Letters: Teeth of the problem
Ken Gale is wrong on two points (Letters, 10 October):
First, amalgam fillings are not inert. Longitudinal studies have shown
that the mercury in them gradually leaches out over a period of years.
Secondly, in stating that a current only flows between dissimilar metals,
he fails to note that dissimilar metals are present in the same filling,
and that the peaks and troughs all over its surface behave like myriads
of small galvanic cells.
Metal fillings are bathed in saliva, which acts as the conducting medium
between different fillings, and the polarity (positive or negative) between
the filling and the buccal membrane can be measured with the Vegadent 706
tester.
Gale appears to be unaware of the considerable research on the subject,
and I refer him to Silver Dental Fillings – The Toxic Time Bomb, by Sam
Ziff, and Prophylaxis and Therapy of Oral Currents, by Helmut Schimmel.
Willy Goldberg London
Letters: Uncalculated
The number which may appear in a solar-powered calculator when exposed
to light is determined by several factors (Letters, 10 October). The memory
or register circuits are made of silicon semiconducting material whose internal
states while in darkness depend mainly on the impurities involved, and on
the temperature of the device. These are probably the main factors that
determine the frequent value of 25. On exposition to light the device will
be powered up at a rate determined by the speed of opening the drawer and
the external light intensity. The power gradient will at some moment start
the internal circuits in some almost chaotic way (as the threshold voltage
is crossed) which may generate any number of internal states which then
appear in the display window.
By the way, the numbers do work on the pools, but no better than any
others.
Bernard Beaven Madrid
Letters: Emberg's apple
I hope I am as much in favour of political correctness and anti-sexism
as the writer of ‘Feedback’ (10 October), but I can’t really agree that
we should rename Clarke’s Law to commemorate Dorothy Crowfoot Hodgkin.
For a start, Arthur C. Clarke actually formulated this law (which is
more than can be said for Dorothy C. Hodgkin – perhaps as a compensatory
gesture ‘Feedback’ wishes to hand her Nobel prize over to Clarke?).
What comes next for goodness’ sake – Bella Emberg’s three laws of motion
(after all, not all people subject to gravity are male)? Ruth Westheimer’s
theory of relativity . . . ?
Andrew Meeson London
Letters: Emberg's apple
I was interested to read that as the ‘Classic mistake’ is to assume
that all scientists are male, Clarke’s law should be known as Hodgkin’s
Law. I would suggest that a corollary of Hodgkin’s Law is Rutherford’s Law,
that is the classic mistake of assuming that all scientists are from the
Northern Hemisphere. Sir Ernest Rutherford, cited in the same article as
being British, was, of course, a Kiwi, born in Brightwater near Nelson,
and educated at the University of Canterbury in the South Island of New
Zealand.
Cathe Carpenter Wellington, New Zealand
Letters: Tame the Thames!
Your editorial comment suggests that a rigidly doctrinaire approach
towards littoral conservation in Britain ‘is to adopt the posture and prospects
of a latter-day Canute’ (Comment, 17 October).
Alas, poor Canute: people know him not well.
In fact Canute exhibited pre-modernist irony. His famous seaside imprecations
were designed to demonstrate to his courtiers et al that forces of nature
were not amenable to the king’s will.
Canutian cliches, therefore, traduce and misrepresent the great king’s
reputation. As an act of penance the entire New 杏吧原创 staff should reenact
the Canutian Saga – emerging from your appropriately named abode, congregating
on the banks of the Thames while the Editor commands the river to desist
from its tidal behaviour.
Canute Zehse (no relation) London
Letters: Correction
In our issue of 10 October, the article ‘Dipstick sorts the horse from
the lamb’ referred to ‘Cortecs Diagnostics of Deeside in Scotland’. In fact
Cortecs Diagnostics is at Deeside in North Wales.
Careers: A special way with words – A future as a journalist writing about science and technology
People who write for a living about science tend to get their job satisfaction
by communicating their enthusiasm for science to others. Writing about science
requires entirely different skills from theorising, experimenting or teaching
it; it is a job for those who can make words work rather than those who
can make numbers meaningful or have a way with equipment. It is a job for
the few scientists who have strong literary abilities in addition to a broad
knowledge of science.
