Letters archive

Bob Ward writes that the BBC is vital to the public debate on climate change but that we are sacrificing accuracy for impartiality in our coverage (newscientist.com/article/dn25353) . The BBC covers the issue of climate change comprehensively and we do our utmost to report on this complex subject as clearly and accurately as possible. The …

Sally Davies, the chief medical officer for England, is wrong on e-cigarettes (5 April, p 29) . If the marketing of these devices is "often aimed at children", as Davies suggests, then it has been a spectacular failure. E-cigarette use is rare among young people, and confined mostly to those who have smoked cigarettes. E-cigarettes …

I have something to add to Alan Larman's experience of seeing ultraviolet (15 March, p 33) . I underwent a cataract operation involving eye lens replacements. Some time later I visited a research lab at the University of Cambridge. The team had just taken delivery of a UV laser emitting a beam with a wavelength …

There are widely reported inaccuracies about human colour vision. The absolute range of retinal sensitivity extends from near-ultraviolet to near-infrared. Strong, and possibly harmful, illumination is necessary to see these extremes. As we age there is increasing absorption of near-UV light by the eye's lens, and so it becomes harder to perceive. A child can …

In your article on metal-eating plants, Katia Moskvitch writes that phytomining – using plants to extract metal from the ground – is for the moment mainly focused on the uptake of nickel by some Alyssum species (22 March, p 46) . This is good news for those of us who worry we are leaving a …

One theme that ran through Katia Moskvitch's feature is that commercial exploitation of phytomining technology is expected to take off when key patents expire. This underlines the importance for researchers to distinguish between the real and perceived impact of patents on the intellectual property. César Milstein and the University of Cambridge are consistently criticised for …

It was good to see the full detail of how China's unpleasant one-child policy worked and its ineffectiveness compared with other factors affecting population such as increased education (22 March, p 26) . Unfortunately China's policy has cast a shadow over the whole idea of any country having a policy on population control. And that's …

From David Shaw, Sárvári Research Trust If the disease Andrew Sanderson observed (29 March, p 31) on his blight-resistant Sarpo potato varieties (but not on his blight-susceptible Kestrel variety) really was late blight caused by Phytophthora infestans , it might indicate that the Sarpos' resistance had been eroded by genetic change in the pathogen. On …

I suffer a milder fear of heights than Jessica Hamzelou (15 March, p 34) but her article's opening picture was nevertheless enough to trigger increased heart rate, tension and a morbid urge to look again. I have found gradual exposure to be very effective but not long-lasting. Over many years I occasionally pruned some tall …

Stripes disrupt a zebra's outline, making it more difficult for large predators to see them (22 March, p 38) . This is certainly true but they may well have other purposes hidden from our visual system. Insects such as the tsetse fly, which goes after big game, can see ultraviolet light. They are attracted to …

Colin Stuart's article on what makes planets ideal homes (15 March, p 38) could have included another important feature of Earth – tectonics. Renewing mountain ranges after the levelling by weather redistributes the elements and sustains the geochemical cycling. Without tectonic cycling, our planet would become stagnant and close to homogeneous, with few niches for …

As the father of two daughters, I would dispute something in Linda Geddes's article on the first signs of human possessiveness. Susan Gelman is quoted as saying that a 3-year-old protesting about another child's toy being taken does not involve self-interest (March 29, p 40) . On the contrary, it is all about self-interest. They …

In discussing gravitational waves (22 March, p 8) , Lisa Grossman quotes Alan Guth of MIT as saying "Inflation depends on a kind of material that turns gravity on its head and causes it to be repulsive." Could this be cavorite, the material dreamed up by H. G. Wells, which astronauts used to propel their …

I always wondered why smokers ignored "No Smoking" signs at the entrance to London Waterloo Station. It seems the reason can be found in your invisibility special (22 March, p 32) : the prohibition signs prompt smokers to smoke! Worcester Park, Surrey, UK