Letters archive

As a former director of the British Olympic Medical Centre, I totally agree with Katrina Karkazis and Rebecca Jordan-Young's condemnation of the new sex-testing rules for female athletes (21 July, p 26) . All elite athletes are statistical outliers of our species, be they genetically advantaged by high-speed type IIx muscle fibres for sprinters and …

Steve Haake's fascinating Instant Expert on sports engineering (7 July) revived a thought I had, long ago, in my shot-putting days. Having relatively small hands, and finding the 16-pound (7.26 kilogram) shot difficult to grip, I could not help thinking that if it were made of tungsten – which is nearly two-and-a-half times as dense …

You report on a successful trial of ocean iron-seeding to promote plankton growth and potential carbon sequestration via the sinking of their remains to the depths of the ocean (21 July, p 15) . In demonstrating that at least half the material disappeared into the deep sea, the trial by Victor Smetacek and his colleagues …

That multiple personality disorder, also known as dissociative identity disorder (DID), might be supported by brain scan evidence and be used as a legal defence by a person's "normal" personality, opens a can of worms (7 July, p 10) . We all have various denial and defence mechanisms from an early age which are integral …

So there have been some nationalistic concerns that the great accomplishments of Pakistani physicist Abdus Salam and Indian physicist Satyendranath Bose have not been sufficiently appreciated within the historical context of the recent discovery of the Higgs boson (14 July, p 5) . Physicist Jim Al-Khalili's depiction of the two is accurate: among physicists both …

Your feature on disgust (14 July, p 34) rekindled a relevant memory. Several years ago while working in Denmark, I visited the magnificent Aalborg Zoo. The gorilla enclosure was separated from visitors by a clear screen rather than bars, and so you could get quite close to the animals. One particular day many parents and …

You mention North Korea's capital Pyongyang as a "drab and featureless" city for lacking billboards, neon signs and shopfronts (19 May, p 3) . But I lived and worked there for a few months, and found it surprisingly beautiful and clean, with lots of parks, viewpoints, attractive buildings, recreation spots and fantastic subway stations.

In his letter, Paul Bennett says that he bears witness to drunken waxwings (16 June, p 33) . I can bear witness to drunken cows. I used to live on a commune in Glastonbury, Somerset, UK, where the farm animals could wander at will. The cows used to go into the orchard and eat fallen …

Letters from Roger Taylor (14 July, p 28) and John Hastings (14 July, p 29) highlight a problem with politicians. Basically, not just in North Carolina where they contemplated a bill to forbid predictions of accelerating sea-level rises, but in most elected governments, politicians are not clever enough to understand complex issues such as climate …

I have always been surprised at the annoyance over Pluto being "demoted" to dwarf planet status (21 July, p 11) . The meaning of the word planet has changed as new discoveries have been made. Pre-Copernicus, the sun and moon were considered planets because they were lights in the sky seen to move in a …

Robert Bright is undoubtedly on the right track with his biological theory of why some objects multiply while others disappear (14 July, p 29) , but is late to the game. Avram Davidson was first, though the life cycle he described in his short story "Or all the seas with oysters" ( Galaxy Science Fiction …

• In our piece on von Economo cells (21 July, p 32) , we claim that time seems to pass more slowly when we feel excited emotionally. In fact, we probably perceive time to pass more quickly when there is more emotional information to process.