Letters: Wrong jet
In the article on the scramjet (Technology, 19 June), reference was made to
the ‘ramjet’ which powered the V1 flying bomb.
The V1 had a pulse jet, which is quite different. Whereas a ramjet requires
forward speed to work, the pulse jet was always started up and running
before launching.
R. Pain
Romney Marsh, Kent
Letters: Keeping trucking
Apropos the comments by Max Wallis on lorries and subsidies (Letters, 19
June). With the advent of speed limiters on juggernauts, the heavies will be
down to 50 mph by June 1994 and there will only be a slight advantage in
using the motorways. With road pricing that advantage will disappear
entirely. I, and thousands of other truckers, will revert to the old routes.
The motorists will then have the motorways all to themselves. However, when
they get off the motorway, the roads will be choc-a-bloc with heavies.
My 38-tonner pays 拢5000 per annum road tax. Fuel costs at
least 拢2 per gallon – 80 000 miles at 8 mpg means that I pay
at least another 拢10 000 per annum in fuel taxes.
So how is the private motorist subsidising me?
E. P. C. Mead
Walthamstow, London
Letters: Car cure
We were intrigued by the article in Feedback (29 May) reporting that the
Electrolux company was to enter the baby soothing market. Many of your
readers will be aware that white noise such as that from a vacuum cleaner
can help to calm babies (presumably the origin of the hush sound which is
used in many cultures). Other electrical appliances such as hair dryers are,
in our experience, equally effective.
This noise may be similar to the sounds experienced by the fetus while in
the womb, possibly emanating from the major blood vessels in the maternal
abdomen. The calming effect may also be enhanced by adding low frequency,
rumbling sounds such as those produced by the maternal digestive system. In
the infant sleep laboratory attached to our nursery we are currently using,
with some degree of success, a tape combining the two elements in an effort
to induce sleep in our young subjects.
Those sleep-deprived readers with young infants may gain some relief, and
save some money spent on proprietary tapes, by placing a battery operated
cassette recorder on the floor of a car and recording the sounds during a
journey. Expensive luxury cars are not suitable since they transmit less
road and engine noise. Our experience is, unfortunately, that
environmentally unfriendly multicylinder cars driven over lots of pot holes
make particularly good recordings.
The effect of such a tape will come as no surprise to the generations of
health professionals who have seen worried, recent parents bring their (now
fast asleep) infant to the casualty department. The usual reason for
consultation is persistent crying and the usual cure was the car trip.
G. A. Malcolm
King George V Hospital for Mothers & Babies
Camperdown, NSW, Australia
Letters: Barnacle bother
Down here in the deep south, yachts on fixed moorings acquire about 20 per
cent more barnacles and weed on the morning side of the hull than the
afternoon side. Does anyone know if there is a predominance of a particular
wavelength between first light and noon?
John Catmull
Cairns, Queensland, Australia
Letters: Old textbooks
John Emsley’s report on will-o’-the-wisps (New 杏吧原创, Science, 19 June)
comes half a century late. More than 50 years ago I learnt at the
‘gymnasium’ in the chemistry class that will-o’-the wisps are methane flames
lit by hydrogen phosphide of bacterial origin.
I think it would be a good idea to reread old textbooks every other
generation to learn new things and thus save money on research.
Svante Z. M. Travenius
Perstorp, Sweden
Letters: Not again.
Jayant Narlikar’s ‘Challenge for the big bang’ (19 June) is, like all
steady-state hypotheses, thought-provoking. If anything, it provokes a bit
too much thought.
So far as I know, no steady stater has ever alluded to some rather
unpleasant but, to my mind, inescapable natural consequences if one believes
that the Universe is infinite and eternal in itself, with only it
constituents changing, that is, creating themselves in ‘little big bangs’
limited in time and place, and then dying off over the aeons as the second
law of thermodynamics takes its toll. This is the problem of eternal
recurrence, the nightmare scenario that, in an eternal, infinite Universe,
all possible occurrences are doomed to repeat themselves endlessly, both in
infinite variation and in infinite exactitude.
Of course, unpleasant consequences do not make a hypothesis any the less
tenable. Nevertheless, I would urge Narlikar, Hoyle, Bondi, Gold, et al to
think very hard and see if they can’t come up with an escape clause out of
this logical horror.
Otherwise, totally innocent perusers of this page will be eternally
condemned – and have been eternally condemned – to read this an infinite
number of times, the only mitigation of this terrifying hopelessness being
that they have forgotten and will go on forgetting that they have done so,
for an infinite number of times.
