Letters archive

Andrew Barron's perceptive view of the simplistic idea that only two types of sexual orientation exist is supported by large data sets that I have been accumulating since 2006 ( 17 August, p 23 ). In 2012, I published a study of 17,785 participants from 48 countries that supports the assertion by biologist Alfred Kinsey …

As Wiebina Heesterman notes, kitchen appliances generate nearly seven times as many emissions as food transport (Letters, 24 August ). Cooking in a microwave or on the hob takes much less energy than heating a conventional oven, but instructions on ready meals and in recipes usually specify the oven, which is unnecessary for curries and …

Scott McNeil raises concerns (Letters, 3 August ) about producing batteries for electric vehicles and welcomes the discussion of hydrogen power ( 8 June, p 20 ). It is some years since you have covered the potential for an ammonia-based fuel economy. Ammonia can be compressed and stored much more easily than hydrogen. We already …

Simon Ings reviews Daniel Milo's Good Enough: The tolerance for mediocrity in nature and society , which argues that, in the absence of proof of a specific evolutionary advantage, giraffes' long necks should be considered the fruit of chance ( 20 July, p 28 ). But since they clearly have major disadvantages, if they had …

We need to look at an organic diet and compare the health outcomes in groups of people who consume organic foods with those who don't, suggests Aroha Mahoney (Letters, 3 August ). There is a study that monitored the diet and health of nearly 70,000 people for seven years. It found 25 per cent lower …

My first reaction on seeing your report on artificial islands for wind farms at sea was dismay at the potential for environmental damage ( 20 July, p 10 ). On second thought, they have exciting potential. Such islands could host wave energy harvesting devices, using the same infrastructure to get energy to the mainland, and …

I read your article on gold prospecting using tree leaves with interest ( 17 August, p 12 ). One way to improve detection might be to analyse the shallow soil where leaves fall and rot each year, concentrating the metals locally over time. As an undergraduate in the 1970s, I saw this on the Downs, …

Ruby Prosser Scully reports that tree stumps are being kept alive by nearby trees ( 3 August, p 18 ). In 2000, Peter Thomas wrote in Trees: Their natural history that grafts between roots of individuals of the same species are common in both hardwoods and conifers. There are cases where stumps have been kept …

You say peacocks have elaborate tail feathers to impress peahens ( 10 August, p 14 ). The iridescent feathers that make up the bird's train and fan out to impress mates are the upper tail coverts. The male peacock's actual tail is dull and is raised to support the train. It is much shorter than …

I don't understand why Ruby Prosser Scully thinks that the erratic behaviour of the magnetic poles is less worrying than once thought, because any flip will take longer than previously imagined ( 17 August, p17 ). Surely any flip would leave Earth unprotected from solar wind, and the longer the flip takes, the longer the …