Approval trap
It is inaccurate to proclaim that student volunteers acted altruistically “even when they can have absolutely no hope of getting anything in return” (16 February, p 8). The students have a very real hope of getting something valuable: approval from the researcher.
Specialists in consumer product research have never been able to eliminate this effect completely. While I was brand manager for a dishwashing detergent, I saw people making an obvious effort to identify which company the researchers were working for and striving to please them. Pleas to talk openly and honestly, and explanations of how the company would benefit just as much from hearing negative opinions, may even have made the subjects more anxious to gain approval.
It is not easy to design an experimental setting in which the subjects’ responses can be analysed based on gender, age and so on, while at the same time convincing the subjects that any selfish acts will not be traced back to them individually. If such a study could be devised, it would be invaluable in determining the true degree of altruism.
Another MOND is possible
Discussing alternative theories to dark matter, you mention Mordehai Milgrom’s MOND theory as if it were the only alternative model (8 March, p 10). This is far from the truth. Search and you will find a dozen or so articles describing other alternatives, including a recent one of my own (arxiv.org/abs/0712.1110). Several of them have been published in peer-reviewed journals. The MOND theory has merely been promoted much more effectively than other alternative theories.
Most cosmologists tend to believe in dark matter, so alternatives to it do not get the attention they deserve. It is much more difficult to get these alternative theories published in peer-reviewed journals because most of the referees belong to the “dark” side. It really makes one question the objectivity of the scientific process.
Beware black holes
Why are Alexander Shatskiy and Daniel Holz concerned about metre-sized black holes with the mass of the Earth disrupting an asteroid’s orbit and sending it crashing into us (8 March, p 16)? It’s the black hole we should be worrying about. If one were to hit the Earth, or even pass close by, the effect would be devastating.
鈥� It’s about probabilities. The asteroid belt in the solar system, the Kuiper belt and the Oort cloud add up to a lot of volume occupied by potential projectiles. If there are black holes lurking out there, any one of these objects might be deflected by them even if they missed the black hole by a considerable distance. The researchers say deflected Kuiper and Oort objects are likely to get stuck in the solar system, orbiting until they do hit something.
Intelligent neighbours
Could the stepped-up search for extraterrestrial intelligence be missing the point (9 February, p 8 and 8 March, p 20)?
Suppose our nearest planet with intelligent life turned out to be a watery one inhabited by intelligent, perhaps dolphin-like, creatures. These could have advanced language and a rich culture of philosophy, storytelling, poetry, music, dance and sport: but if they had no technology, we would never know about them, nor they us.
We have some very intelligent animals sharing this planet with us. But can we imagine dolphins, for example, using their flippers to invent and build transistors, integrated circuits and all those other wonders of modern technology? It seems that intelligence is necessary but is not sufficient to equip possible aliens with the ability to receive and transmit signals, either accidentally or deliberately.
We evolved our survival feature in our heads, being physically inferior animals in terms of our ability to avoid our predators by running, scampering up a tree, fighting or digging a burrow with our fingernails. The evolutionary pressure that drove the manual dexterity we now exploit to make tools, and the language we use for high-level cooperation, also drove that survival feature in our heads. Thus we became able to modify and expand our evolutionary niche and adapt to environmental extremes so that the whole world is now our niche.
The Gap, Queensland, Australia
Fly by rights
David Hollenbach’s illustrations to Jessica Marshall’s article on remote-controlled creatures (8 March, p 40) show up an aspect not mentioned in the text: that this is a new cabinet of horrors.
The ethics of such cyborg animal experiments deserve serious debate. It is one thing to perform animal testing for medical purposes 鈥� to save human lives.
It is quite another to perform experiments on animals with the aim of gathering military intelligence. In my opinion, the latter end does not justify the means: not for rats; not for green June beetles; nor for any species with a nervous system developed enough to perform the complex tasks required. The idea of using cyborg animals for search-and-rescue missions is interesting but doesn’t in itself justify these experiments.
Skill supply
Alan Jones has missed the point about the supply of scientists (26 January, p 23), as has subsequent correspondence about it (16 February, p 22 and 23 February, p 20). A “skills shortage” doesn’t mean “we cannot find decent engineers or scientists, no matter how hard we try”. It means “we cannot find decent engineers or scientists for the salaries we have become accustomed to paying”.
No great private-sector drive is required to motivate students to enter accounting or law, or to tell them these are “fun” or “exciting” occupations. The status and pay that come with these professions are all that is required to encourage students to choose them.
