Letters: Priceless picture
In none of your articles on the Moon was there any mention of the true
reason why the human race, expressing itself through the people of the US,
went to the Moon, what it had to get and indeed successfully brought back.
I am referring of course to That Photograph – the picture of our home, fragile
and beautiful, alone in space, that within a year of Apollo 11’s return
had appeared right across the world.
The magnitude of the impact of this picture on the mass consciousness
of our race cannot be exaggerated. The timing of its arrival at the height
of the Cold War, with Russia and America facing each other with thousands
of deadly nuclear missiles, was opportune to say the least.
You have to have lived through the 1960s, especially 1962, to appreciate
fully the reality of the paranoia and fear in people’s minds at that time.
1969 was years before Nixon’s and Brezhnev’s tentative ‘detente’ or any
whisper of the Strategic Arms Limitation Talks – indeed, the mass publication
of the picture may have played some part in bringing them about.
We had to go to the Moon to get the picture in the ‘frame’ so to speak;
Earth orbit is too close. There was no need to go back – we’ve got the Photo.
The very fact we haven’t been back there and that the Apollo programme
itself faded away shows that the spiritual need that was driving the whole
enterprise was satisfied. The photograph is beautiful and priceless and
is the true legacy and achievement of our first ‘step’ out into the Universe.
Stephen Val Baker Newton Abbot, Devon
Letters: Priceless picture
Extraordinary to read in ‘Return to the Moon’ that the Moon might be
a good place for an observatory. Inferior to all other places en route one
would think. A lunar observatory, like one on Earth, would always be blind
to half the sky, solar power would be cut off at least 14 days a month,
and the visitor’s return ticket would cost very much more than a shuttle
ride.
True, the Moon offers cheap raw materials such as aluminium, oxygen,
glass and so on, but won’t it be cheaper to catapult buckets of Moon rock
into space for smelting than to lower a smelting factory to the lunar surface?
A shield against Earthly electromagnetic radiation will cost no more than
a roll or two of cooking foil.
A planet’s surface may make a good nursery for simple life forms, but
for Homo sapiens space itself abounds with cheap energy (all-day solar power),
raw materials (Moon rock, asteroids, comets), transport (except to surfaces
of planets) and, well, space.
Mars and the Moon would seem such dumb places to live compared with
the great palaces, pleasure domes and universities we can construct in between
– just as soon as we learn to relax our mental preoccupation with the surface
of rocks.
John Worley Havant, Hampshire
Letters: Priceless picture
In ‘Tales the spacemen tell’, Andrew Chaikin claims 23 of the 24 lunar-bound
astronauts survive and that only one (Jack Swigert) has died. In fact, Ronald
E. Evans died on 6 April 1990 and James B. Irwin died on 8 August 1991,
leaving only 21.
Evans was the command module pilot on Apollo 17, and remained in orbit
around the Moon while Cernan and Schmitt explored the Taurus-Littrow landing
site. Irwin was the lunar module pilot on Apollo 15 who, with David R.
Scott, explored the Hadley-Apennine valley. Each man subsequently succumbed
to a heart attack.
It is interesting to observe that early Moon explorers had dangerously
imbalanced electrolyte levels due to dehydration and Irwin had a mild heart
attack during his mission. The medical casebooks provide fascinating and
alarming evidence of just how close we came to losing a man under these
circumstances.
David Baker Cambridge
Letters: Noise nuisance
Two important points arise from your article on wind farms (‘Can we
learn to love the wind?’, 16 July). First, for many, the most disturbing
emissions are not audible noises from mechanical gearboxes, but low-frequency
sound waves, mostly resulting from the blade friction against air. Although
it has long been appreciated that this infrasound is unrelated to and unaffected
by wind speed or direction, planners and developers have been slow to recognise
how serious can be the stress caused either by infrasound or audible noise.
Secondly, the methodology behind the ‘survey’ alleging to ‘have found
that about 80 per cent of those living near wind farms approve of them’
is questionable. To begin with, the ‘survey’ was undertaken eighteen months
before its publication, at a time when the public understood little of the
issues at stake.
