Homeopathic whisky
If homeopathic methods of drug administration work so well, why hasn’t anyone started selling homeopathic whisky? This approach also strikes me as a great way to get round illegal possession of recreational drugs, as no trace of the offending substance will be detectable by conventional forensics. Big dealers must surely have explored this obvious trick, so the absence of homeopathic cocaine, cannabis and heroin suggest that there’s nothing in it in more ways than one.
Cheerio humanity
It was frustrating to read the claim that enhancing ourselves would be objectionable because it would result in us “throwing away” our humanity (13 May, p 32). When an offshoot of Homo erectus evolved down a path towards humans, did they lose their “Homo erectusness”? Of course they did 鈥� and it was without doubt a good thing.
With suitable enhancements to ourselves we will undoubtedly and gladly throw away our primitive humanity and be better off for it. Thriving with the amazing advantages to be had in this transition we will no doubt look back with enlightened pity on the tragic “humanity” that people once held so dear.
Beware Arctic cruises
I wonder what your former editor, Alun Anderson, makes of the juxtaposition of the article about polar bears suffering the effects of global warming (6 May, p 10) and the advertisement on page 22 of the same issue in the UK edition for the “Kingdom of the Ice Bear” cruise he is hosting, with flights to Canada from London.
Anderson was editor-in-chief when an article entitled “Beware the ecotourist” was published, beginning: “Something weird is happening in the wilderness. The animals are becoming restless. Polar bears and dolphins…are becoming stressed. They are losing weight, with some dying as a result. The cause is a pursuit intended to have the opposite effect: ecotourism” (6 March 2004, p 6).
Alun Anderson writes:
鈥� There are some important issues here. First, you need to check that the operator of any “ecotourism” holiday meets top standards. This particular tour does, and you can find more details on the operator’s website. Then there is the bigger issue of whether we can justify any form of travel that emits greenhouse gases. My personal answer is to use a carbon offset service. At a cost of 拢10 or so for a one-way long-haul flight, it is a way of ensuring that your impact on the environment is reduced. I would encourage anyone travelling anywhere (except on foot or by bicycle) to offset their carbon emissions. Finally, global warming and its impact on the Arctic will be a lecture theme on this cruise, and I would hope that those going on it will return as activists who will try to do something about it.
How bird flu spreads
The rapidity of the spread of H5N1 avian influenza has meant that policies have had to be formulated in advance of proper scientific understanding (20 May, p 24). This has led to conflict between ornithologists and virologists, some of whom have entrenched views as to the relative importance of the main routes of transfer.
The reality is that movements (legal and illegal) of poultry and poultry products, the wild bird trade and movements of wild birds have all contributed to the global spread of the disease. Highly pathogenic avian influenza viruses are very rare in wild birds, and there has been much debate amongst ornithologists as to whether wild birds can transmit the disease. Our organisations have always accepted this possibility, and the spread of H5N1 to many European Union countries in February, prior to any outbreak in poultry, confirmed that view.
Our scientists have been working together since August 2005 to advise the UK government on the risks of wild birds bringing the disease to the UK and to undertake monitoring and surveillance. We will continue to devise future surveillance and risk assessments, in order to better inform policy decisions.
It is high time for a multidisciplinary approach, concentrating on the real issues. In the developed world, the disease poses huge risks to the poultry industry and national economies. In developing countries, it threatens food security and has had a devastating effect on people’s livelihoods. Culls of wild birds won’t stop the virus spreading, but the risk from wild birds can be managed through surveillance and biosecurity.
The risk to human health posed by wild birds is minimal, provided people avoid diseased birds. However, the risk of the virus mutating or recombining to a form capable of sparking a human pandemic is greatest in south-east Asia and Africa. In these regions, unrestricted poultry movements, lack of capacity to control the disease and poor public awareness are the overriding issues.
Image explained
Feedback wonders about picture captions that say “Image for illustration purposes only” (13 May). I work for a large office automation firm in South Africa and we have similar notes on pictures of our products. This is because it is not feasible to take a picture of each and every small hardware upgrade to our existing range of products. The product in the photo might differ slightly from the actual machine our clients receive.
