Letters : Mathematical mice
Milton of Potterton, Aberdeenshire
Perhaps Richard Brown’s mice are not counting revolutions, they are counting
footfalls
(Feedback, 25 October).
Brown says he noticed the phenomena “shortly
after starting his experiment”. Therefore he inadvertently “trained” the
subject.
The mice naturally learned the total revolutions of the wheel as a gross
distance to be run. Rather than counting the number of wheel turns, or timing
themselves, they simply arrived at their destination.
Mice spend much of their lives moving in the dark between familiar points.
They also prefer to travel in straight lines. This may be because they have
learnt the amount of movements required to reach their goal.
Letters : Hot air on wind
Tintagel, Cornwall
I approve John Etherington’s assault on wind generators, but he is being
optimistic when he states that “50 per cent of annual capacity is rarely
achieved”
(Letters, 18 October, p 58).
In the trade-wind belt, where the wind blows strongly and constantly, a
generator can achieve its full potential. In Britain, where winds vary from zero
to some 100 mph, the theoretical maximum is only one-third of its potential.
A windmill does not turn until the wind speed reaches about 15 mph. Its
output cannot be connected to the national grid until it reaches around 25
kilowatts because a margin is necessary for control of voltage and
frequency.
When the generators reach maximum output they must be shut down or they
overheat. Generators are designed for shutdown at 50 mph.
Whatever way the calculation is made, windmills can generate electricity, but
the only income that results is by way of government or European Commission
grants and subsidies. In any case, windmills are a joke because rotating
turbines must always be kept online as a backup. It can take up to 20 minutes, I
am told, to run up a large generating set.
If you live near a wind farm (ours is about 800 metres away) they are a pain
in every part of the anatomy. They are not pretty, not quiet, not useful.
Letters : . . . . . .
Southall, Middlesex
Etherington asks if “our last wild places [are] to be sacrificed to the myth
of green wind energy”. As your readers will know, the potentially catastrophic
effects of global warming will not be solved by energy efficient light bulbs,
and equally, wind energy is not the whole solution. However, they are both
integral parts of the government’s broader aim to reduce carbon dioxide
emissions by 20 per cent by the year 2010.
This strategy translates to a reduction target of 36 million tonnes of
carbon, of which wind energy can save at least 750 000 tonnes. This will not
require the 40 000 wind turbines to which Etherington refers. However, the
thousands of wind turbines it will need will be absorbed into our landscape in
the same way as the 10 000 wind turbines that operated throughout England in
past centuries.
The fact is that if we are to have any hope of protecting the ecosystems and
landscapes in the long term, we must act now. Wind turbines in the landscape are
both an important part of the CO2 reduction programme, and a symbol of
our real commitment to long-term protection of our wild places.
Letters : Death of science
Chicago
I read with interest your editorial “Death of an expert witness”
(8 November, p 3).
As one of the defence’s expert witnesses (I am a neuropathologist) in the
Louise Woodward trial, when the verdict “guilty of second degree murder” came
in, I viewed the real verdict as “death”. Not the death of Woodward, who as it
turned out, was saved by Judge Zobel’s intercession, but a death of logic and
science.
During the last phase of the trial, virtually every television reporter, and
many of the “former” prosecutors who had been retained as commentators, usually
prefaced their comments with statements to the effect that “they didn’t know
science, and therefore could not interpret the evidence”. More shocking still,
they would then go on to imply that this same level of ignorance extended to the
jury and that because various experts had taken opposing positions, the
scientific testimony should be disregarded as irrelevant and the outcome judged
on the demeanour and testimony of the defendant. To my horror, when the verdict
was reported, it appears that the jury had done exactly that.
The prosecution’s expert testimony was heavily laced with beliefs and
dogma鈥攆or example, retinal haemorrhages mean shaking, infant head injuries
rarely, if ever, have latencies, and so on. A jury properly briefed on the
science would have recognised that.
Perhaps what is being said here is not so much that we should be excused for
our lack of detailed scientific knowledge, but that we should also be excused
for not knowing how to think critically and evaluate information that comes to
us. If this is the case, and I suspect that it is, then we are all in very deep trouble.
Our educational institutions must have, indeed, failed utterly.
