Estimating oil
Your correspondent John Feather is right to say that there have been many
mistakes about estimating oil resources in the past
(7 August, p 52).
However, geologists have become far more sophisticated in recent decades. The key to
energy prediction is the amount of energy that has to be put in, in order to get
a unit of energy out. The significance of the ratio becoming 1 to 1 hardly needs
to be spelt out.
Thus Colin Campbell, who predicts that oil is running out, is not simply “one
geologist”. His judgment is in the mainstream of geological thinking.
Water sport
Feedback asks, “How did a new type of meat-eating dinosaur . . . come to be
named Urinator montanus?”
(24 July)
and points out that the loon was once also known as “Urinator”.
“Urinator” means “diver”. This is probably the connection with the loon,
which is remarkable for the way it disappears into the water and reappears at an
unexpected point far away. See www.wordsmith.org/awad/archives/0697 for more on
this.
Bump and boinng
Jules Older coined the term “boinng” for sexual infatuation, according to
your correspondent Pat Williams
(21 August, p 52).
However, the etymology of “boinng” may predate its attribution to the
Otago University Medical School in New Zealand.
“Boinng” as a state of arousal first appeared in a 1960s Peter Sellers
movie鈥擨 am not sure which. Sellers, who was inspecting a nudist colony in
the company of an equally bare female co-star, held a guitar in front of him to
save his modesty. When his naked companion complained “I’m getting
cold鈥攆eel my goose bumps”, a “boinng” sprang from the guitar. The sound
thus derived not from a bedspring, as your cartoon suggested, but from a guitar
string.
Not so hot
I just had to comment on your short article describing the leakage of 20
tonnes of radioactive water from the Tsuruga power station
(24 July, p 25).
The figure of 46 000 becquerels in 20 tonnes of water sounds similar to the normal
concentration of radioactivity I would expect in ordinary groundwater in some
regions of Cornwall or Scotland.
The British “standard man” as defined by the National Radiological Protection
Board contains 4166 becquerels of natural potassium-40. This is about a tenth of
the radioactivity you reported had leaked from the Japanese reactor. I reckon
there would be more radioactivity in the team of safety workers cleaning up the
spillage than there was in the spillage itself.
Hairy theory
The 7 August Editorial
(p 3)
said: “It is both a weakness and a strength of
evolutionary theories that they can explain almost anything: testing the
theories is a lot more difficult”. I was therefore doubly amazed by the Opinion Point
(p 47)
in the same issue in which Terence Kealey proffered an array of
theories, for example that ancestral use of body paint and hairstyles as sexual
displays can explain our evolutionary lack of body hair and yet an abundance of
head hair.
Where was even passing reference to well-documented evolutionary principles
such as the likelihood that many genetic attributes have absolutely no advantage
or disadvantage but, due to chromosomal positioning, are associated with other
more valuable genes?
Perhaps overly hairy ancestors were selected against if their bodies
overheated while wearing or carrying their animal-hide coverings? I could go on,
and I’m sure your readers could provide an avalanche of “ideas” off the top of
their hirsute noggins to equal those in the article.
Fear of flying
Andrew Weir claims that the most appropriate comparison of air safety to car
safety is on a per-trip basis
(7 August, p 42).
While he could have a point that
most air fatalities occur near takeoffs and landings, of which there are one
each per flight, car accidents are nowhere near as concentrated on parking the
car. A thousand-mile car trip is quite likely a thousand times as dangerous as a
one-mile car trip, even if the same is not true for the corresponding air
trips.
In a real-life situation, someone contemplating the mode of travel to use in
going from New York City to Chicago would be ill advised to base their choice
solely on the fact that the average airline trip is 12 times as dangerous as the
average automobile trip, considering the considerably shorter length of the
average automobile trip.
While a per-mile basis might be biased against auto travel, a per-trip basis
is biased against air travel.
Letter
I have to endorse Weir’s opinion. One gets an idea of the degree of danger of
flying simply from the presence of insurance companies doing business in
airports. If flying was safe, they wouldn’t be there in the first place. You
don’t find the same companies in train stations.
