Letters archive

None of the methods of time travel discussed holds any hope for objects like human bodies to be able to do it. And why travel in time anyway( 14/21 December 2024, p 54 )? Even assuming it were possible, the dangers would be enough to make it unthinkable: diseases to which one had no immunity, …

We don't have to go to the past, we just need to send data to the past. Perhaps 2025 will be the year that I get the message I am hoping to send to myself with the names of the Grand National horse race winners for the next 10 years.

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 …

Ian Phillips considers distrust of one's senses to be the most likely explanation for subjects denying having seen anything unusual in a video despite an unexpected object popping up, even if they could nevertheless convey some details of it. Alternatively, could it be to do with the phenomenon of blindsight? Visual processing involves many layers …

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 …

The first step in reducing urban heat should be to reduce the burning of fuels. All of the energy used in vehicles eventually ends up as heat. Some of the fuel's energy is used for propulsion, which becomes heat through mechanical, air and tyre friction. Most is wasted directly as heat. A study of Beijing …

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, …