Trauma of Gulf wars
You quote a report by Simon Wessely of King’s College London as saying that “serving in Iraq does not increase the risk of post-traumatic stress disorder”. You then add that the report “also found no evidence for the existence of ‘Iraq war syndrome'” (20 May, p 7). These statements surely raise the question of what led to the apparent differences in the health effects of these two Gulf wars.
The privately funded inquiry chaired by Lord Lloyd into the ill-health, and in some cases death, of more than 6000 British troops following the first Gulf war reported in November 2004: “The roles of multiple vaccines, pyridostigmine bromide and organophosphate-based pesticides require serious consideration as possible causal agents, particularly in combination.” It is surely incumbent upon the UK’s Ministry of Defence to assess the differences in administration of the above substances, even if this means it will have to admit responsibility for at least some of these British casualties.
The editor writes:
鈥� In their report, Wessely and his colleagues mentioned similarities between the treatment of soldiers in the two wars, as well as differences. The same pesticides were used in both. Depleted uranium was used in both conflicts. The same anthrax vaccine was used in both wars, though the combination and administration of vaccines was different. The authors of the report say in the The Lancet: “Although pyridostigmine bromide was issued in both conflicts, the pattern of vaccination changed. In 1991, personnel were offered the combination of vaccinations against anthrax (linked with pertussis as an adjuvant) and plague. In 2003, anthrax and plague vaccines were given without pertussis. Efforts were also made to space out the timescale in which vaccines were given…but observational data such as ours do not permit any definitive conclusions about whether or not these changes made any difference.”
Leaky gravity
The visible stars and other bodies do not move in the manner we would expect, given the gravitational pull of the matter visible to us. This has led to the theory of “dark matter” as the source of the remaining gravity, even though we don’t know what this dark matter is, and cannot even detect it beyond its gravitational effects on the celestial motions of visible bodies.
Perhaps it is not detectable because it is not there, at least not in this universe. When discussing extra-dimensional travel and its consequences on time travel (20 May, p 34), it was mentioned that in string theory the graviton, the hypothetical carrier of the gravitational force, is represented by a closed loop. As such it is not bound to this “brane” and is free to leave and travel into the 10-dimensional “bulk”. This is suggested as the reason why gravity is so weak compared to other forces: it leaks away out of this universe.
If gravity can leak out of this brane, then why shouldn’t it be able to leak in as well? If so, the dark matter which holds galaxies together could in fact be galaxies (or some other collections of mass) in other, neighbouring branes from which gravity is leaking into our own. This would explain why dark matter is undetectable and has a consistent pattern to its distribution.
Law-abiding insect
Buried in your article about Chikungunya virus is what appears to be the amazing discovery of an insect that respects international borders (22 April, p 14). According to the map shown, the tiger mosquito has managed to spread through the entire lower 48 states, and reach Alaska, yet stop short of the Canadian border. Perhaps, despite its fearsome name, the tiger is frightened of our cold winters, and sparrow-sized home-grown mosquitoes.
For the record
鈥� Apologies to Stanley Deser of Brandeis University, whose first name we got wrong when we quoted him in “Head ’em off at the past” (20 May, p 34).
Cost of power
The electricity grid may have worked well as a centralised network for the last 70 years, as Alan Shaw says in his letter (20 May, p 26), but times have changed, as have priorities and energy markets.
The economies of scale he refers to are not the only ones that are relevant. Mass production of equipment suitable for domestic installation is another scale economy, and it means that generators in the 1 to 20-kilowatt range are now much cheaper per kilowatt rated capacity than any large power station, regardless of type. While these generators are less efficient by the narrow measure of the proportion of mechanical energy they convert to electrical, this is more than offset by the absence of transmission costs and losses, and the opportunity to capture and utilise what would otherwise be waste heat.