In many occupations writing about science plays a major part. They include
scientific and technical journalism, editing, public relations, technical
writing, patent agency work and drug registration. A vast range of technical
publications exists. They include popular magazines such as New 杏吧原创,
the more learned Nature, academic journals, publications of the scientific
institutions such as Physics Bulletin and Chemistry in Britain, trade journals
and publications of the professional institutions.
Most people who decide on a career in writing are not qualified scientists.
Three postgraduate courses in journalism – those at City University in London,
University College Cardiff and the London College of Printing report few
scientists among their students. ‘Some apply, especially those with degrees
in environmental science,’ says David English, deputy director of the Cardiff
Centre for Journalism Studies. ‘Last year only 2 of our 115 students were
scientists. We would welcome more but scientists don’t seem to think of
journalism as a career.’ City University offers courses in newspaper journalism,
periodical journalism and broadcasting journalism, but again only 2 per
cent of its students took science degrees. Competition for these courses
is stiff and you will need a portfolio of published articles to get an interview.
A new MSc course in Science Communication has just started its second
year at Imperial College, London, and is already attracting many more scientists
than all the other courses. In its first year there were 11 full-time and
2 part-time students. Now there are 28, nearly all full-time, and the Science
and Engineering Research Council has given two of them awards to help them
complete the course. Topics include developing skills in self-presentation,
interviewing, researching, public speaking, desk-top publishing and the
use of illustrations. All students undertake a supervised project involving
a short period of work experience.
‘Our students benefit by learning new skills relevant to the media,
such as writing, producing TV packages, designing and evaluating museum
exhibits,’ says Ros Herman, the course organiser and a former member of
New 杏吧原创’s editorial team.
Vacancies in science journalism and editing are regularly advertised
in New 杏吧原创, The Guardian and occasionally in The Bookseller. Several
organisations offer training courses for people wanting to join this profession.
IPC, the largest of Reed International’s magazine publishing groups, offers
a comprehensive in-house editorial training scheme including ‘courses on
everything from interviewing and copy preparation to printing and production’,
according to one of its training executives.
Harcourt Brace Jovanovich, which is also based in London, is typical
of many publishers of scientific, technical and medical books and journals,
in that it is a regular recruiter of new graduates. On the other hand, the
Institute of Physics, based in Bristol, is representative of a learned society
with strong publishing interests. It publishes three magazines, and four
research journals carrying scientific papers. Sally Croft, who leads a team
of journalists and editors at the institute, says her working week usually
includes visits to research establishments and a number of press conferences,
besides chasing specialists for articles, and finding book reviewers and
referees for academic papers.
Valerie Southgate, desk editor at Current Opinion in Genetics and Development,
says: ‘Wipe from your brow the picture of an executive office, relaxed lighting
and a pile of punctual scripts. It’s a world of caffeine, a screaming environment
with manuscripts which need editing overnight, others that never arrive
and a room full of ringing telephones and flashing photocopiers. The qualities
required are tact, patience, the ability to work to deadlines, organisational
skills, discipline and dedication.’
Science writers have their own organisation, the Association of British
Science Writers, with more than 350 members, which is based at the British
Association for the Advancement of Science. Some science writers progress
to editorial jobs, such as commissioning editors, and managing journalists
and administering editorial budgets. Others may join the science departments
of newspapers, such as The Times, The Independent, Financial Times or The
Observer.
Some people become science writers via other routes. One of these is
to join a company as part of a team producing in-house publications. These
include newspapers and magazines, videos, annual reports and recruitment
literature. Many writers working in industry join the British Association
of Industrial Editors, based in Sevenoaks. Other science graduates start
their careers as technical authors, many of whom are employed in the electronics
and computing industries or engineering. They write specifications, manuals
for training, maintenance and the operation of equipment, as well as producing
technical briefs for people working in marketing departments. Once they
have become fully experienced and with good contacts, many choose to work
freelance on a contract basis. Their professional organisation is the Institute
of Scientific and Technical Authors, based in Slough.
