Letters : Dope and deceit
Austin, Texas
Recent reporting about research on laboratory rats corroborating the
marijuana “gateway” theory, that smoking cannabis leads to a desire for harder
drugs, was carried as a major story by nearly every newspaper and news programme
in the US (This Week, 5 July, p 4).
By contrast, another marijuana study, also funded by the National Institute
on Drug Abuse (NIDA), garnered practically zero media coverage when it was
published in this April’s issue of the American Journal of Public
Health. The unpublicised report, entitled “Marijuana use and mortality”,
studied a sample population of 65 171 people (the largest such study ever done)
and found “little, if any” link between marijuana use and premature death.
The difference in coverage given to these two studies can be explained by the
NIDA’s disinclination to publicise science which doesn’t serve its political
agenda. Unfortunately, the mainstream media seem mostly content to play the role
of government stooge, dutifully regurgitating information which they have been
spoon-fed by agencies such as the NIDA.
The result is a media bias which deceives the public with lengthy stories
based on carefully manicured “lies by omission” while other viewpoints are
relegated to a few lines on the editorial page.
Letters : Cultured hunters
London
It is a common misconception that hunter-gatherers were culturally
impoverished compared with the early agriculturists (“Ancestral echoes”, 5 July,
p 32). However, it is now well known that many hunter-gatherer societies have an
extraordinarily rich culture鈥攁nd that their way of life is not necessarily
nasty, brutish and short.
In the barren environment of the Kalahari Desert, the present-day Bushmen
need only devote an average of two-and-a-half days’ work a week to obtaining
food, leaving plenty of time for leisure and cultural pursuits. They have many
sources of food at their disposal and nutritional standards are high.
By comparison, primitive agriculture is very hard work. Dependence on a few
staple crops reduces nutritional standards and exposes the population to
periodic famine. It is now thought that the prime motive for introducing farming
was not the comprehension of a stunning technological opportunity but simple
population pressure. Hardly a great leap forward.
Agriculture is perceived as an advance because farmers can produce more food
within a small area than they could possibly obtain as hunter-gatherers. This
surplus productivity, however, has its downside. It provides an opportunity for
rapid population growth and for the appropriation of food by a governing elite.
Farming introduced the concept of land ownership and thereby, ownership of the
product of other people’s labour.
The archaeology and literature of early agricultural societies reveals how
they gradually became more and more stratified, eventually adopting such
civilised customs as slavery, standing armies, mass warfare and authoritarian
state religions. Writing was introduced, not to allow communication of ideas and
further the expression of the human spirit, but first to administer the
distribution of goods and later to record the genocidal exploits of warriors and
kings.
A century or two ago, it would have been unthinkable to suggest that the
slave economies of the ancient world in which Western civilisation gradually
took shape were anything but vastly superior to the numerous hunter-gathering
“savages” whom the West felt free to exploit or exterminate in the colonies. One
would hope we had learnt enough by now to think again.
Letters : . . .
Manchester
Roger Lewin has omitted the Orkneys from his map illustrating the march of
agriculture in Neolithic Europe. Radiocarbon dates from the Orkneys are
consistently earlier than those from southern British sites. It was the first
area in the British Isles to cultivate and ritually process cereals. This ritual
processing and the necessary pottery manufacture then spread south.
Knap of Howar, on Papa Westray, is the earliest standing prehistoric domestic
site in Britain, with evidence of wheat and barley cultivation from between 3800
BC and 2800 BC.
Skara Brae (mid-3rd millennium BC), on the Orkney mainland, is also
associated with cereal cultivation and processing. We are currently
investigating prehistoric ritual cereal cultivation and its implications for the
spread of agriculture in Neolithic Britain. Early cereal cultivation is
associated with domestic and sacred sites, and with special pottery.
Letters : . . .
Towcester, Northamptonshire
I fear you may have proved Douglas Adams’s theory of how intelligent life
arrived on Earth to be correct.
The illustrations accompanying your article show that early Earthlings appear
to have immaculately groomed fingernails and toenails. The Golgafrinchan
manicurists and pedicurists abandoned here clearly had their work cut out.
Letters : Strange stance
Edinburgh
I am happy to accept that there is a risk (though tiny) of the transfer of
antibiotic resistance genes from genetically modified maize to the gut flora of
ruminants (Letters, 12 July, p 49).
However, I am constantly amazed that groups such as Greenpeace (for whom Ian
Taylor was speaking) spend so much effort in publicising this risk, when the
meat on sale in our supermarkets is obtained from animals which are
prophylactically fed antibiotics so that we pay a few pence less at the
checkout. This is unnecessary and is carried out purely for economic reasons.
The risk to animal and human health is surely far greater here.
Taylor argues that if the antibiotic resistance gene is transferred to the
guts of domestic animals then the efficacy of veterinary medicine could be
reduced. This seems to imply that he would rather see animals pumped full of
even more antibiotics, with a subsequently higher chance of selecting for
antibiotic-resistant strains of bacteria.
We should be far more concerned about the hidden ingredients on our
supermarket shelves that are a result of intensive farming methods and which we
as consumers have the ultimate power and responsibility to do something
about.
Letters : Worth the risk
Dundee
I was in general impressed by the tone and content of your editorial
concerning the safety of space flight (5 July, p 3), but I do feel constrained
to point out an error of arithmetic.
If “several hundred humans have followed Yuri Gagarin into space, and 11 have
died”, as the editorial states, then the death rate is not “at least 1 in 10”.
It is at most 1 in 20, and possibly considerably less, depending on exactly how
many hundred humans have been up.
Though this is still no small risk, the colonisation of America cost a great
many of the colonists their lives too, and few people think that those deaths
should have dissuaded later colonists from trying. I personally know a fair
number of people who would gladly take this kind of risk to colonise space.
