Essential Amazon
We are writing to express our horror at the deal struck between the Brazilian
government and the World Bank’s Global Environment Facility for a mere 10 per
cent of the 5 million square kilometres of the Legal Amazon region of Brazil to
be saved from destruction
(10 June, p 16).
What appalling ignorance this reveals among the decision makers of the
irreplaceable role that the Amazon basin plays in stabilising global climate.
Neither tree plantations nor agriculture will come anywhere near serving the
function of the intact forest in pumping water into the atmosphere and recycling
nutrients鈥攊f indeed it is possible to grow anything on much of the basin’s
poor, nutrient-deficient soils.
As Brazilian physicists and climatologists showed long ago, the forests to
the west of the Atlantic are watered through a chain of evapotranspiration, in
which the same Atlantic-derived water falls as rain up to seven times as it
moves on the air currents that run from east to west across the Amazon
basin.
More than 20 per cent of the rain that falls never hits the ground, but
promptly evaporates from the canopy. That is a function of the dense natural
forest. As much as 48 per cent is transpired鈥攁gain, a function of the
forest. The Amazon river carries back to the ocean less than half of all the
rain that falls. The remainder fuels the stream of massive cumulonimbus clouds
that finally send their latent energy into the Hadley circulation and help
spread the energy from the Sun to the higher latitudes, to the benefit of all of
us in Northern Europe.
A few numbers tell us what is at stake. The Amazon basin receives 12 million
million tonnes of water a year. In energy terms that amounts to 950 terawatts of
latent heat, which is 73 times the energy deployed by all humanity across the
globe. Just a 20 per cent decline in precipitation and consequently in
evapotranspiration will amount to a drastic drop in the energy transported to
the higher latitudes, equivalent to at least 15 times the world’s use in
energy.
Letter
If traffic between websites will form a simulation of a neural network, and
the amount of Internet traffic will determine which “neuron/sites” live and
thrive and get greater connectivity, and which ones die from (comparative) lack
of use, then I would humbly submit that newscientist.com and its extremely
worthwhile content would sadly wither and die on the vine long before
pornography sites and other sites of equally dodgy taste and value expire.
Now what does that say about the global brain?
The Internet is not a brain. It is not a frontier. It is a collection of
computers passing voltages to each other. It’s important to remember that we can
take our mythologies about our machines a wee bit too seriously.
The biggest brain
Your articles on the nascent global brain
(24 June, p 3 and
p 22)
point out the potential use of the Web for compiling a dossier of individuals’ Web usage.
Such a dossier would have irresistible appeal for governments and would open the
way to classification of individuals for political and perceived security
purposes based on their interests and enquiries.
Letter
Considering the content of the article, was it a wise idea to post this on
the New 杏吧原创 website? After all, it could be this article that
gives the Net the idea in the first place.
Letter
A few months ago we were treated to reruns of the BBC Horizon
programme demonstrating the behaviour of rock slides, which mimic water flow
almost exactly under certain circumstances and produce etched gullies and
outflow deltas that are very similar to water erosion.
The enthusiastic excitement of the NASA scientists about the possible
existence of water on Mars, after the discovery of recently formed gullies on
its surface, might be tempered somewhat if they compared the pictures they have
received from the Mars Global Surveyor with the terrestrial rock slides shown so
graphically on the Horizon programme.
Martian rethink
The further evidence this week that liquid water may exist on Mars
(1 July, p 6)
is very exciting. However, a few points in the article worry me slightly.
It seems that the gully features, allegedly caused by flowing water, only
occur near the poles and on slopes facing away from the Sun. It is noted that
this seems puzzling as these areas are often up to 100 掳C below the melting
point for water. A solution to this puzzle may lie in the fact that these
gullies are not caused by flowing water, but instead by flowing carbon
dioxide.
At atmospheric pressure, CO2 changes straight from a solid to a gas
at 鈥�78.5 掳C, with no liquefaction. However, if the pressure is
increased to around 5 atmospheres, solid CO2 becomes liquid CO
2, which is produced at 鈥�57 掳C鈥攃lose to the average surface
temperature on Mars.
It seems possible, therefore, that the gullies on Mars result from deposits
of solid CO2 formed in areas away from the heat of the Sun, such as the
poles, warming under pressure and producing streams of liquid CO2.
Letter
The proposed legislation on Internet snooping seems to rely on the idea that,
given the correct cryptographic key, the security services can convert any
message they do not comprehend into one they can.
Many scientists and engineers presently use e-mails for their legitimate
business. Has anyone considered how the state snoopers will recognise an
encrypted message to a terrorist cell as being different from an e-mail claiming
to contain some operation code for an obscure silicon chip, for example?
Why should an encrypted plan to import illegal immigrants appear to be any
different from one claiming to contain part of the human genome sequence? Is
this message really a letter to New 杏吧原创 or is it a cleverly
encrypted proposal to rob a bank?
Outwitting snoopers
The British government can never succeed in its purpose of snooping on secret
electronic communications
(17 June, p 3)
if the practice of steganography is widely adopted.
This term refers to the concealment of secret messages within a larger,
apparently innocent communication. Thus, for example, a few bytes in an image
file can be altered here and there to conceal a short text message without any
apparent degradation of the image.
A Web search using the keyword “steganography” will bring up many sites from
which suitable software for doing this may be downloaded.
There is nothing new about this technique. As a boy, I had a book in which
examples were given of spies’ messages being concealed in pencil drawings of
landscapes. One drawing showed a river scene with grass growing along one of the
banks. The long and short stems contained a message in Morse code.
Trained to kill
Several contributors have argued the case for and against violent video games
contributing to violent behaviour
(10 June, p 44).
