Letters: Help for Cambodians
Congratulations on your timely article on the plight of Cambodia’s amputees
(‘The killing minefields of Cambodia’, 19 October). Since its foundation
in November 1989, the Cambodia Trust has been deeply concerned about this
problem and it will shortly be opening a major limb fitting centre in the
Cambodian capital, Phnom Penh, where leading British prosthetists will give
instruction to four Cambodian trainees and fit upwards of 2500 patients
a year.
The technology chosen for this project, the Multiple Assembly Prosthesis
(MAP), was standard in the British National Health Service between 1968
and 1990, and consists of three principal parts – a polypropylene socket
(shaped by draping heated polypropylene over a plaster cast taken from a
patient’s stump), an extruded aluminium shank, and a polyurethane moulded
SACH (Single Action Cushioned Heel) foot built around a wooden keel. Easy
to assemble and adjust, but highly durable in rugged Cambodian conditions,
it can be produced at a fraction of the cost of the computer-designed ‘Seattle
Shapemaker’ foot. So suitable is it for Cambodia’s needs that both the International
Committee of the Red Cross and the Lyon-based Handicap International – which
hitherto made simple wood and leather prostheses – have adapted it for their
own prosthetic programmes.
Our project has already received important backing from the British
government’s Overseas Development Administration, but this money ( 拢155
000 in the first year) is conditional on us raising matching funds from
private sources. For under 拢19, a MAP prosthesis can be fitted to
a Cambodian amputee (70 per cent of whom are under 25). This is one small,
but important, way in which we in the West can help Cambodians lead active
lives and participate in the rebuilding of their war-shattered country.
Peter Carey Cambodia Trust Oxford
Letters: Struggle to study
I was interested to read David Elliott’s account of his PhD students’
struggle to cope with the effects of the recession at the top of the student
tree (Talking Point, 19 October). Down here an inch above the roots it isn’t
a lot different.
I am a female mature student of computer aided engineering. I started
with the Open University but, feeling that I lacked the practical background
which might entice someone to employ me after graduation, I switched last
year to a Higher National Diploma with a mandatory grant and a year’s placement
in industry. Having reached that point in the course, I have not been able
to obtain a placement.
I have tried without success to get an evening job which would still
be viable when I do find a suitable placement.
On the first day of term I went to the Job Centre to sign on. They said
my claim would have to go to adjudication. This took five weeks, which brought
me to the brink of insolvency. I am now told that I am not entitled to benefit
‘because I am a full time student’.
My grant for the year ending July is long gone, and the placement which
I am seeking would, like any conventional job, provide me with an income
to live on. The only way I can get benefit to replace this income is to
withdraw from the course. But why should I?
Do you remember all that advertising a couple of years ago in which
the government promised to help and support adult women (and men) entering
science and engineering? With friends like that, who needs enemies?
Angela Lewis Dereham, Norfolk
Letters: Faraday floored
Anecdotes are lawful science. Great Uncle Alfred Barnard was a not infrequent
visitor in my school days, and always pulled out of his pocket some scientific
trifle (such as floating an aluminium foil fish and, with camphor in its
tail fork, making it swim). Then he told tales about how he often listened
to Michael Faraday in the Royal Institution. And, when the lecture was over
– and the great and the good left the demonstrations running at the semicircle
bench and sauntered off in conversation, down the stairway to clip-clop
home – then, like mice, the children tiptoed down the iron gallery steps.
Faraday would look up and soon all the apparatus was humming and sparkling;
on one occasion it gradually became rumbustious – Faraday was floored, with
Kate pulling his white hair, Harry jumping on his stomach – until they too
sauntered down and home. At least, at the age of 80, so I recall his recollection.
Harold Faraday (!) Barnard Beverley, Humberside
Letters: Saving the seabed
Georg Breuer’s article ‘A strategy for the sea floor’ (12 October) raises
some important points concerning the designation and safeguarding of seabed
sites of special scientific interest. Unfortunately his concern appears
to have been restricted to sites in the deep ocean, yet seepages on the
continental shelves are equally valuable in scientific terms.
Research on gas seepages in the North Sea, for example, has shown that
they are characterised by a methane-derived carbonate precipitate and by
a benthic ecosystem which may, in part, be dependent upon chemoautotrophic
bacteria. For sites outside territorial waters protection may be just as
difficult on the continental shelves as in the deep oceans. Shelf sites
are of similar scientific importance and equally deserving of protection,
but are far more accessible and therefore even more vulnerable. It is understood
that the rich fish populations of such seepage sites have already attracted
the attention of fishermen.
