Letters archive

Michael Le Page notes that using air conditioning in response to climate change produces yet more heat ( 4 August, p 18 ). But there is a useful alternative to the refrigeration method: evaporative air conditioning. The effect was used by the ancient Egyptians, who wafted, or had slaves waft, a current of air over …

Le Page's outline for designing houses to combat climate change sounded rather familiar. Our house is shaded by trees, has dense walls 760 millimetres thick and is partially underground. It is approximately three times as long as it is wide and high, with small windows left open at night. Without air conditioning, it has remained …

I have often wondered whether mouth wounds heal faster than skin wounds, and it was good to see research answering this ( 4 August, p 16 ). It seems to open up new research possibilities related to wound healing. I now wonder whether the genes involved are evolutionarily conserved, ancient and now widespread. They would …

Is Ian Angus saying that it is morally wrong to seek a lower human population as we combat climate change ( 25 August, p 22 )? In the Scientists' Warning to Humanity , first issued in 1992 and repeated in the journal BioScience in 2017 , the majority of the then-living Nobel laureates signed up …

Guy Cox describes how eukaryotes are thought to have evolved by an archaeon engulfing a bacterium that then became the mitochondrion (The Last Word, 28 July ). Other engulfed bacteria became chloroplasts in plants. These processes seem to have happened only a few times, suggesting they were very unlikely to succeed. Archaea and bacteria have …

Clare Wilson suggests buying another freezer to guard against food shortages in case of a Brexit disaster ( 4 August, p 21 ). This may not be helpful. If the UK crashes out of the European Union with no deal, it is probable that the pound will similarly crash against the euro and dollar. Oil …

The speaker schedule for your New Scientist Live event on 20-23 September includes " Should robots have rights? " ( 11 August , back page). More pertinent, especially to those displaced by robots, is: should robots pay tax? No rights without responsibilities!

Howard Bobry takes his local emergency preparedness meeting to task for assuring him that a discharged alkaline battery weighs less than a fresh one (Feedback, 7 July ). But as Paul Hewitt notes in his textbook Conceptual Physics , a change of energy of any object at rest is accompanied by a change in its …

Erik Foxcroft suggests using vacant glacial valleys as water reservoirs for pumped storage hydropower (Letters, 18 August ). By the time the glaciers have retreated enough to make this viable I think it will be a bit too late to think about such storage.

Penny Sarchet doesn't mention a factor that, I am sure, contributes to allergies: stress. I refer to unrelenting mental stress to which there is no conceivable ending or solution. I am sure, for example, that at least some children who develop an allergy after starting school are the targets of bullying.