Letter: Mechanical dreams
The article by Ros Herman on the virtues of Lego as a practical teaching
medium (‘The stuff that dreams are made of’, Forum, 12 May) brings to mind
an earlier time when school children satisfied their mechanical dreams with
Meccano. Meccano had, however, another useful attribute. Its range of gears,
shafts, bearings, pulleys and structural metal made it a valuable research
tool. I recall a time long ago when I worked at the Post Office Research
Station at Dollis Hill in North London that every individual lab seemed
to be well equipped with a comprehensive stock of Meccano parts, to the
delight of the local toy shops at this unexpected trade.
Meccano has been long displaced in children’s dreams and in toy shops
by moulded thermoplastics, but, in its heyday I wonder how many research
projects and perhaps major discoveries in part owed their success to its
versatility. Can that be said of its successor?
Robert Jones Sydney, Australia
Letter: Dread plots
If taken at face value, the caption to the final graph in your admirable
‘Risky business’ (Inside Science, number 33, 19 May) would lead your readers
to conclude that food irradiation is many times more risky than mountain
climbing, and microwave ovens are deadlier than motor vehicles. In fact,
the caption is wrong. What the graph plots is not ‘dread’ against ‘risk’,
but ‘dread’ against the degree to which a risk is ‘unknown’.
Both these terms come from the work of Baruch Fischhoff, and roughly
speaking they measure the degree of outrage that we feel about a risk, irrespective
of its magnitude.
We tend to dread a risk if its consequences are certain to be fatal,
if it is not equitably distributed, if it affects many people at once and
if it affects us directly. It is not hard to see why we dread nuclear weapons.
We tend to think a risk is unknown if it is new, is forced on us involuntarily,
is not directly observable, its effects are delayed, and if we cannot be
certain that we have been exposed to it. A moment’s reflection will show
that the risks from food irradiation and microwave ovens have most of these
characteristics, and so score highly on the ‘unknown’ axis. However, this
says nothing at all about their actual risk, narrowly defined, as in the
article, as the annual probability of dying because of them. It certainly
does not show that this risk is high.
The mistake illustrates that risk is a difficult topic for the experts
too. The business of risk assessment is certainly too important to be left
entirely in their hands.
Chris Hope University of Cambridge
Letter: Driving force
We would like to reply to your review of our book The Driving Force:
Food, Evolution and the Future (Review, 27 January). The book was written
for the lay reader, and offers a new view of the evolutionary process, ranging
well beyond the confines of the current neo-Darwinist paradigm.
The ‘driving force’ is the environment – food being the major link between
environment and organism – which causes initial genetic diversity, which
itself is specifically non random: selection ‘favours’ or ‘grades out’ the
results. Contrary to impressions given in your review, our thesis strongly
supports Darwin’s (130 year old) theory which – at that time – stated there
were two major driving forces of evolution: natural selection and ‘conditions
of existence’. Our only criticism of Darwin is that he overemphasised ‘selection’
at the expense of environmental, or ‘impact’ energies. It was those who
came after Darwin who chose to ignore what he had said about ‘conditions’.
Darwin suggested that there were so many different external forces acting
on evolution, and that their interplay was so complex, that the results
may be put down to ‘chance’. He stressed, however, that the term ‘chance’
was used more for convenience than for accuracy. Today’s orthodoxy chains
us to ‘random’ mutations and, since Weismann, has remarkably little to say
about alterations in genetic expression.
Our thesis suggests that environmental chemistry – including food (and
such food not exclusively lipid) – causes change in genetic behaviour and
later, mutation. This concept provides a simple chemical explanation as
to how horses’ toes eventually turned into hooves, for example.
While certain scientific passages are difficult for some uninitiated
readers, your reviewers should not have needed us to point out to them that,
in a chapter debating hooves and claws, it is the secondates, not the primates,
that are being discussed. Secondate herbivores face severe limitations of
neural or brain lipids, caused by the destruction of many essential fatty
acids in the digestive process. The physiology of primates is, by contrast,
elegantly designed to capture the neural nutrients during placental and
early development.
Your reviewers failed to mention the essential difference between our
thesis and Hardy’s (25 year old) aquatic theory. Contemporary biochemical
analyses of neural lipids point to the birthplace of the main line of developing
hominid as being not the forest, but the land-sea interface, a niche containing
incredibly rich resources of the long-chain fatty acids, specifically used
in the brain and nervous system. Migration inland, up rivers on to the savannah,
would eventually cut off such landlocked dwellers from the finest sources
of these nutrients.
To some, your review appeared overemotional: yet despite its wordiness
it lacked any real objective appraisal of the central thesis – that the
environment and chemistry, through prohibiting, limiting or encouraging
development in one direction or another, collectively represent a major
directive force in evolution which has remained largely unexplored. In these
days of considerable environmental and nutritional concern, we feel such
topics should be re-examined in the context of evolution theory – as they
are currently being re-examined in the context of medicine.
To attempt to cast our thesis aside with a review composed at random
(there have been 20 excellent ones) echoes Darwin’s definition of ‘chance’:
a review written more for convenience than for accuracy.
Michael Crawford David Marsh London
Letter: Barrier grief
I was interested in the comments from Ian Fallon, of the National Rivers
Authority, about the Thames Barrier (Letters, 26 May). If sea levels rise
by 30 centimetres, how much will this reduce the ‘1-in-1000’ chance of the
Thames Barrier being overtopped? If it comes down below 1-in-100 years,
it is certainly time to worry. And, since scientists tell us that when the
greenhouse effect gets to work there will be more storms in the North Sea,
how can the authority be sure that an unprecedented storm surge will not
temporarily raise sea levels even higher? If it is true that the design
of the barrier took no account of the greenhouse effect, then surely it
is obsolete? Or does Fallon mean that if the barrier were being designed
today a greater risk of flooding would be acceptable than that planned for
originally?
