51¶¯Âþ

Since 2002, I have been teaching in the further education sector and have seen the impact of new technologies. AI is the most disruptive so far ( 27 December, p 24 ). I started to think about how these models learn, in the context of some well-established theories of learning. While large language models (LLMs) …

Tim Rafferty's claim that simulators would only have to "simulate our ability to observe the universe" is often called lazy evaluation, but it faces a number of hurdles ( Letters, 3 January ). Objects cannot simply "pop" into existence: their current state requires a massive, recursive calculation of their entire history, effectively forcing a full-scale …

I enjoyed Tim Rafferty's letter about simulation time. However, many simulations run to an end to see a result and then decisions are made based on that result, so it would make sense to run the simulation as fast as possible. This raises the question: do those of us in the simulation experience time at …

The repeated reference to returning samples to Earth for study in your article "How to spot an alien" gives me a great sense of foreboding. As a virologist, I don't understand how any rational scientific mind could ever contemplate bringing material back to Earth if, never mind because, it shows some signature of alien life. …

An analysis of 14 million children's health records showed that 3.4 million of them received their first covid-19 vaccine dose from January 2020 to December 2021, while 3.9 million of them had covid-19 for the first time (15 November, p 7) .

I'm a fanboy of Annalee Newitz and hesitate to question anything they say about science fiction. But one aspect of their recent column has me scratching my head ( 27 December 2025, p 16 ). Can they really be mystified by why humans are far more interested in anything a member of their species does …

Bryn Glover gives a negative assessment of the likelihood of life elsewhere in the universe. This is based on a 51¶¯Âþ article stating the odds of the formation of the last universal common ancestor from a soup of chemicals as "less than 1 in a billion" ( Letters, 3 January ). Of course, we …

Decades ago, 51¶¯Âþ ran a feature about Rupert Sheldrake's hypothesis of morphic resonance, which posits that once something comes into being, recurrence becomes easier. He used crystallisation as an example: once accomplished, it becomes subsequently easier to do. We are in the universe; the universe is in us. All is one. As far as …

After reading Alex Wilkins's article on the mystery of the missing meteorite, I asked Google's AI assistant whether you can make a pigment for painting rocks using iron meteorites, and whether iron objects look shinier in low morning or midday light. Its answer to both questions was yes. If accurate, this may indicate that Gaston …

Regretfully, I must strongly assert that there is no giant "iron of God" meteorite. If ever there had been, there would be widespread legends about it, artefacts made from it and religious rituals or taboos involving it. If we accept that Ripert was an honest observer and truly saw something, consider that desert mirages are …