I don’t think committees can replace individual experts’ opinion, but open
forums for discussion can provide a context within which dissident opinion can
be weighed, and “junk” science and dogma exposed. How the legal system can
effectively utilise expert opinion is a thorny problem. It is high time that
judicial conferences, lawyers’ organisations, advocacy groups, and other
interested parties visit the broad issues raised with the Woodward case, and try
to find a better way to elicit solid opinion and employ it in the delivery of
justice.
Letters : Colour of allergy
cradockc@oup.co.uk
So what’s new? I’ve avoided anything with cochineal in it for years
(This Week, 15 November, p 5).
A simple dilute dose of orange squash is enough to
bring me out in an eczematous rash so bad that patches of skin break open in
weals and take weeks to heal.
Thank God for food labelling. Now how about medicines? Ever tried to find an
expectorant without some colouring in it?
Letters : We'll have to adapt
Norwich
The treaty to curb global warming is only “wrecked” for those people who
think that global warming can be significantly curbed by a treaty
(This Week, 1 November, p 5).
Despite the strong arguments鈥攚hich I endorse鈥攆or governments to
take action now to nudge their economies towards a less carbon and
energy-intensive path, the fact remains that the world will continue to warm at
a significant rate for many decades to come, whatever targets may be agreed at
Kyoto.
This is because of inertia both in the climate system, in the form of
continued warming from past emissions and in the world’s energy industries.
Rather than pretend that an agreement in Kyoto will significantly curb global
warming, we should all face up to the reality of climate change now and the
reality of climate change to come.
According to one of the climate models used by IPCC, the difference between
doing nothing as a result of Kyoto and adopting the European Union position of
15 per cent cuts for industrialised countries is the difference between,
respectively, 1.9 掳C of additional warming and 1.65 掳C by 2100.
This inertia in the behaviour of global climate calls for creative,
insightful and internationally just strategies to reduce our own, and our
children’s, vulnerability to climate change. It also urges us to develop more
flexible institutions which can exploit some of the opportunities climate change
may bring in its wake.
Both mitigation and adaptation are appropriate responses to climate change,
but adaptation may well prove the more achievable and necessary response in the
near term. Let the idealists placing their trust in Kyoto not blind us to this
reality.
Letters : Toy trouble
Colchester
We recently bought what looked like a fine new idea for an executive toy. It
consisted of a very strong magnetic base with lots of ball bearings attracted to
it, which it was possible to form into beautiful sculptures.
What we did not realise at the time is that magnets and office desks are not
cheerful companions. But we soon found this out when the discs with our accounts
on them were mysteriously wiped, and the monitor screen went all colours of the
rainbow. It is now only possible to use our office desk toy when not at our
desks, and well away from the office.
Letters : Kangaroo culls
Bellingen, New South Wales
It is disappointing that Australia’s fledgling kangaroo meat export industry
has been derailed in Britain by misguided animal liberationists. While there is
no doubt that universal vegetarianism would be of great benefit to the planet,
it is unlikely to occur overnight.
Sheep and cattle farming have been the ecological ruination of the Australian
countryside, and the driving force behind the pastoral “leases” which have taken
the land from the traditional Aboriginal owners. So destructive have these
farming practices been that the only hope for many marginal areas would be the
total destocking of domestic livestock, and
the reduction of the kangaroo numbers which now abound around the pastoralists’
waterholes and uncapped bores, denuding the vegetation.
The kangaroo cull will continue, even though the carcasses may now be left to
rot.
Letters : Unnecessary tests
London
Your recent editorial on alternatives to animal experiments states that it is
the responsibility of every scientist “to avoid the unnecessary use of animals
in experiments”
(Editorial, 25 October, p 3),
but that there remain huge questions on the extent to which this is possible
(see also Letters, 15 November, p 57).
The British Union for the Abolition of Vivisection believes that alternatives
are vastly underused. For example, the LD50 (median lethal dose) animal
test is still used, although less severe alternative methods such as the fixed dose
procedure are included in OECD guidelines.
In addition, a proposed ban on the use of animals in cosmetic testing was
recently postponed on the grounds that validated alternatives were not
available. However, in tests for photoirritation and skin penetration there are
no OECD guidelines for, and no international acceptance of, any animal tests. In
both cases, the in vitro methods are as far or further advanced towards OECD
acceptance than any animal tests.
Further examples of unnecessary animal use include the use of rabbits for
pyrogenicity testing, despite the in vitro limulus amoebocyte lysate
test being recognised by British regulatory bodies, and the use of animals in
painful procedures for the production of monoclonal antibodies, despite the
variety of in vitro techniques now available.
