Letters: Downward spiral
At the age of 70 years, I am inclined to believe that I am nothing but
a pimple on an entropy surface.
Am I correct?
K. Johnson Truro, Cornwall
* * *
Yes, in essence you are correct. However, we question the ‘nothing but’
– Ed
Letters: Thatcher Derug
The comparison of Prozac with ecstasy is fascinating. The two drugs
act in a similar way on the brain by affecting the neurotransmitter serotonin.
They produce a similar list of side effects, from preventing orgasm to allowing
suppressed psychological problems to manifest. Both drugs have also been
credited with replacing years of psychiatric treatment.
The quality of mood elevation they produce is similar, except that what
ecstasy concentrates into a few hours, Prozac spreads out over a week. In
fact, the similarity is such that many Prozac users find that ecstasy no
longer ‘works’ for them.
Many mothers on Prozac who are horrified by their children’s use of
ecstasy may have more in common with them than they realise.
Nicholas Saunders London
Letters: Thatcher drug
Although I was delighted to see a major article on modern-day psychopharmacology,
I was dismayed at the earlier Comment where cannabis was grouped along with
other drugs known to ‘produce nasty side effects’.
Through reading ‘All the feelings that fits’ naive people might be led
to believe that a hangover, addiction and tolerance are all part of cannabis
abuse, while in reality the drug does not cause any of these problems.
Michael Fowler Bournemouth, Dorset
Letters: Thatcher drug
During quite a number of years in industry I found that in only a handful
of cases were ambition and ability correlated, the former being mostly
associated with slightly enhanced mediocrity. Are we to expect that Prozac
will produce battalions of even less capable persons who think that they
should be captains of industry to, in the long run, the detriment of progress?
‘Design your own personality’ (12 March) stated that the majority of Prozac
takers were women, who take it so they can achieve what society expects
of them. I suspect that only a fragment of society expects in that way,
and that much of the driving force where it does is to emulate this country’s
leader in the 1980s. We should remember that that decade impoverished more
people than did the South Sea Bubble. When the smokescreening stops and
the dust settles, perhaps the era will be known as the MT (empty) Bubble.
J. Duncan Ashford, Kent
Letters: Wrist watch
Q: For several years I have been fascinated by wrist size differences
between people born before and after the mid-1940s. If you choose two adults
of the same sex and height, one born before the mid-1940s and one after,
in nearly all cases the younger person will have smaller hands and wrists.
More thorough observation will also show that people in the younger age
group have a lighter physique than the older age group. There seems to be
no solid research carried out in this area – can anyone supply any reasons
for these differences?
Nick Akrill Sheffield
Letters: Mystery digits
Q: Computerised address labels on much of my mail contain the same five-figure
number, which means nothing to me, and is not obviously related to any element
of my address. Placement of the number on the label varies. I don’t think
it can result from one organisation selling a mailing list, since the labels
originate from varied sources: subscriptions, direct sales, charities, even
the Inland Revenue. Can anyone explain what this code might be?
L. W. Millgate Cambridge
Letters: SuperBee?
Q: I have read that honeybees can see ultraviolet light. I have also
read that certain metals, such as silver and sodium, are transparent to
ultraviolet light. Assuming that an ultraviolet lamp were provided, could
honeybees look at you through a metal wall? I thought only Superman could
do that.
Robert Erck Argonne National Laboratory, Illinois
Letters: Dirty films
Q: When I clean the inside of my car windows, I notice that they are
covered with an oily film that leaves a noticeable black residue on the
cleaning cloth. Have others noticed this buildup on their car windows, and
can anyone suggest what might be causing it?
Paul Ireland Colchester, Essex
Letters: Speedy return . . .
Last week, we told you that on 9 April we would be publishing more questions
for our new column in which readers ask and answer questions about the science
of everyday life. Well, we’re back early. We already have more questions
than we expected so we’re publishing some this week and more again next
week as planned. Please send in further questions and answers to the questions
we have already published and help make the new section a success. Remember,
a 拢10 book token will be sent to the author of each answer we publish.
