Letters archive

Tremendous! Your special issue on the root cause of our problems – the pursuit of unrestricted economic growth – brings together information and insight superbly (18 October, p 40) . It's something to read and digest again and again. Warm thanks and congratulations. From Thomas Hogg Arguments for a stationary no-growth economy, while well-intentioned, are …

Your questioning of the predictive ability of some financial models is too cautious (27 September, p 5) . Financial systems are complex and highly non-linear (though probably not truly chaotic). This means that they are inherently unknowable and it is impossible – especially when national finance systems are linked together into a single meta-system – …

I find Andrew Robinson's list of Einstein's scientific "errors" in his critique of Hans C. Ohanian's book on the subject (27 September, p 48) rather odd, to say the least. One of them is apparently that Einstein "should have realised that the constancy of the speed of light had to be established by experiment, not …

Doubts about the use of polygraphs have been around for much longer than you report (4 October, p 8) . In G. K. Chesterton's Father Brown story The Mistake of the Machine , published in 1914, a polygraph detects stress in a prisoner accused of murdering Lord Falconroy. The reason isn't guilt: the prisoner is …

Katsufumi Sato's observations of albatrosses lead him to conclude that the maximum weight of a soaring bird is 40 kilograms, casting doubt upon the abilities of a 250-kilogram pterosaur (4 October, p 10) . If both albatrosses and pterosaurs of 200 million years ago flew using air currents, would this imply that the currents were …

I have just noticed that Lawrence Krauss's great programme on origins at Arizona State University (27 September, p 49) , and the big public event to be held in Phoenix next April, have only chaps listed as speakers so far. Humph.

Thanks to David Burman for pointing out the dangers inherent in the use of lithium-ion cells in electric cars (11 October, p 20) . Thank goodness we do not have many vehicles using flammable, potentially explosive energy-storage systems on our roads today. Think of the carnage if every vehicle carried fuel tanks which, if damaged …

• Several readers expressed surprise at our report of meteorologists at the University of Reading detecting gravity waves in the jet stream (11 October, p 23) . To resolve any ambiguity: fluid dynamicists have been talking about "gravity waves" at the interface of air masses (or air and water) since the 1950s at least. These …

While I agree wholeheartedly that we are on the wrong path with regard to what we wish to bequeath to our descendants (18 October, p 40) , you need to address responsibility and risk. Power needs to be mediated with unavoidable responsibility – as it is for engineers. Economists, as far as I know, have …

Rob Jameson looks at how investment bankers, hedge funds, pension fund managers and their fellow institutional travellers employ a "value at risk" number to try to make a profit using the vehicle of derivatives (27 September, p 8) . Unfortunately, the theoretical aggregate value of these derivatives has grown to a monstrous, inconceivable $120 trillion, …

Feedback deplores a misleading argument in favour of plastic bags, in the claim that burying them in landfill is carbon sequestration (27 September) . The issue is not as simple as Feedback makes it out to be. Where I live, most garbage goes into a landfill. Our old landfill – Fresh Kills on Staten Island, …

I was intrigued by Helen Phillips's description of "athletic minds" (4 October, p 28) . After I retired from the British army I started a business developing optical sights – which involved thinking about aiming. It is clear to me that the brain can point a finger at a chosen point whether you are currently …

• We unaccountably passed through a misspelling of the classic heavy metal artist Ozzy Osbourne (Web letter, 18 October) . Sorry. Johann Pachelbel, Björk Guðmundsdóttir and Einstürzende Neubauten, nae probs.