Letter: Sharp practice
As a dental surgeon, I am required to use disposable hypodermic needles
to prevent the spread of infection between my patients. Questioning of farmers
attending my surgery reveals that all of them are inoculating their cattle
and other livestock with the same needle (changing it only when it is blunt).
Nothing is more likely to spread the BSE agent laterally in infected herds
than this most unhygienic practice, which involves blood to blood contact.
Farmers give hundred of thousands of injections in the course of a year
and seem to be unaware of the dangers.
Tony Lees Brecon Powys
Letter: Nuclear risk
Ian Stewart’s article on risk was an illuminating one but I must point
out a numerical error in his illustration of the risk of a nuclear accident
of Chernobyl scale in Britain (Inside Science, 19 May). The ‘old Central
Electricity Generating Board’ presented evidence to both the Sizewell B
and Hinkley C Public Inquiries on a wide range of potential accidents. The
evidence was that due to the design, engineering and operating safety standards
adopted in Britain the frequency of such catastrophic accidents was less
than one in 10 000 000 years. This is one thousand times smaller than the
figure quoted by Stewart.
Such probabilistic analyses are carried out not because the end results
are absolutely precise, but because they confirm that the design intent
has been achieved. This is that catastrophic accidents should never occur.
A reactor with Stewart’s probability of catastrophe would not be licensed
in Britain.
D. J. Western Nuclear Electric London
Letter: Sexual assault
Mike Baxter’s article on pornography and sexual violence was marred
by an extremely simplistic treatment of statistics on rape offences in South
Australia and Queensland (‘Flesh and blood’, 5 May). Sexual assault statistics
are notoriously difficult to interpret, and national victim surveys indicate
that less than 30 per cent of such offences are reported to the police.
In the 1970s South Australia took a number of initiatives to broaden the
definition of rape, encourage reporting, treat victims with greater sensitivity
and provide them with greater support. All of these changes tended to increase
the reporting of rape.
It is difficult for anyone to be confident that they can accurately
account for South Australia’s increased rate of reported rape in the 1970s
but the impact of pornography is in no way proven. Indeed, there is little
empirical evidence that pornography, however defined, was more effectively
available in South Australia than Queensland.
The Police Commissioner’s Australian Crime Statistics Subcommittee prefers
to use the broader category of ‘sexual assault’ rather than ‘rape/attempt’
because of state differences in sexual assault laws. Even so, it disseminates
statistics with the warning that sexual assault is an offence category which
is not comparable between states. Note, however, that the 1983 victim survey
conducted by the Australian Bureau of Statistics reported Queensland’s rate
of sexual assault as being higher than South Australia’s.
Frank Morgan Office of Crime Statistics Adelaide, Australia
Letter: Quality teaching
I am glad that Peter Ellis managed to talk himself into agreeing with
my view that students in independent schools choose to avoid science because
of its lack of material rewards and status (Letters, 2 June). I am only
sorry that he should have been so defensive in the early part of his letter
about the quality of science teaching in independent schools. All the evidence
I have is that science teaching in such schools is good – there must be,
therefore, other reasons why their students choose not to make their careers
in science. I defy him to find anywhere in my article the suggestion that
science teaching in such schools is bad.
In state secondary schools, up to a third of teachers are teaching subjects
which they did not read at university. The irony is that school students
are choosing science despite many being badly taught. I rest my case.
John Galloway London
Letter: Mission impossible
Michael Cross’s suggestion on the international date line is quite appealing,
but his memory for history is none too prime (‘One of my days is missing’,
Forum, 2 June). The Doolittle raid in Tokyo was a suicide mission in the
Western sense, with high risk to the men and the almost certain sacrifice
of all aircraft. Indeed, the aircraft were all lost, but only a few men
died in the course of the mission. Some were captured and executed by the
Japanese, but most, including Major Doolittle, survived the war. Cross does
Doolittle and his men a disservice by comparing them to kamikaze pilots.
Michael Koenig River Forest, Illinois, US
Letter: College cleaners
I find it extraordinary that Ariadne should calmly assume that London
University ‘is surely . . . rich enough to pay for’ cleaning up London streets
(9 June). For over ten years New 杏吧原创 has been reporting drastic cuts
in university budgets: the budget deficit of many of the London colleges
runs to millions of pounds and, not long ago, one of the larger colleges
had to take out a bank loan to pay the wages bill.
In our department we are still waiting for the university to find the
money to replace the obsolete, 5-amp round-pin sockets which are the only
electricity supply in our research laboratories. If I heard that the university
was spending money on street cleaning I would be absolutely furious!
P. Donovan Birkbeck College, London
Letter: Bread winners
It is rather quaint that the schoolboys of Sherborne are taking their
roles as future family breadwinners so seriously (Letters, 19 May). Before
getting too disheartened, I would advise Isaacson to do a quick poll of
the sixth-form girls at Sherborne. He may well find that plenty of girls
not only do not relish the prospect of being supported, but are also willing
to contribute to the cost of raising kids. After all, we are supposed to
be encouraging more girls to become scientists too, are we not?
Liza Sandell Dakar, Senegal
Letter: Green gases
I was struck by the juxtaposition of articles in the 16 June issue.
On the one hand industry is rapidly developing alternatives to CFCs (‘The
race to heal the ozone hole’, by Hugo Steven and Andy Lindley); on the other,
Fred Pearce’s ‘The consumers are not so green’, in the Greening of Industry
supplement, points out that while ‘CFC-free fridges will be advertised as
the ultimate green product. . .’ they also consume electricity, therefore
contribute to the greenhouse effect and could be made considerably more
efficient. Furthermore, the new stable hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons
(HCFCs) themselves may act as potent greenhouse gases.