Letters: Watery grave?
Q: I have recently encountered the practice of drinking only distilled
water for health reasons. Are there any long-term consequences of this practice,
especially in comparison to drinking mineral water or filtered water? Are
the minerals and trace elements to be found in non-distilled water useful
or even necessary for health?
C. J. Dearling St. Anstell, Cornwall
Letters: Minor readjustment
The scientists who dream of terraforming Mars in ‘Mars: the final frontier’
(5 February) over a period of 100 000 years have overlooked the recently
discovered effects of chaos in the solar system. Independent computer simulations
by Jacques Lasker and Jack Wisdom indicate that the angle of the spin axis
of Mars can vary between 0 degree and at least 60 degree. Such changes would
have drastic effects on the climate and so ruin the progress made. The reason
similar effects have not made Earth uninhabitable seems to be the presence
of the Moon, whose gravity overwhelms the perturbations from other planets.
Though Mars has two moons, they are far too small to have such a stabilising
effect.
I have my own, somewhat more grandiose plan for terraforming planets.
First move Mars closer to the Sun and Venus further away; after all they
are in the wrong orbits for an Earth-like climate. Put them in orbit around
each other so that they stabilise each other’s spin the way the Moon protects
Earth, and transfer some of Venus’s atmosphere to Mars. Then add photosynthetic
microbes to make both planets’ atmospheres Earth-like. Though I have skipped
over more than a few of the technical problems involved, it makes a great
science fiction scenario.
Stuart Henderson Farrer, Australia
Letters: Well-behaved eyes
Readers of Alison Brooks’ piece in Forum (5 February) may be interested
to learn that some optometrists do indeed offer an alternative approach
to dealing with certain types of myopia.
The conventional wisdom that myopia is purely hereditary is presently
being challenged and current opinion is that there may be environmental
aspects in the development of this refractive error. The ‘use and abuse’
theory, for example, has found favour in some parts of the world. It suggests
that stress on the visual system alters the way the visual system functions.
This visual stress can eventually result in an alteration of structure which
manifests itself as myopia.
Alison Brooks’ assertion that optometrists decry theories that vision
can be improved through exercise suggests she has not discovered behavioural
optometry, which considers vision to be much more than the ability to read
the bottom line on the chart.
It regards vision as the complete perceptual process that recognises
a visual stimulus, derives meaning from it and then directs and monitors
the appropriate action. Problems with any part of the whole process (including
poor vision) can lead to reduced visual performance, which usually responds
well to an appropriate exercise approach.
Readers can learn more about this approach to vision care by sending
an SAE to the British Association of Behavioural Optometrists, 29 St.
Georges Drive, Cheltenham, Gloucestershire GL50 3DU.
Paul Adler Stotfold, Hertfordshire
Letters: Expanding Clarke
As Harry Harrison makes two unsolicited testimonials to me in his review
of Flux (12 February), I am embarrassed to say that I always believed the
description of science fiction as ‘the only genuine consciousness-expanding
drug’ originated not with C. S. Lewis but with . . .
Arthur C. Clarke Colombo, Sri Lanka
Letters: Not so shocking
I feel I have to disagree with Lee Coleman, when he describes families
who allow the use of ECT as ‘copping out’ (‘Shock therapy returns’, 5 March’).
In October 1993 I became severely depressed and was admitted to hospital.
Life was going well for me, I was 32 years old, had a good job as a chemist
for a toiletries manufacturer, two children, and we had recently moved to
a new house. What then was the real cause of my depression?
Before being taken into hospital I was taking antidepressants, and continued
to do so in hospital. I was diagnosed as having clinical depression and
the treatment of ECT was suggested to my family and myself. My wife discussed
the treatment with the doctors and expressed her concern. One of her questions
was, ‘Is this a quick way of treating depression so that more patients can
be allowed out of hospital sooner, therefore not taking up valuable beds?’
