Letter
How does the Cheshire Cat disappear leaving only its grin? Slowly, wasn’t it,
and starting at the tail? Perhaps this question is in the great smart-arse
tradition exemplified by the famous (possibly apocryphal) question in the old
Oxford entrance exam one year, “Is this a question?”, to which the
scholarship-earning reply was, “If this is an answer.”
Emotional rescue
Commenting on the demise of the contraceptive Norplant, Frank Furedi claims
it is unwise to reject technologies solely on the strength of the emotional testimonies of “victims”
(Opinion, 3 July, p 50). Has Mr Furedi ever been
married to someone with a Norplant implant?
When my wife had Norplant fitted, she began to have massive mood swings.
Trustingly (stupidly), we did not connect this with the implant at first. I was
never sure if I was going to get a carving knife in my back. After several
months and many episodes, which included my wife kicking in a door, I realised
that the aggressive, erratic behaviour was caused by the sporadic release of
large amounts of progestogen. We arranged for the implant to be removed and
immediately life returned to normal.
Our problems with Norplant cannot be blamed on side effects, lack of
explanation or failings of the healthcare system. Norplant is not “fit and
forget”鈥攊t was fit and run for your life. We knew about the Norplant
Action Group but we were just glad to be rid of it. I had the doors replaced at
my own expense.
Light as air
The late Eric Laithwaite, who invented the linear induction motor, was also
interested in why some butterfly wings have iridescent colours
(“Sheer brilliance”, 26 June, p 34).
Several years ago, when I was working in research
as a materials scientist, he and I collaborated on an investigation using
scanning electron microscopy.
The wings of all butterflies and moths are covered with scales that have
etched surface structures. In some species, these structures cause diffraction
of light. In our investigation, we concluded that the diffraction is a
by-product of a development that helps butterflies fly.
To produce the familiar flutter, a butterfly has to close its wings above its
body, then rapidly open them. The problem is that a partial vacuum is created
between the closed wings, so great force is required to separate them against
air pressure. The scales assist via an unusual mechanism. Each scale is hinged
to the wing at one edge. When the wings start to open, the scales swing out to
release trapped air into the void, which reduces the vacuum.
From looking at the wings of several species of butterflies and moths, we
concluded that this trapping and releasing of air is strongly influenced by the
etched surface structures of the scales.
Pete Vukusic may be right to claim that Morpho butterflies have
developed their scales for visual purposes. But Laithwaite and I concluded that
butterflies evolved scales that diffract light to help them in flight.
War of words
Robert Proctor is correct in thinking that few people know much about the
public health measures of Hitler’s physicians
(Opinion, 19 June, p 48), but he
is wrong to imply that scientists have been ignorant of the medical research of
the period. Opinions may differ about its quality and the conclusions that could
be drawn from it, but it is just plain wrong to say that “Richard Doll . . .
knew nothing of the Schairer and Sch枚niger article until he [Proctor] sent
him a copy in 1997″. I published its findings in an article on the causes of
lung cancer in Advances in Cancer Research, vol 3, p 9 in 1955 and have
invariably referred to it in appropriate circumstances ever since.
Letter
Despite being a refugee from German fascism, I am appalled at the West’s
continuing moral indignation towards all German science under the Hitler regime.
Some German scientists, such as nuclear physicists, actively resisted
participating in the development of weapons; others simply worked in areas not
greatly affected by ideology. Who knows how some of those who now profess moral
indignation would have behaved under a fascist regime?
Day after day we hear revelations about wartime tests on human guinea pigs by
“our” side. In Australia, this included vaccine tests and phosgene experiments
that permanently destroyed the health of subjects who either volunteered in
ignorance or were conscripted. The phosgene tests revealed nothing that hadn’t
been known since the First World War.
At the time of the Auschwitz exterminations, the “virtuous” Allies were
working on nuclear weapons and experimenting with firestorms in Dresden and
elsewhere. At present, about half the world’s scientists are employed on
war-related science and technology, while others are standing by as science is
subverted to the dubious purposes of multinationals. Meanwhile, universities are
crawling through the moral mire to attract sponsorship from such
organisations.
