Letters: Ravenous jaws
I was surprised and amused to read in a back issue of New 杏吧原创
(In Brief, 21 March) that cockroaches were a pest in the Palm House at Kew.
Living as I do in a 200-year-old cottage not far above the equator, cockroaches
swarmed the place for many years and actually bit me twice in my sleep,
once in my abdomen, once lower down. Each time I awoke with a scream, feeling
as though someone had plunged a red-hot needle in those sensitive parts,
my grasping hand coming away each time with a squashed cockroach. In a village
outside Madras where I lived for nearly 20 years, cockroaches were responsible
for gnawing dead skin from childrens’ toes, until the child woke with a
scream of pain when raw flesh was reached by those ravenous jaws. I could
continue a catalogue of their evil deeds that would fill a whole copy of
New 杏吧原创.
Then a planter in the hills of south India gave me an infallible formula
for destroying cockroaches, and I have never seen one in my home or office
since.
Take two heaped tablespoons of boric acid crystals (easily obtained
from any chemist), add four or five parts wheat flour and one part sugar
and mix into a light dough with milk. Form into little balls and drop wherever
cockroaches are thought to lurk, smear some also into cracks or crevices.
They can’t resist it and simply disappear, presumably to die outside.
Harry Miller Madras, India
Letters: Clever slant
Those figures made up from bits of the figure 8 which form the display
on my pocket calculator, for example, are a very clever invention by somebody.
But the question that keeps occurring to me is: why they slope to the right
instead of being upright? Perhaps the actual inventor might read this letter
and let us know why he/she made them slope.
Alec Vans Newnham, Gloucestershire
Letters: Floating feeling
I was dismayed to find basic misconceptions reinforced in ‘Making the
most of weightlessness’ (11 July).
The statement that ‘the influence of gravity on the orbiting craft will
be one hundred-thousandth (10 -5) of what it is on Earth’ at
an altitude of 515 kilometres is quite wrong. A simple calculation shows
that it will be 85.6 per cent of its value at the surface of the Earth.
Had the article left it at that I might have put it down to a rather dubious
oversimplification to save space, but the ‘explanatory’ box on the next
page compounds the error at length.
Freefall is not the same as weightlessness, although for many purposes
the effects are the same. To be truly weightless you must either have zero
mass or be in a gravitational field of zero strength, neither of which conditions
holds in a drop tower. Once your speed has increased to the point where
air resistance is equal to your weight you have reached your terminal velocity
and might as well be standing on the ground (until you hit it).
The worst error is the statement that ‘. . . the centrifugal force on
the craft counters the gravitational force . . .’ which is so wrong that
it is hard to know where to start. If the statement were true, there would
be no force on the craft, therefore nothing to keep it in orbit and it would
float aimlessly off into space. The correct explanation is that the only
force on the craft is its weight, caused by the gravitational field of the
Earth. This unbalanced force provides the centripetal force needed to cause
orbital motion. One final point. It is much more helpful to use units of
newtons per kilogram than metres per second per second for g as this keeps
the physics of the situation more clearly in mind.
The school where I teach science will continue to subscribe to your
invaluable magazine, but I will gleefully use the article in question as
a critical comprehension, and an example of the non-infallibility of the
printed word.
P. Mostyn Hemel Hempstead, Herts
Letters: Floating feeling
We do not have a sense of ‘weight’, a sense which tells us when we are
being pulled by gravity. We only perceive weight through the forces and
pressures that it causes between us and our surroundings, or within ourselves.
When I sit I am aware that I have weight only because I can feel the force
that the chair has to exert on me in order to oppose weight. I also have
a vague sensation of the force that my intestines exert to support my stomach
as it rests on top of them.
In freefall, in a lift say, I would accelerate uniformly under gravity
as would the lift. We would accelerate together, each under the influence
of a single force. There would be no force acting between me and the lift
and I would feel weightless. In addition, my stomach and my intestines would
be falling at the same acceleration and there would be no force between
them. So I would feel a lightening in the pit of my stomach as the vague
sensation of a force supporting it disappeared.
In orbit there is no centrifugal (outwards) force, only one centripetal
(inwards) force caused by gravity and acting on both spacecraft and contents.
Both objects thus fall towards the Earth but, because they are moving sideways
so fast and because the Earth is curved, they keep on missing it. Since
they are actually falling, there are no forces between contents and the
spacecraft, nor is there any extra force between different component atoms
of the contents trying to oppose gravity’s effects. The lack of a force
opposing weight leads to a feeling of weightlessness.
In summary, weightlessness and apparent weightlessness both feel like
falling, not like floating.
Matthew Munro London
Letters: Wrong side
My husband, having been painstakingly taught by me on how to locate
the radial pulse in the wrist, was more astute than me in recognising that
the illustration on the opening spread of ‘The Dutch way of death’ (20 June)
was incorrect.
‘Hey’, he said, with the enthusiasm of new-found knowledge, ‘They’re
feeling for the pulse on the wrong side of the wrist.’