The doctor explained that the treatment was not a quick fix which was
handed out to every depressed person just to get rid of them. In fact, it
was to stop people like myself suffering the terrible thoughts and feelings
brought on by this form of depression. Indeed, antidepressants would have
worked eventually, but why prolong the suffering when this treatment is
available?
I agreed to have the treatments, and after three sessions was well enough
to be let out of hospital. I suffered slight memory loss, but only of events
between the treatments. Five months later I am back at work, and have been
told that after April 1994 I will no longer need to take antidepressants.
ECT was a very effective treatment for me.
David Eastham Huncoat, Lancashire
Letters: Back to the wheel
I was interested to read the article ‘High hopes for faster transit’
(5 March), as I was involved with feasibility studies and cost benefit analyses
of similar systems around 1970, first at the Royal Aircraft Establishment,
and then at the Transport and Road Research Laboratory (now TRL).
The first system studied was an individual small vehicle system (Cabtrack,
developed from the Brush Autotaxi) similar to PRT2000. First results looked
very promising, but the more detailed the studies, the more problems emerged.
Stations became larger as we studied the statistical problems of operation.
Junctions were impracticably large and complex for two-way tracks, but a
system with one-way tracks gave rise to excessively roundabout journeys
between station pairs.
Finally, we engaged a firm of architectural and civil engineering consultants
to investigate the problems of installing such a system in a real town.
Their studies showed that the real construction costs would be very much
higher than the original estimates based on a hypothetical simple town,
and that the system would be environmentally very intrusive. These findings
effectively killed the proposal.
The next idea was to avoid junctions and simplify stations by using
much larger shared vehicles, so that passengers would walk between vehicles
at interchanges, rather than having a direct vehicle for all journeys. This
was in effect a miniaturised version of the Docklands Light Railway, which
we called Minitram. We envisaged smaller vehicles operating at a much shorter
headway than the Docklands system. It had been taken for granted that full
automation was desirable in order to reduce staffing costs, and to permit
much higher service frequencies than could be attained with a manned system.
However, in order to achieve the replacement of a driver by an automatic
system, it was essential to have a track fully segregated from pedestrians
and all other traffic, either by tunnelling or by construction of an overhead
system. This in turn involved penalties of high capital cost, poor access
for potential users, and environmental intrusion if an overhead system was
used rather than an even more expensive tunnel.
We decided to investigate the effect of replacing the automatic control
system by expensive drivers, with a consequent drop in service frequency,
but with the offsetting advantages of easier access for passengers and lower
capital costs. (It may be noted that much of the Docklands Light Railway
uses an existing railway viaduct.) The result was that in many situations,
the ground level non-automatic system showed much better cost/benefit results
than the apparently more sophisticated automatic Minitram. We had reinvented
the conventional tramway.
M. Landon Farnham, Surrey
Letters: Reviews reviewed
I was interested to read your article announcing that the Department
of Trade and Industry had decided that the National Weights and Measures
Laboratory in Teddington will continue as a government laboratory (In Brief,
12 March).
This follows a long and detailed study by KPMG, the consultants commissioned
by the department to review the future of the five government laboratories.
They recommended that NWML would serve its customers most effectively if
it remained in its present form as a government agency.
Somewhat inconsistently, senior department officials have now decided
to undertake a further review. This will try to identify areas in the private
sector that could supply the services presently provided by NWML. We are
assured that this will not be influenced by yet another review which is
currently addressing the possibility of selling part of the Teddington
site.
As you can see, the future of the laboratory is anything but decided.
I am not prepared to make any predictions as to what the department is trying
to do, but I am sure that it is not looking to reinforce KPMG’s recommendations.
How many reviews will it take?
Shaun Hartigan IPMS National Weights and Measures Laboratory Branch
Teddington, Middlesex
Letters: Light sneeze
Q: I have noticed that many people tend to sneeze when we go from dark
conditions into very bright light. What is the reason for this?
D. Boothroyd Harpenden, Herts