Alan Judd Sunderland Polytechnic Sunderland
Letters: Prejudiced sceptics
Dealing with the contribution made by Michel Gauquelin on the question
of planetary position at birth and supremacy in certain areas like sport
and science, Wendy Grossman (Forum, 19 October) states that the ‘Mars Effect’
is an example of the inherent difficulty facing sceptics: ‘it takes a few
seconds to make a paranormal claim, but it takes an unpredictable number
of years of patient, experimental research to explain it.’
The suggestion seems to be that Gauquelin made his claims without the
years of patient, incremental research necessary. This is completely false.
Gauquelin and his wife, Francoise Schneider-Gauquelin, laboured incessantly
for something like 30 years, patiently collecting tens of thousands of records,
visiting birthplaces of high-level sportsmen, scientists, soldiers etc to
establish birth dates, and spent countless hours over the analyses of their
data. In addition, they published all the relevant data, and made them available
to critics. Sceptical opponents carried out similar research to disprove
their claims, but only succeeded in essentially verifying them. Independent
sceptics like Professor S. Ertel from Gottingen reanalysed all their data,
and found that essentially their conclusions had been justified.
Critics, on the other hand, have on the whole behaved in a thoroughly
unscientific manner. Some refused to publish their data when these turned
out to be favourable to Gauquelin; others agreed that if he carried out
certain control studies, they would consider his claims to be proved, but
when he did so they reneged. In particular the behaviour of the Committee
for Scientific Investigation of Claims of the Paranormal has been quite
unspeakable, leading to the resignation of prominent members in protest.
My own view has always been that the Mars Effect (and the Jupiter Effect,
and the Saturn Effect) are interesting phenomena which deserve scientific
investigation; whether they will turn out to be paranormal in any sense,
or will receive an ordinary scientific explanation, is an issue on which
I would not want to make any prediction.
Hans Eysenck Institute of Psychiatry University of London
Letters: Double fault
There is no puzzle to the lack of reference to disease and/or parasitism
in connection with the disappearance of the dinosaurs (Letters, 5 October),
as it patently has no validity as a hypothesis. John Brunner almost answers
his own question in stating that ’emergent diseases’ have occurred many
times among humans (many more times, probably, than among dinosaurs, due
to our wandering ways) yet we are not even close to extinction – well, not
through that mechanism anyway. But even this is not the answer to why it
is seldom proposed.
Stephen Jay Gould stated the basic rule that Brunner is blithely ignoring,
namely that ‘there is no separate problem of the extinction of dinosaurs’.
The Cretaceous extinction ended the reign of more than 10 per cent of the
most successful marine families, including the ammonites and almost all
marine plankton species. Hence it is fundamental to any hypothesis that
it must also explain the extinction of a huge range of organisms from a
variety of habitats.
Therefore Brunner’s hypothesis fails on the double fault of the improbability
of a suitably devastating pandemic arising, and of the failure to explain
the far greater loss of life that was occurring all around.
David Brownless Rutherford Appleton Laboratory Oxfordshire
Letters: Sprouting spikes
The ‘spooky spike’ observed by Judy Turner (Letters, 2 November) is
an ‘ice fountain’. When the freezing begins, the ice is not of exactly the
same thickness everywhere. But the water beneath expands as it freezes and
in attempting to relieve the pressure breaks through the weakest place.
The droplet of water ejected there then freezes even more thinly than the
main surface, so the continuing pressure of the expanding water below breaks
through the freezing droplet rather than elsewhere and increases its size.
It is rather like lava spilling out of a volcano crater.
The breakthrough is always at the weakest point, the tip of the ‘fountain’,
which builds in length until all the water is frozen solid or a thaw destroys
this beautiful phenomenon.
I enclose a photograph of a double ice fountain which grew in this Plymouth
garden a few years ago. The bigger spike was 130 millimetres long and the
smaller 110 millimetres; they grew to that size in less than ten hours.
Air bubbles were entrapped in the ice of both spikes.
