M枚bius like
Ben Sewell wasn’t looking hard enough for his one-sided paper
(Feedback, 6 January).
All he had to do was find a long piece of two-sided paper, twist one
end by 180 degrees and join the two ends together.
Correction
The temperature figure in Ross Firestone’s answer to the “Hot iron” question
(Last Word, 6 January)
is in degrees Farenheit, not Celsius.
Radio farm
I see that cows will be “fenced in” by a tingling electric shock in their
nostrils if they stray too far from a central mast
(6 January, p 7).
I have a vision of vandals chopping down the mast in order to watch the poor
things running all over the place in search of relief from the pain in their
noses. If this happened, a rustler with a portable radio transmitter could then
lead the cows away over the fenceless fields, rather like the Pied Piper.
And if it works on cows, why not use the system on toddlers to stop them
wandering too far from their parents, or crying too loudly?
Sex on eight legs
Your article describing the sex pheromone of the wandering spider failed to
acknowledge that I and my colleagues in Vienna initiated the project and managed
the complex biological experiments on spiders that made it possible to trace the pheromone
(6 January, p 6).
And I named the pheromone “cupilure”, not Stefan Schulz as stated in the article.
It may also interest your readers to know that this is the first sex
pheromone which is known to be tasted rather than smelt. To find his mate, the
male spider “tastes” the drag-line attached pheromone with his pedipalps鈥攁
pair of leg-like appendages attached to his head. If other spiders also have a
close-range attracting sex pheromone that acts only by contact, it might rule
out the possibility of catching them with pheromone traps, as proposed in the
story.
For any readers wanting more information on this fascinating project, my full
account of the biology will appear in a forthcoming edition of the Journal
of Comparative Physiology.
Letter
Seed claims renewable energy is unreliable and suitable only for local and
trivial use. Tell that to the Danes, whose offshore wind farms are big business
and will produce 13 per cent of their power this year. Or to Iceland, where
geothermal power is helping wean the country off fossil fuels completely. These
are the forward-thinking countries.
Seed has a strange view of what constitutes renewable energy. Biofuel is
certainly not trivial, accounting for 13.8 per cent of the world’s energy
consumption, and much of it is sustainable as it uses crop wastes, animal wastes
or wood products.
What’s more, 160 times the amount of energy stored in the world’s known
reserves of fossil fuels falls on the Earth in the form of solar energy every
year. The wind harbours twice the world’s proven fossil-fuel energy
reserves.
Granted, not all the energy potentially available to us can be tapped. But
Seed, with his oil-company and nuclear-energy mindset, doesn’t even want to
try.
Off the rails
Your Christmas edition brought the usual joy and wonderment. I was intrigued
by the article about drinking in space
(23/30 December 2000, p 46). It’s a great
comfort to know that future space travellers can enjoy a beer. But surely a
hobby would be needed to while away the hours? Thus, my one concern about
lengthy space travel is how I would run my model railway. How could I keep the
rolling stock on the track in zero gravity?
Finding the energy
A frequent disincentive for using wind and solar energy is its high cost,
something which Leslie Seed fails to mention in his otherwise perceptive letter
(23/30 December 2000, p 81).
Despite many years of development, with regular
promises of breakthroughs, the cost of “renewable energy” is still unacceptable
to most people.
Electricity consumers in New South Wales can opt to have their supplies
generated from “pure energy” (sun, wind, water and landfill gas), but staff at
EnergyAustralia say that fewer than 1 per cent are prepared to pay extra to do
so. Even if they were, solar energy and wind farms could not produce more than
about 30 per cent of our electricity, and in practice are unlikely ever to
produce more than 10 per cent.
For most of the world’s electricity requirements, the only alternative to
fossil fuel is uranium. And since the world goes on demanding more electricity,
this will either mean a big swing towards nuclear power or more
greenhouse-gas emissions.
Letter
Seed is clearly rooted in the past century. There are now so many alternative
energy sources that it’s impossible to list them all. However, here are a few
general directions worth looking at:
Some unconventional but interesting possibilities also exist, such as:
This last category is true fringe science, yet the most intriguing of all the
possibilities.
To gently glide
One thing your article “Walk like a pendulum”
(13 January, p 38) doesn’t say
is that there is a way that most of us can greatly increase the efficiency of
our walking, without having to carry a big load, either on our heads or anywhere
else.
Anyone who learns the Alexander technique acquires a much easier and more
efficient mode of walking. In fact, it’s not so much a matter of learning a
truly new and, perhaps, freaky method, but rather of unlearning the habits of
body misuse which we accumulate during our lives. The illustrations of the
walking figure in the article beautifully displayed the inefficient and
distorted way of walking (and the distorted spinal alignment, which is part of
the problem) that we learn as we grow up.
The Alexander technique allows us to unlearn all that misuse and inefficiency
and reclaim the looseness, balance and poise that we had as young children. It
certainly transformed my own walking (I’m a keen hiker on mountains and
wilderness), and I’ve found that even walking up steep mountain slopes has
become an experience of gently gliding up rather than stressfully hauling myself
up step by step.
