Letters archive

Creating an accurate map of the brain's connections is certainly a monumental undertaking (5 February, p 32) and Douglas Fox rightly compares it to the early days of genome research. Like the sequencing of the human genome, which was long believed to be impossible, mapping the entire human brain will be greatly aided by advances …

In spite of the impressive achievements of artificial intelligence in controlled environments, no mathematical technique of information processing will ever produce an "intelligent" robot able to perceive implicit possibilities in a non-controlled environment (29 January, p 28) . The reason is simple. We store concepts and memories of objects not as combinations of logical properties, …

The gushing praise in your publication and elsewhere for IBM's Watson supercomputer seems to me unwarranted (19 February, p 6) . Watson did indeed win the Jeopardy! matches, but I became suspicious while watching them as I could answer a sizeable percentage of the questions, and I am sure the two human competitors could have …

I was horrified by the proposition that we should send life to other planets (5 February, p 40) . Why anyone should seriously favour contaminating ecosystems on other planets with terrestrial bacteria I find hard to understand. Let's not forget that it is likely that such ecosystems do exist. Organic compounds are common even on …

I found it strange that your article about the darkening of some of van Gogh's yellows suggested that the cause of chrome-based paints darkening over time was unknown (19 February, p 5) . Having worked with a major manufacturer of chrome pigments for 20 years, I can tell you that the overwhelming cause is exposure …

While reading Roger Highfield's article "Days of wonder" about the strange science of everyday life (19 February, p 34) , I was particularly interested in our apparent inability to recognise even very obvious changes which happen right before our eyes. After having had a beard for 27 years, I shaved it off. People who had …

In the interests of experimental repeatability I decided to test the idea that women find men wearing red more attractive than those wearing other colours, as mentioned in Helen Thomson's article (12 February, p 36) . I bought myself a plain red shirt and went to the local bar on a Saturday night. Despite remaining …

There is a small error in your editorial "The legacy of BSE" (29 January, p 3) . You state that "in one infamous spectacle, TV viewers watched the agriculture minister John Gummer ostentatiously feeding a beefburger to his young daughter to reassure an increasingly uneasy and sceptical public". In fact, what TV viewers saw was …

The question of whether you prefer the circle constant pi or tau is essentially the same as whether you prefer radius or diameter (8 January, p 23) . Mathematicians tend to prefer radius, as it makes for neat equations and can be used for setting their compasses. Engineers, on the other hand, prefer diameter, as …

• We incorrectly stated that the bellbird has become extinct on New Zealand's North Island (12 February, p 18) . It has actually become locally extinct in the north of the North Island, but can still be found in the south of the island. • Lagrange points actually lie 60 degrees ahead and behind a …