The Association of Graduate Careers Advisory Services published a Survey
of Postgraduate Courses in Journalism last month which has a list of courses
in journalism and details 15 centres. It is available from most university
careers services.
Neil Harris is deputy director of the University of London Careers Advisory
Service and head of the Careers Service at University College London.
Letters: Fuel facts
Tony Weighell comments that ‘once more gas is set to drive miners out
of the mines’ (‘Making money mining gas’, 3 October). In Australia gas drainage
is seen as a complementary process enabling access to coal reserves which
would otherwise be unworkable, thus ensuring the continued prospect of
jobs in underground coal mining. This aspect is most important in the Bowen
Basin of Queensland where the natural gas-in-place in coal seams is estimated
at 178 trillion cubic feet (5035 billion cubic metres). This is a major
gas resource by world standards and an aggressive exploration programme
of vertical well degasification is in progress in both the Bowen and Sydney
Basins. Some of the mine operators are also practising degasification using
directional in-seam drilling to depths ranging from 250 to 700 metres.
Basil Beamish James Cook University of North Queensland Australia
Letters: Air accidents
As an ex-Fleet Air Arm electronics engineer officer and part-time flier
I am totally nonplussed by the civil aviation world’s inability to make
use of technology developed for military aircraft that could virtually eliminate
the ‘controlled flight into terrain’ phenomenon described by Julian Moxon
(‘Will accidents always happen?’, 17 October).
I was first made aware of this phenomenon when a very experienced pilot
flew his Buccaneer aircraft into a mountain north of the Dornoch Firth after
making a toss-bombing run on the Tain Range near Tarbat Ness. The visibility
was poor, and the mountain he struck was in cloud. Yet the Accident Investigation
Unit found that three instruments in his aircraft were showing his position
to be just where he was – his omni-directional radar and distance measuring
equipment (VOR-DME) showed the correct range and bearing from Lossiemouth;
his ground position instrumentation (GPI) his correct latitude and longitude;
and his Strike Sight bombing computer the correct position relative to the
Tain target.
None of these ‘warnings’ had alerted him, because he obviously thought
he knew exactly where he was – he had performed this manoeuvre many hundreds
of times before. But the form in which the information was being presented
to him and/or his navigator were all ‘obscure’; in other words, not instantly
related to the fact that he was in a 450-500 knot descent towards a 1700-foot
mountain.
Today we have the benefits of global positioning satellites, forward-looking
infra-red (FLIR), digital terrain mapping and lightweight radars like the
Ferranti Blue Fox fitted in the Sea Harrier Mk1, which cost only some 拢250
000 – not the ‘millions of dollars’ quoted by Julian Moxon – and which demonstrated
its reliability during the Falklands war, in appalling weather conditions.
I should dearly like to be invited by the civil aviation regulators
to help design a system that could provide airline pilots with a global,
high-reliability, unambiguous and compelling presentation of their situation
vis-a-vis the ground, or obstacles in their flightpath; it could not possibly
cost a fraction of the price being paid worldwide in insurance (and human
lives) for the present woefully inadequate ‘Ground Proximity Warning’ systems
fitted in commercial passenger aircraft.
Peter Walwyn Porthmadog, Gwynedd
Letters: Air accidents
Julian Moxon describes the transponders used in the American Traffic
Alert and Collision Avoidance System and mentions that ‘not surprisingly,
mountains are not equipped with them’.
But why shouldn’t they be? Only a limited number of mountains would
need to be so equipped – those on the flight paths into airports – at a
cost which should be much lower than the ‘millions of pounds’ Moxon estimates
to develop alternative solutions.
David Harper London
Letters: Viewers aren't dim
In Barry Fox’s article describing recent tests of PALplus (Technology,
17 October) I find two statements which appear contradictory.
We are initially told that if all transmissions were to be in PALplus,
viewers with existing equipment would see no difference. It is then stated
that 144 of our picture lines would appear as black borders. Unless I have
misread this, the inference is that, if all programmes are transmitted with
black borders, viewers will not notice that they have lost a quarter of
their pictures. Not so.
