Letters archive

Jessica Hamzelou reports that the risk of dying from covid-19 rises with age, diabetes and heart disease, with around half of deaths from the infection involving people with underlying diseases ( 14 March, p 9 ). But when it comes to age, calendar age isn't the only way to look at this. People age, biologically …

I read Adam Vaughan's discussion of several initiatives to plant or protect a trillion trees around the world with interest ( 29 February, p 20 ). But, like all the pieces I've read on the subject, it seems to address only part of what is required to make this effective. Surely there should be a …

Ed Subitzky, New York, US Reading the recent letters about whether or not we live in a computer simulation led me to think about the matter of software bugs if this were true (Letters, 22 February ). Every piece of software of any complexity contains them, and presumably the software engineers who coded the simulation …

Discussing how soon we may have a vaccine against covid-19, Carrie Arnold writes of "the stark realisation during the West African Ebola outbreak that Big Pharma could no longer be relied upon to solely underwrite expensive vaccine research" ( 21 March, p 44 ). I take umbrage at this. As you have reported, pharmaceutical firms …

Chris Stokel-Walker asks why the video-sharing platform TikTok has risen so quickly ( 14 March, p 31 ). This is an interesting question, but so, too, are the concerns in the US that the app threatens national security ( 14 December 2019, p 14 ).

Adam Vaughan discusses plans to plant trees to lock away carbon dioxide ( 29 February, p 20 ). These won't work here in Australia. In the most recent bush-fire season, around 126,000 square kilometres of vegetation and more than a billion animals were burned. We have to address the main causes of climate change. Time …

Donna Lu reports new lightweight materials made of gallium, indium and glass bubbles ( 14 March, p 12 ). In the same issue, Layal Liverpool describes a gold-coated fabric that can emit light in different patterns ( p 18 ). These seem remarkable from a technological point of view, but I wonder how recyclable such …

You report that one mechanism by which silver prevents harmful bacteria spreading has been clarified ( 7 March, p 15 ). In 1989, and again in 2009, I was too ill to work. It seemed to me that the cause was bacteria and fungi growing in air conditioning ducts in relatively new buildings. When I …

Your exploration of the problems of reality is fun and fascinating, but it deals with two very different concepts: accepting reality and understanding how it all works ( 1 February, p 34 ). To give a simple analogy: at our farm, because I am a biologist, I understand a lot about how the grass, trees …

Colin Walls offers a simple and superficially attractive way of thinking about life and death ( Letters, 7 March ). But frogs die – like the rest of us – from natural causes, and presumably some must die while hibernating. So consider two otherwise identical frogs lying frozen side by side. One is in suspended …