Anyone out there?
So much energy is being spent on trying to detect messages from intelligent aliens
(“Bright encounter”, 6 January, p 30), but are we doing anything in
return? The SETI programme scans at 1.5 gigahertz, the radio frequency emitted
by hydrogen, and is also trying laser detection, but is it sending any messages
of its own by these methods?
In everything that I have read and heard about the SETI programme, it seems
as though participants listen, but never talk. Surely any alien civilisation
that is trying to communicate with us in this way would also be expecting to
find information on this channel.
Stand your ground
One would not doubt the stress that being hunted to death causes any animal
(6 January, p 38).
In the current debate on animal cruelty one major point is
being missed: what of the thousands of animals reared on intensive farms and
then transported, often for days, to a cruel death? They are not the subjects of
any loud debate, and since there are far more of them and their suffering lasts
a lot longer, should they not take precedence as objects of pity and
discussion?
Could it be that animal rights are not the real reason behind the anti-hunt
protests? After all, many people consider cheap meat to be a good thing. And
hunting is only for a small number of rich people and not for the common people,
who are allowed to inflict cruelty on innocent animals by demanding that their
meat be cheap.
Defending Einstein
It is one thing to criticise specific aspects of Einstein’s behaviour to
Mileva Maric, his first wife. But Marcus Chown goes too far in his review of
Dennis Overbye’s Einstein in Love
(16 December 2000, p 52) when he says
that “he dehumanised her so he could treat her appallingly without guilt”. It’s
a tendentious verdict on a relationship to which he was not privy.
Chown strongly suggests that Einstein was largely to blame for Maric being
“plunged into the deepest shadow as her dreams withered and died”. This
overlooks the fact that her failure in her final examinations at Zurich
Polytechnic cannot in any way be blamed on Einstein. But Chown obviously prefers
a simplistic story of victim and villain to the complexities of the
personalities and events to which he pays lip service in his final
paragraph.
Blame game
Tam Dalyell appears to be advocating that victims should take more
responsibility for the crimes carried out against them
(Westminster Diary, 6 January, p 43).
The prime reason that cyclists need to consider wearing helmets is other
people’s poor driving. Compulsory wearing of helmets will not deal with the
problem. The real difficulty is making motoring safe for everyone鈥攃yclists
and pedestrians as well as motorists. This is why compulsory wearing of seat
belts is a sensible law, because it applies to the people who are the cause of
problems鈥攖he drivers. Cyclists are already the victims of motorists, so
let’s not victimise them further. Before long we’ll be advocating compulsory
body armour for pedestrians.
Stay at home
In your editorial “Space Odyssey”
(23/30 December 2000, p 3) you seem to
imply that some sort of solution to Earth’s problems can be found by colonising
space. What nonsense!
While it may be becoming technically possible to establish a colony in space,
the only justification for doing so would be to benefit us on Earth. The notion
that large-scale migrations might occur is mere wishful thinking. And the idea
that such migrations could provide any “solution” to the problems we face is
utterly unrealistic. We are an Earth-bound species and should be used to that
fact.
Until fairly recently (before our species came to dominate the entire globe)
we were free to destroy the environment in one locality and then move on to
another. This “frontier mentality” is apparent in your article. We now have to
alter our thinking, because Earth has no more frontiers for us on dry land. We
can no longer move on to fresh pastures. To prolong the frontier mentality by
discussing ideas of colonising space is to indulge in outmoded, rear-vision
thinking.
Despite what you say, our only future lies “here on this overcrowded planet”.
The real challenge to humankind lies in accepting this simple fact.
What happened to the depleted uranium?
Current concern over the possible effect of depleted uranium
(13 January, p 5)
on friendly troops in battlefield situations raises questions about those
unfortunate firefighters called in to deal with the crash last year of a Korean
Air Boeing 747 at London’s Stansted Airport.
We were told that some of the aircraft’s several hundred kilograms of DU
ballast were spread over the countryside around the area of impact. At one time
it was reported that 8 of the 20 units of DU built into the aircraft’s tail were
missing.
The interval since that event seems to be about the same as the time taken
for the cases of leukaemia to emerge among some of the troops who served in
Kosovo. Could these unfortunate firefighters now be acting as unwitting subjects
in the debate over the safety of DU?
Quite apart from any health risks from exposure to fumes from burning, we
have never been told whether the eight missing units were recovered.
Letter
Until recently, A-10 tank-buster aircraft such as the one shown in your 13
January issue (p 5), were extremely active over Salisbury Plain. Local people
became all too familiar with their appearance and the sound of their short
bursts of fire.
If these aircraft were firing depleted uranium (DU) ammunition, the uranium
oxide formed on impact will find its way into the soil, form a soluble salt and
end up in the water supplies of southern England.
I and others have sought assurances from the Ministry of Defence that DU
ammunition was not used on the plain, but none has been forthcoming.