Ralph Estling
Ilminster, Somerset
Letters: Not again.
David Schramm’s note ‘The big bang strikes back’, though a comprehensive
summary of big bang cosmology, was evidently not written specifically as a
reply to Jayant Narlikar’s article on quasi-steady-state cosmology
immediately preceding it in the same issue. There are a number of general
assertions that big bang cosmology better fits the observations, but the
article scarcely ever meets Narlikar’s particular objections and criticisms.
Cases in point are the nucleosynthesis of the light elements and the time
factor in the formation of the large scale structures of the Universe.
It is however quite rightly pointed out that the question of the singularity
is a ‘red herring’, since most big bang cosmologists today, who try to
relate relativity and quantum theory, do not include it in their models; and
it is properly pointed out that the ‘iron needles’, introduced to explain
the cosmic microwave background, would make the Universe opaque to radio
waves, contrary to observation.
Richard Tylor
Nivensknowe Park, Midlothian
Letters: Green science
Wynne and Mayer make many valuable observations about the unsatisfactory
link between science and British environmental policy. However, I remain
deeply convinced that their argument for a ‘greener’ science culture is
fundamentally flawed and will not help environmental policy.
Do we really want to go down the line of greener, redder or even browner (in
the German sense) science culture? Surely we have been down this dangerous
path before. Scientific research, being a compulsive if highly dependent
endeavour, will always serve those who find it useful and can pay for it.
Scientific institutions and methodologies must (and generally do) strive to
maintain their freedom from ideological commitments or values which would
prejudice their results. They must strive against ‘misuse’ by politics, a
misuse which comes naturally to all, including Greenpeace, who have tied
their policies to scientific authority. When science fails them, as it tends
to do, they hit out at science, rather than examining their own assumptions.
The onus to ‘prove’ that there is an environmental threat from the emission
of greenhouse gases surely should not lie with environmentalists. This would
be like asking a member of a Conservative party whether the market is a
‘good’ thing, or a socialist whether social equality is desirable. How could
environmentalists ‘prove’ that which cannot be proven, but which must be a
matter of faith or belief based, admittedly, on observation and logical
argument? Political parties have a right and duty to persuade and influence,
but should not decide without first listening carefully to the whole debate.
Science is not to blame if the existing ‘system’ uses scientific advice
badly. Science cannot change politics.
The concept of an ‘independent’ scientist begs the question. 杏吧原创s
employed by Greenpeace are no more independent than those employed by
Nuclear Electric. Both can lose their jobs if they publicise unwelcome
conclusions and I suspect that the demands to toe the line are greater at
Greenpeace than in many industrial or government laboratories. The
environmental lobby treats science in as political a fashion as their
opponents, and may have done itself harm by this.
Sonja Boehmer Christiansen
University of Sussex
Letters: Green science
The role of science in environmental appraisal is absolutely crucial. But
what also is absolutely crucial is that the science be quantitative. It is
not enough to say that a substance is potentially harmful or that some
action is potentially risky. The extent to which it is harmful and the
degree of risk need to be explicitly identified. The difficulty of
explanation arises because these cannot normally be specified with much
precision. But it is essential that, in addition to giving best estimates of
the amount of a substance likely to be harmful or of the likely risk, the
uncertainties in those estimates are also quantified. The estimation of
uncertainty is at the heart of the scientific method. We do not need any new
science in order to take it on board.
What then do policy makers do with information provided by the environmental
scientist? They need to weigh the information regarding possible harm and
risk (including the uncertainty involved) against the cost and other impacts
of all the possible measures which can be taken to address the problem. Such
appraisal is not new. The Royal Commission on Environmental Pollution
introduced the concept of the ‘Best Practicable Environmental Option (BPEO)’
in its fifth report in 1976 and in 1988 devoted its 12th report to a
detailed prescription of BPEO and how it can be achieved.
The scientific assessment prepared by the Intergovernmental Panel on Climate
Change (IPCC) has attempted to follow this quantitative approach in its
assessment of likely climate change next century due to human activities.
Clear distinctions have been drawn between what is likely to occur (with
appropriate ranges of uncertainty given) and changes which are much less
likely and more speculative; because of the possibility of surprises both
need to be considered. This clarity of approach very considerably aided the
wide acceptance of the IPCC’s findings by policy makers and the signing by
nearly all countries of the Climate Convention at the Rio conference last
year.
