertent act of recycling.
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Crime watch
I am astonished that your recent article on closed-circuit television (This Week, 23/30 December), should paint such a negative picture when it has drawn its conclusions from research which is itself almost wholly positive.
Any objective analysis of the Airdrie study could only conclude that it supports the introduction of CCTV. Its five main findings, highlighted on the front page of the study, are all positive. They were:
鈥� an overall drop in crime of 24 per cent;
鈥� a 48 per cent drop in crimes of dishonesty (housebreaking, shop theft, car crime, etc);
鈥� fire raising and vandalism down 19 per cent;
鈥� a 16 per cent improvement in the clear-up rate;
鈥� “no evidence that crimes were ‘displaced’ from the town centre to areas without CCTV”.
This last point is a direct quote from the report itself. No dispassionate reader could claim that this summary indicates anything but success.
I would agree that there is a shortage of good quality research on CCTV (although Home Office research publications have looked at it). That is why we welcome Jason Ditton’s work. However, it is hardly helpful to your readers to represent his conclusions so badly.
You treated the Sutton research in much the same way. Leaving aside the fact that this is a preliminary report on the first year of the system’s operation, the main findings were also positive:
鈥� an overall reduction in crime of 13 per cent (vehicle crime down 57 per cent, burglaries down 42 per cent, criminal damage down 47 per cent);
鈥� assaults and criminal damage at night down 10 per cent and 24 per cent respectively;
鈥� street theft down 7 per cent (as opposed to a 30 per cent increase in thefts inside premises);
鈥� more efficient use of police and better response times;
鈥� massive public support 鈥� no one opposed its introduction and a large majority feel safer (especially the disabled and elderly).
This does not call CCTV into question. Indeed, if there was a proposal to shut the scheme down in Sutton there would be a public outcry, quite rightly.
The Home Office has undertaken it own research. Our thorough and lengthy study of three CCTV schemes, in Newcastle, Birmingham and King’s Lynn, was published on 29 December. It shows that in the right circumstances CCTV has had a major effect. Used correctly and in combination with other crime prevention measures, it can help prevent crime, deter criminals, assist with detection and investigation, improve clear-up rates and increase conviction rates.
As the Sutton project demonstrates, we have never advocated that CCTV is an exclusive answer. But I am not the only one who supports CCTV. The police are very clear about its merit. John Stevens, the Chief Constable of Northumbria, wrote in The Times this summer: “We are leading the world in CCTV technology and its use. In every case where cameras have been installed, crime has dropped and the number of arrests increased.” Peter Joslin, Chief Constable of Warwickshire, also wrote to me: “Without doubt CCTV, where introduced, has been a great success. It is useful both in the prevention and detection of crime and substantial falls in crime have been recorded in this country where CCTV has been introduced.”
CCTV is overwhelmingly popular. People want it in their town because it makes them feel safer, reduces the fear of crime and lets them use and enjoy their high streets again.
The money we are putting into CCTV is partly a response to this public support, but it is also an indication of our confidence that it is worth it. Research like the Airdrie and Sutton studies show that it works. When the evaluations of the schemes helped by the Home Office become available I am sure they will show the same.
It is quite extraordinary that a respected journal concerned with research and with the use of new technology could turn the results of the Airdrie and Sutton studies on their heads. I hope you will now allow your readers the chance to judge the facts.
The Home Secretary picks out the most positive aspects of the two reports. However, although CCTV can undoubtedly reduce some particular types of crime within an area under surveillance, it is much harder to make claims about its impact on crime overall. Studies released so far make clear that the effects of CCTV are complex. Currently available data will be analysed in the next issue of New 杏吧原创 and the debate continued 鈥� Ed
Preying on pigeons
Edward Camilleri’s letter, with its patently false extrapolation from “where they are available a peregrine eats an average 0.8 pigeons per day” to his calculation that the 1300 pairs of peregrines in Britain eat “about three-quarters of a million pigeons a year”, is just one more wholly bogus piece of baseless, science-free, propaganda from an organisation whose members lose literally hundreds of thousands of pigeons every year because they insist on racing them regardless of weather conditions (Letters, 16 December).
Some races, even those which take place in areas far from any peregrines, for example East Anglia and eastern England, end up with only a tiny fraction of birds returning home. Those missing birds were not killed by predators, but were inadequately trained, got lost, joined city flocks or starved. Perhaps your correspondent would like to publish some facts about the number of racing pigeons that are lost each year. I think the figure would be considerably greater than the total capacity of all the raptors in the country, even if as Camilleri tries to claim, they ate nothing else.
Rick Osman (in the same issue) does not agree with his pigeon-fancying colleague about the effects of peregrines, being able to accept the realistic statement from the Royal Society for the Protection of Birds that “racing pigeons form a small part of the peregrines’ diet”. However, he then goes on to claim that the decline in numbers of small birds, of which peregrines apparently “kill millions”, is mirrored by the increase in the raptor population.
This is a complete red herring in the debate about peregrines and racing pigeons. There is no good scientific evidence that any passerine population is being held back by birds of prey, let alone actually declining.
Both these letters demonstrate that the pigeon fanciers are unable to argue their case on the basis of scientific evidence because there is none to support them. There is plenty to contradict them, however.
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Osman claims that attacks by raptors on pigeons are increasing, and with the recovery of raptor populations I do not doubt him. He goes on to suggest, without any hint of evidence, that this recovery is responsible for the decline in small bird populations, and that having eaten all the small birds, peregrines are turning to pigeons as an alternative. Having made this accusation, Osman suggests that it would be folly to protect the peregrines at the expense of seeing them ripping small birds apart (I paraphrase).
I could equally well argue that the problem is caused by artificially high pigeon numbers sustaining a peregrine population above the environment’s natural food capacity, or I could blame mist-netting and mass shooting of migrants crossing Europe for the decline in small birds; I could go on to argue that it would be folly to protect small birds (and domesticated pigeons) at the expense of our recovering raptor population 鈥� but I have no more evidence than Osman, so I won’t.
Meanwhile, Camilleri (at least trying to use quantitative data) estimates that peregrines take around 750 000 pigeons a year. Is this a lot? Londoners would probably think not. Of these, what proportion are domestic pigeons as opposed to wild pigeons and feral pests? Besides, the estimate used states the rate at which peregrines take pigeons “where they are available”, not an average over the whole population, so he is probably overestimating.
As for Osman’s emotional appeal on behalf of skylarks, I would rather see a falcon “towering in her pride of place” than the huge flocks of airborne rats that he so loves (pigeons that is, I have nothing against skylarks). A subjective preference for something small and twittery over something with nasty sharp claws (or vice versa) is not a valid basis for making conservation decisions.