Letters archive

Robert Adler's review of variables defining success and sustainability seemed to have a couple of fundamental flaws (5 July, p 30) . Firstly, gross domestic product (GDP) is still used as a measure. This may be because it is easy to quantify, whereas well-being, happiness and peace do not fit neatly into the arithmetic of …

I read your report on sea-level rise twice because I couldn't believe how unsure climate scientists appear to be (28 June, p 8) . Phrases like "that could mean", "may have already passed" and "if they are right" were scattered throughout. The best was "I would probably take the question mark off now." Probably! Oh, …

Your item on deducing Neanderthal diets from fossil faeces assumes there is only a choice between eating meat and being vegetarian (28 June, p 7) . The importance of fish is often overlooked, and that of shellfish almost always forgotten. The interesting discovery of plant sterols in 50,000-year-old stool samples does not necessarily mean that …

Regarding your article on conflict zone minerals, gold is used for connectors because it is corrosion-resistant, not because it is a good conductor (14 June, p 22) . Copper and silver are better and far cheaper conductors, but surface oxidation can be a problem. In addition, tin is not replacing all lead in solder – …

While I understand Ryan Pandya's ethical and environmental concerns about the dairy industry, I feel that he may do better producing cultured milk that mimics human rather than cow's milk (28 June, p 28) . Cow's milk contains considerably more casein than human milk, a protein that can be difficult to digest – it is …

Because his milk does not contain antibodies, Pandya says it would not be suitable as replacement breast milk for infants. A version could be created for adults if there was a demand for it, although he admits that would be "kind of weird".

I was surprised to find that the anti-obesity effect of testosterone was summarily dismissed in your feature (5 July, p 34) . The only fact given is that testosterone causes a slight decrease in body fat and a slight increase in lean body mass, with no change in overall body weight. This may be true …

In your article on ants' swimming skills, the measure used is how many body lengths an ant can cover per second (14 June, p 18) . However, it is well known that under crude measures such as this, small animals always outperform large animals. A common example of this limited usefulness is measuring fleas' jumping …

I read with rising concern the opinion piece by Marc Bekoff and Daniel Ramp on the role of selectively killing animals in conservation efforts (21 June, p 26) . What started as a promising argument in favour of valuing life rapidly descended into a confusion of welfare and death. For the umpteenth time, commentators started …

For more than 30 years, whenever I talked about my near-death experience caused by an anaphylactic reaction to peanuts, I would emphasise how pleasant it was (28 June, p 17) . I remember feeling adrift and calm. My husband, who was present throughout the ordeal in the emergency ward, said what he saw was very …

Michael Brooks's article on the struggle to provide energy that is cheap, reliable and clean looks at half of the picture (21 June, p 32) . It is not enough to consider supplying power when consumers want it. We also need to encourage power use when it is available, particularly with renewables. The technology needed …

Managing consumer demand is a keen area of interest. Appliances that turn on when energy is most plentiful featured in our article on smart homes (5 July, p 18) .

You report on a woman becoming unconscious when electrodes in her brain stimulated "the claustrum", suggesting this area of the brain could be the seat of consciousness (5 July, p 10) However, we have a claustrum on each side of the brain. What would happen if her other claustrum were zapped? And can there be …

New Scientist reported on proposals to use a plasma shield to slow a spacecraft's descent, reducing the need for heavy heat shielding (5 July, p 13). This reminded me of other proposals I have seen that suggest something similar to protect astronauts from energetic particles on long space flights. I claim no expertise in this …

You propose that the Turing Test needs updating (14 June, p 5) . However, you need look no further than the New Scientist archive, for in your 9 October, 2004 edition, with tongue slightly in cheek, I suggested an improved version of the test. Surprisingly, my proposal did gain some attention from those studying the …

In Jonathon Keats's assessment of warped maths, a more up-to-date example than damage to US bombers 70 years ago was available (21 June, p 46) . The recent observation by a top brain surgeon that cycle helmets were of questionable value related to his experience of seeing as many head injuries from those wearing them …

• Material error: the ball with dimpled morphing skin was made from two kinds of silicone (5 July, p 20) . • In our review of Aaron Panofsky's Misbehaving Science , Arthur Jensen's name was misspelled (12 July, p 42) .