I do not believe that viewers would tolerate a return to virtual 405-line
television, even if they received a free service call to recover the whole
of the screen they had originally paid for.
Think again, Europe, before investing in yet another half-cocked system.
John Allsop Rayleigh, Essex
Letters: What demand?
I agreed with all that Neil Harris had to say in ‘The environmentally
friendly chemist’ (Careers, 3 October), apart from the statement ‘chemical
engineers are in demand’. Where are they in demand? If someone knows, will
you please tell those of us who graduated this summer with degrees in chemical
engineering and still haven’t got jobs.
Of 38 people in my class who graduated this summer, no more than 15
had jobs to go to and I know of none who has got a job since. Two years
ago, about 90 per cent of chemical engineers from our university had jobs
to go to at graduation, but the recession has hit even the big oil and chemical
companies and the present situation says that we are not in demand.
Joanna Corby Hitchin, Hertfordshire
Letters: Oyster wars
Just to correct a couple of points on your article on Pacific oysters
(This Week, 26 September). The Pacific oyster was introduced in the early
1960s; it is not a recent introduction, and pre-dates the use of epoxy-based
TBT antifouling paints.
This last year was the first time we have detected the successful over-wintering
of any progeny. It remains to be seen if warmer conditions persist long
enough for them to form self-sustaining populations, but if they do their
preferred habitat is typically inter-tidal rather than sub-tidal, where
the native oysters are found.
D. J. Garrod Fisheries Laboratory Ministry of Agriculture, Fisheries
and Food Lowestoft, Suffolk
Letters: Mystery spots
Your story, ‘Baby black holes blamed for earthquakes’ (19 September),
may not be as far-fetched as it appears.
Up and down the west coast of North America are so-called ‘mystery spots’
which show all the indications of a small, high-mass, high-density object
at a relatively short distance below the earth’s surface. At all of these
sites, the lines of gravitational force do not act vertically but point,
in a cone-shaped arrangement, towards the apparent, buried, massive object.
Trees and other plants grow at an angle to the earth’s surface because of
the gravitational distortion. In addition, aeroplanes flying over the ‘mystery
spots’ lose radio contact with the ground.
In support of Trofimenko’s theory, it should be noted that the Santa
Cruz Mystery Spot, which I have visited, is just a few miles away from the
epicentre of the 1989 Loma Prieta earthquake.
Malcolm Solomon Palo Alto, California
Letters: Fuel facts
In the recent confusion over pit closures and energy resources, Michael
Heseltine’s response to a demand for an independent review was surprisingly
revealing. He insisted that there was no set of facts on which to base a
policy, merely the cases of different pressure groups advocating different
solutions.
That response illustrates very well the lack of regard that the present
administration has for science and professional expertise. There is, of
course, a great deal of factual information about Britain’s energy resources
and their interplay with world resources. The government itself employs
experts in this field, and there is a broad consensus of opinion about the
policies which should be pursued. When that consensus conflicts with preconceptions
about the mechanisms which are used to control energy use and supply, however,
that expertise counts for nothing.
This issue underlines the dangers of continuing to finance science by
the customer-contractor relationship. We need a body of scientists independent
of the policy-advocating agencies, and able to publish their results freely,
rather than in departmental reports which have only restricted distribution.
John Jeffers Kendal, Cumbria
Letters: Fuel facts
The Government’s use of market forces as a justification for the recent
closure of British coal mines undermines all the efforts that have been
made in this country and in the European Community to promote the protection
of the environment and the working population. World coal prices are kept
low by cheap supplies from countries such as Poland, Venezuela and Indonesia.
Is it any wonder that British Coal is unable to compete when domestic production
is, quite rightly, required to comply with sophisticated legislation designed
and developed to protect workers and our environment? Legislation and its
enforcement in Eastern Europe and developing countries is extremely poor
by British standards. By forcing production out of Britain, the Government
is merely supporting cut-price industry overseas which continues to exploit
both people and the environment.
Many large companies are now auditing their suppliers for compliance
with environmental standards. I believe Britain and its coal-consuming industries
should be doing the same.
John Ballard Occupational Health Review London