Letters: Really random
I was interested to read William Bown’s article, ‘Gambling on the wrong
numbers from Monte Carlo’ (New 杏吧原创, Science, 24 April).
I wonder whether anyone has used ‘perfect’ primes for random number
generation. A perfect prime (n) is a number which has a reciprocal with a
repeating period of n-1 digits. For example, the number 7 has a reciprocal
(that is, 1/7) of 0.1428571428571 . . . in which six digits recur. Also, if
you divide 7 into any number not divisible by 7, the remainder will be the
same sequence of digits. If a very large perfect prime, say 10 digits, is
taken, there would be good potential for random number generation by simply
hopping from place to place on the sequence of 10 000 000 000 digits given
by its reciprocal.
Philip Mottram
Sauvo, Finland
Letters: Self-help
As an unemployed graduate of 1992, Bernard McAuley (Letters, 17 April)
should not give up hope yet. I graduated in 1991 and am still unemployed. I
have given up counting the job applications and have had just three
interviews. Some of my rejection letters tell me how many applicants there
were: 400-600 are quite usual and one company apologised for the length of
time it took them to sort through over 1000.
After a year of feeling very unwanted and useless, I decided to set up my
own research project, not because I wanted a PhD, but simply to give myself
something to do, expand my skills and demonstrate to a potential employer
that I am hard-working, determined and can use my initiative. My idea was
accepted by Exeter University and I am now registered as a part-time MPhil
student. I have a couple of small grants towards the costs of field work,
but have no foreseeable way to pay off the bank loan which I took out to pay
the registration and bench fees.
Is this the way that a scientist’s career is now meant to begin – loans to
top up the pitiful student grant, then further debt to improve skills and
qualification just to stand a chance of getting a one-year contract (with
possible extension to three years, of course)? I am surprised that the
abandonment of science by graduates was considered newsworthy enough to
warrant an entire article (Careers, 27 March).
I shall keep on at my research and fill in yet more application forms. In
the meantime, if anyone out there needs a freshwater and marine biologist .
. .
Lisa Trevethick
Exeter
Letters: Sperms' rights
Feedback’s comment (1 May) on the new pro-lifers’ slogan ‘Everyone deserves
the right to be born’ (‘is that ‘everyone’ as in every egg?’) surely should
read ”everyone’ as in every sperm’. (See Monty Python’s The Meaning Of
Life).
Jonathan Cowie
Northumberland Heath, Kent
Letters: Son of Adelaide
Lawrence Bragg was Australian, not British as stated in Gunther Stent’s
article (‘DNA’s stroke of genius’, 24 April). He was born in Adelaide, and
educated at the University of Adelaide, where his father, William Henry
Bragg, pioneered x-ray research as Professor of Mathematics and
Experimental Physics. The Braggs moved to England in 1900.
Paul Davies
Adelaide
Letters: Tally of toys
Now is the time to raid your children’s toy cupboard in a good cause. The
British Crystallographic Association (BCA) wants to encourage children to
appreciate the principles of symmetry using ‘colouring books’ of patterns
built up on the principles of plane groups, or using 2-D or 3-D
‘construction kits’ which demonstrate ways to tile the plane, or building
space filling models. The BCA may also produce some simple microcomputer
programmes which encourage exploration of pattern design.
The BCA Council has asked me to report to them in November 1993, listing
available materials, and how they might be used.
I am asking your readers for help in this project. Please send me your
suggestions for suppliers and what projects the BCA might support. I would
be particularly pleased to hear from teachers, who may already be using such
materials in their courses. If any of you have contacts in other
countries, I would be interested to learn how they teach their children to
enjoy crystallography.
Kate Crennell
Rutherford Appleton Laboratory,
Chilton Didcot, Oxon OX11 0SE
Letters: Here and there
Feedback (1 May) does not seem to realise that over here, ‘outre Manche’
means ‘over there’.
J. Wright
Hove, Sussex
Letters: Quayle's potato
It is not without irony that, as the public becomes more concerned about
the loss of biodiversity, the ability of biologists to describe and study
biodiversity has been increasingly hindered by lack of funds. Many museums,
formerly bastions of systematics and taxonomy, are now apparently content
to devote their scarce resources to attracting and entertaining crowds in
the belief that numbers reflect success in science education. Taxonomy runs
the risk of becoming an endangered discipline.
Rather than bemoan the lack of public funds and the Disneyland tactics of
museum directors, it is time for taxonomists to privatise and raise their
own money by selling to the public the right to name new species.
Taxonomists have been naming species after people for years for nothing. Now
it is time to charge for it. For example, a member of the public, concerned
about rainforests, could send 拢50 to have a soil nematode
named after her. Framed on her wall, the page describing and naming her
species would be proof-positive ever after that she made a contribution to
biodiversity.
Dull and tedious individuals might object that few people will donate money
to have any animal, much less a soil nematode, named after them. With proper
marketing, anything is possible. For example, taxonomists should, as a
matter of urgency, name a rainforest bee after the rock singer Sting.
Madonna clearly needs a gynaecoid orchid named after her; Margaret
Thatcher, a bombardier beetle; and Dan Quayle, a species in the plant family
Solanaceae, which could then be properly known as Quayle’s potato.
