Letters archive

As a philosopher with a background in biological science, I applaud your recent special issue on reality ( 29 September, p 34 ) as a valuable marker of where we are, and aren't, on this important topic. The take-home message is that those parts of "reality" that are simply our human constructions – "objects" such …

I suggest an alternative to "truth decay" in explaining the half-life of citations (22 September, p 36) . New lines of research that give hope of a breakthrough attract many researchers, who then publish on them. Over time, progress generally slows and the breakthrough fails to happen, so researchers switch in droves to the next …

In her letter, Susan Hall identifies many behavioural patterns that would have been socially acceptable in the past, but which we now find unacceptable, such as racism (13 October, p 31) . It is worth pointing out that various behavioural memes connected with rationality, fairness, altruism, propriety and egalitarianism have been growing and spreading in …

Amanda Gefter endorsed physicist Eugene Wigner's sentiments on "The unreasonable effectiveness of mathematics in the natural sciences" (29 September, p 38) . Perhaps there is a simple and straightforward explanation for the prescience of mathematics. Think of mathematics as essentially the study and classification of all possible logical structures, of all possible patterns. The range …

It is not the case that "farmers in England and Wales are keen to get on with the controversial cull" of badgers (20 October, p 8) . No cull was planned in Wales: instead the Welsh government has opted for a trial vaccination program.

Michael Marshall's article fails to address the major concerns of those of us who are alarmed at the roll-out of GM crops (13 October, p 8) . My summary of these concerns includes: the lack of real checks to counter the economic and political lobbying power of the large corporations that promote these technologies for …

I was struck by the relationship between the letters from Mike Pollard (6 October, p 30) , who believes we need to accept carbon capture and storage as the pivotal technology to combat climate change, and Joe Muggs (p 30) , who wonders whether we can identify those crucial decisions in life that define our …

Your look at animal memory mentioned Santino the chimp, who collects and hides rocks to later throw at zoo visitors (6 October, p 34) . This reminded me of a visit to a French zoo, where the chimps were in a glass enclosure, the glass panels held in place between steel columns, with small gaps …

My autobiographical memories fit the general pattern described in your feature (6 October, p 36) : I have few before the age of 5 or 6. But my wife has many memories before 5 and even one before 1. In 1980 she recounted for the first time a memory of being held in her mother's …

You report the US Presidential Commission for the Study of Bioethical Issues as concluding: "policies should protect individual privacy by prohibiting unauthorized whole genome sequencing without the consent of the individual from whom the sample came" (20 October, p 5) . What, given a lawyerly reading of this, would stop sequencing of, say, 80 per …

Back in the mid-1970s (yes, I am that old) I was involved with some iconoclastic engineers and scientists. One of the issues much discussed was an impending technological dark age caused by the disparity between focusing on "application" and "knowledge" about a technology – electronics, for example. How many "computer" scientists or engineers, or indeed …

So, infusions of young blood keep older brains healthy – in mice, at least (20 October, p 10) . Would this suggest that Dracula, with his taste for the blood of young virgins, was on to a good thing?

• We got the title of Stephen Cave's book wrong (20 October, p 40) . It is in fact Immortality: The quest to live forever and how it drives civilisation .