Letters archive

Michael Brooks makes the case for hydrogen existing as a metal by pointing out its position in the periodic table at the head of the group of alkali metals ( 4 January, p 43 ). All elements in this column have a single valence, or outer shell, electron. When this is delocalised and produces electrical …

If metallic hydrogen were a room-temperature superconductor, experiments on it might produce useful information. But, given the enormous pressures that seem to be required to keep it metallic, it surely isn't practically useful. A thought occurs to me: have any of the teams doing these experiments considered using pure deuterium, an isotope of hydrogen? I …

I know what you mean when you write that there is no such thing as scientific truth – only successive attempts to get closer to it (Leader, 14 December 2019 ). So, I think, will most New Scientist readers. But be careful what you write. There are truth corrupters out there who will deliberately misrepresent, …

Sam Edge mentions the common assumption that conscious entities such as human minds are self-causal and non-deterministic (Letters, 4 January ). Of course, like everything else in the universe, our mind/brain is deterministic, if you accept that every event has a reason or cause. We can't mechanistically predict what someone will think about anything because …

The dating service Tinder doesn't seem to be as good at finding you a partner as you might think, according to a study that found only 25 per cent of participants reported using it to find someone interested in a long-term relationship ( 7 December 2019, p 15 ). This sounds damning, until you read …

• We misnamed a dog breed on our chart showing their sizes and life expectancies: it is a Bernese Mountain dog ( 4 January, p 38 ). • It is the nerves within the clitoris that are rarely depicted or described in textbooks ( 4 January, p 12 ).

You might think that as a livestock farmer I would resent vegans claiming that my way of life is unethical, and you would be right. You quote Michael Clark saying that eating animals fed on plants must be less efficient than people eating plants. This ignores the fact that many herbivores can, and do, get …

Extinction Rebellion's demands are unrealistic, says Mike Clarke (Letters, 2 November 2019 ). I think they are deliberately so. In persuasion psychology there are two common techniques called the "foot-in-the-door" and the "door-in-the-face". The first of these involves asking for a small favour to later ask a larger one, referring to earlier deeds or promises. …

The UN Environment Programme has defined the huge scale of the task of limiting temperature rise to 1.5°C, reports Adam Vaughan ( 30 November 2019, p 7 ). But things could be worse. In recent research, Rishav Goyal and his colleagues showed that the world dodged a bullet when the 1987 Montreal protocol to protect …

Your report on artificial intelligence helping tackle one of the biggest unsolved problems in maths is the latest of an increasing number on what seem to be AI's opaque capabilities ( 14 December 2019, p 16 ). These have got me thinking about the name of this technology, although it is probably too late to …