Letters archive

I was extremely pleased to read Lee Smolin's article on the multiverse (17 January, p 24) – it's nice to know that I am not the only person who thinks parallel universes should be confined to speculative fiction. I am, however, puzzled by his proposed "principles". They look remarkably like axioms. In particular, the second, …

Lee Smolin asks questions about recent ideas in cosmology and how they are formed. While inevitably theoretical, cosmology eventually has to subject itself to empirical, observable reality. My perception is that this isn't happening as much as it did. Call me old-fashioned, but I still think Karl Popper's idea of "falsifiability" remains a good standard …

As a biologist I found it rather sad to read the defeatist article by Lee Smolin. If understanding the mechanics of the universe were easy it would have been worked out years ago. Doesn't he see that it is likely to be the ultimate puzzle to solve in science? We do have one clue: the …

The connections drawn by Harry Burns between public health, child development and social welfare are important and deserve respect (24 January, p 26) . However we should not accept the narrative that attributes poor public health in Glasgow to the de-industrialisation of the 1970s and 1980s. Shipbuilding and steelmaking were physically hard and hazardous occupations. …

Fred Pearce worries that falling fossil fuel prices may discourage investment in alternative energy sources (17 January, p 22) . But can we exploit falling oil and coal prices to encourage investment in renewables? Consider an international agreement fixing the price to the retailer of each fossil fuel type at its present level. When the …

Colin Barras's article on plasticity proposes that advantageous behaviour can persist until a compatible mutation makes it permanent and a base for further change (17 January, p 26) . For a long time I have struggled to see how evolution could have worked in the limited time available. Conventional thinking requires each evolutionary step to …

You described the UK as "rushing to build" its nuclear weapons and facilities (24 January, p 5) . The reason for this was treachery from our ally, the US. At the end of the second world war, the US passed a law forbidding the sharing of nuclear technology with any other nation. This was manifestly …

Hal Hodson points out that the "speech" of great apes is limited to discrete sounds (10 January, p 39) . They don't have the vocal flexibility of gibbons, which are able to "sing" a greater degree of meaning into their sounds. Perhaps the apes' problem isn't with their vocal cords but with their ears. If …

One of the graphics accompanying Linda Geddes's article on red meat gave the percentage of various animals that is edible (24 January, p 30) . It indicated that only 40 per cent of a cow could be eaten. But in a less wasteful society most of it is eaten, as it used to be in …

The review of the book The Cultural Lives of Whales and Dolphins has whetted my appetite (10 January, p 43) . It acknowledges that "sperm whales have the largest brains on the planet" but goes on to say that "relative to body size, the brains of dolphins are second only to humans". Why is the …

Aviva Rutkin reports that "by the age of 3, children from affluent families have heard some 30 million more words than their impoverished counterparts" (29 November 2014, p 14) . If they are awake for 12 hours a day, that amounts to 38 extra words a minute, every minute. Add the words an impoverished child …

• The figure was an estimate calculated by researchers Betty Hart and Todd Risley and assumed a 14-hour day. In their 1995 book Meaningful Differences in the Everyday Experiences of Young American Children , they note that, "even if our estimates are too high by half, the differences... are so great that even the best …

In a New Scientist leader last year, asbestos was included in a list of "synthetic" chemicals (29 November 2014, p 3) . I am not aware of any chemical plants that synthesise asbestos, but the silicate minerals with this name have been mined for at least the last 4000 years. The inclusion of asbestos on …

I was delighted to learn that New Scientist knows how to say a prayer (17 January, p 5) , and even more delighted that it appears to have been heard. The same morning that I read you had offered a prayer for the Catholic church to review its attitude to contraception, I learned that Pope …

• In our interview with NASA chief scientist Ellen Stofan (10 January, p 26) , we printed a rough estimate of the distance travelled on Mars by the Opportunity rover. The latest figure from NASA is 41.8 kilometres, double the distance stated. • We understated the nitrogen content of Earth's atmosphere by a fair margin …