Measuring cats
Schr枚dinger’s cat must be the most misunderstood animal in the history of science (12 May, p 32). The “measurement” that destroys quantum uncertainty is the interaction of the quantum object with some other object, and has nothing to do with a human observer.
When I take an electron micrograph, the electron ceases to be in a superposition of states when it interacts with a crystal of silver bromide in the film, not when I look at the developed picture the next day. Likewise, the uncertainty surrounding Schr枚dinger’s atom disappears when it interacts with the vial of poison gas, not when we open the box. The cat is always either alive or dead, never in a superposition of states. A video camera in the box, monitoring the health of the feline, would not perturb the experiment in the slightest.
This is not a criticism of the fascinating and important experiment by John Martinis that you report. The anthropomorphic analogy obscures the significance rather than elucidating it, though. In the end, the observer has nothing to do with the health of the cat, but is an essential part of Martinis’s experiment.
Quacked humour
Richard Wiseman’s theory that “Quack” is funnier than “Moo” holds true for English speakers (12 May, p 46). But is it true for those whose languages assign the “k” sound to other animals’ cries and not to ducks? Or are there no such languages? The only foreign duck sound I know is the French “quank”, in which the “k” would probably have less effect, overshadowed by the preceding nasal sound.
From Kevin Whitesides
You suggest that the spoken hard “k” sound is likely to be funnier because of “facial feedback”, for the reason that saying the “k” sound can supposedly make one mimic smiling. This is easily refuted. Try it yourself and you will very quickly recognise that your smiling face is the result of the vowel that precedes or follows the “k”.
For example, contrast the facial expression of the word “quack” (as in the article) with the word “cook”, which clearly does not create a smile when said. It is the hard “a” sound in “quack” that makes the smiling face. If there is indeed some reason that “k” is funnier than other sounds, it’s not because it makes you look like you’re smiling.
Also the people in the article were reading a joke, not being told the joke orally. So the facial aspect would not have come into play, unless the person was reading the joke aloud or at least mouthing it.
Arcata, California, US
The editor writes:
鈥� Further personal experimentation suggests that it is the combination of “k” with certain vowel sounds that produces the strongest “forced smile”. For example, “key” does so more than “be”, “dee” or “fee”, although “k” with some other vowels lacks the effect.
Gravity of the matter
The makers of Mary Lunnen’s scales may be very pedantic, but not as silly as Feedback implies (12 May). The acceleration due to gravity varies slightly with latitude. I remember my students in Nigeria being confused by the fact that their measurements of the gravitational acceleration g consistently came out slightly smaller than the “right” answer in their British textbook.
From Charles Sawyer
You don’t have to go to other planets to change “the weight of a mass”: a mass that weighed 150 kilograms in Quito, Ecuador, would weigh about 151 kg in Scotland, because Quito is around 20 kilometres further from the centre of the Earth.
Byron Bay, New South Wales, Australia
For the record
鈥� The satellite image of Australia showing the Adelaide area that was used to illustrate the article “Earth audit” (26 May, p 34) was mistakenly printed as a mirror image.
鈥� As many readers have noticed, in the illustration of Americans lifetime consumption of resources (26 May, p 40) the amounts of phosphorus and aluminium should have been 8322 and 1576 kilograms respectively, not tonnes.
On a wing and…
Feedback’s reporting an insurance expert芒聙聶s views on the usefulness of flight-safety procedures (19 May) put me in mind of a flight I took from Singapore to Bali several years ago, with the now-defunct Indonesian airline Sempati.
Looking through the seat pocket in front of me, I could see no sign of the usual card giving details of the emergency procedures and exits.
There was, however, a large laminated sceet bearing the text, in several languages, of three or four prayers. It seems the Sempati executives shared the views of your insurance expert.
Mountain anxiety
Kate Ravilious’s account of the Gamburtsev mountains in Antartica mentions the Rockies as an example of a range created by tectonic activity (12 May, p 38). In North America, is it not the Cascade and Sierra Nevada ranges that are currently rising from tectonic movement, rather than the Rockies?
The editor writes:
Yes, those would have been clearer examples.
Bat and blade
New 杏吧原创‘s report on the large number of bats succumbing to wind turbines reinforces a common misperception 鈥� that the blades move slowly (12 May, p 4). It is true that the blades of older, small wind turbines rotated rapidly and so would appear to a bird or bat as a semi-solid disc to be avoided.
Modern 2-megawatt wind turbines make an apparently lazy 10 to 20 revolutions per minute, but the blades are around 40 metres long. Simple geometry shows that the blade tips travel at between 150 and 300 kilometres per hour.
For a bird or bat in misty weather, these aircraft-sized blades appear from nowhere at intervals of between 2 and 4 seconds, a scenario that even a fighter pilot would find alarming.
From Jack Harrison
Surely it should be a simple matter for each generator to emit an ultrasonic cacophony that confuses bats and tells them, in effect: “This is confusing, best stay away.”
Great Chishill, Cambridgeshire, UK
The editor writes:
鈥� Maybe that’s a good idea 鈥� if we can be sure that this wouldn’t confuse them even more.
