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Before Christmas, I was trying to explain quantum theory to the grandchildren and mentioned Schrödinger's cat, where the cat is both alive and dead before the box is opened. The children were sceptical. "Surely," they said, "if you carefully observe the box from the outside, sooner or later the 'cat' will interact with one or …

I have always found it strange when physicists say that they repeat quantum experiments. They repeat only certain parameters – they cannot ever repeat precisely the total physical environment. All they can do is repeat part of that physical environment. And that being the case, how can they be sure that aspects of the overall …

Regarding why climate action is stalling while Earth gets hotter: perhaps the disaster takes too long to hit. We have been hearing about it for years now, and while it is getting worse, it doesn't have the urgency that, say, covid-19 had. Most people believe there is still time to act, so they stall ( …

The trend towards SUVs that Anthony Laverty writes about is also evident here in Australia. But is it really bad for the planet? These SUVs tend to be diesel and therefore much more economical on fuel. I drive such a vehicle, a 15-year-old Audi Q5 SUV, and it delivers around 60 miles per gallon. That …

Oh, how we all too often underestimate the amazing abilities of insects. So, thank you for the excellent and informative article, "Heroes in disguise", on the fabulous hoverfly ( 29 November, p 42 ).

In response to Chanda Prescod-Weinstein's article on the research into dark matter: dark matter seems to me to be "aether with mass". It can't have any viscosity, for example, because if it did, normal matter passing through it would lose energy, which we would be able to detect. This applies at the cosmic scale even …

While John Tons's idea of painting every roof white is effective at cooling the home and reducing the urban heat island effect, it has a negligible effect on a global scale, because the total area of roofs of buildings is minute compared with Earth's surface area ( Letters, 29 November ). Antarctica's surface area alone …

I was fascinated to read that a mosquito's proboscis can act as a surprisingly hardy 3D printer nozzle ( 29 November, p 18 ). I wonder if they can also manufacture a replacement mosquito proboscis?

With regard to Feedback's musings on what kind of music mice like, I was once party to an accidental experiment on this when I worked in Newcastle. Our education department shared a wall with an adjacent lab's mouse facility, where the animals were suffering from unexpectedly poor fertility ( 29 November, p 56 ). Suspecting …

Your article on when our feline friends spread around the world was very strange in repeating the long-debunked theory that cats have ever been domesticated. As every scientist, and indeed individual, who has ever met a cat with its servant knows, it is humans who were domesticated ( 6 December, p 9 ).