Letters : People make you ill
Bournemouth, Hampshire
Your 28 June report on Sheldon Cohen’s work on resistance to colds (This
Week, p 5) does not give enough information to prove that a feel-good factor is
boosting the immunity of people with wide social circles. Their background
history of colds also needs to be known.
Assuming that they have had lots of friends for a long time, it could equally
be that these people have been exposed to so many colds during their lifetime
that they have developed immunities to a greater number of rhinoviruses than
people who lead more isolated lives.
This is indicated by the finding that it was the diversity of the social
contacts, rather than their actual number, that was important. This finding
would surely correlate well with the number of diseases of all sorts
encountered, but not necessarily with happiness.
Letters : Imported from Mars
Yellow Rock, New South Wales, Australia
In reading the article by Leonard David about how a future Mars mission might
manufacture fuel for the return journey to Earth (“Escape from Mars”, 28 June, p
24), I found myself wondering about the application of these processes to the
manufacture of fuel on Earth.
The feedstock for the processes consists essentially of water, carbon dioxide
and electricity. Both water and CO2 are plentiful on Earth. If the
electricity were to be generated using solar-voltaic or wind technologies, then
how efficiently could that energy be converted into easily transportable fuel
such as the methanol produced by the Mars fuel technology?
Letters : Model expert
Harlow, Essex
I think I should point out to Stephen Gloor (Letters, 5 July, p 53) that Mark
Drela is well known in model glider flying circles as something of an expert at
flying indoor hand-launched gliders, which operate at the extremely low Reynolds
numbers of 15 000 or thereabouts. He has held records for this. It is extremely
unlikely that he is unaware of Michael Selig’s work).
My initial reaction to the article (“Where aircraft fear to go”, 31 May, p
34) was similar to Gloor’s. However, on reflection I realised that Drela is
right; he is looking at a flight regime which combines very high subsonic speeds
with a Reynolds number of under 300 000, something that neither the Selig
group’s wind tunnel nor the Delft group can come near.
This point should have been given greater emphasis in the article. Only a
careful second reading uncovered the mention of shock waves forming on the upper
wing surface at the high point that indicates the speed regime. A future article
comparing Drela’s results with the findings from the Pathfinder flying wing,
which operates at the other end of the speed range, would be extremely
interesting.
Letters : Desperately seeking
by e-mail
If the indexing of all Web sites is not possible, why do search engines index
hundreds of thousands of adult sites (“Lost in cyberspace”, 28 June, p 12)?
Shouldn’t academic criteria take precedence over adult sites? I do not oppose
sex sites but I am sure that if search engines limited their sex site listings,
then some entrepreneur would establish a search engine that focused on those
sites.
If this happened, HotBot and Alta Vista users could use their search engines
more effectively, while anyone wishing to access adult material could use the
specialist search engine.
Letters : Matter of gravity
by e-mail
Feedback in the 14 June issue asks what product could carry a disclaimer that
promises many hazardous properties such as attracting all other objects in the
Universe, and causing a huge explosion if all the matter were converted to
energy. The answer, of course, is a can of baked beans, or any other product
that has mass.
This disclaimer first appeared some years ago (see Letters, 5 July, p 53).
Unfortunately, as in the game of Chinese whispers, where a message gets
corrupted after being passed on by too many people, one of the properties listed
by Feedback has been corrupted and applies to no product. In the original, the
force of attraction is inversely proportional, not to the distance between the
objects, but to the square of that distance.
Letters : Bite back
by e-mail
I was at the Bite Mark Breakfast which Feedback found so amusing (31 May). It
was actually a fairly serious gathering, but (for reasons that were never
explained to me while I was in training), forensic pathologists like cute titles
for macabre presentations.
Sex attackers often leave bite marks on their victims, and the question then
arises of whether the marks can be linked to a specific person. In addition,
deciding whether bite marks found on a dead body were made by an animal on the
corpse, or by a human while the body was still alive, can be a vexing problem
for pathologists.
Even though bite-mark comparisons are admissible evidence in most countries,
the scientific underpinnings for these comparisons are quite thin, though they
are more substantial for bite marks than for other areas, such as tool markings
and signature comparisons.
Letters : Shark treatment
Lowestoft, Suffolk
We were not surprised to read that shark tissues contain compounds that kill
microbes (Technology, 26 April, p 23).
At Lowestoft and Yarmouth fishermen must have been aware of this for years:
they packed sharks and rays among the rest of the catch to maintain its quality,
and they bound their wounds with dogfish skins (probably before 1928, when it
became compulsory to carry first-aid kits on fishing vessels).
Letters : You what?
London
John Casti, writing about Hao Wang’s book A Logical Journey, states:
“By now, almost everyone is familiar with G枚del’s work on incompleteness in
mathematics, as well as the possible implications of this work in areas such as
artificial intelligence” (Review, 5 July, p 46).
What an extraordinary claim! Are you familiar with it? Can you imagine going
out on the streets with a clipboard, stopping passers-by at random and asking
them whether they are familiar with G枚del’s work on incompleteness in
mathematics? I predict that in 99.999 per cent of cases the answer would be “You
what?”
Letters : Correct cuts
Taunton, Somerset
Thank you for much laughter in a not very funny world, but I must take you to
task for deriding the instructions on how to cut a cake that were on the cake’s
tin (Feedback, 7 June).
Some cakes are indeed cut in the same way as bread, with a sawing motion.
Others need to be cut by even pressure on an almost level knife blade.
One suspects that Feedback has never helped with the teas for an afternoon
charity do and, in particular, has never dissected a cream sponge.