Letters archive

In Rowan Hooper's article on the multiverse, physicist Seth Lloyd is quoted pondering the notion that multiple worlds are actually out there somewhere, but we cannot access them (27 September, p 32) . Later, Hooper describes the double-slit experiment, in which a photon appears to act like a wave, diffracting at both slits and creating …

Seth Lloyd offered Don Page $1 million to play quantum Russian roulette, where each pull of the trigger divides the universe into a version where the gun fired and another where it did not. Page declined because he didn't like the thought of his wife's distress in the worlds where he died. But he was …

Seth Lloyd enjoys the "marginalisation of humanity" wrought by the endless repeated worlds in the multiverse. But the theory also implies each individual becomes infinitely extended in space and time by the ever-multiplying copies of their former selves. Is this ultimate human marginalisation? Or collective elevation to effective godhood? Each to their own! Warley, West …

Dan Jones reports that people who are told voting patterns can be predicted by measuring brain activity still believe the subject's decisions are based in free will (27 September, p 11) . We could get the same result without the fancy technology by giving someone a thorough personality test that will also predict their decisions …

If determinism precludes any real decision-making, then does it also preclude the spawning of new multiverses? Bournemouth, UK

Rosemary Bryant Mariner makes a compelling argument to place women on an equal footing with men in military combat roles (20 September, p 26) . In a nutshell, this enables everybody to participate in armed conflict. But I would prefer to look at a change in the status quo from the other end of the …

In her article exploring whether dolphins live up to their reputation for intelligence, Caroline Williams tells of being forcefully rebuffed by a dolphin after attempting to connect with it (27 September, p 46) . In this era of climate change, the possibility that dolphins don't want to be friends with humans makes them seem more …

I read Debora MacKenzie's article on the decline of the nation state with great interest, having arrived at similar conclusions in 1990 (6 September, p 30) . At that time I came across chaos theory, which made it clear to me that the complex system we call community is better governed from the bottom up …

I was interested to read about a computer-controlled loom that can create 3D fabrics (27 September, p 21) . That is certainly an innovation. However, there is another, more established, way of creating 3D fabrics. It's called knitting. Sanderstead, Surrey, UK

I can't quite agree with Tim Stevenson's rejection of magic in technology (27 September, p 31) . I'm glad to say computing is still both my job and my hobby after more than 40 years in the industry. The fact that there is always something new to learn is a source of continual magic to …

I had an experience which supports the idea reported by Bob Holmes that baby mammals share the same distress cry (20 September, p 14) . When our firstborn was 5 months old, my husband and I decided to have a day out on the hills, and we climbed Ben Lomond in the Scottish Highlands. On …