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Philip Ball reports scepticism over the claim by a colleague of chemist Dmitri Mendeleev that the periodic table came to him in a dream ( 2 March, p 34 ). But there is evidence of the role of the unconscious mind in problem-solving ( 28 July 2018, p 34 ). This seems to be linked …

As both Earth and life are rare and precious, it's time to appreciate our home planet Fleeting Flo draws a conclusion from the news that out of 4000 exoplanets, none may be right for life ( 30 March, p 14 )

George Chaplin (Letters, 23 March ) and Lawrence Bernstein (Letters, 30 March ) note the omission of the role of hormones in my article on male and female brains ( 2 March, p 28 ). The focus of the piece was on brain structure and function, but the role of hormones is very much part …

Terrance Chapman says his mother-in-law had her teeth removed in her teens in the 1930s (Letters, 16 March ). The practice continued in New Zealand in the 1950s. A neighbour's daughter had her teeth out when I was a child and I was puzzled at anyone voluntarily going through this. She told me it was …

You report that older people's memory may worsen if they watch lots of television ( 9 March, p 20 ). Does content matter? My husband and I watch quiz shows such as University Challenge – at which we compete fiercely – documentaries and comedy panel shows. Will we end up drooling?

I see that some critics of the idea that evolution by persistence could explain why our planet has been able to maintain relatively stable environmental conditions argue that spontaneous self-regulation can arise easily only in simple systems, and that it would be less likely to evolve the more complex a system becomes. But the more …

James Lovelock's Gaia theory has always made sense to me. The concept of selection by persistence seems entirely logical too. But a fundamental rule predating individual selection seems to be missing. Any randomly emerging biological chemistry cannot be selected for if it makes its immediate environment toxic to itself. Untold chemical trials and errors could …

Your article about the potential of wood makes much of building with cross-laminated timber or CLT ( 16 March, p 33 ). Plywood has been around for many years – Samuel Bentham applied for patents in 1797 . It has been used in furniture, buildings, cars, aircraft, spoons and much else. The nominal distinction is …

Your article on attempts to improve the layout of the periodic table was interesting ( 2 March, p 36 ). But I am not holding my breath for anything to come of it, any more than I was after your previous articles on this ( 12 July 2014, p 38 , and 12 February 1994, …

Wendy Glauser's interview with Timothy Caulfield about the misinformation landscape was engaging ( 9 March, p 42 ). May I suggest that the root cause of the misunderstandings that fertilise this is that science education in general doesn't tackle the difference between determinism and probabilism until much too late in any individual's career. School exams …