Letter: No bananas
The choice of the two illustrations for the article ‘Awesome secret
of the Indiana banana’ (This Week, 15 February) was unfortunate.
The plant referred to in the article is, of course, the pawpaw (Asimina
triloba), which belongs to the Annonaceae. The illustrations are of Carica
papaya, which belongs to the Caricaceae. C. papaya is properly called the
papaw or papaya, but it is commonly called the pawpaw where I have lived
in various parts of Africa and probably in other parts of the world as well.
G. K. Berrie Faversham, Kent
Letter: La difference
‘Denying sex difference is a rational strategy . . .’
I’ve actively failed to deny sex difference for a quarter of a century.
I might not be rational but I’ve sure as hell had fun.
Jan Holt Isle of Skye, Inverness-shire
Letter: La difference
The article by Helen Haste advertised on your front page as ‘Splitting
Images: Sex and Science’ is undoubtedly actionable under the Trade Descriptions
Act: there is no science in the article.
The author states that ‘denying sex difference is a rational strategy,
supported by much scientific evidence’, but when Dr Wilson and I searched
the literature in connection with our book on The Psychology of Sex we found
a great deal of evidence to show that these differences were in fact substantial,
and based on a firm biological foundation. To give scientific credence to
Haste’s opinion, one might at least have expected some proper discussion
of the many articles and books contradicting her views; yet there is no
mention of these numerous experiments in her article. This is not my idea
of a scientific argument.
Haste’s use of the word ‘strategy’ in the quotation given above would
seem to give the game away. ‘Strategy’ is defined in the Collins English
Dictionary as ‘the science of the planning and conduct of a war’; it has
nothing to do with the dispassionate search for objective truth which is
supposed to characterise science. Haste’s article is simply a propaganda
device to persuade readers of the truth of her opinions, without regard
for the available evidence.
Hans J. Eysenck University of London
Letter: La difference
There is an unfortunate dogmatic tendency among many feminists to claim
that all behavioural, mental or temperamental differences between men and
women are definitely the result of ‘stereotyped’ thinking about women’s
characteristics, rather than possibly resulting, at least in part, from
differences in genetic make-up (‘Splitting images: sex and science’, 15
February). Here they are failing to face up to the notorious difficulty
that exists whenever we try to discover the proportion of influence that
‘nurture’ or ‘nature’ has in determining practically any human characteristic.
Also, feminists often seem to be deliberately closing their eyes to obvious
resemblances between the social interactions of our nearest nonhuman relatives,
the apes, and ourselves. In particular, differences between the sexes in
respect of child-caring behaviour, dominating behaviour and aggressive and
submissive behaviour among the apes strongly suggest a strong instinctual
component in the corresponding differences of behaviour among human beings.
I happen to share with Helen Haste and other feminists the belief that
human beings need not be content with what we have inherited from our monkey
forebears, especially if that results in an unjust distribution of the pangs
of tedium and the delights of variety, discovery and adventure in our daily
lives. But I also fear that we may be heading for unforeseen disasters if
we depart too precipitantly and too radically from the patterns of living
within which our instincts evolved.
Arthur Syred Derby
Letter: Wandering woodlice
Some of the suicidal woodlice (Forum, 15 February) in my house have
shown great initiative by climbing up inside the legs of trousers that have
been left to dry over a radiator.
Curiously, when subsequently pressed (iron set to ‘cotton’) they produce
a green stain.
David Saul Lancaster
Letter: Shep the seal
Juliet Clutton-Brock has well described how land animals have been tamed
(‘How the wild beasts were tamed’, 15 February). But I wonder whether seals
could be trained to herd fish or to protect shellfish against marauders.
Seals seem to have trainable, dog-like personalities. How about it? We could
then farm the sea as well as the land.
Michael Bell Hitchin, Hertfordshire
Letter: Soap success
James Williams’ suggestions for TV soaps to include scientific themes
are noble, but I have one reservation – all of his nominees are male.
Julie Cave London
Letter: Soap success
James Williams (Letters, 22 February) muses on the place of science
in television soap operas. He is not alone in seeing the potential in this,
although it is not as easy as might be thought.
COPUS (Committee on the Public Understanding of Science) successfully
persuaded the makers of Brookside to recognise that scientists are real
people too. Alison Gregory (played by actress Alyson Spiro) was a biochemist
who moved into Brookside Close with her partner who was a medical doctor.
Unfortunately, for us, Brookside mirrors real life and the pair left Liverpool
to pursue Alison’s career in the States – all part of the brain drain! So,
back to the drawing board.