I believe that a crucial point has been overlooked: that playing violent video
games trains people for efficiency in attack.
David Grossman is a psychologist and former US Army colonel who believes
people are not naturally killers and have to be trained. The Land Warfare
Studies Centre invited him to Australia for its 1999 conference, and his book
On Killing was nominated for the Pulitzer Prize.
In an interview with ABC’s Radio National, he said: “Point and shoot video
games are making killing a conditioned response. I served as a consultant in the
Paducah school shootings [in the US]. A 14-year-old boy named Michael Curneil,
who had never fired a pistol before in his life before stealing that gun . . .
brings a .22-calibre pistol to school and opens fire.”
Grossman said that “the only way you’re going to be capable of hitting is
through practice, practice, practice, practice.” But Curneil, who had “played
and played” these video games, shot the schoolchildren with startling accuracy.
“How many hits does he get? Eight shots, eight hits . . . Five of them are head
shots, the other three are upper torso . . . What was he doing? He was playing a
video game.”
Infant synchronicity
“James Morley tells us that his two-and-a-half-year-old son came in from the
garden at the weekend and announced: `I’ve just seen a spider on his website'”
(Feedback, 24 June).
This is uncanny. Six months ago, when my daughter was two-and-a-half, we were
in the garden and she said, “Mummy, there’s a spider website.”
Your article about the global brain in the same issue is accurate, although
perhaps already out of date. And you don’t even have to be online to experience
it. You just have to be part of the new generation. Spooky.
Lunar power
I read with interest your article on a rover that could process Moon dust to
produce crude solar panels
(24 June, p 14).
It suggested that this could power a Moon base, but I think that the true potential
of this idea has been vastly underestimated.
If indeed the rover could be autonomous and self-sufficient, then why not
launch a fleet of them and use the near side of the Moon as an enormous solar
panel? Advantages would be the presence of the necessary raw materials, the
strength of sunlight in the absence of an atmosphere and the lack of land
value.
The phases of the Moon could be a problem, but at least, unlike Earth-bound
panels, the change in output would be predictable. I would guess that when the
Moon was full, the power beamed to Earth could supply the whole planet’s
needs.
Poor Hollywood
Barry Fox says that Hollywood’s combined print bill for an English-language
film release is around $6 million, and that “it would hardly break the
bank for a billion-dollar industry” to double this cost by releasing films
simultaneously around the world
(17 June, p 50).
This would be true if the billion-dollar industry was based on only one film
per annum. In 1999, the majors released 218 films. My guess is that the industry
is worth more than a billion a year, but that $1.3 billion is still a big
disincentive to simultaneous release.
The prohibitive cost of $100 000 cinema-quality digital video
projectors Fox quotes seems unlikely to last. As Moore’s law鈥攚hich says
the power of chips doubles every 18 months鈥攈as analogues in other areas of
electronics, it seems likely that the cost of projectors will fall.
Metric ageism
I read Katja Street’s letter with some annoyance
(1 July, p 48).
Although I am a 60-plus retired engineer, I too can recognise the lack of logic in the
imperial system of measurement.
Perhaps Street should recognise that the reason there is now a logical system
of units is thanks to my generation. We recognised the inconsistencies of the
imperial system and decided to change things. If she finds feet and inches
difficult, perhaps I could point towards slugs, poundals and Centigrade heat
units, among other such monstrosities that she will never have to face.
We are not all dinosaurs and I for one am looking forward to the euro,
instead of that other sort of pound.
This correspondence is now closed鈥擡d
Rubber stamping
The ability to identify the brand of condom to help bring criminals to justice
(17 June, p 6)
will be extremely limited. It would not identify individuals.
Genetic profiles are far more accurate in identifying individuals
(one in several billion). They are excellent for excluding suspects and are far
more incriminating when a match between a crime sample and suspect is found.
As well as being easily generated from semen left in a condom, genetic
profiles are now also regularly generated from swabs of the inside of condoms
into which the offender has not ejaculated
(21 June 1997, p 11).
Contact between skin and an object often leaves sufficient DNA for typing.
Furthermore, in a number of case studies we have also been able to acquire
the genetic profile of the victim by taking swabs of a condom’s external
surface. These results have been far more helpful in bringing criminals to
justice than the branding of discarded condoms will ever be.
No pain
Feedback began the latest outing of nominative determinism by mentioning “Dr
Notcutt at the pain relief clinic at James Paget Hospital in Great Yarmouth,
Norfolk”
(20 May).
I enjoyed the piece, but sadly you missed the best. I am an anaesthetist.
Therefore, Will Notcutt is surely even more appropriate.
Masculine/feminine
I am perplexed by two articles that appeared in your 24 June issue. My index
finger is a good half-inch longer than my ring finger, which means I’m supposed
to exhibit highly feminine characteristics
(p 32).
But at the same time, my first name is considered one of the most masculine
female names around
(Feedback),
which is also supposed to reflect on how people
perceive me. Do the two somehow cancel each other out?
Getting an earful
Veterinarian Andy Sokol obviously hadn’t been keeping up with the literature
when he recommended that a man afflicted with a tarantula-in-the-ear problem
stick his head in the freezer
(Feedback, 24 June).
K. O’Toole and colleagues reported a successful treatment 15 years earlier in a case
involving two cockroaches, one in each ear, in The New England Journal of
Medicine.
Using an admirably scientific approach, they tried mineral oil in one ear, 2
per cent lignocaine in the other. The lignocaine method proved superior, as “the
roach exited the canal at a convulsive rate of speed”, where it was terminated
using “the simple crush technique”.
I recommend that Sokol try this method the next time the tarantula problem
arises, although he may wish to omit the crush procedure if the tarantula is a
pet.