ÐÓ°ÉÔ­´´

Letters : Good wood

Washington DC

The brief commentary on “shaky” engineering presents an interesting theory
about the performance of Japanese wood-frame homes during earthquakes (In Brief,
1 June, p 13). Unfortunately, the message conveyed is that homes built today are
more vulnerable to earthquakes than homes built 100 years ago. This is contrary
to numerous reports following the Kobe earthquake where both Japanese and
foreign investigation teams repeatedly found that newer wood-frame homes
performed well in comparison to older homes. In fact, we are not aware of any
reports of severe damage to newer wood-frame homes which utilise modern
techniques of framing and bracing.

The article incorrectly implies that Japanese home construction can be simply
categorised as those homes built more than a century ago and those homes built
using European building techniques. As in the United States, home construction
in Japan has evolved over time. Both experience and analysis has shown that
initial efforts to reinforce structurally deficient residential structures in
Japan were inadequate. Many homes built before the early 1980s used inadequate
bracing and connections to resist the seismic forces generated by the Kobe
earthquake. Most of the extensive damage, however, was observed in homes that
were more than 40 years old.

Newer homes with improved framing, bracing and connection techniques
performed well. Research and field experience have confirmed that properly
designed and constructed wood-frame structures can be expected to withstand
seismic events with little or no damage.

Letters : Sinister swirling

Godalming, Surrey

Having lived for many years on a hill overlooking Gatwick Airport, three
miles away as the plane flies, I became accustomed to the sinister sounds of
swirling air that would follow aircraft passing overhead— although
visitors walking in the garden would frequently express alarm (“Trails of
destruction”, 16 November, p 28).

The effects of these vortices on the ground may be more serious than that,
however. On a number of occasions, young trees in the garden or nearby woodland
would be inexplicably stripped of their upper branches. The only explanation
that I could identify was the effect of these vortices moving across the
ground.

Letters : No flies on iguanas

Via the Internet

Iguanas are obligate folivores, and in captivity should only be fed carefully
selected leaves and vegetables rather than your suggested diet of flies
(Feedback, 26 October, p 92). Thousands of captive iguanas die every year from
kidney disease, gout and other conditions caused by animal protein in the
diet.

Some books still misleadingly state that juvenile iguanas should be fed
crickets. This is not the case, although malnourished or otherwise sick iguanas
may attempt to eat them.

An excellent Website with further details is at http://www.sonic.
net/~melissk

Letters : Bending time

Langenbach, Germany

Commenting on the Old Greenwich Observatory’s millennium claims (Letters, 19
October, p 59), Johan Brink has actually missed something: parts of the islands
of Tonga as well as the Tchuktchen peninsula in Siberia and Wrangel Island, all
lying west of the International Date Line, are 13 hours ahead of Greenwich. Thus
the new millennium will not be 12 but 13 hours old when it arrives at
Greenwich.

What is more, the president of Kiribati has bent the International Date Line
around his island state so that one of the islands will be the first to greet
the new millennium. This would mean another hour of delay for Greenwich.

Letters : A load of . . .

Armidale, NSW, Australia

Feedback was right to be cynical about the “mouse balls” story (Feedback, 9
November). The piece quoted was circulating on IBM’s VNET as long ago as
1982—very shortly after the worldwide release of the first-generation IBM
PC.

At the time, I was a senior consulting systems engineer employed by IBM’s
European headquarters and assigned to IBM UK. The piece was typical of the
humour emanating from the field engineering division of IBM in the US.

It was superimposed upon a standard field engineering announcement template
and certainly looked the part. The distribution it received was so wide that,
within two weeks, an official denial was issued by the vice-president of field
engineering. This ordered the withdrawal of all copies of the piece from
circulation—but the horse had long since bolted. Like most urban myths, it
seems to have become immortal.

Letters : Turn off the lights

Guildford, Surrey

Gabrielle Walker presents an optimistic view of the prospects for a fine
astronomical spectacle next year (“Fireball from the deepfreeze”, 2 November, p
30). Let’s hope she’s right, for all the scientific reasons given.

But however splendid Comet Hale-Bopp becomes for those of us who know when
and where to look, the ordinary person in the street is unlikely to notice
anything at all. It is true that Comet Hyakutake last March “was visible even
through the glare of city lights”: members of the British Astronomical
Association, myself included, saw it on 27 March from the centre of Piccadilly
Circus. But it was hardly spectacular, and even from more sensible urban
locations the faint blur was hard to spot. This is in marked contrast to the
bright comet of 1957, Arend-Roland, which many readers will remember and which
could indeed be seen easily.

The difference, of course, is in the immense growth of misdirected and
over-bright illumination which has stolen the night sky from our towns, cities
and suburbs, at goodness knows what cost to the philosophical and aesthetic
development of our children’s minds. If the general public is to appreciate the
spectacle that Hale-Bopp may indeed present, this glare must—albeit
temporarily—be removed.

By March 1997 we will be able to judge if the comet is living up to
expectations. If it is, I propose that with due publicity, preparation and hype,
all public and advertising lighting in our cities, and, I hope, most domestic
lighting also, be turned off one cloud-free, moon-free night, even if for only
ten minutes, to enable every man, woman and child in the country to see and
marvel at the spectacle.

A society is built from shared memories. Let us take the opportunity next
spring to add this historic celestial visitor to the folklore of a
generation.