Walter Bodmer COPUS, London
Letter: Crystal clear
Mrs Andrew Deacon (Letters, 15 February) was into real science when
she put the jar of solution and crystals into the microwave (Letters, 15
February).
Microwaves heat water uniformly, so there is no convection. A strong
dense solution draining off the dissolving crystals can then collect at
the bottom. Any boiling has to start at the top and should not cause much
mixing. On cooling, crystals will first separate where the solution is strongest
at the bottom, with a good chance of getting a single crystal.
Ordinary heating causes convection and mixing, so that the solution
is homogenous, and on cooling can deposit crystals anywhere – and generally
does.
Tom Nash Sherborne, Dorset
Letter: Shrieking gnomes
In his article (‘Piecing together the Pacific’, 18 January), Garry Davidson
mentioned that ‘In 1881 Osmond Fisher . . . suggested that the basin of
the Pacific was the depression left over when the Moon broke away from the
Earth’.
Charles Darwin’s grandfather Dr Erasmus Darwin FRS (1731-1802) was one
of the most versatile scientists of the 18th century. In 1789 he published
the comic epic poem The Botanic Garden, which established him as one of
the leading literary figures of Europe. Erasmus Darwin discussed many scientific
ideas in the poem, including the speculation that the Pacific Ocean was
the scar left by the Moon separating from the Earth:
Gnomes! how you shriek’d! when through the troubled air
Roar’d the fierce din of elemental war;
When rose the continents, and sunk the main,
And Earth’s huge sphere exploding burst in twain.
Gnomes! how you gazed! when from her wounded side
Where now the South-Sea heaves its waste of tide,
Rose on swift wheels the MOON’S refulgent car,
Circling the solar orb, a sister-star,
Dimpled with vales, with shining hills emboss’d,
And roll’d round Earth her airless realms of frost (Book 2, lines 73-82)
The Botanic Garden became immensely popular and was published in many
editions, including pirated editions in Dublin and New York. Thus, Osmond
Fisher’s suggestion was far from novel when he published it in 1881.
Garry Tee University of Auckland, New Zealand
Letter: Noisy wires
Most radio amateurs can answer Simon Gardner’s question (Letters, 8
February) on how a portable CD player could interfere with a plane.
The sad fact is that boxes of digital consumer electronics radiate hefty
radio frequency signals from connecting cables. In the case of the portable
CD player the radiating cable is the headphone lead. The source of the radio
frequency spectrum is the fast risetime of digital waveforms (even at the
CD player’s 44 kHz sampling rate) which generates noise up into the VHF
region.
When such noise is placed within the confines of a metal box (such as
an aircraft fuselage) an unpredictable standing wave pattern will be built
up, with signal strength peaks and nulls all over the place. Site the source
of the spectrum close to the point where, say, the wiring loom to the tailplane
controls happens to pass, and the unpredictability of spurious signal pick-up
becomes of the nail-biting sort. Actual effects are likely to be more subtle
than this crude scenario indicates but subtleties can still produce a devastating
effect in an electronic cockpit at critical times.
Peter Connors Stockport
Letter: Clever Cinders
Welsh research is not quite the Cinderella that the 1989 ratings quoted
in William Bown’s article (This Week, 8 February) seemed to imply. Those
ratings applied to cost centres which in many cases comprised more than
one subject, and several of the lower cost-centre ratings in fact hid much
higher subject ratings.
For example, in my own field (pure mathematics) Swansea was rated 4,
definitely not a Cinderella grade. This and other subject ratings were sent
by the UFC to the universities some time after the cost centre ratings and
received much less publicity. In detail, the ‘Mathematics’ cost centre at
Swansea comprised Pure Mathematics (rated 4) and Management Science and
Statistics (1). The overall rating was 2.
Two other Welsh mathematics departments were rated 4 (Pure Maths at
Cardiff and Applied Maths at Aberystwyth). Welsh mathematics is alive and
flourishing.
Roger Hindley Department of Mathematics and Computer Science University
College of Swansea
Letter: Testing relativity
Jim Baggott’s review of Time, Space and Philosophy, by Christopher Ray
(Review, 25 January) contains some serious errors on the observational tests
of general relativity. He cites as tests ‘the perihelion of Mercury’ and
the ‘bending of starlight by the Sun’, and ignores all of the more modern
high precision experimental tests of general relativity already accomplished.
These latter tests include: the Pound-Rebka gravitational red shift test;
the Taylor et al. binary pulsar test; reruns of the Eotvos tests; the Hafele-Keating
aircraft tests combining gravitational red shift and time dilation; the
Vessot-Levine rocket tests of the same; the Shapiro time delay tests; the
Nordtvedt null test of the strong equivalence principle; and variants and
improved repetitions of all such tests.