Imagine the possibilities of celebrities posing with their beasties.
Bookings on the American Tonight show would follow. Appearances in People
magazine and the tabloids would be routine. Taxonomists, long the
wallflowers of cocktail parties, would soon find themselves surrounded by
beautiful people hoping against hope that the taxonomists would deign to
immortalise them with a species’s name.
The public would soon get into the act, naming parasitic wasps after stingy
ex-boyfriends; butterflies after lady friends; dung beetles after their
bosses; and, for the quietly ostentatious not content to follow the herd,
even soil nematodes after themselves. The rich could splurge for a genus
name or even a family. The prices for rarer new species such as mammals and
birds would naturally be higher, following the rules of supply and demand,
but bulk sales of more numerous and cheaper taxa would still ensure funding
for taxonomists.
It may not save biodiversity, but it is a start and museum directors just
don’t seem to have any better ideas.
David Cameron Duffy
Shelter Island Heights,
New York state
Letters: Flash with a hole
My attention has just been brought to the letters in the issues of 3 April
and 24 April concerning ‘blue flashes’. Some of us in the caving club here
at Loughborough have also seen the occurrence of crystalloluminescence, or
more probably triboluminescence, on some of our trips underground. The
following extract from the club newsletter The Mole (15 March) explains:
‘It was in this cave (Ogof Clogwyn, South Wales) too that David dished out
the Polo mints having told us to snap them close to our eyes. Lo and
behold, you see a flash of blue light (generally followed by hysterical
laughter).’
A considerable amount of discussion followed in an attempt to explain what
was happening, so Andrew Alexander and Gary Evans’s scientific
interpretation of our experience was particularly welcome.
Phil Naylor
Loughborough University
Letters: Select sex
‘Let’s not panic until there is some evidence.’ Thus Bernadette Modell of
University College Hospital in London reacts reassuringly to the plethora of
worries voiced in ‘The hidden cost of sex selection’ (1 May).
My experience supports Modell’s view. Thirty years of research into a
natural ‘traditional’ method of sex selection with a high success rate, and
thousands of letters from all over the world confirming it, lead me to agree
that preference for girls or boys would be perfectly balanced if all women
had the opportunity to choose the sex of their offspring.
Although preferring the element of surprise in their first-born, nearly all
women want and expect the full experience of motherhood which entails the
bearing and rearing of children of both sexes. They are frustrated and
offended by the indignity of not being able, with their own bodies, to
produce what they want. This discomfiture gives way to despair in societies
where antiquated systems of male heirship and female dowries still hold. The
final degradation strikes when a woman is blamed for a situation which is
often the man’s responsibility, owing to his sperm count.
I applaud the work of any organisation or individual that is trying to
change such societies. But many women cannot wait for such fundamental
change. They need help now. And sex selection is the way to give it.
I allow that, when sex selection becomes widespread, there will probably be
an initial world-wide swing towards boys because of present values. But
when, as is already reported from China, problems arise from the dearth of
women, that must be the first warning sign. When females become really
scarce, their value will increase. It will become apparent that, in a world
made up of two interdependent sexes, neither can do without the other in
equal proportions for the good of all.
Hazel Chesterman-Phillips
London
Letters: Select sex
Gail Vines implied that giving couples the opportunity to choose the sex of
the child could have serious social implications, particularly with regard
to the standing of women in society.
I would not wish to see any slide in the already low status of women.
However, any bias towards one sex or the other created by such selection
can only reflect existing prejudices in society; it cannot create new ones.
This article does nothing to challenge the existing climate of the moment,
where the progressive use of science and technology is rejected in favour of
leaving things to nature. Women’s equality will not be achieved by
restricting their ability to make choices. The suggestion that this
technology should not be made available because it would give parents ‘a
spurious sense of control over reproduction’ is not too far removed from the
arguments used by anti-abortionists that have done so much to damage the
cause of equality for women.
J. Burton
Liverpool
Letters: Turning tight
I would like to add to the article by Kerry Spackman and Sze Tan (‘When the
turning gets tough . . .’, 13 March).
My brother is a senior driver training instructor for the Australian Capital
Territory police and I have collaborated with him in the teaching of
elementary physics of vehicles to police officers. Speaking to the
instructors, who are all seasoned drivers, I found that they all
instinctively knew, by the seat of their pants, as it were, that the fastest
way through a corner was to brake deep and accelerate out. But they lacked
the mathematics and physics to be able to justify their knowledge.
In the process of revising their training manual we realised that travelling
on a constant radius curve at the limit of performance is extremely
dangerous. If, for some reason, one starts to slide in this situation there
is no way to recover control. For a start, the force due to static friction
of the tyres (before sliding) is greater than the kinetic friction (sliding)
so that once one starts to slide it is very difficult to stop. On a constant
radius curve, with neutral throttle, one has no way to remedy this
situation.
Consider, alternatively, accelerating out of a corner at the limit of
performance and the wheels starting to slide due to a combination of lateral
acceleration and forward acceleration. By reducing the throttle, the forward
acceleration can be reduced, allowing the tyres to handle more lateral
acceleration. In this way one can bring the car back into the performance
envelope and recover control.
So, the fastest way through a corner is also the safest. Peter Sobey
Giralang, Australia