If you work in technology, a skills shortage is probably a good thing for you. Market forces should cause your salary to rise.
None of the correspondents who have rightly been bemoaning the failures of science education in the UK and elsewhere (5 January, p 16) has mentioned one well-tried alternative. The high point of UK science education was reached in the 1960s, with the Nuffield science project. This emphasised investigation over lists of facts, and understanding rather than rote learning.
Then along came the national curriculum with its prescriptive lists. The inevitable consequences were tests, and teachers teaching only what can be tested. Our schools are now being filled with a generation of science teachers themselves taught under this sterile regime. If some genuine science teaching remains, it is in spite of the national curriculum, not because of it.
Bromsgrove, Worcestershire, UK
Depressing numbers
Discussing the efficacy of antidepressants, A. C. Grayling concludes: “In the debate to come about Prozac and the rest, let us get the facts right” (8 March, p 49). So I shall try. How much money is spent on them? Expenditure on antidepressant medication in the UK in 2006 is estimated at 拢291 million, of which 拢120 million is for SSRIs, including Prozac. Take the UK population as 60 million: that’s about 拢2 per head per year on SSRIs. Extrapolating to the 740 million people in roughly comparable developed countries, the market for these drugs is likely to be worth around 拢1.5 billion a year.
If SSRI sales have risen linearly from the 拢500 million a year worldwide reported by Joseph Glenmullen in his book Prozac Backlash for the year 1990, when aggressive marketing began, gross spending in the past 18 years will have been around 拢17 billion.
Grayling tells us that there is some justification for saying that pharmaceutical companies “manipulate data in order to protect profits”. If this has happened, and if it accounts for even a fraction of 拢17 billion, it would be one of the larger financial catastrophes.
Deciding whether drugs should be prescribed for depression does not require anything as dramatic as the settling of the mind/body problem, as A. C. Grayling suggests. Common observation suggests the term “depression” covers a variety of psychological states occurring in a wide variety of combinations and with varying degrees of severity.
Just as it is clear that all drugs cannot alleviate all of these symptoms all of the time, it is also clear that some drugs can help some of these symptoms some of the time.
As I understand it, this was the conclusion of Irving Kirsch’s study (1 March, p 7). Given the crudity of drug function and the complexity of brain function, it is hardly a surprising one.
We need research to flesh out this general conclusion so that prescribing practice may be better targeted. Where a drug effect is shown to be “placebo” rather than due to its pharmacological properties, research needs to establish what this effect (which, after all, is real) is down to.
More precisely targeted research would get us away from the dismal, almost tribal, pro-drug vs anti-drug spat, towards a culture that is better tuned to patients’ real needs.
Accidental engineering
You suggest that the ice-making capacity of the bacterium Pseudomonas syringae may be essential for rain (8 March, p 14). How reassuring to know, then, that in 1987 a genetically modified version of the bacterium which lacked this capability was released into the environment in an effort to protect strawberries from frost (19 November 1988, p 19).
If that GM strain became dominant, could we all look forward to much less rain? The ice-making capacity seems to be a key mechanism for distribution of bacteria, so perhaps the GM version is self-limiting. That would be a lucky escape 鈥� this time, but it does highlight the possibility that genetic modification carries more risks than we can test in field trials.
For the record
鈥� We located the CeBIT electronics exhibition in the wrong German city (8 March, p 26). It takes place in Hannover.
鈥� The “dark fluid” on which HongSheng Zhao and colleagues have based their modified Newtonian dynamics (MOND) theory is not, as we stated (8 March, p 10), a mixture of dark matter and dark energy. What Zhao envisages is something different from either that mimics the effects of both.
鈥� It was Norway, not Sweden, that contributed $5 million to a nuclear fuel bank (8 March, p 7).
Oxygen drain
Feedback rightly dismisses the absurd claim on the website that in Tokyo, Japan, the oxygen content of the air has dipped to 5 or 6 per cent from its normal 21 per cent (23 February). Nevertheless, there is a grain of truth in the claim that oxygen is being lost from the atmosphere, albeit not in the vast quantities alleged.
When the first measurements of carbon dioxide in the atmosphere were being made at Mauna Loa, Hawaii, in the 1950s, the chief industrial carbonaceous fuel was coal, whether burned directly or as coke or used to make town gas. One atom of carbon produced one molecule of carbon dioxide by consuming one molecule of oxygen from the atmosphere. So each part per million increase in carbon dioxide was at the expense of an equivalent decrease in oxygen in the air.
