Letters archive

Congratulations on "The last human", a superb article on the increasing evidence that human survival through harsh times was a result of our skill at working together ( 27 November, p 38 ). It is timely, both post-COP26 and in this centenary year of the death of Russian scientist Peter Kropotkin, who argued that evolution …

Richard Sebes stating that no health-conscious vegan would live on junk food misses the point of the original article ( Letters, 20 November 30 October, p 38 ). As a meat eater, I share the view that no health-conscious carnivore would live on junk food either, but a very large proportion of the population does. …

Abigail Beall says that it seems unlikely that there are no aliens, given the huge number of planets in the cosmos ( 20 November, p 36 ). But we have no idea how life gets started, so even if there are zillions of planets, we can't say that it is likely that there is life. …

Fred White exhibits a very British attitude to the decadent air conditioning, though many of us have come to love it in our cars ( Letters, 16 October ). He is obviously well aware that cooling in general already accounts for 10 per cent of global emissions, a figure set to soar as billions more …

Harking back to your coverage of the achievements of DeepMind's AI approach to protein folding, I wondered if the long-standing problems of creating a suitable material for a room-temperature superconductor and of practical fusion power might be good subjects for this technique ( 31 July, p 14 ). Breakthroughs in these issues would certainly contribute …

In "Why is the universe intelligible?", the idea that in the future the cosmos may be only intelligible by machines gave me a jolt of recognition ( 20 November, p 36 ). As part of a research project, I am using automated content analysis software to analyse a large number of environmental reports. I feed …

When you ask "Why do we exist?" and so on, this implies a reason , a goal, a purpose, so therefore a design and ultimately a designer. I would have been more comfortable with "How do we exist?", as this asks for the laws of nature that make things possible and that govern the way …

"Why is quantum theory so strange?" It isn't a final theory , even though it passes all current tests. It is a bit like Pythagoras's theorem, which also passes every test, but is just a glimpse of a universe of geometries.

You report that some of the metals essential for modern renewable technologies are obtained in very environmentally damaging ways ( 13 November, p 38 ). An alternative is to get them from asteroids. In his book Mining the Sky: Untold riches from the asteroids, comets and planets , John Lewis says that a single asteroid …

To make the devices that are needed to save us from climate change, we need to have a completely circular economy. In addition, we must examine sources of minerals that don't have to be mined – for instance, tailings from old mines in which only the mineral that was targeted at the time was removed. …