Good pharma
The article on the influence pharmaceutical sales representatives have over doctors is misleading (28 April, p 18). The pharmaceutical industry does not as a whole promote branded products over generic alternatives. Rather, it seems to me 鈥� knowing of one cancer survivor who almost lost his life because a physician was not adequately up-to-date, and as someone who works in IT for a drug company 鈥� that the industry’s focus is on getting innovative therapies through regulatory approval so that they can benefit patients.
This requires a high degree of (highly regulated) interaction with physicians to identify suitable candidates for clinical trials, to investigate additional clinical benefits and to inform physicians of the benefits of certain therapies compared with prior best practice. Through this synergistic relationship hundreds of millions of lives have been saved, improved and extended.
The pharmaceutical industry takes enormous financial risks to bring new therapies to market. Unlike a pop star or an author, it rarely has as much as 10 years of exclusive return on its innovations. To achieve a reasonable return, even on a breakthrough medicine, can require significant investment in promotional effort simply to make physicians aware of what the regulators have approved. To suggest physicians are susceptible to the lure of a free sandwich or the gift of a ballpoint pen is a slur on the profession.
Pet killer?
Andy Coghlan writes that a literature search shows that melamine has “never been shown to produce the kidney damage seen in most of the affected pets in the US” (5 May, p 8). Not so. A study by R. Clark in 1966 on melamine in sheep showed the same effects as recently detected in dogs and cats in the US (Journal of the South African Veterinary Medical Association, vol 37, p 349).
Clark found that a single dose of 100 grams of melamine caused kidney failure in sheep, all of which died after about 10 days. When the sheep were examined post mortem the tubules of the kidney were packed with crystals. Given 10 grams of melamine daily, two out of three sheep died within 31 days.
Literature searches often ignore older research material, which can often contain important information. The CAB Abstracts Archive has digitised such records in the field of applied life sciences back to 1912 so that this older material can be access more easily.
The editor writes:
鈥� In response to New 杏吧原创‘s question about the Clark study, the US Food and Drug Administration says: “We are aware of that study and the melamine used was at an extremely high level. We have never said that melamine was harmless to pets, but by due diligence we are also looking at melamine-related compounds.”
Avian flu testing
You report “discrepancies between levels of flu recorded in British birds and those elsewhere in Europe” and that such findings “raise concerns about whether British tests would pick up H5N1 bird flu if migratory wild birds carried it into the country” (19 May, p 12).
There is no evidence of any difference between the sensitivity of the methods used by the Veterinary Laboratories Agency and those used in the study quoted that would explain the difference in the apparent crude prevalences in the UK compared with Sweden and the Netherlands combined. One does not expect a similar prevalence or presence of infection in all countries, nor a constant presence or prevalence of infection over time, as Ab Osterhaus, who led the study you quote, has indicated. It is therefore misleading to say that “on average 6 per cent of ducks in Europe are infected” with influenza A viruses. The study was restricted to Sweden and the Netherlands and there are a number of species of ducks for which the apparent prevalence varied considerably.
Full official epidemiological investigations were undertaken of the recent H5N1 outbreak in Suffolk, the results of which have been published. The combined reported evidence strongly supports the hypothesis of transfer of infection from continental Europe via existing epidemiological links, and makes transmission via wild birds appear improbable.
Samples were taken from 60 wild bird carcasses found in the disease control zones. Of these, 49 were from high-risk species of waterfowl. Furthermore, 526 faecal swabs from wild birds as well as environmental samples from the affected premises and the adjacent slaughter and meat processing plants were also analysed. No evidence of H5N1 was detected.
We would like to emphasise that we endeavour to continually review and revise all aspects of our surveillance activities in light of new substantive international evidence, as it arises.
Rainforest renewed
Joseph Wright and Helene Muller-Landau suggest that regeneration of tropical forests might lead to far less species loss than is feared by most tropical biologists (12 May, p 42). There is currently very little reason to think so.
Irrespective of the validity of any models produced by Wright and Muller-Landau, the relevance of their study ultimately rests on the assumption that the rise in regeneration of forests predicted by those models will provide adequate replacement habitat for many species otherwise committed to extinction. However, there is scant evidence indeed to indicate that secondary, degraded and plantation forests are able to harbour anywhere close to the full complement of species found in old-growth tropical forests.
Given the seriousness of this assumption to the real-world relevance of the model we feel that it is critical to evaluate the strength of available evidence that could support such a claim 鈥� something Wright and Muller-Landau fail to do. We have addressed this problem by providing the most comprehensive review to date of studies that have considered the biodiversity value of these anthropogenic forests (Biotropica, vol 39, p 25).
Wright and Muller-Landau point to “the conservation value of degraded and secondary forests” (Biotropica, vol 38, p 443), but without evidence to demonstrate the value of such forests we believe the entire debate is highly misleading. Moreover, the lack of evidence means the claims made by the researchers prescribe a conservation strategy based on nothing more reliable than hope.
The fates of tropical forest species remain highly uncertain, and it is the responsibility of scientists to be transparent about the extent to which existing evidence supports our predictions of the future.