This seems to highlight the central position of science in environmental
issues as both the root of many of the problems and the potential means
to solve them. Is it too churlish to ask why the potential of HFCs and HCFCs
as greenhouse gases was not discussed by Steven and Lindley, or to suggest
that this has anything to do with the desire of commercial interests to
nurture a green image? The speed with which progress has been made in developing
alternatives to CFCs is impressive, but again could not this position have
been reached sooner if research had commenced when the potential of CFCs
for destruction was first realised?
The responsibility of science ought to be one of discovering the truth
(even the unpleasant parts) and facing up to the consequences, including
the long-term ones. Perhaps it is time for yet another organisation to ensure
that science is genuinely more environmentally friendly and not just cloaked
in green. May I propose the name SAVE (scientists against virtually everything)
as suitable for such an august but hopefully not too self-important body?
A. D. Wilson University of Bristol Bristol
Letter: Time inflation
Recent reports of comparisons of radiocarbon and uranium/thorium dating
of corals in Barbados (Science, 16 June) and of thermoluminescence dating
of sediments associated with stone artefacts in northern Australia (Science,
19 May) appear far apart in subject matter. But there is an important link
between them.
The comparison of dating techniques confirms the discrepancy between
radiocarbon years and calendar years, long known to operate over the last
8000 years. We now have evidence that the discrepancy continues to increase
as we move further back in time. We have to think of radiocarbon dates like
modern currencies: they continually change their value with time. The older
they are, the more time they can buy. Although we still do not know the
proper exchange rate for radiocarbon determinations of 30 000 years or more,
we can be sure that they are considerably older than that date suggests.
The most widely accepted dates for human presence in Australia are of
the order of 40 000 BP (radiocarbon years). The new thermoluminescence dates
from Malakununja II in northern Australia are used to support vigorous claims
for an earlier date, perhaps as old as 60 000 years ago. One problem is
the way in which the thermoluminescence dates are used. The key date is
52 000 m11 000 (at one standard deviation). Statistically-minded readers
will immediately appreciate that this no more indicates an age of 63 000
than it does one of 41 000.
Even if a ‘conservative’ date of 50 000 is used, does this indicate
the earliest date yet for first settlement? The Barbados research reminds
us clearly that it is inappropriate to compare different chronological currencies.
Is a date of 40 000 in radiocarbon years ago younger than, or the same age
as, 50 000 thermoluminescence (or calendar) years? We may have a larger
number, but not necessarily a different value. Important though it is to
establish the antiquity of Australia’s first human settlement, there are
more interesting questions concerning what people did once they arrived,
and how quickly they moved across the vast areas of the continent. Discussion
of the rate of these developments will require not only more excavations
and more precise dating, but a clearer understanding of the changing value
of the ‘year’.
David Frankel La Trobe University Melbourne, Australia
Letter: Zoo research
I would like to make two small, but important corrections to the statement
attributed to me by Annabel Birchall (‘Zoos ‘must join forces’ to save threatened
habitats’, This Week, 16 June). While it is very complimentary to be credited
with a ‘first’, I did not say ‘our field study is the first to be done in
partnership with another institution’, nor did I say ‘only three British
zoos currently fund field research’.
I am only aware of three other institutions, namely Jersey Zoo, London
Zoo and Marwell, which make direct funding to field research as opposed
to making contributions toward another organisations which carried out the
research, such as WWF. The difference is important in that by direct funding
the zoo is able to promote the project more effectively and, hopefully,
obtain much more support. The unusual, as opposed to unique feature of our
project is the cooperation between our zoo and Wildlife Conservation International,
in order that we can concentrate on one specific project rather than our
money going onto a large kitty for general purposes.
I believe much more could be raised for field studies from the 10 million
visitors to British zoos if the former approach was pursued by more institutions.
P. M. C. Stevens Executive Director Paignton Zoo Devon
Letter: Corn treader
Terence Meaden is obsessed by his ten-year study of corn circles and
by his preferred explanation of plasma vortices (‘Circles in the corn’,
23 June). He shares the naivety of scientists taken in by spoon-bending
and similar phenomena when he states categorically that ‘there is no possibility
that all these complicated patterns are hoaxes’. I have examined a few corn
circles and am not convinced. Even Meaden must accept that some of the circles
are hoaxes for his theory to survive – those, for instance, with rectangular
shapes do not fit his vortex theory yet look otherwise much the same as
the others.
My suspicion is that the circles are the work of dedicated, artistic
hippies, which is why the circles are formed at night and tend to cluster
in the ‘hippy-UFO’ belt, at places like Warminster, around ancient monuments
such as Avebury, and in isolated fields in beautiful locations, with tractor
tracks leading conveniently to them. This would also account for other evidence
that Meaden’s theory has trouble accommodating. Why, for instance, have
the circles been mainly sighted since 1980? Why are they growing in number,
size and complexity each year? Why did none appear during a 14-night ‘circles
vigil’ only to appear the night after the vigil ended?
And why do the circles seem to be mischievously playing games with their
investigators? For example, a Meaden publication explaining authoritatively
why the corn in the ring was always swirled in a different direction from
the corn within the circle, was contradicted on the very day of publication
by a new type of circle, with corn in both ring and circle swirled in the
same direction.
Nicholas Albery Chairman The Institute for Social Inventions London