Finally, the Global Positioning System of satellites, for its effective
and accurate functioning, also requires incorporation of general relativity
effects (as well as numerous special relativity effects, of course) to achieve
its measured accuracies. All in all, there is large-scale experimental verification
of general relativity, very considerably beyond the two ‘classical’ tests
cited by Baggott.
B. Augenstein Santa Monica, California, US
Letter: Credit due
Andy Coghlan’s article ‘Speedy detector will pinpoint polluters’ (Technology,
8 February) failed to give due credit to researchers at Bangor University
who played a crucial role in the invention and development of a spectrometer
for distinguishing different kinds of biological cells. The article describes
how Bernard Betts and Jeremy Hawkes of the University of York developed
a prototype spectrometer based on a phenomenon called dielectrophoresis.
I am sure that Hawkes, whose doctorate at Bangor was supervised by me,
would readily acknowledge that Julian Burt and Jonathan Price – two of his
former companions at Bangor – developed the concept on which the York team’s
prototype spectrometer is based. They developed the concept with Talal Al-Ameen
– not with Hawkes – while working for their doctorates. The concept was
refined in 1987 through collaboration between Bangor and Frederick Becker
and Peter Gascoyne at the MD Anderson Cancer Center in Houston, and this
work is documented in the scientific literature. Hawkes’s own move into
dielectrophoresis was facilitated in November 1989, after he had acquired
from us the required microelectrodes.
A major effort in dielectro-phoresis continues at Bangor, and we collaborate
with other groups around the world, funded by several sources.
Ronald Pethig University of Wales, Bangor
Letter: Fuzzy thinking
For many years I would look at someone and say, ‘That man is quite tall,’
and think no more of it. Apparently this is wrong. The correct procedure,
according to fuzzy logic, involves a foot rule, clipboard, calculator, three
sheets of graph paper and a digital writing implement. First I get the person
concerned up against a wall, then I measure his exact height, refer to my
graphs, and finally pronounce, ‘Aha! This man has a membership of 0.9 in
the set of tall people and 0.1 in the set of average height people.’ This,
according to the article, is how humans reason. It follows that I am not
human, since my perception of someone’s height depends on whether he is
surrounded by basketball players, whether he is a policeman and how much
I have had to drink.
Fuzzy logic is claimed to use vague concepts and imprecise data. This
is false. Fuzzy logic takes precise, analogue inputs, does some fancy processing,
then produces precise analogue or pseudo-analogue outputs. I call this analogue
signal processing, and the only people who benefit from calling it fuzzy
logic are the manufacturers of Z keys.
If my (digitally controlled) washing machine had a softness sensor and
a weight sensor, I am sure it would wash better, even without fuzzy logic.
But it hasn’t and doesn’t.
S. Johnson Lichfield, Staffordshire
Letter: Fuzzy thinking
Science is not a democracy, and an idea’s popularity in the commercial
market does not make it true. There is, as it happens, exactly one logical
way with dealing with imprecise information, and that is ordinary probability
calculus (‘Fuzzy logic goes to market’, 8 February). This has been proved
to be the only calculus which allows consistent reasoning – so that the
result of applying given ‘rules’ is independent of the order in which they
happen to be applied. There is simply no room for alternatives. In so far
as it differs from probability theory, fuzzy logic is internally inconsistent.
Of course, simplistic thinking may be adequate in simple cases, and
fuzzy logic may indeed be capable of scheduling lifts and washing machines.
But so are probabilistic arguments. The real danger with inconsistent, faddish
reasoning would come if it were ever applied to important matters like air
safety or reactor control. Fuzzy thinking about such matters would be dangerous
as well as deplorable.
John Skilling Department of Applied Mathematics and Theoretical Physics,
University of Cambridge
Letter: Timber tasks
The article by Peter Hadfield (This Week, 14 December) omits to mention
that at the last meeting of the International Tropical Timber Organisation
a resolution was passed outlining the criteria for forest management at
both national and unit level.
This adds to earlier actions by ITTO, namely: The introduction of action
plans for its three permanent committees; the production of ‘Guidelines
for Sustainable Management’; the commitment by producer nations to achieve
sustainability by the year 2000 at the latest.
As a voluntary organisation consisting of 47 nations working by consensus,
progress is often slow and on occasions frustrating – but better this than
nothing.
A. V. Morrell The Timber Trade Federation London