Richard Duvaille Eastbourne Sussex
Letter: Lamb chopped
How ‘idyllic’ is the life of the typical male lamb, when a tight rubber
band applied by the farmer to its scrotum causes its testicles to drop off
from gangrene? As a farmer, Jennifer Rees (‘Let them eat meat’, Forum, 19
May) should be better informed (even if she has not heard of the Australian
practice of flaying a sheep’s rump without anaesthetic to avoid fly-strike).
Certainly, hill-farming will become uneconomic as mutton consumption
drops, but conifers would be only one option. With the large areas available,
there should be ample room for both broad-leaved woods for recreation, and
conifers for fuel or wood. Why suppose a switch from mutton to white meat?
The abandonment of red meat (initially for health reasons) is only the beginning!
A significant shift to real vegetarianism would instead mean a reduction
in the consumption of all meat, freeing land devoted to growing animal feeds
to be used for less intensive agriculture. More hedges could be planted,
imports of animal feed and fertiliser would drop, fewer pesticides need
be used, and world grain prices would fall. These developments would benefit
the balance of payments, the environment, the Western consumer, and perhaps
even people in the Third World.
Lindsay Gamsa-Jackson Chelmsford Essex
Letter: Early warning
Far from being ‘an unexpected new tool for predicting earthquakes’,
the emission of radio waves during seismic activity is a well known phenomenon
which has been actively investigated since the widespread radio disturbances
caused by the great Chilean earthquake of 1960 (‘On shaky ground’, 12 May).
The problems today lie not in detecting seismo-electromagnetic effects
from earthquake precursors but in reliably distinguishing them from all
the other radio signals, interference and noise which may be present. The
first time that people are asked to evacuate an area for a non-event will
seriously damage public confidence in forecasting methods. In a collaborative
project between the universities of Sheffield and Naples we are attempting
to avoid this problem by developing a new underground radio monitoring system
and statistical analysis package which can detect seismic radio waves with
an exceptionally low false alarm rate.
The future success of earthquake prediction is almost certain to arise
through the intelligent integration of data from disparate forms of remote
sensing including the monitoring of electric currents and radio signals,
conventional geophysical measurements and even zoological observations of
animal behaviour.
Simon Kingsley University of Sheffield
Letter: Weighty research
‘Electrons switch on to heavy metal’, 19 May, was a valiant and overall
a successful attempt to give a flavour of the heavy fermion materials.
However, as well as correcting the name of Zachary Fisk, I must point
out that the discovery of heavy fermion materials did not emerge from a
search for new superconductors but from basic research in magnetism of alloys.
Also, the Fermi surface enclosing occupied states is in wave-vector
space. Finally, the unusual character of superconductivity in these materials
is most strongly indicated by the growing evidence that magnetic fluctuations,
not lattice vibrations, provide the mechanism that couples the quasi-particles
into pairs.
Bryan Coles Imperial College, London
Letter: Mites are fun
As an asthmatic and a fellow Glaswegian (although one who thoroughly
enjoys the informative yet fun-to-read articles in New 杏吧原创, of which
Harvey and May’s on asthma and mites, 3 March, was a superb example), I
have only two words for Dr Colloff who took offence at the manner in which
the subject was treated (Letters, 24 March). These are ‘lighten up’.
Charles Wright Vancouver General Hospital British Columbia, Canada
Letter: Population debate
Paul Harrison’s excellent article tends to oversimplify the ‘neo- Malthusian’
position (‘Too much life on Earth?’, 19 May). Population Concern, the UK
organisation prominent in this field, would endorse most of his arguments.
We would certainly not claim that population growth is responsible for most
of the developing world’s ills, but we do say that it is a very significant
factor, and one that is consistently underplayed or even ignored.
It is also clear that, given the exponential nature of population growth,
doing too little now can have a very large effect later on. As Harrison
says, while reducing population growth will not have short-term effect,
it should not be neglected in favour of short-term measures.
Allowing access to a choice of methods of family planning is not just
aimed at reducing the size of future populations. It can contribute to a
much better quality of life now, particularly for women and children, since
spacing births is an important factor in reducing infant and maternal ill
health and mortality.
Diana Brown, Chairman Population Concern London
Letter: Porn experiments
One reason why experiments using pornography are far less dangerous
than Maggie Sinclair thinks (Letters, 19 May) is that to get any measurable
aggression at all in the laboratory, subjects must be hurt by a confederate
of the experimenter before exposure to the sexual materials.
But superficial reviews of complex fields like this are dangerous –
as they fail to stress the fact that what is studied is retaliation after
being provoked. More crucially, the situation is one which tacitly legitimates
such a reaction. Rather than underestimating the supposed porn/violence
causal connection, such experiments may inflate it.
The answer to Sinclair’s second question is of course that correlation
does not prove causation, and popular surveys are often scientifically incompetent.
In any case, while a victim of sexual violence may believe her attacker’s
use of porn ’caused’ the act, such a diagnosis made after a traumatic experience
will be extremely unreliable. Subjective analyses of psychological causation
have been poor at the best of times.
In fact, even the dominant academic causal theories of sexual violence
are grossly inadequate. They take no account of the moral evaluations which
are normally likely to be critical determinants of whether or not people
act upon fantasies induced by sexual depictions.
Ian Vine University of Bradford