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Letters archive

Join the conversation in New Scientist's Letters section, where readers can share their thoughts and opinions on articles and see responses from experts and enthusiasts across a range of science topics. To submit a letter, please see our terms and email letters@newscientist.com


12 February 2025

Fading diaper disgust or just plain, simple relief?

From Lerida Arnold, Swanage, Dorset, UK

A reduction in parental disgust as an infant develops isn't surprising, since breastfed babies tend to produce huge, explosive poos, which are like runny, yellow cottage cheese and can easily escape the nappy to coat the child, as well as their parent and surroundings. This often happens at inconvenient times, such as while at airport …

12 February 2025

Now for Severance: The documentary

From Maggie Cobbett, Ripon, North Yorkshire, UK

Like Bethan Ackerley, I am completely hooked by the TV drama series Severance . People I have discussed it with are mostly horrified by the concept of workers having their brains altered so their office/home life memories are strictly partitioned, but I confess that I can see the attractions ( 25 January, p 30 ). …

12 February 2025

On the causes of depression

From Beth Morrell, Raleigh, North Carolina, US

Even if depression isn't caused by low serotonin, as Joanna Moncrieff sets out in the book you reviewed, I am glad to see some researchers have pointed out that this doesn't mean SSRIs, drugs commonly used to treat it, are ineffective ( 18 January, p 28 ). In my view, the most obvious explanation for …

12 February 2025

Smell and taste could be considered a single sense

From Sam Edge, Ringwood, Hampshire, UK

When it comes to the importance of our sense of smell, perhaps the majority of the taste of food and drink is predicated upon the aromas we experience before and during the act of consumption. This is why anosmia can lead to nutritional deficiencies, when all food seems too bland. In fact, one could argue …

12 February 2025

How to experience a good read at bedtime

From Geoff Harding, Sydney, Australia

Disappointingly, due to the disruptive effect of lighting, sleep experts discourage reading in bed, which no doubt many find the only time for this enjoyable pursuit. Perhaps the best solutions are ebooks with a blue-light-blocking mode or the audio version of New Scientist . In the latter case, a potential problem is the highly worrying …

12 February 2025

The space race is using up much-needed resources

From Bryn Glover, Kirkby Malzeard, North Yorkshire, UK

Rocket launches are deemed environmentally OK if hydrogen is used as rocket fuel, because it doesn't add to the carbon dioxide burden. However, the world must cut the total energy it consumes, and so any non-fossil fuel, such as hydrogen, ought to be used to replace fossil fuels in everyday life, not for a new …

12 February 2025

Mars colony: Fiction may become reality

From Nick Hunn, London, UK

Harm Schoonhoven raises the concern that people in a Mars colony would never be able to return to Earth. This eventuality was covered by The Hitchhiker's Guide to the Galaxy . In essence, its message was that those chosen to colonise a new world are those the home planet never wants to see again. Could …

12 February 2025

Space-time's true nature is a bit baffling

From Denis Watkins, St Just in Roseland, Cornwall, UK

While the idea that the possible underlying structure of space-time could be to do with a strange geometric entity is fascinating, I suggest this raises another issue for many: the impossibility of comprehending the reality behind such descriptions ( 25 January, p 10 ).

12 February 2025

Cheaper vanadium makes for a good flow battery

From Simon Goodman, Griesheim, Germany

Considering redox flow batteries, you state that they rely on "metals like lithium and cobalt, which are in short supply". In fact, many such batteries use cheap and common vanadium salts. This makes them attractive bulk electricity storage systems ( 18 January, p 19 ).

12 February 2025

Glad to see the back of many worlds

From Ton Smit, Utrecht, Netherlands

I always found it hard to believe in the many worlds version of the multiverse that is proposed to explain quantum behaviour ( 11 January, p 32 ). In essence, it says that a person, living on a tiny speck in the universe, measuring an even tinier subatomic particle that was in superposition, would create …

12 February 2025

Getting the measure of ultimate precision

From Phil Eden, Sheffield, UK

Your article on gauging vast distances with extreme precision says the 113 kilometres between two labs was measured to within 82 nanometres. I was wondering, was the measurement from the top of the grains of sand on the bricks or the bottom( 25 January, p 17 )?

12 February 2025

For the record

Efforts to rewild the Scottish Highlands with lynx are being led by the Lynx to Scotland Project ( 1 February, p 22 )

Issue no. 3530 published 15 February 2025

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