Letters archive

The UK's National Health Service does cost more than it did when founded, but I dispute that this is the fundamental problem that Christopher Burke suggests (4 April, p 54) . When it was founded, the UK was bankrupt after two world wars. Now we boast of being the sixth most healthy world economy. We …

In his article on belief, Graham Lawton writes: "One of the most interesting things about belief is that it varies enormously from person to person, especially on issues that really matter such as politics and religion" (4 April, p28) . My default "credulous brain" believes the premise that the formation of belief is an intuitive …

There is an evolutionary hypothesis for the strength of deeply held beliefs, outlined by Robert Trivers, who you have interviewed (8 October 2011, p 32) . He thinks deceit is necessary for all living creatures in their quest for survival. As clever apes we find it impossible to deceive effectively unless we actually believe the …

Lawton quotes psychologist Peter Halligan as saying: "The prime directive of the brain is to extract meaning. Everything else is a slave system." The purpose of the brain is rather to take in data, process it and make decisions – with the objective of maximising the chance of passing on the animal's genes. Whether any …

In his fascinating look at belief, Lawton concentrates on the distinction between knowledge and belief. But the philosopher David Hume argues that we find actual knowledge only in maths and logic: everything else is belief, to which we ascribe probabilities based on our experience in the world. Such belief is obviously subjective, but it also …

"Nothing about a vortex is tranquil" Joe Singleton comments on Facebook about our Picture of the Day of super-typhoon Maysak

I disagree that "the scientific method... is still... the best way to distinguish what we believe from what we know" (4 April, p 5) . The phrase "scientific method" tends to be used of study in which the data obtainable are quantifiable and have a high degree of certainty. Humanities researchers often try conscientiously to …

Researchers at the Children's Hospital Los Angeles wonder why parental income appears to influence the intelligence of their offspring (4 April, p 16) . Surely this is putting the cart before the horse: as this trend tends to persist over many generations, it seems logical to suppose that intelligence leads to high income rather than …

Emma Young's article on learning describes good learning practice (28 March, p 30) . Yet we have little quantitative science about the process. There are two aspects of learning: absorbing novel information from the world, and introspection. We can be forgiven for not understanding what goes on inside our heads, but there are scenarios where …

So far the main problems raised about driverless cars have been technical, with social aspects mainly concerning the safety of passengers and pedestrians (14 February, p 20) . But no one has discussed their impact on jobs. Long-distance haulage, taxis, buses and coaches will no longer need human drivers. There are 92,000 registered black cab …

Both Steven Miles (21 February, p 54) and Alan Webb (4 April, p 54) talk about "true scientists" not accepting an axiom without proof. But the definition of axiom in mathematics and logic is that it has no proof. Axioms are simply posited, and proofs of subsequent theorems are built on them. The notion of …

When I say I am an atheist, those with any religious belief will imagine it is their god that I don't subscribe to. But to quote Freddy Mercury, "I don't believe in Peter Pan, Frankenstein or Superman". I don't believe in Zeus or Hera either. A believer in the Christian god who doesn't believe in, …

Please, please can you tell me how to shave a spider's moustache (14 March, p 17) ? Upminster, Essex, UK

• In the experimental group, spiders were anaesthetised with carbon dioxide then their white "moustaches" were removed with a razor blade under a dissecting microscope. In the control group, the spiders were anaesthetised, but this time the researchers scraped their moustaches with the blunt side of the blade, so as not to damage them.

You say the launch of a mission to the International Space Station mission would be "on Friday", and in the next paragraph "on 28 March" (28 March, p 6) . Could it be that it was 28 March in Kazakhstan but still Friday in the US? Les Essarts-le-Roi, France

• Yes.

• California is not the largest of the United States, but the most populous (21 March, p 7) . Apologies to Alaska. • We said electric cars emit "almost 20 per cent less heat" than petrol and diesel cars, when in fact they emit just under 20 per cent of the heat that conventional cars …