Letters archive

In your exploration of chance, you state that the probability of 26 consecutive black numbers in roulette is 1 in 136,823,184, and mention this happened in Monte Carlo in 1913, as if that was somehow surprising (14 March, p 28) . What is surprising is that this doesn't happen more often. There are some 3500 …

Regina Nuzzo suggests that choosing between Bayesian and frequentist methods of probability is "horses for courses" (p 38) . Like choosing to get home by taking the Bayesian bus or the frequentist train; both will get you there, but via different routes. It is not so. In essence, a Bayesian estimates the probability that a …

Sumit Paul-Choudhury's interesting review of The Nether (14 March, p 44) , a play which examines the morality of a virtual clubhouse for paedophiles, got me thinking. What about books with content that I find horrible and offensive? If people are to be prosecuted for their imaginations, and for indulging in their fantasies in a …

I read the various comments on proposed head transplants with interest (14 March, p 54) . Even if such transplants are desirable and the spinal cord can be successfully reconnected, no one has mentioned the autonomic nervous system. Parts of this run outside the spinal column and are important in regulating a variety of internal …

Helen Thomson's article on head transplants was exciting stuff. I generally feel the stir of a good debate to be quite healthy. Surely though, in line with current transplant procedures, in which the new body part is featured in the title of the operation – heart, liver, kidney, etc – the proper name for Sergio …

Jacob Aron's article on the new generation of virtual reality (VR) equipment focuses on its use in films or games (7 March, p 20) . As the article notes, this can cause problems: in the case of games, the viewer can't see his or her controller, and in the case of films, he or she …

I confess to being less than convinced by Pat Shipman's explanation for the extinction of the Neanderthals (14 March, p 26) . She begins by describing the similarities between modern humans and Neanderthals, and the fact that we interbred, but her assertion that this was rare is not substantiated. I would have thought that the …

I enjoyed Helen Phillips's recent article on the neurological changes in the brains of people who experience migraine (7 March, p 38) . About 35 years ago, when much less was known about the disorder, I attended a lecture in which an eminent US physician described the typical patient at his migraine clinic as a …

With a family history of migraineurs going back at least three generations, I was prone to motion sickness which was exacerbated by flickering lights, such as that caused by driving past tall trees. I suffered no headaches until I started using a contraceptive pill in the 1970s. Frequent migraines occurred thereafter, even without the pill, …

David Hambling mentions that the UK Royal Navy developed a laser system to blind attacking pilots in the 1980s (7 March, p 44) . In fact, it was a Ministry of Defence establishment that put an experimental laser on HMS Hermes during the Falklands war but it was never used. I learned recently that naval …

Further to letters on self-driving cars (28 February, p 54) , people only misbehave when they think they can get away with it, or if they don't care about the consequences. Self-driving cars will have cameras recording everything around them. Anyone breaking rules to disrupt traffic flow will be easily identified. If the consequences include …

Further to earlier letters, there is another reason why aliens may not have visited us (7 March, p 53) . Any aliens advanced enough to cross the galaxy are likely to have strict rules about contaminating new worlds with their presence, much like scientists here have when visiting undisturbed places. To such an advanced race …

Victoria Esses's article on immigration is a breath of fresh air in a stale and depressing debate (7 March, p 26) . She is more qualified than I to estimate the importance of rationality in this zone, so it is encouraging to hear her optimism for the possibilities in nations built on immigration. Yet I …

Calculations of the carbon footprint left by our consumer purchases tend to be complicated by how deep one gets into the supply chain. What would be the carbon footprint of driving my rare-earth filled electric vehicle (14 February, p 35) 30 kilometres to the nearest store selling LED-grown greens (p 30) , and paying for …

The idea that global greenhouse emissions contributed to the Syrian civil war may be true, but this is quite a minor factor (7 March, p 6) . A more important factor is the quadrupling of the Syrian population since 1960. With a population explosion like this, the country was bound to reach a point where …

• Colossus was used to crack Nazi Germany's codes, but not Enigma (14 March, p 36) , which was blown apart by the bombe machine at Bletchley Park. • While NASA's probe Dawn is the first to orbit two different worlds (7 March, p 6) , earlier spacecraft have visited multiple planets.