Steaming streets
While reading the article on Iceland and hydrogen fuel cell cars
(This Week, 1 May, p 20),
I started to wonder about the environmental effects of replacing
petrol engines with fuel cell versions.
The petrol engine was originally hailed as a clean alternative to the horse,
which left the streets ankle deep in muck and attracted disease-spreading
flies.
When our cities are filled with vehicles producing water vapour, will we look
back on the golden age of petrol engines, when the streets weren’t more humid
than a Turkish bath and there wasn’t a rainstorm every night?
Correction:
The article “Of Dumbbells and doughnuts”
(1 May, p 34)
failed to note that the magnesium-24 results mentioned were carried out at the
14UD accelerator facility in the Australian National University, Canberra.
Letter
Has anyone considered the possibility that short-sightedness might be linked
to fluorescent lights?
Fluorescent lights are used in greenhouses to make tomatoes grow. Would they
have the same effect on eyes?
Lights out
You report on a theory that children sleeping with bedroom lights on tend to be myopic
(This Week, 15 May, p 6).
This reminds me of some very basic research
I did with colleagues as part of the WHO’s Malaria Eradication Programme in
Pakistan in the 1960s.
At the time we were recruiting large numbers of young adults from both rural
and urban areas all over the country for training as microscopists. As part of
the selection process we assessed the visual acuity of the potential recruits
and, of course, this included picking up myopia (short-sightedness), presbyopia
(long-sightedness) and colour blindness using tests that were then standard.
Our results were amazingly consistent throughout the country : myopia was 10
per cent higher in the urban recruits than it was in those from rural areas, and
the incidence of colour blindness was the inverse: 10 per cent higher in the
rural recruits than the urban. The numbers screened were quite large, around
1000, and, with very few exceptions, male. As our team did not include an
ophthalmologist we did not feel at the time that it was ethical to publish this
data.
I would suggest that our data backs up your report, since the lack of
electricity in rural areas in those far-off days made it most unlikely that our
rural recruits had the benefits of much night-time exposure to light of any kind
other than low level candle-power or a non-pressurised kerosene lamp.
I leave it to New 杏吧原创 to explain the reverse discrepancy in
the colour blindness indices of our rural and urban recruits.
Field practice
The atlatl principle is not confined to the rigid spear launchers of ancient
hunters and numerous modern renaissance practitioners in Europe and North America
(“Stone Age Kalashnikov”, 15 May, p 40).
Forty years ago there was certainly an interesting variant alive and kicking
in Britain. In the 1950s I worked at the National Physical Laboratory,
Teddington. During our lunch breaks a friend and I used to throw a flexible
wooden dart, around 1.2 metres in length, between opposing goal posts on the
football field. Our “atlatl”鈥攁 name we had certainly never heard
of鈥攚as simply a length of string with a knot at one end.
You wrapped the plain end around your throwing hand, gripping the dart near
the sharp end. The knotted end passed around a slight groove just below the
flight end of the dart, with the string passing over the knot then down to the
hand. Tension of the string was achieved simply by sliding the hand down towards
the point. We regularly threw the dart up to 120 metres鈥攆urther than the
length of the field.
One other point: the bow is not, as you quoted Bob Perkins as saying, a
linear accelerator. An arrow let loose from a bow follows exactly the same sort
of curved pathway around the bow as the atlatl. The stiffness (“spine”) of an
arrow must be matched to the characteristics of the bow if the arrow is to fly
properly. Too stiff a spine and the arrow shaft hits the side of the bow and
flies off to the left (for Western bows using the fingers to hold the
string鈥攆rom an Eastern bow using a thumb ring the arrow would fly off to
the right). Too soft a spine and the arrow curves too far around the bow, and
flies off to the right.
This is known as “the archer’s paradox”, and has been widely investigated in
the development of archery.
Make them pay
I agree with much of the response to Peter Berrie’s original letter on macros and viruses
(Letters, 15 May, p 52),
but I feel that all the correspondents have missed the point.
There are parallels to be drawn here with many of the off-the-shelf
palliative medicines: treating the symptoms and not the cause will never cure
the problem. And the problem is not the virus, it’s the people who write the
viruses. They frequently argue that they are doing everybody a service by
spotting “security flaws”. I don’t buy that. My back door is often left
unlocked, but this isn’t an invitation for all and sundry to walk in.
These virus writers now cost me over 拢100 a year, which is money that,
quite frankly, I’d rather be spending elsewhere. Let’s have a bit of the
“polluter pays principle”: hit these virus writers hard and hit them where it
hurts.
Letter
For me, in Norway, this sounds very strange. Some of us have grown up under
the midnight sun, and many of our parents could read newspapers by the light
from the sky even at midnight in the summer. And for several months I have
problems getting my children to bed on time, as they refuse to go to sleep when
it is still daylight outside.
Probably the Inuits of Greenland have had the same problem. Still, they had
no previous problems with myopia. Isn’t it strange?
Signs of the times
Richard and Joanne Payne say that Scandinavian Sign Language is taught to all children
(Letters, 15 May, p 51).
Being not just Scandinavian, but Danish, I
have to object to this. We were never taught sign language at school, and I have
never heard of anyone who was. Nor have friends who are Swedish or
Norwegian.
You also have to remember that we are three different countries, with three
different languages. I find it difficult to believe that there is such a thing
as a “Scandinavian Sign Language”.
A basic knowledge of sign language would be an excellent idea, but I am
afraid that there wouldn’t be enough time and resources to teach this as an
extra language. We already have to learn at least two foreign languages, and for
many that is enough. But giving children a way of communicating with deaf people
and some insight into deafness would benefit both hearing and deaf people.