A programme of replacement of worn-out central heating units with micro combined-heat-and-power units coupled with heat recovery systems could match the output of several nuclear power stations, and in less time. Training the necessary service personnel would also take a lot less time than the 10 years a nuclear power station is quoted as requiring for construction.
From Steuart Campbell
A. Wills claims in his letter (20 May, p 26) that “large amounts of carbon” are emitted during the nuclear fuel cycle. This is contradicted by an authoritative study based on 22 countries carried out within the framework of the DECADES project, undertaken jointly by the International Atomic Energy Agency and eight other international bodies. The study shows that, taking account of the full fuel cycle for various methods of generating electricity, nuclear power produces far less carbon dioxide per kilowatt-hour than any other method: 60 per cent less than wind turbines and 93 per cent less than hydro (see ).
Edinburgh, UK
From Bob Muirhead
Wills makes the obvious point that nuclear power generates CO2 and has other problems if one considers mining, transport, equipment manufacture and so on. So does every other method of power generation.
There are also other factors that might be considered. Coal-fired power stations cost the lives of hundreds, possibly thousands, of miners every year. Let’s put a value on those too. The silicon for solar panels has to be produced from sand in an energy-hungry process. Wind farms and large solar arrays occupy land and destroy visual amenity wherever they are built. What is that worth? Let’s also include all the costs of beefing up the national grid to cope with the variability of solar and wind power, if they ever comprise a significant portion of the total load.
We may expand the box as wide as we like when looking at the life-cycle cost of any method of power generation. The important thing is to use the same box for all methods of generating power, even the so-called “green” ones. Nuclear power may not look too bad if it is evaluated in an objective, ideology-free manner.
Port Melbourne, Victoria, Australia
From Mark Barrett, Bartlett School of Graduate Studies, University College London
Alan Shaw may be interested in our submission to the Energy Review, which includes a summary of a 95 per cent renewable electricity system. The matching of renewables with demand using load management, storage, trade and fossil back-up is explored with models that combine hourly simulation and optimisation. The submission may be downloaded from .
Such a renewables-based system uses technologies that are, or can be, mass produced, present no risk of human or energy supply catastrophe, produce no enduring waste, are immune to the scarcity and prices of imported fossil or nuclear fuels, can be insured on the open market, and do not require economic underwriting or special security measures and information restriction by future governments for decades and centuries. At the end of their lives, renewable technologies can be removed, virtually without trace, and replaced with improved or different technologies. These technologies are compatible with a free market and a flexible long-term energy strategy.
This is not the case for nuclear power. Furthermore, a largely renewable system requires variable back-up that nuclear cannot provide technically and economically. Irreversible sunk investments in nuclear power will delay the development of a fully sustainable renewable system for at least 50 years 鈥� the time span for constructing and operating a new tranche of nuclear stations.
The best policy is to use fossil fuels efficiently in combined heat and power plant during a transition to renewables over the coming decades. Even better technologies and integration than that proposed in scenarios exemplified by our submission will have been developed by then.
London, UK
From Tom Robertson
The production of fuel for nuclear generation does indeed, as Wills has pointed out, require the expenditure of energy and, inevitably, an associated release of carbon dioxide into the atmosphere. But fair’s fair, if this applies to the production of nuclear fuel, it also applies to the processes that are needed to extract a fossil fuel, convert it to a usable state and then deliver it to various dispersed points of use.
Wills also appears to have overlooked the point that energy, not fuel, is the final product. CO2 emission per unit of energy produced is therefore the proper criterion for assessing the relative environmental impact of different energy sources.
Is he really under the impression that the energy obtainable from a chemical fuel approaches that of a nuclear fuel on a weight-for-weight basis?
Milton, Oxfordshire, UK
From John Skidmore
Wills’s analysis of the carbon cost of nuclear power generation is misleading. Although it is correct that carbon is emitted at early and late stages of the nuclear cycle of power generation, carbon is emitted at all stages in the cycle of power generation by fossil fuels. So if the objective is to minimise the emission of CO2, the answer is to build new nuclear power stations.
Kangaroo Valley, New South Wales, Australia