Let's hear it for houseflies
I hope that the electrostatic flytrap described in your news story (9 February, p 19) does not work as planned. It seems a little too efficient for our own good. In ten days a fly could infect a huge number of others with the fungus and housefly numbers would plummet.
But this might not be a good thing. Houseflies, or at least their maggots, perform a valuable service by disposing of dead organic matter. Left alone it would breed bacteria, attract rats and encourage a whole host of less desirable fauna than the housefly itself.
I am reminded of the Chinese effort to rid their fields of sparrows because they ate the grain. Soon they were overwhelmed with all the nasty insects the sparrows had been keeping under control. Why do we humans think we have the ability, let alone the right, to modify entire ecosystems? I’d personally rather stick with the fly spray鈥攁n ozone-friendly one of course.
Dirty fusion
At the beginning of your interesting article on advances in fusion research you describe the dream of unlimited, clean energy with relatively little radioactive waste (9 February, p 36). But to quote from a relatively positive article in Ullmann’s Encyclopaedia of Industrial Chemistry (vol 17, p 804): “Assessments indicate that tokamak fusion reactors produce huge amounts of radioactive waste during their lifetimes 鈥� It must be disposed of in geologic repositories. Indications are that the high and low-activity wastes are comparable in volume and initial activity to those of a fission reactor with the same power output.”
These wastes come from the corrosion and erosion of materials made radioactive by the intense radiation in the reactor.
Public science
Your editorial and article on the Export Control Bill were inaccurate and misleading (23 February, p 3 and p 5).
Your editorial accused the government of “imposing” the bill, failing to “compromise” and implied there had been no debate. It failed to mention nearly four years of prior consultation, significant changes made to original government proposals specifically to address academic concerns, and the announcement we made last October of a full public consultation upon the controls to be introduced under the bill, to be held before the controls come into force.
The bill will not lead to control of publication of scientific papers. As made clear last October, new controls will specifically exclude scientific knowledge in “the public domain” (this includes information which is put into the public domain, including by publication) and my statement that the bill is fully compatible with the Human Rights Act, which protects freedom of expression, is recorded on the front of the bill.
New 杏吧原创 also failed to mention that the bill for the first time imposes strict limits upon what goods and technology the government can control. Under current legislation, there are no limits whatsoever.
The bill will not make licensing of foreign students “compulsory”. There are no powers in the bill to license foreign students and suggestions that ministerial approval will be required for coffee-break discussions are simply absurd.
The only new controls which could conceivably apply to discussions in Britain will apply only where a person knows, or has been informed by government, that such information if communicated to a particular person or persons is or may be intended for use in connection with a weapons of mass destruction programme or missiles capable of their delivery. I imagine most scientists would wish to avoid their work contributing to such programmes.
Far from being an unprecedented introduction of sweeping new powers as you imply, the bill seeks only to allow existing controls on exports of goods and technology in tangible form to be extended to exports of the same goods and technology in intangible form. You also fail to mention that controls on e-mails and other electronic transfers of civil technology with military applications have been in force under European legislation since September 2000. Collaborative research has flourished since then, and it will continue to flourish after the bill comes into force.
Strictly for the birds
It’s not just chickens that are immune to a chili’s punch (16 February, p 23). Maybe you Brits don’t have the problem with squirrels that us colonials have had for years. The little mammals like birdseed and are forever in a battle with bird lovers as to who gets the food.
The simple solution is to sprinkle cayenne pepper or something else rich in capsaicin on the seed. The fuzzy guys can’t take it but it doesn’t bother the feathered guys.
Focus on methane
In Fred Pearce’s article on controlling methane emissions, Euan Nisbet is quoted as criticising the hundred-year rule used for calculating the atmospheric warming effect of methane (16 February, p 6). This time frame is used because it is intended to account for the indirect as well as the direct contributions of methane. Although methane has a turnover time of about ten years in the atmosphere, the CO2 released as it is broken down has a turnover nearer to a hundred years.
However, as noted in the Intergovernmental Panel on Climate Change’s Supplementary Report (1992), the indirect effect of the CO2 released applies only to fossil methane emissions. The use of the same global warming potential (GWP) to convert all methane to its CO2 equivalent gives too high a value because methane from biosphere sources has a GWP of 11 whereas fossil methane has a GWP of 21. As biosphere methane emissions account for 70 to 80 per cent of anthropogenic methane emissions, the current calculations overemphasise rather than underemphasise its contribution to global warming.