Letter
I get irritated when I read articles that seem to imply that this idea was
thought up by Daimler Chrysler and the Icelandic people. There was no mention of
the 25 years of effort by the International Association for Hydrogen Energy
(IAHE) under the able direction of Nejat N. Veziroglu (University of Miami,
Florida) and the many other pioneers who have been studying, promoting and
pushing this concept for years (29 in my case).
There’s nothing new about using renewable energy to produce hydrogen or
running cars on liquid hydrogen. Derek Gregory wrote on the renewable energy
aspect in 1973 (Scientific American, vol 228, no 2, p 13) and I wrote
on liquid hydrogen for automobiles in 1973 (Cryogenics, vol 13, no 6).
Studs in the hills
Fell runners have known for some time that pyramidal studs are superior to round ones
(This Week, 15 May, p 11). Norman Walsh of Bolton started equipping
his fell running shoes with square pyramidal studs many years ago and rival
manufacturers have followed suit.
They give a much more positive grip than round studs, and their distinctive
pattern can be observed in the soft ground on any British mountain. It is
surprising that footballers have taken so long to catch on.
Too many masts
The zoology department of Oxford University is seeking planning permission to
erect 110 radio masts, each 12 metres high, in Wytham Great Woods near Oxford
and over the surrounding countryside
(Forum, 29 May, p 51). The intention is to
enable zoologists at Oxford鈥攁nd around the world through a
website鈥攖o track small mammals on a 24-hour, real-time basis.
The impact on the landscape and woodland, widely acknowledged as among the
most beautiful and most naturally preserved in the country, would be
devastating, and a protest campaign is getting under way to prevent the
blighting of the countryside and the abuse of its protected status as Green Belt
land.
Rather than accept that this is another case of the conflict between
conservation and scientific research which must be fought out in the media and
the courts, I wonder if any of your readers could suggest a better technological
solution to the zoologists’ problem than an array of 12-metre-high radio masts?
Radio collars capable of transmitting data via the GPS system are, apparently,
too large for animals smaller than deer, and the researchers need to track
badgers, foxes and even small rodents.
Whoever can come up with a solution would be doing a great service not just
to the thousands who enjoy the woods and countryside of Wytham but to the
greater cause of public sympathy for scientific research itself.
Gravity knows
Robert Nield implies that we only know that “gravity notices neutrinos” now
that they have been found to have a positive rest mass
(Letters, 1 May, p 60).
A physicist friend of mine confirmed my suspicions that this is not true.
Neutrinos have a relativistic mass proportional to their total energy, and even
in Einstein’s original paper, energy (or relativistic mass) was considered to
affect the gravitational field. Neutrinos also follow the curvature of space,
which means they are influenced by gravity.
Photons are particles which have no rest mass, and yet they also influence
and are influenced by the gravitational field.
The reason the discovery of a non-zero rest mass for the neutrino is
important is that neutrinos produced in the big bang have lost most of their
kinetic energy due to red-shifting. Their contribution to “dark matter” would be
very small unless they have a significant rest mass.
Under her skin
It is not accurate to say that the contraceptive implant, Norplant, delivers
progesterone through the skin
(This Week, 8 May, p 5). It delivers progestogen.
Progesterone and the many artificial progestogens are not interchangeable as
treatments nor in print.
It would be a pity if some of the many women successfully using progesterone
as a treatment for PMS were to be made anxious about the side effects described
under the heading “Implant exits”.
The big chill
It seems to me that people have put on blinkers when they claim that
everything has to point to global warming
(“Chill in the air”, 1 May, p 28).
The upper atmosphere cools and suddenly there’s a convenient theory saying, in
effect, that a temperature see-saw swings around the tropopause.
Don’t forget that we live at the culmination of 10 000 to 15 000 years of
warmth and, statistically, are due for rapid cooling of the magnitude of 1
kelvin a year. It reminds me of the idea that the heat of global warming could
create enough chaos to trigger an ice age.
Since no one really knows the effects of human pollution on the environment,
and since the signs of impending glaciation are mostly mysterious, isn’t it at
least a possibility that we are looking the right way, but worrying about the
wrong thing?
Cool arsenal
I’ve enjoyed Feedback’s regular “product warning” stories and was delighted
to come across this whilst turning out a kitchen drawer today. It was in the
instruction book for our 34-year-old Bosch fridge and came at the end of the
installation and connection instructions on the first page:
“It certainly goes without saying that your refrigerator must not serve for
storing explosives.”
Fortunately, I obeyed this instruction, which is probably why the fridge has
lasted so long.
Train for Tolstoy
Further to Feedback’s reports on humorous railway announcements
(15 May), we
were at Haymarket station in Edinburgh waiting for a train to Glasgow. The
scheduled Intercity was very late. Eventually a decrepit local train labelled
“Glasgow” drew in. The announcer said,
“The train at platform 4 is for Glasgow Central, via Carstairs, Motherwell,
Bathgate, Wishaw” and many other places. He then added, “This is a very slow
train. If you are bound for Glasgow don’t board it unless you have a copy of
War and Peace.”
Letter
While I was working at the Department of Human Physiology and Pharmacology at
Adelaide University, a vacancy for a pharmacologist colleague appeared in the
local press (the Adelaide Advertiser) under the bold heading “Farm
Ecologist”, which involves a quite different line of expertise.
Garbled speech
The “head on a stick” item in Feedback
(8 May) reminded me of a story told to
me by an ex-colleague at the British Trust for Ornithology. A scientist dictated
a letter onto his Dictaphone containing the word “juxtaposition” and sent the
tape to his secretary. He was rather surprised when the typed version came back
with this word rendered as “jock strap position”.
I wonder if the letter made any sense, and exactly what the secretary thought
he was on about.