Letters archive

Webb Keane's anthropological account of morality in his book Animals, Robots, Gods encounters the familiar problem experienced by reductive explanations of the moral faculty. However sophisticated the concepts deployed, morality is explained away as essentially a social construct, a matter of social conditioning. I am given no reason, ultimately, why I must do the right …

While I remain in awe of the detective work that has gone into suggesting a Scottish origin for the altar stone at Stonehenge's centre, I remain dumbfounded by the belief that it was human agency that brought it there ( 24 August, p 16 ). Surely a far more believable story is that the stone …

Acquiring objects from abroad, particularly if they have cultural significance, is something humans like to do. Stones, whether gems or edifices, are particularly popular. Might the altar stone have been acquired in the same way? We now know that it must have come from an area of north-east Scotland. Orkney is at the centre of …

The altar stone isn't the only Scottish connection to Stonehenge. Isotopic analysis of pig teeth near Stonehenge found they had been brought from the Orkney islands for feasting.

In engineering, cynicism is a very practical way to approach big challenges. You must assume that anything that can go wrong will go wrong and proceed accordingly. Only after everything that can go wrong has gone wrong and you have cleaned up the mess can you get on with making things go right ( 17 …

I was delighted to find that moderate consumption of caffeine is good for Homo sapiens . It may not be for some other species: I was once told of experiments on the use of waste pulp from coffee berry processing as cattle feed in Mexico in the 1970s. Although this was full of apparently useful …

High-frequency trading already demonstrates that the financial markets are nothing but a shell game profiting only the already ultra-rich and causing misery for the rest when they go off the rails. Making such trading even more volatile with quantum technology will only cause harm ( 17 August, p 14 ).

From 27 July, p 28

In your review of Anil Ananthaswamy's book Why Machines Learn , I was astonished to read his statement that the mathematics behind AI is simple, "the kind one learns in high school or early college". This may be true of a basic model, but not for ChatGPT, Claude and other neural network-based models, which involve …

It is fascinating to consider the possibilities of quantum biology, but surely its existence would be no great surprise. It seems to me that nature is already functioning happily at all the "levels" we humans think we can discern, and many more we have yet to identify ( 10 August, p 18 ). Surely molecules, …

You report the growing impact of emissions from food production on the climate. The only way to avoid this kind of damage is for every person to limit their meat intake to less than 200 grams per week. This is a fraction of what many people now eat. We do need dietary vitamin B 12 …

A 100-nanometre glass bead is a thousandth of the width of a human hair ( 31 August, p 16 ). Orkney is in Scotland, off the mainland ( 24 August, p 47 ).