Even so, voting in the parish of Llangwyryfon before development (December
1991) showed 71 favourable to the wind farm and 58 against it. After construction,
almost everyone living within about 2 kilometres and having no financial
interest, including some who had previously been favourable, are now against
the industry here. The main reason is noise, though blade distraction for
motorists, scepticism at claims of global usefulness and the cavalier attitude
of developer and contractor are also significant factors.
Stephen Briggs Llangwyryfon, Dyfed
Letters: Not so hip
Your article ‘Hipbone connected to the titanium implant’ (16 July) gives
an imbalanced report. Contrary to statements in the article, titanium certainly
does provoke an immune response. This occurs both locally as metallosis
and systemically as raised serum levels with activated T-lymphocytes.
This is of concern given the current controversy regarding the potential
carcinogenicity of such apparently inert metal alloys, which was not reported
in the article. Bone resorbing mediators have been associated with titanium
wear debris. Rate of production of wear products dramatically increases
with and contributes to loosening of the prosthesis.
The tribological (friction/wear) characteristics of titanium were not
adequately discussed. Titanium and its alloys wear five times as rapidly
as stainless steel, and cause vastly more wear of the polyethylene cup.
These characteristics alone make it hard to justify the use of titanium-bearing
surfaces in total join replacements.
Roger Hackney Nottingham
Letters: Soya and safety
The information on pancreatic cancer and raw soya flour in rodents
cited by K. G. Wormsley (Letters, 6 August) was published 10 years ago,
and further data since then has been obtained and extensively reviewed.
There is little epidemiological evidence to support a relationship between
soya consumption and incidence of pancreatic cancer in humans. For example,
age standardised truncated rates for Japanese populations are between 9.1
and 12.6 per 100 000 per year in males and 5.3 to 7.0 in females. This
compares with British rates of 7.3 to 12.2 in males and 5.2 to 8.8 in
females.
Protease inhibitors are under active research. Currently a soya bean
extract, called the Bowman-Birk trypsin inhibitor concentrate, has proved
to have anti-cancer activity in animal models and in in vitro systems. In
consideration of the possible effects of protease inhibitors, we have observed
no biological effects of preparations of soya protein that contained these
inhibitors, but not isoflavones, in our recent animal and human studies.
This included anti-cancer effects, and hormonal effects on the menstrual
cycle.
S. Bingham, K. Setchell, Aedin Cassidy Dunn Nutrition Centre Cambridge
Letters: That's the limit
In ‘The debate over the limits’ (2 July), Helen Saul gave considerable
space to the Danish study but made no reference to the critique of it by
A. G. Shaper. Saul asserts that as the Danish study found no significant
signs of alcoholic liver disease in those classed as ‘abstainers’, this
deals with the possible complication that some non-drinkers have given up
alcohol because they are already unhealthy.
In fact, this study found a slightly increased risk of alcoholic liver
disease in the men classed as abstainers despite this being only a small
group. Moreover, as Shaper points out, as no information is provided on
the health status or lifestyle behaviour of the abstainers, there is no
justification for simply attributing their excess mortality to a lack of
alcohol.
There is considerable evidence that nondrinkers and very occasional
drinkers tend to have a cluster of adverse health characteristics rendering
them vulnerable to coronary heart disease independently of their drinking
or nondrinking behaviour. Clearly, such a group is likely to be an inappropriate
reference group for estimating how much it is safe to drink. The estimate
that it may be safe to drink up to 42 drinks per week is, therefore, extremely
dubious, to say the least, especially as the adverse effects of alcohol
are hardly restricted to premature death, which is all the Danish researchers
took into account.
Similar considerations also apply to the American research cited by
Saul, which she states showed that drinkers had a lower risk of heart attack
than nondrinkers. In fact, in this study the comparison was not between
drinkers and nondrinkers but between regular drinkers and those consuming
less than one drink per month. It is true that the study appears to show
that ‘the regular drinkers were’ at substantially less risk of heart attacks.