Methane emissions from biosphere processes form part of the contemporary carbon cycle and do not add new carbon to the atmosphere. Surely the emphasis must be on reducing all emissions that feed new carbon into the atmosphere.
Stocks of doom?
It seems likely that the anthrax used in the recent attacks in the US originated from stocks held by the US government, and quite possibly from someone working within a US government programme (9 February, p 8). This is very damaging to the US’s argument for keeping stocks of such potential weapons. The justification has always been the need to develop means of fighting possible attacks. However, it is now clear they can also be the source of the attacks themselves.
Thankfully, whoever was behind this seems to have had access only to anthrax, and not to another agent such as smallpox. It is now time to think again about destroying all remaining stocks of smallpox and other potent biological weapons before they too are turned against their supposed masters.
Anthrax and several other organisms that could be used as weapons are widely available in the wild, unlike smallpox. However, the “weaponised” forms exist only in labs 鈥� we hope鈥擡d
Furious fish
The finding that fish can distinguish between different types of music will come as no surprise to fans of the British TV comedy The Goodies a few decades ago (19 January, p 24).
The lads had bred a giant salmon as an offensive weapon, but they were disappointed to find that it wouldn’t attack people. They cured this particular drawback by playing Max Bygraves’s Tulips From Amsterdam to it through underwater speakers, which made the fish extremely aggressive.
I know exactly how it felt.
Down the tubes
David Stevenson’s contempt for the research done by Eunok Jung on the “valveless pump” is not justified by his explanation of the phenomenon (23 February, p 53).
Static longitudinal displacement of the column of liquid in the rigid tube produces no net change of pressure or volume in the flexible section. Therefore the liquid in the rigid section of the tube does not behave like a metal rod suspended between two springs, as he claims. Its “ends” are linked kinematically and dynamically by the fluid in the flexible section.
The term “phase differences between the frequencies of oscillation” is meaningless鈥攆requencies don’t exhibit phase differences. A linear model of the system (for very small amounts of squeeze) does not exhibit mean flow “start”. Perhaps Stevenson could direct us to the publication in which this non-linear phenomenon is modelled and rigorously explained, thereby supporting his contention of wheel reinvention.
Letter
You express surprise that the valveless pump appears to have an auto reverse (2 February, p 38). Some 30 years ago I played with such devices while studying for my electronics degree鈥攁nd realised that the solution was similar to the electronic circuits with which I was familiar.
Consider the hydrodynamic impedances looking in either direction from the squeezed portion. Clearly, it would be difficult to make them exactly equal. Unequal impedance in opposite directions will provide the equivalent of a diode, and hence allow a preferential flow in one direction.
The tricky part of the problem is in the calculation of the impedance. The ring is a lossy circuit鈥攊t dissipates energy. In electronics terms, it has relatively low Q. With some tedious but not difficult mathematics it is possible to show that the variation of impedance varies with pulse rate and follows an “S” curve. In other words, low frequencies meet a “diode” facing one way and higher frequencies a “diode” facing the other way.
I am not surprised that the circuit could have several reverses. You’d expect the number of pulses in the system to cyclically vary the impedance, making the “S” curve one part of a sine wave, although I didn’t take my considerations that far.
Vomit recognition
I was fascinated by your piece on “Jurassic barf” (16 February, p 9). I wondered how it was that Peter Doyle’s team recognised the prehistoric puke in the first place. Little bits of fossilised carrot, perhaps?
Correction
The story “Vaccinate or go to jail” (23 February, p 17) should have read “Washington DC’s Department of Health”, not the “US Department of Health”. The measures referred to have only been taken by the city, not the entire country.
Also, our article on antimatter (23 February, p 11) stated that antihydrogen atoms were first detected at Fermilab in 1996, when in fact similar observations were made at CERN in 1995. Antimatter particles have been trapped before. The team was instead reporting on the possible creation of antimatter atoms.
Finally, the Great Britain team won one more medal at the Winter Olympics than the two predicted by Harvard economists, returning with a gold and two bronze, not one less as reported last week (2 March, p 5).