Letters archive

It is no surprise that it is "value ranges" of processed meat products that are being identified as containing horsemeat, sparking public concern and official investigation (16 February, p 6) . And perhaps it is not surprising that this is being seen in products that should contain beef – a more expensive meat than, say, …

Your story on how the brain stores and organises words gave a fascinating glimpse into the neurological underpinning of category formation (5 January, p 10) . It reminded me of the distinction, emphasised in old-fashioned books on logic, between the denotation and connotation of words. The denotation of the word "salmon", for example, is the …

Brian Farrington suggests that people who do not want wind power on their doorstep should be offered an incentive to accept it (2 February, p 28) . I suggest that for equity those affected by thermal power stations should be offered an incentive, backdated to when the facility was built. While we are at it, …

You report the discovery of the largest known prime number in the Great Internet Mersenne Prime Search (9 February, p 7) . Mersenne primes are based on the formula 2 p – 1, where p is a prime number. Let's call the result L. Logically then, 2 L – 1 must also be a prime, …

I am shocked at the possibility that the UK's Royal Institution will close its doors (26 January, p 27) . As a retired professor of physics, whose membership of the institution extends back decades, I am drawn to visit it when in London. Its history of active research and educational outreach to a very wide …

Stephen Corry writes of the poor outcomes for tribal people when nation states are imposed on their way of life (9 February, p 32) . Settlers encountering inconvenient tribalists are likely to wipe them out completely. There was a lot of this in North America, including intentionally distributing blankets from smallpox victims to Native Americans. …

Thank you for the cute photograph of a lonely red squirrel in Aperture (9 February, p 26) . The text, however, raised some questions, saying the grey squirrel has "outcompeted the native reds for food and habitat" over most areas of the UK during the last century. But how much is grey competition to blame …

There are indeed liberals and progressives who have unscientific beliefs, as Alex Berezow and Hank Campbell point out (2 February, p 24) . But in political parties with left leanings, these unscientific beliefs are relegated to the fringe, whereas, they are in the mainstream of the US Republican party. Maybe the fact, as reported in …

I'd like to shed more light on the possible purposes of sleep and dreaming ( 2 February, p 30 ). Throughout my active life I have always solved my most intractable problems, mostly technical, while asleep – provided that I first prime myself by going through the history of the problem in a logical sequence. …

Your look at how fonts can mess with our minds highlighted the fuss over Comic Sans being used in a presentation announcing the possible discovery of the Higgs boson at CERN (22/29 December, p 68) . In a technical context, lack of precision can easily lead to misunderstanding or even danger. Comic Sans is one …

Your article on fertilising crops with human sewage omitted one key point (16 February, p 48) . Plants have a highly efficient water-treatment system of their own. In the outer layer of the roots – the cortex – water travels largely through and between the cell walls, which form a very fine physical filter. At …

• We are irate at having said that an Aristotle quote was from Rhetoric , rather than Nicomachean Ethics , in our look at the possible upsides of anger (9 February, p 48)