Geoff Lewis Plymouth, Devon
Letters: Sprouting spikes
Let me offer a possible explanation for the ‘spooky spike’. Both the
(frozen) water in the dish and the (liquid or frozen) particles in the air
are highly polarisable. So the small particles can be regarded as tiny electrostatic
dipoles, and one can imagine that a random distribution of small dipoles
near the surface of the freezing polarisable water in the dish can disturb
the charge neutrality locally.
A locally excessive charge attracts the airborne dipolar particles in
its immediate vicinity, which attach themselves, and a small corrugation
in the flat frozen surface appears. Such a protrusion concentrates the excessive
charge, thus becoming an even stronger attraction for the particles. The
sharper and longer the growing finger, the more it concentrates the electrostatic
field close to its tip and the stronger it attracts available particles.
This process can lead to the formation of long structures.
Note that it is important to have quiet weather, as witnessed by Judy
Turner, for otherwise the wind can overwhelm the effect of the electrostatic
interaction between the charged tip and the particles, blowing them away
and disrupting the process.
Raphael Blumenfeld Cavendish Laboratory University of Cambridge
Letters: Bench-top bubbles
I was interested to read Mike Petty’s letter on the mechanism and persistence
of globules on top of coffee (Letters, 2 November). While these sometimes
occur during pouring, a fortuitous combination of modern technology greatly
facilitates a bench-top demonstration – although a desk top may prove to
be more apt. Most expanded polystyrene coffee cups display, in contact with
a polished surface, exactly the right differential between static and sliding
friction to excite audio-frequency vibrations in the shell of the cup. The
pressure of contact is relevant, but one slurp down from a full cup is about
right.
When the cup is drawn across the desk with finger and thumb a couple
of centimetres up from the base, a harmonic-laden tone around 500 Hz will
be heard, and first ripples and then Chladni patterns will be seen on the
surface. If, by careful adjustment of velocity, the frequency can be made
to strike a resonance, peaks of liquid a few millimetres high can be generated
which break down at the tips into the desired drops, which sometimes bounce
spectacularly on the surface-tension film.
The demonstration can be quite fascinating, but I would recommend that
either remote observation or protective equipment should be considered as
enthusiasm mounts.
Chris Atkinson BBC Network Radio Safety Services London
Letters: No nasty niffs here
I read with considerable interest your recent article on the ability
of an extract from the yucca plant to absorb unpleasant odours (This Week,
31 August).
Here in New Zealand we have been working very successfully with a product
containing yucca extract in an attempt to reduce smells in piggeries.
We have found that this product, rejoicing in the name De-Odorase, drastically
reduces such smells and seems to have the welcome side effect of improving
pig health and growth rates, presumably as a consequence of the recorded
30 to 40 per cent reduction in atmospheric ammonia inside the buildings.
Where will this line of investigation end? Perhaps yucca impregnated
shorts for All Black forwards to ameliorate unsociable odours in the scrum?
Or even a food supplement for our 60 million sheep to lessen those methane
emissions that supposedly thin the ozone layer.
These possibilities aside, New Zealand pig farmers (and their neighbours)
are now poised to benefit significantly from an extract harvested from a
humble plant growing in the Mexican desert. Isn’t nature wonderful?
Michael Cundy Auckland, New Zealand
Letters: Bigger yawn
B. Marsh hypothesises that yawning ‘is initiated by inequality brought
on by atmospheric pressure changes’ (Letters, 19 October). For over 30 years,
my wife and I have been ‘tapesponding’ with relatives and friends around
the world. To us, and all our tapespondents, it is our experience that hearing
someone yawn during a taped message made weeks before and thousands of miles
away can and does cause listeners to yawn. Would someone like to hypothesise
on that?
Kenneth Hooton Phoenix, Arizona, US
Letters: Green flash
When I lived on the west coast during the war I was told to look out
for the green flash as the Sun disappeared, its last ray skimming through
the water. When I found that, with the right clear, gold sky and a distant,
treeless horizon, I could see it on land, I was told it was an optical illusion,
green being the complementary colour to the last brilliant red spot.
Then I found that, with the same clear sky in the morning, by fixing
my eyes on exactly the spot I knew the Sun would appear, I could sometimes
see the green flash before the Sun, and no one had an explanation.
Can anyone account for it? Is it still to be seen or have our murky
skies (‘Painting the sky red’, 19 October) hidden it forever?
Eunice Overend Chippenham, Wiltshire