Letters archive

Christa Lesté-Lasserre's view on the horrific lives of racehorses comes across as a one-sided apology for a brutal sport in which more and more of these animals are injured and die while entertaining human spectators ( 20 May, p 27 ). Activists aren't to blame for the downsides of horse racing. Their passion and feelings …

Jon Cartwright's discussion of the incompatibility between general relativity (GR) and quantum mechanics (QM) touches on something crucial: stories ( 13 May, p 38 ). GR has a compelling story. It says that what we call "gravitational force" is essentially just objects travelling along the equivalent of straight lines through curved space-time. QM has a …

Perhaps we have trouble saying whether AI can be conscious because "consciousness" isn't a single thing. For example, we all think we recognise grass – a short, green, blade-shaped, densely packed, fast-growing plant – but then we have wheat (tall, yellow grass), tussocky grass and artificial grass, which resembles the real thing, but isn't. There …

AI will never be able to successfully handle the inherently irrational aspects of human politics and religion. These governing factors of human existence can't be defined or analysed to result in anything approaching predictive behaviour. For AI to achieve sentience, it must somehow accept irrationality as an element of being, which is impossible for anything …

If you are wondering what life will be like once AI becomes all-powerful, just ask any creationist. They have been telling us about a world ruled by an omniscient, omnipotent and omnipresent non-organic life form for millennia. Start praying.

After two episodes of viral encephalitis, my family noticed in July 2022 that my physical impairment had appeared to progress, while hallucinations and losses of memory had returned. In February 2023, after a brain biopsy, we learned that this wasn't a third bout of encephalitis, but a stage 4 glioblastoma. Oddly, there was no direct …

Of the caves in Carajás National Forest, Brazil, only 10 currently house large bat populations ( 27 May, p 9 ).

We can't communicate with chimps who share 99 per cent of our DNA, says Chris Impey, so what are the chances we could communicate with aliens? However, my computer shares 0 per cent of my DNA and there is two-way communication between me and it. Surely some exchanges are species-independent? I can convey a threat …

If we do contact other intelligent life, maybe we shouldn't mention that humanity is divided into nation states, many of which were founded on conquest and plunder. We might also skip over the fact that we still commonly settle our disagreements through war. It would be wise to avoid revealing that, throughout history, various groups …

It is a relief to know that our past radio and TV emanations are now too weak to be understood by any aliens. What would they make of the unending stream of violence with which we "amuse" ourselves?