And indeed, they charge a nominal fee per trip, regardless of the distance
flown. Despite this, I remain a very frequent flyer, due to professional
commitments.
Island isolation
The article about Gough Island
(31 July, p 21)
wrongly implies that Britain
is not fulfiling its obligations under the World Heritage Convention.
Gough’s isolation is one reason for its acceptance as a World Heritage Site.
It is 368 kilometres from Tristan da Cunha, the world’s remotest inhabited
island. Nevertheless we can reach it and do so regularly.
An environmental inspector appointed under the Gough Island Wildlife Reserve
Management Plan visits yearly. Furthermore, an agreement between the governments
of Britain and South Africa provides for the Tristan da Cunha administrator and
the chief islander to be conveyed annually to inspect conditions and ensure that
the management plan is rigorously implemented.
Citing UNESCO’s requirement for “continuous monitoring” is misleading.
UNESCO’s letter refers to the fishing operations and not continuous monitoring
of the waters around Gough. A fisheries management plan gives the Tristanian
authorities complete control over their sustainable fishing policies. The
provision of a patrol vessel under this plan was unconnected to Gough’s World
Heritage designation. Distance and weather prevent this vessel patrolling
Gough’s waters from Tristan, hence the condition that all licensed fishing
vessels at Gough must take an observer (a member of Tristan’s conservation
department) with them. They are not, therefore, “hitching a ride”.
I did not say that Gough was “invaded by industrial fishing vessels”, nor
that I approached the government for radar surveillance equipment鈥攎erely
that the cost was prohibitive. Surprising, therefore, that the article did not
mention the forthcoming establishment of the South East Atlantic Fisheries
Organization, which will enable fishing vessels around Gough to be monitored by
satellite.
We apply strict rules to protect Gough’s unique environment and to imply that
we do not is simply wrong.
Risky trials
Philip Cohen raises many pertinent issues with regard to the ethical conduct
of clinical research in humans
(7 August, p 18).
Placebo surgery is an extreme
example at one end of the spectrum of exposure to risk for subjects in
randomised controlled trials. The focus of Cohen’s article was on the risk of
placebo surgery to the control group. However, it must be noted that the
subjects in the treatment group who are getting the experimental surgery are at
equal (if not greater) risk from surgery that may in time prove to be
ineffective.
It should also be noted that placebo surgery is not only necessary to allow
for the placebo effect, but also ensures that control subjects are treated in
exactly the same manner as treatment subjects (apart from the intervention).
This ensures that any bias on the part of doctors, nurses and relatives after
surgery is virtually eliminated.
In all areas of clinical research, the risks involved need to be considered
with regard to the overall burden of the disease to individuals and society.
Where the burden is great and the potential benefit large, it is then up to the
individual to decide whether or not to take part in the trial.
No apocalypse
Early humans teetering on the brink of extinction, perhaps due to genocidal
overkill, is a gripping fin de millennium image. Unfortunately, there are plenty
of other ways to explain why the diversity of human mitochondrial DNA is low
compared to that of chimps and gorillas
(14 August, p 32).
A recent selective sweep is one answer, in which a new DNA molecule with some
selective advantage replaced all others in the population. Another is simply
chance. Studies on other parts of the genome, such as the Y chromosome, will
help to resolve this issue.
Even if a common population bottleneck is indicated for all genes, this need
not mean these were the only humans alive at the time. All it means is that any
other humans were replaced without contributing to the gene pool when our
ancestors, possessing perhaps some cultural innovation, multiplied. Genocide?
Possibly, although competitive exclusion is an alternative explanation. Either
way, the low diversity of our mitochondrial DNA may indicate too much success
rather than near failure.
Salty summer
According to Fred Pearce, winter freezes in the North Atlantic increase the
salinity of the remaining water (since ice does not capture salt) and thus
contribute to the power of the “pump” which is driving the Atlantic currents
(24 July, p 6).
But if this process were of any significance, melting of the ice cover in
summer would have the opposite effect and one should expect seasonal variations
in the strength of the Gulf Stream. To my knowledge such variations have not
been observed.