He was right.
Margaret Curtis Aylesbury, Buckinghamshire
Letters: Naughty birds
Re ‘Faithless female seeks better genes . . .’ (4 July). Migratory birds
returning to their natal area to breed are probably in danger of pairing
with a sibling. Could the reason for promiscuity be to dilute the effect
of in-breeding?
Margaret Parslow Chester
Letters: Sperm competitors
In their article ‘Faithless female seeks better genes . . .’ Tim Birkhead
and Anders Moller credit Geoff Parker with coining the term ‘sperm competition’
in 1970. This honour should probably go to the Danish geneticist, O. Winge,
who studied sperm storage in the guppy fish in the 1920s and 1930s. In his
letter to Nature in 1937 he noted that ‘. . . there is competition between
the spermatozoa . . .’ with sperm from a new male outcompeting the sperm
stored in the female from a previous mating. In 1954, W. H. Hildemann and
E. D. Wagner explored this further in the guppy in a paper in The American
Naturalist entitled, ‘Intraspecific sperm competition in Lebistes reticulatus’.
Benoni Seghers University of Oxford
Letters: Bright Brits
Your editorial suggested that Britain’s universities are ‘jam-packed
full of bright ideas’ but that venture capitalists are too overworked and
lacking in understanding of science and technology to do much to help the
ideas escape the ivory towers.
It is true that there will never be enough capital to fund all the bright
ideas that seek funding. But this is very largely because most bright ideas
are just that – they are not the basis for an independent and successful
business. Where there is the germ of a real business, and a scientific entrepreneur
with the tenacity and ingenuity to make something of it, there is certainly
money to match it – and a hard core of increasingly experienced venture
capitalists willing to work as partners in the process. Don’t write off
the whole sector simply because we’ve learned some lessons and become more
discriminating – in the long run this should help, not hinder, the creation
of viable technology based businesses.
Carolyn Hayman Korda & Company London EC1
Letters: Second leg needed
Readers of Tam Dalyell’s Thistle Diary (30 May) may well have wondered
how, given the failure of the research councils to fund Frank Watt’s interdisciplinary
research, Frank nevertheless has been able to establish a scanning proton
microprobe (SPM) facility which leads the world in its field. Among other
successes, it so impressed scientists at the Louvre museum in Paris that
they now have one of their own (Technology, 4 July).
As a senior member of the Oxford Nuclear Physics Department in 1986
when the critical decision was taken, I know the answer: dual support was
still, just, alive. Although University Grants Committee research funds
for the department were being cut, it was agreed Frank Watt should approach
the Wellcome Trust for the cost of the 2 MeV proton accelerator he needed,
with the department underwriting the other costs – including salaries –
for his small group. There is no possible shadow of a doubt that were the
same decision faced today the department’s answer to Frank would be ‘No’.
The point missed by Tam Dalyell, and also by William Waldegrave as reported
in Thistle Diary (11 July), is that whatever improvements are made in the
operation of research council peer review, there will still be failures
of the kind which nearly stopped Frank Watt in 1986. The restoration of
a strong second leg of dual support, independent of the central research
council committee structure, putting funds at the disposal of local managements
able to judge ability and potential – especially for interdisciplinary,
speculative, or non-fashionable areas of research – is essential for the
vitality of British academic science.
Finally, your reporter should have noted that Oxford Microbeam, who
designed and built the high precision magnetic lenses at the heart of the
Louvre’s ‘arty accelerator’, are Frank Watt and his colleague Geoff Grime.
John Mulvey Save British Science Oxford
Letters: Bright Brits
Britain is far more successful at commercialising ideas than New 杏吧原创
gives credit for (Comment, 11 July).
Britain does have more than its fair share of bright ideas. But the
view that the output of the 5 per cent of British university R&D should
be a neat fit into Britain’s 4 per cent of world industry is an old-fashioned
one – the view that technology transfer is a ‘linear process’ has been discarded
by most observers. Rather, Britain’s world-class companies, be they Glaxo
or Rolls-Royce, scan the world for the technology they need. Equally, Britain’s
universities commercialise their technologies worldwide with those companies
best able to develop, produce and market them.
Britain has an excellent track record. In a recent US survey, just the
British Technology Group’s revenues from licensing British academic research
were greater than the total royalties from the US university and government
research institutions combined. Compared with continental Europe, BTG’s
experience is that British universities (through BTG or otherwise) commercialise
their research far better than most of their equivalents in, say, France,
Germany or Holland – which is why BTG is now working with a substantial
member of such institutes.
With respect to funding, there is capital available for good ideas,
well-thought-out business plans and people capable of implementing them.
If you doubt that, look at the recent stock market flotations – it was British
Biotechnology, the exciting (but still loss-making) biotechnology company
which was the most successful.
We in Britain can always do better. But do acknowledge success and do
not suggest that people just throw money at an area far more complex than
your leader suggests.
Ian Harvey British Technology Group London