Letters archive

Roger Taylor notes that recycling is one area where common ground can be found with climate change sceptics (Letters, 21/28 December 2019 ). There are many more. Restoring fish stocks, reducing waste, combining conservation with careful usage, using alternatives to fossil fuels, making less use of cash crops, promoting tree growth and use via silviculture …

Recent letters, like that from Adam Osen, focus on planting trees to help mitigate climate change through their storage of carbon (Letters, 7 December 2019 ). It may not always work. Planting trees on open ground may change the reflectivity, or albedo, of land. At higher latitudes this can cause a warming effect, as three-dimensional …

David Westmoreland and Connor McCormick say the flat-Earthers they meet are savvy about science ( 11 January, p 21 ). They also report flat-Earthers measuring shadow lengths at various latitudes to look for curvature of Earth and coming up with inconclusive results. The African-Greek scholar Eratosthenes used this method to calculate Earth's circumference before 200 …

Paul Bowden is among the many people who are concerned that AI will not be able to reveal its reasoning (Letters, 14 December 2019 ). Although we should be aware that someone can make decisions without being able to give their full reasoning, or may even answer differently each time asked, I do think there …

I read with great interest Joshua Howgego's discussion of using evidence and reason to maximise the impact of kindness ( 7 December 2019, p 42 ). It reminds me of utility theory in economics. The usefulness, or utility, of a given outcome depends markedly on the person involved and on their situation. Worse, utility can …

A serendipitous concurrence of events has set me thinking ( 11 January, p 34 ). In your article on breathing and better memory and sleep you say that humming sets up swirls of air in the sinuses, which boost the production of nitric oxide 15-fold. And recently there was coverage of the finding that gorillas …

Graham Lawton says 2020 is a pivotal year for the environment and links this to leaders in denial ( 11 January, p 22 ). I suggest that denial isn't the main problem in the public perception of climate change – the main problem is misconception. We see news reports of forest fires, melting ice and …

Many psychiatric conditions share an underlying cause known as the "p factor", reports Dan Jones, while neurological conditions have little to nothing genetically in common with each other ( 25 January, p 34 ). Nevertheless, the characterisation of the p factor may have implications for rethinking neurology, as well as mental health. Much neurological practice …

In your top tips for bathroom basics, you give the advice that we should wash our hands for 20 seconds ( 11 January, p 38 ). This was also previously given by Timothy Leighton for combating antibiotic resistance ( 26 March 2016, p 32 ). As a retired nurse, I must point out that technique …

Michael Le Page casts doubt on the feasibility of making food from the atmosphere and questions whether it would be more efficient than conventional farming in soil ( 18 January, p 10 ). It is perfectly possible to extract hydrogen from water, and carbon and nitrogen from the air, but surely something is missing here? …