But here again this is hardly surprising, as in comparison the occasional
drinkers were older, had the highest hypertension, the lowest level of physical
exercise, were more likely to be overweight, to have a history of diabetes
and a family history of heart disease.
Andrew McNeill The Institute of Alcohol Studies London
* * *
Helen Saul writes: The Danish research found that adults who drink
between one and six units of alcohol a week are least likely to die. Risk
of dying only rises significantly once people drink 42 units a week but
the authors did not suggest this is a safe level of drinking.
The American study controlled for compounding risk factors for heart
disease, but as the heaviest drinkers were also the heaviest smokers, this
made little difference to the results.
Neither the Danish nor the American study on its own would be conclusive
evidence that alcohol confers a protective effect, but both are consistent
with findings published over the past 15 years.
Letters: Under the sun
‘Sunny days for solar power’, (2 July) gave me a strong feeling of deja
vu. I happen to be reading A Golden Thread, 2500 years of Solar Architecture
by Ken Butti and John Perlin. They quote Frank Shuman, who wrote in about
1908 that throughout most of the tropical regions sun power will prove very
profitable. David Mill’s claims for the year 2000, which you quote, are
almost identical.
Butti and Perlin discuss Mouchot, who developed the solar dish in the
1870s and Ericson, who developed the parabolic trough in 1884. Most of
the technical and engineering problems you discuss were resolved in the
early years of this century.
For example, there is only a problem of having temperatures high enough
for superheated steam (Ericson was aiming for 1000 F to make solar power
commercially viable), if inappropriate engineering solutions, like using
conventional steam engines, are used. The early solar engineers soon realised
it was better to design engines able to run efficiently at lower operating
temperatures.
Such devices would not have to follow direct sunshine, but would work
in haze and cloudy conditions. Ammonia hydrate and sulphur dioxide were
found to be far superior to water by Charles Tellier, the father of refrigeration.
The development of refrigeration and solar power occurred together. Tellier
published a book, The Peaceful Conquest of Africa by the Sun, in 1890.
It is obvious rationally that the long-term goal is the integration
of appropriate technologies in a sustainable future and that this smelly,
dirty period of history of the last two hundred years is the aberration.
Clive Durdle Ilford, Essex
Letters: Warp pollution
I too think that publishing an article on ‘warp drives’ is a courageous
move (New 杏吧原创, Science, 11 June), but I find Peter Grove’s letter
‘Warped’ (Letters, 9 July) fascinating in its consideration of ‘space-time
pollution’ caused by the contraction and expansion of space-time.
I cannot say what future environmentalists would make of the ‘Alcubierre
drive’, but I thought that it might be worth bringing Star Trek back to
the argument.
I am sure your readers will be intrigued to know that a recent episode
of Star Trek: The Next Generation, entitled ‘Force of Nature’, involves
the discovery by some alien scientists that use of warp drives is wearing
out the fabric of the space-time continuum.
Needless to say, the Enterprise is soon involved and the Federation
looks as if it might need to review its eco-policy.
Life imitates art – does art imitate New 杏吧原创? Highly illogical,
no doubt.
Daniel Wright Hastings, East Sussex
Letters: Warp pollution
Frank Everest has a fine memory (Letters, 9 July). In my novel Bill,
the Galactic Hero I did invent a faster-than-light drive some years before
Star Trek existed. I wanted to parody all the nonsensical science-fictional
FTL drives, so created one – I thought – that would be even more fantastic.
When the drive was turned on the binding energy in the molecules of
the spaceship was weakened. This allowed the vehicle to swell enormously
and, like a stretched rubber band, the front end moved out to its distant
destination. Then, when the drive – the rubber band – was relaxed at the
starting point, it shrunk back to its original size. And lo! the ship was
at its destination. I called this the Bloater Drive.
Harry Harrison Dublin, Ireland