These examples illustrate that unnecessary use of animals in research
laboratories is taking place.
Letters : Positive pollutant
East Grinstead, West Sussex
One reason for retaining limited use of certain persistent organic pollutants
(POPs) is their cost-effective and scientifically proven benefit in protecting
human life from vectors of diseases or destruction of essential crops
(This Week, 18 October, p 5).
The case of DDT in Sri Lanka illustrates the folly of withdrawing a product
before it is replaced by something at least as good.
In 1948 Sri Lanka had 2.8 million cases of malaria and DDT was introduced to
kill the mosquitoes. By 1961 the number of cases had dropped to just 110, so DDT
spraying was stopped.
By 1977, cases of malaria were back to 400 000 and rose to 2 million.
In India, the figures were greater. The DDT campaign started in 1948 when
there were 75 million cases of malaria. By 1963 there were just 100 000, and DDT
was withdrawn. By 1977 there were 10 million cases.
Properly controlled use of DDT and lindane in public health campaigns need
not cause more problems than it solves. Much of the world’s population, faced
with starvation or death from insect-borne disease, would not be too worried
about the accumulation of a little DDT in their body fat, even if they had
any.
Letters : . . . . . .
helen@msilancs.demon.co.uk
I’m curious about the thought processes involved in the Internet service
provider Demon choosing to have all its access numbers ending in 666.
Well, accessing the Internet over a phone line can seem like being in
purgatory. Except if you’re blessed enough to have ISDN access (numbers end
667), I suppose.
Letters : What the devil?
ramage@law-office.demon.co.uk
The Redemptorist Publications choice of Internet provider seems inappropriate
(Feedback, 1 November),
but mine may, at least to some minds, be less so.
Letters : Harness the hiss
andy@seventhstring.demon. co.uk
Using lava lamps to generate random numbers (This Week, 8 November, p 10) is
of course an entirely admirable activity, but I’m not sure whether it’s really
necessary.
Isn’t thermal noise in electrical circuits (the hiss from an audio amplifier)
a quantum effect, and therefore truly random?
If so, then all you would need to do is sample such noise digitally in an
appropriate way and you would have all the random numbers you want, completely
uncontaminated by lava.
Letters : Drops and dishes
Ottawa, Canada
Though unexplained until now, the way solutes and suspended particles are
deposited at the edges of a drop has been known to chemists for many decades
(“The thrill of the spill”, 25 October, p 34).
It is the reason for the difference in shapes of a crystallisation dish and
an evaporation dish: the crystallising dish has vertical sides so that the
deposit will be formed selectively rather than by total evaporation of thin
edges of the solvent.
This edge effect also accounts, albeit in reverse, for the formation of rust
in small rings on iron objects exposed to rain.
Letters : Ancestral sex
finch@bcs.org.uk
Whether young persons should be advised to look to the birds and the bees for
sexual enlightenment takes on a new dimension in your article on sex chromosomes
in birds
(This Week, 18 October, p 12).
I knew that bees have a different sex chromosome arrangement than our XX
(female) and XY (male). Now I discover that birds have ZZ (male)and ZW (female)
arrangement.
How far back must we go to find a common ancestor? What was its sex
chromosome arrangement?
Letters : Guarded welcome
Barnard Castle, Co. Durham
Rob Edwards, in his report on the Langholm study, includes the statement that
hen harriers will not be welcomed by gamekeepers, and that it would be a “death
sentence”
(This Week, 8 November, p 4).
This is not necessarily so. We understand the basis of the Game Conservancy
Trust scheme is a quota system for harriers on grouse moors.
With a suitable scheme in place, the harriers, if not welcome, could be
tolerated, and that, as far as the harriers are concerned, is certainly not a
death sentence.
Letters : Oxbridge bias
Wokingham, Berkshire
The error of placing the alpha scattering experiments in Cambridge rather
than Manchester is a common one
(“Blessed is the weak”, 11 October, p 28, and
Letters, 8 November, p 61).
When I taught at a school whose teachers were largely Oxbridge graduates,
lessons in Nuffield physics or chemistry always placed the experiment in
Cambridge. It was impossible for them to conceive of important physics being
done at that time anywhere other than at the Cavendish. Presumably their
students carried this idea into their later life.