Sir John Houghton
Royal Commission on Environmental Pollution
London
Letters: Green science
The main thrust of Wynne and Mayer’s argument is that science ignores the
inherent uncertainties in data and how these should be recognised. I believe
this view is fundamentally wrong and ignores the great advances that science
has made.
It is now possible with new methods to measure environmental pollutants at
levels down to nanograms that a few years ago could only be measured at the
milligram level. From a knowledge of the physiochemical properties of
chemicals, in surprisingly many cases, one can predict correctly the
toxicity and biaccumulatability of these chemicals using quantitative
structural activity relationships (QSARs).
Biomarker techniques, measuring the effects on organisms of a wide range of
pollutants, are now widely used. These techniques have been recently applied
to testing a gradient from the river Elbe estuary in Germany to the Dogger
Bank and showed effects at the edge of the Dogger Bank which were not
expected. Subsequent chemical analyses showed that this area was a site of
deposition of contaminants.
Molecular biomarker techniques, such as those measuring directly genetic
damage on phyto- and zooplankton in relation to increased UVB radiation,
have wide applications. Thus Wynne and Mayer’s criticism that two-thirds of
the expenditure on British environmental research in biology goes to
molecular biology is misplaced. Molecular biology is the area likely to
produce the most effective techniques for measuring the effects of
contaminants on the environment.
I am convinced that the real problem is not the science itself, but in the
application of science. We environmental scientists are producing new and
more sensitive techniques, new data and new approaches to analysing data
which clearly show the effects of human influence on the environment. What
fails is the translation of these findings into political and management
decisions.
John Gray
University of Oslo
Letters: Green science
Alex Milne convincingly argues the case that the precautionary principle is
inconsistent with scientific method. It is moral philosophy, as he points
out. Milne errs, however, in criticising the precautionary principle as bad
law.
New South Wales has recently established, without difficulty, an
environmental protection authority with the statutory objective of seeking
ecologically sustainable development through application of the
precautionary principles: ‘If there are threats of serious or irreversible
environmental damage, lack of full scientific certainty should not be used
as a reason for postponing measures to prevent environmental degradation.’
The criticism that the precautionary principle is ‘uselessly vague’, because
it does not measure how much caution is required or how much harm may be
done, could equally be made of many qualitative legal principles, such as
the reasonable person test. These principles remain good law because they
are pragmatic, sensible and adaptable.
David Robinson
Poole, Dorset
Letters: Green science
The existence of environmental capacity assumes that some contaminants have
no undesirable effects, that each environment has a finite capacity to
accommodate some wastes without unacceptable consequences and that this
capacity can be quantified and utilised. The precautionary principle
requires action to limit polluting emissions even where there is no
scientific evidence to prove a causal link between emissions and effects.
Recently it has been tied to a shift in the burden of proof to the polluter,
requiring demonstration of harmlessness of inputs before release and a
commitment to the concept of zero discharges.
I would like to ask the following questions about the precautionary
principle, since we now see it being adopted internationally, without
rejection of the use of assimilative capacity:
Is the use of environmental capacity compatible with the precautionary
principle, or are the ideas mutually exclusive?
Is the precautionary principle a scientific concept as Wynne and Mayer have
claimed, or is it really something else? When we debate the precautionary
principle it must be clear whether we are in the realms of science, politics
or religion.
Is the concept of zero inputs a corollary of the precautionary principle?
Is the requirement that the polluter prove harmlessness of discharges in
advance of their release also a corollary of the precautionary principle?
A. R. D. Stebbing
Plymouth Marine Laboratory
Devon
This is a small selection from the many letters received on this topic. A
wider selection will be published in a newsletter available free to
interested readers. See Comment – Ed
Letters: Potato points
A recent issue has a piece on ‘hot potatoes’ (In Brief, 12 June). Monsanto
biotechnologists must be especially clever to have invented ‘a gene’ that
confers resistance to two quite different potato viruses simultaneously.
Even nature never managed that trick, I think, but perhaps the Rockefeller
Foundation propelled them to new heights of brilliance? The statement that
Monsanto is going to give the gene away for free to Mexican potato breeders
prompts (in this reader, at least) the unworthy speculation that there might
be something wrong with it.