Perfectly matched
Guillermo Gonzalez’s theory linking the size of the Moon with intelligent
life and the apparent rarity of extra-terrestrials
(This Week, 19 June, p 18)
sounds very much like an idea of Jerome Pearson, which appeared in the 25 August
1988 issue of New 杏吧原创 (“The lonely life of a double planet”, p 38).
Eleven years ago, Pearson pointed out that the unusual characteristics of
the Earth (tides, low spin, high magnetic field and molten core) are necessary
for life, and are due to the presence of a large, nearby Moon.
Pearson suggests that double planet systems like the Earth-Moon pair are
rare, but likely to harbour life. Consequently, the number of intelligent,
space-faring civilisations is likely to be very low. Also, astronomer Neil
Comins’s 1993 book, What if the Moon didn’t exist? contains two
interesting chapters about the biological and physical consequences of having
the Moon closer to Earth, or no Moon at all.
Radio silence
Robin Somes asks what effects radio-frequency signals will have on magnetic
storage media, given that mobile phones cause buzzes on tape recordings.
(Letters, 3 July, p 56)
Fortunately, the answer is “not much”, since the radio
waves are not recording noises directly onto the tape but are simply being
picked up by the audio circuitry and producing interference. This is duly
recorded onto the tape by the recording circuitry.
Sting in the tale
I was interested in Feedback’s observation of the stinging sensation created
when fizzy drinks are burped through the nose
(26 June).
I used to work in carbon dioxide applications for British Oxygen Company (BOC) Gases where the gas
was classified in the safety literature as asphyxiate/toxic. One of the telltale
signs of a CO2 leakage was a stinging sensation in the nose. I think
that this would occur at concentrations above 15 per cent CO2 due to
carbonic acid formation on the mucous membranes of the nose. Perhaps others in
the gases industry could confirm this?
Should fizzy drinks carry warnings against breathing in too soon after
burping to prevent CO2 poisoning, and a strong hint to burp only in a
well-ventilated space?
Tiger tiger
Tam Dalyell comments gloomily on the future of Indian tigers
(Westminster Diary, 19 June, p 57).
No doubt the ideal solution would be for people in the
Far East to abandon historical beliefs in the value of tigers’ bones as
effective medicines, thus reducing the demand which makes poaching profitable.
However, since this is likely to follow, rather than precede, the extermination
of wild tigers I have an alternative suggestion, designed to fit in with the
modern enthusiasm for free-market policies.
Tigers are bred readily in zoos and wildlife parks, so if we were to farm
them the Chinese and other medicine markets could be flooded with tiger products
on a scale sufficient to drive down their price, so hunting wild tigers would no
longer have the same attraction for poachers. The proposal would also give the
impoverished British livestock industry an additional source of sales.
One drawback is the high “yuck” factor which will be felt by anyone to the
left of the Adam Smith Institute. However, I suggest that this is a smaller yuck
than the one we will feel upon the death of the last wild tiger.
All smiles
Feedback was perplexed over a General Studies school examination question
which asked the examinee to explain how Lewis Carroll’s Cheshire Cat could
disappear leaving only his grin
(26 June).
Questions relating to the thoughts of
a polymath such as Carroll seem eminently suitable for a General Studies paper,
but I fear that you are barking up the wrong tree if you expect physics to
explain this phenomenon. I was once told that Carroll suffered from migraines
and that the Cat’s disappearance was a representation of his progressive loss of
vision during such an attack.
Letter
The answer lies not in the science of invisibility but the art of masonry.
Christ Church, Oxford is said to be a major source of Lewis Carroll’s
inspiration. This church, like others, has gargoyles on its roof. As you move
towards the building the gargoyle’s face slowly disappears leaving only the grin
in view.
Lost time
So, the Universe is 3.7 days old is it (“Gamma force”, 3 July, p 43)?
Several readers have pointed out the mistake on p 43 of the 3 July issue.
1015 years should have read 1015 测别补谤蝉鈥抬诲