Letters archive

I enjoyed your take on the worthiness of toys and especially agree with the advice to make sure kids have access to all types of toy, not just those traditionally associated with biological sex. My 5-year-old granddaughter is going through a unicorn and Barbie phase, but still enjoys dinosaurs, trucks, diggers, marble runs, farm animals …

Your story "Antarctic ice is at a crisis point" should be a five-alarm wake-up call for the entire planet ( 7 December 2024, p 8 ). The fact that Earth is warming at a worrying rate shouldn't really be a big surprise, though: 3 million years ago, when carbon dioxide in the atmosphere was at …

A study of haunted house visitors showed that of 22 people with elevated inflammation, 18 had reduced levels three days after getting a good scare at the fairground attraction. But there was no control group of people with inflammation who didn't visit a haunted house. Would they have improved in three days, regardless? It is …

Instead of looking for evidence of tectonics on distant exoplanets, wouldn't it be easier to look instead on Mercury? While not tidally locked, it experiences a very large temperature range of more than 600°C from its day to night side, and its day side remains in sunlight for many Earth months at a time. This …

A decade and a half ago, when my son was in year 7, the government in New South Wales, Australia, issued laptops to students with safeguards to prevent them freely roaming the internet. Within a week, he and all of his friends had bypassed these and spent their time watching videos in class ( Letters, …

In your ultimate guide to skincare, David Robson says that showering a few times a week may suffice to keep the body's outer layer in good condition. Speaking as an older reader who didn't encounter a shower in someone's home until the age of 18, I can assure him that showering zero times a week …

If weight loss were to occur as a side effect of using semaglutide to treat heart disease, that might not always be a good thing. I am talking about for treating older people, who may be severely underweight already. Weight loss wouldn't be healthy there ( 11 January, p 19 ).

Cities like Singapore, Tokyo and Hong Kong enjoy relatively low crime rates and long lifespans despite population densities 100 times the planet's average – hardly evidence of a John Calhoun-style breakdown due to population growth. There are problems due to overpopulation, but not of the sort he predicted ( 14/21 December 2024, p 52 ).

It is wrong to claim that Calhoun's forecast of social breakdown in an increasingly crowded world "hasn't (for the most part) materialised". It seems to me that Earth's population is indeed in the middle of its "behavioural sink" and unfortunately appears likely to destroy itself.

We are urged to try the writing of philosophers, such as the "impeccable logic" of Bertrand Russell, as a remedy for poor fact-checking in popular science books. Turning to Russell's 1948 book Human Knowledge: Its scope and limits , we read that "helium... has a nucleus consisting of four protons and two electrons" ( Letters, …