Meanwhile, please recall what I pointed out in these columns some months ago
(Letters, 6 February), that there are oodles of good X and Y resistances in
the potatoes anyway, there for the using and all for free. They have been
familiar for decades and their numbers grow. Among the more recent are
several Y-resistances derived from (surprise. surprise.) the wild Mexican
species, Solanum stoloniferum; they work a treat.
Apropos tungro virus, Andy Coghlan states that ‘No rice is naturally
resistant to this virus’ (Technology, 12 June). In fact, the International
Rice Research Institute has been breeding resistance to the virus and its
vectors for nearly 30 years, though not without some troubles, of course.
Norman Simmonds
Edinburgh
Letters: Patently ours
In his article, ‘Cleaning up with cheap technology’, (23 January), Matt
Ridley describes the Noxout process whereby urea is injected into coal-fired
boilers to remove nitrogen oxides from the flue gas. He also described the
adaptation of the Noxout process to use a slurry of urea and calcium
hydroxide for the simultaneous removal of sulphur dioxide and nitrogen
oxides from the flue gas. I wish to emphasise that combining urea or other
nitrogen-based additives with calcium-based sorbents such as limestone,
calcium hydroxide, dolomite, etc, and subsequently injecting it as a slurry
into the boiler for the simultaneous removal of sulphur dioxide and nitrogen
oxides, is a process patented by Ontario Hydro and known as SONOX.
In the SONOX process, coals varying in sulphur content from 0.54 to 2.8 per
cent and nitrogen oxide emission levels of 450 to 620 parts per million were
studied. Under optimised conditions, 80 per cent sulphur dioxide and 90 per
cent nitrogen oxide removals were achieved. Testing at Ontario Hydro’s
Combustion Research Facility has also shown a significant reduction in
hydrogen chloride emissions which is expected to minimise formation of
chlorinated toxic compounds emission.
The process is applicable to utility and industrial boilers as well as
municipal waste incinerators and has the following advantages:
SONOX provides a low cost solution to the removal of acid gases; it is
suitable for retrofit applications; it is applicable to coals with various
sulphur dioxide and nitrogen oxide levels; it has minimum impact on ESP
performance; and it requires short lead time for installation.
The following patents can be cited: Canadian patent: 1 304 939, 17
September, 1990; United States Patent: 5 084 514, 22 October, 1991;
European patent application: 90 311 523.
Rene Mangal
Ontario Hydro
Toronto, Canada
Letters: No hope
Shareholders have no say in the running of British industry (This Week, 12
June).
The people at the top are accountants and lawyers with little or no
knowledge of their industry. There are very few scientists or engineers
above middle grade.
Research and development is expensive. The benefits are long term and less
than certain. It may take ten years or more to develop something that may
not be a success.
Hard headed managers and directors will always tend to reduce R & D.
There is no solution.
John Waterstone
Caterham, Surrey
Letters: Green science
I can but hope that Alex Milne is not typical of other industrial scientists
in Britain (‘The perils of green pessimism’, 12 June). In his rejoinder to
Brian Wynne and Sue Mayer (‘How science fails the environment’, 5 June),
there is not a word on the failings of the assimilative capacity approach,
yet the development of what should be called the principle of precautionary
action is entirely due to the mounting evidence of failure in the past
framework for pollution control.
The assimilative capacity approach has signally failed to predict
environmental capacities – look at tree dieback, PCB effects on
immuno-competence and fertility, CFC damage to the ozone layer, DDT damage
to top predators. And in areas where at least the mechanisms are known in
advance, the approach still fails with regard to thresholds and rates of
change, such as global warming, acidification, nutrients and algal blooms.
Environmental science has failed to ascribe conclusive causes to, for
example, seal and dolphin deaths, forest damage, and leukaemia around
Sellafield and Dounreay, largely because these may be multi-factorial, which
the simple science of assimilative capacity cannot deal with.
I happen to agree that Greenpeace has too easily grabbed the moral high
ground, and that ‘proof of harmlessness’ is scientific nonsense, however
justified a weapon in the reversal of ‘burden of proof’. But Alex Milne may
be unaware of the years of carefully argued logic, backed by extensive
scientific review, that industrial interests ignored and vilified in the
decade 1975-1985, while protected from any legal action by the ‘proof of
harm’ clauses that are still embodied in all legal instruments.
The major shift towards precaution has come on the heels of massive
environmental degradation, and has been led by those countries with more
open scientific communities. Greenpeace did not invent the precautionary
principle.
Peter Taylor
Harlech, Gwynedd