Letters : Guy's guilt

Chester

David Cursons suggests that Guy Fawkes may be responsible for as much
atmospheric sulphur pollution as Powergen or National Power (Letters, 16
November, p 60). The verdict must be not guilty. A single boiler in a
600-megawatt power station can consume fuel at a rate of around 4000 tonnes per
day and, in Britain, they rarely have equipment to control gaseous pollutants.
In some cases they burn coal with a sulphur content of over 3 per cent, compared
to 10 per cent for black powder. So, to equal the mass of sulphur belching from
the stack of just one power station boiler during 5 November we would need to
let off over ten million boxes of fireworks.

The would-be regicide might, however, be charged with one other offence
against the Clean Air Act. The smog that may form on 6 November is caused by
vast quantities of particulate matter released from bonfires. This is one
pollutant that coal-fired power stations do attempt to control.

Letters : Ground them

Bedworth, Warwickshire

For some years I have been worried about debris from satellites, expensively
thrust into orbit and then allowed to become a nuisance. Space litter is
potentially as bad as or worse than that down here on the Earth’s surface.

Now we have the utter irresponsibility of the Russian satellite launch,
complete with half a pound or so of plutonium, crashing to Earth or, rather,
into the sea. No other form of construction would be allowed to proceed in such
a hazardous manner. Already a faulty rocket in China has cost lives of people on
the ground.

There should be a total moratorium on further launches, whether into orbit or
to nearby planets, until proper fail-safe measures are available to ensure a
successful launch in the vast majority of cases and the safety of people on the
ground.

This includes ensuring that what has expensively been shoved into orbit stays
there unless and until, as in the case of a shuttle, it returns in one piece. It
would completely rule out carrying radioactive or poisonous elements, such as
plutonium. It is likely that this would involve doing far more construction or
assembly in orbit, rather than risking a whole series of experiments in one big
launch.

Primitive launch technology hardly better than V-2 rockets should be at an
end, and a more scientific and less hazardous method of space exploration
sought.

Letters : Ask the machine

Reading

Ramon Moliner’s “spark of consciousness” is another example of the vitalism
that still infests the pages of New ÐÓ°ÉÔ­´´ from time to time (Forum,
9 November, p 47). Moreover, the notion of a “transition from an amoeba-like
form to human” suggests that he believes in the upward-striving model of
evolution.

He distinguishes conscious from nonconscious entities on the grounds of
structure and chemistry. The reason why sophisticated robots do not exhibit much
sign of consciousness is that they are made of a relatively small number of
processors. But if an AI lab made a robot with massively parallel architecture
and something approaching 100 000 000 000 processors then we should not have to
speculate about whether it possessed the priceless gift of consciousness; we
could simply ask it. I do not see that the chemistry it is based on makes any
difference.

Since the structure of such a machine would be similar in complexity to the
human brain, I think we should reverse Moliner’s conclusion and regard machines
as potentially conscious until proved otherwise. Most people are nervous about
it not being proved otherwise, because that would knock humanity off its
pedestal.

Letters : Shaky argument

Glasgow

Tom Curtin of UK Nirex would do well to read one of Nirex’s own scientific
reports before he denies that Sellafield is an earthquake-prone site (Letters,
16 November, p 60). The Nirex Report on Seismological Database,
SA/95/003, May 1995, shows that it is very likely that several earthquakes of
local magnitude 4.7 or greater will occur in the area within the next 10 000
years. These magnitudes are among the largest experienced in Britain, for which
an independent nationwide catalogue has been published by Roger Musson of the
British Geological Survey (see the excellent Web pages at
http://www.gsrg.nmh.ac.uk for details).

Let us look at the facts. The Whitehaven earthquake of 11 August 1786 is
listed in the Nirex catalogue as magnitude 4.7, using a surface wave scale
derived from macroseismic intensity data. In Mussons’s catalogue it is estimated
as 5.0 (local magnitude). Its epicentre was only about 12 kilometres north of
the Sellafield potential radioactive waste repository zone, and the focus was at
a depth of between 5 and 15 kilometres.

Even more worrying is the report of the Rampside or Barrow earthquake of 15
February 1865, which was about 40 kilometres along the geological strike to the
south. Although of small magnitude (2.2 or 3.0, depending upon the method of
estimation), its focus was extremely shallow—probably less than 1
kilometre down—and it pumped some 100 000 cubic metres of water to the
surface. This is a very rare occurrence indeed in the historical records, and is
obviously of concern to those of us who wish Britain to select a radioactive
waste dump site which is supposed to be safe for at least 10 000 years.

As Stuart Haszeldine of Glasgow University showed in his evidence to the
inquiry, this event occurred within the same geological context as the proposed
dump site. Curtin is wide of the mark in his reference to geological faults. It
doesn’t matter that we cannot normally ascribe even shallow instrumentally
located earthquakes to specific faults—it is the dynamic geological regime
that matters.

Lastly, Nirex claims to have “rebutted” the scientific evidence presented by
the objectors at the recent planning inquiry (In Brief, 16 November, p 11), and
now published in a 520-page compilation by the University of Glasgow.

Rebutted it may be, but refuted it certainly was not. Any scientist
understands the crucial difference between these two verbs. Our book is intended
to widen the debate, and shows that promises made to the inquiry inspector about
further research work Nirex would undertake this year have already been broken.