Choose life

Letters– Nanotubes in mind From Ian Rubenstein Your fascinating article on the recently discovered “membrane nanotubes” linking cells (15 November, p 43) immediately led me to a potentially novel hypothesis: perhaps these structures are involved in the generation of consciousness. There are two rather common medical phenomena that are still somewhat mysterious, which this idea may help explain. The first is concussion. On the current assumption that conscious processes depend solely on “classical” neuronal synapses, it is hard to envisage how a sharp blow to the head could cause shear stresses on the brain sufficient to disrupt synapses and cause a brief loss of consciousness without causing major tissue damage. If conscious processes were dependent on these tiny, dynamic cell-to-cell interactions – which are prone to mechanical disruption but quickly repaired – then this might explain concussion. The other persistent mystery is how inhaled anaesthetics actually work. The 1965 rule proposed by pharmacologist Hans Meyer and biologist Charles Overton is that anaesthetic effectiveness of inhaled agents is proportional to their solubility in lipids. It is unclear why this is. It has always been assumed that it is because the agents dissolve in membranes and disrupt ion channels, but this is unproven. Perhaps these cellto-cell connections are easily disrupted by subtle chemical changes and could be involved – especially as these anaesthetic agents have a predilection for membrane structures. Ponders End, Middlesex, UK

sci-fi was based on science, which is debatable. Dominated by dystopias in the mould of the likes of Blade Runner, this is a genre in danger of burning itself out. New writing strives to weave in new physics ideas, but belief is often suspended too long by a hair too fine; and who reads books much today? Or is the problem that new physics itself is treading water? Or that sociology is not a science, at least not one you can write science fiction about? Melbourne, Australia From Charles Raymond Science fiction is not about predicting the future. The socalled “failure” of sci-fi to predict the transistor (15 November, p 46) is not so much a failure of sci-fi, but a triumph of real science doing something revolutionary and unexpected. The entire basis is “what if”. Some recent short stories by Bruce Sterling involve speculation into the not-distant future based on science as we know it now: bedroom-based biohackers, or people practically commanded by their cellphones to do seemingly random tasks. Perhaps the most valuable thing of all about sci-fi is getting people interested in science, to ask “What is the basis behind this?” or even “I wonder if that could really exist…” Waddington, New York, US

Science friction From Tony Appleyard You unearth some problems with modern science fiction (15 November, p 5). Future fiction it is, science it ain’t, often – if ever 18 | NewScientist | 20/27 December 2008

Small-scale energy From Chris Knapton Adam Hockenberry rightly asks why we should continue to use

the massive and centralised approach to renewable energy rather than diffuse and small systems (22 November, p 24). The answer is that both government and the power industry need these systems to control and profit from our energy use. Self-sufficiency can never be a goal for such organisations. If society wishes to change to a self-sufficient energy model it must contrive that not only the suppliers of the technology but also the power industry and government have a viable revenue stream. If that cannot be done, I suspect no effective effort will be made to allow us to harvest our own power. It will remain a cottage industry, tolerated until it becomes too large to ignore – then taxed. Southwell, Nottinghamshire, UK

Choose life From Derek Coggrave Last year David Cohen reported that “zinc could be used up by 2037” (26 May 2007, p 34). You later introduced Mark Buchanan’s commentary on the recent misery created by the excessive use of credit/leverage within the free market system by saying: “Forget textbook economics, the answer lies elsewhere” (19 July, p 32). Your special issue on resources shows the human population increasing exponentially (18 October, p 40). All this indicates a bubble in the making, and the likely outcome is a crash resulting in misery on a grand scale. David Suzuki wrote that politicians are “just focused on the next election. When you talk to business people, they’re just focused on the quarterly report” (18 October, p 44). And Gus Speth concluded that “we’re trying to do environmental policy and activism within a system that is simply too powerful” (18 October, p 48). If governments and world institutions cannot provide change from the top down, the only alternative is to work from the bottom up. A solution to the inevitable

failure of the current economic system would be an appeal to the billions of individuals who will decide the future. It would be on the lines of a declaration by those prepared to participate: each individual would agree to live by such means that they would preserve and where possible enhance, by the time of their death, the environmental conditions they inherited at birth. This is not too much of a sacrifice to make for the benefit of those who will come after us. London, UK

Fat for fuel From Barry Osborne On the theory that every little bit helps in trying to close the US oilfor-fuel gap, I suggest we collect the fat obtained from obesityreducing lipectomies and convert it into biofuel. The idea is a bit icky and weird, I know, but I find the subject does make for some fascinating conversations: on what kind of mileage I might expect to get if I were to turn in the roll of chubbo that rings my own middle, for instance. Santa Barbara, California, US

Dangerous sex in a pill From Bernd Brunner I am terrified by Clare Wilson saying an “intelligent and wellinformed” gay man “sometimes” has unsafe sex (22 November, p 40). Is that not a contradiction? I do not believe that this kind of behaviour is “not that unusual”. Berlin, Germany www.newscientist.com