But burning petroleum consumes more than an equimolar quantity of oxygen, with the result that for each 2 ppm increase in carbon dioxide more than 3 ppm of oxygen will have been consumed. For natural gas (methane) the oxygen demand is even higher: one molecule of methane burns to give one molecule of carbon dioxide and two molecules of water, consuming two molecules of oxygen. Here a 1 ppm increase in carbon dioxide should be accompanied by a 2 ppm decrease in oxygen.
Although at this rate it will require decades of ppm increments of atmospheric oxygen to shift the total far from the oft-quoted 21 per cent, the regular depletion should be significant, measurable and meaningful in understanding atmospheric mechanisms.
鈥� We said the oxygen concentration “has remained constant at around 21 per cent for at least 3 million years”. Direct measurements by the US National Oceanographic and Atmospheric Administration (NOAA) at Mauna Loa show that between 1991 and 2005 the O2 content of the atmosphere has . Overall, since the industrial age began, oxygen levels have probably fallen by between 0.02 and 0.03 per cent 鈥� close enough to constant for our purposes.
Forest options
There is indeed no justification for clearing any more pristine, natural, unlogged tropical rainforest (16 February, p 19). What little there is left should be protected and preserved as it is becoming very rare. Once logged to any substantial extent, it will never recover.
Logged land will be invaded by different species, mostly light-demanding trees and scrub which cannot survive under the dense canopy that shades the ground under pristine tropical rainforest. Once that shade has been destroyed, the species that form the natural rainforest cannot survive: they cannot stand direct sunlight, having evolved to live in cool, shady, damp, wind and sun-free conditions until they have either grown tall and dominant enough to become part of that canopy, or are able to mature and live their lives as sub-dominants at lower levels.
I have seen vast areas of such rainforests that have been logged and then left become stands of small, light-demanding trees and scrub. I have seen these burn during dry spells, the fires started either by hunters or by lightning strikes. Eventually they have degenerated into stands of lalang (Imperata cylindrica), a coarse grass weed which benefits from fires. Taller growths could smother it, but after a fire lalang rapidly regrows and becomes dominant again.
In those countries where corruption is rife, there is no proper protection for pristine rainforests. They are being “mined” by wealthy loggers who get rich on the profits to be made from the insatiable worldwide market for timber, especially for the superb tropical timbers that they can sell from their first loggings, but now also for timber from the much inferior regrowths that follow. Thus, regrettably, large areas are still being cleared for these reasons alone. This has absolutely nothing to do with getting land for growing biofuel crops 鈥� though that may be the excuse for obtaining permits from the local authorities to “develop” the land. Once the timber has been removed and sold, the “developers” usually disappear from sight, along with the money they have made.
So, what to do with the logged-out land? The “carbon debt” has been incurred and no way will it be repaid. Utilising the land is better than leaving it to scrub and lalang. It could be used to grow oil palms for fuel or food, or for other “permanent” crops such as acacia or eucalypts for paper and pulp, rubber, cocoa, tea, coffee or similar crops suitable for the local soils and climate. If this were properly done, with well-planned plantations and road and drainage systems, the use of terraces or planting platforms as appropriate, and the use of creeping leguminous cover crops in the early years of establishment, at least the degradation of the lands could be minimised and benefits such as employment created.
So I suggest that the blanket condemnation of the extension of oil palm plantations, fashionable though it seems, is not necessarily logical or justifiable.
The science of… science
I was upset that Michael Brooks chose to lump The Science of Discworld together with the other “Science of…” books, especially as he was reviewing yet another addition to that tired genre (1 March, p 52).
In The Science of Discworld, Terry Pratchett, Ian Stewart and Jack Cohen use Pratchett’s fantasy books as a starting point for a haphazard romp through the history and philosophy of science, managing along the way to cover the basics of nuclear physics, astronomy, cosmology, geology and the evolution of intelligence. They do not attempt to rationalise fantasies with speculative science, but instead set out to educate the reader about the world around them by looking at it from an external viewpoint.
So clear and entertaining is its coverage that unwilling friends on whom I have pressed the book 鈥� many of them scientific illiterates 鈥� have often responded with (to my relief) grateful thanks. This would be an excellent school book 鈥� were it not for the chaos that would result from filling classrooms with critical thinkers sceptical of what Stewart and Cohen label “lies to children”.