Letters archive

I greatly enjoyed Matthew Chalmers's article on the subjective nature of reality and how "quantum weirdness is all in the mind" (10 May, p 32) . The same problem of subjectivity arises in psychology when theorists tie themselves in knots trying to relate abstractions such as intelligence or personality to everyday experience. Quantum theory cannot …

If quantum weirdness is all in the mind, what about optical interference? Set up apparatus that can record the arrival of an individual photon on a screen after passing through one of two slits, and then ask: "Which slit did that particular photon pass through?" It will never arrive at a point not allowed by …

Quantum Bayesianism, which views quantum states as existing only in our minds, seems a red herring that leads you into a strange maze of inter-subjectivity. What happens when the scientists communicate with each other and collate their individual observations? They cannot help but arrive at objective laws of physics, such as entanglement, and so we …

Chalmers highlights the way a metaphor may be mistaken for reality. This reminded me of George Lakoff and Mark Johnson's book Metaphors We Live By , which reveals how fundamentally these structure our thinking. They demonstrate the deeply embedded nature of metaphor within language, and the way this routinely escapes our notice. For me, their …

Clare Wilson's article on how doctors diagnose mental health problems took a tone that was rather sensationalist and negative (10 May, p 10) . It strikes me that those working at the front line of anthropogenic climate change are generally portrayed in your magazine as heroes. Their scientific evidence requires further refinement, but it is …

The view that psychiatry needs a reboot comes not from our own quarters, but from the practitioners themselves. Last year, Thomas Insel, director of the US National Institute of Mental Health, announced on his blog (bit.ly/ns-Insel) that the organisation "will be re-orienting its research away from DSM categories".

In Anil Ananthaswamy's piece on why robots will never be conscious, Phil Maguire says that his team's proof would not hold up if information integration in the brain was reversible (17 May, p 12) . He will be disappointed to learn that memories can indeed be broken down and edited . Memories are also not …

I am appalled by the proposal from Explore Mars to use a battery of ground-penetrating missiles in the search for life on the Red Planet (10 May, p 14) . Clearly executive director Chris Carberry slept through Ethics 101. If there is life of any sort on Mars, by what right do we rain down …

In discussing the infinitely multiplying multiverse, Lisa Grossman states that given enough time, anything that has a chance of happening will happen (17 May, p 8) . This is not the case. If you start counting in the usual way: "1, 2, 3..." and carry on until infinity, you will never get to -3, 42.5 …

Aviva Rutkin's article about a 3D printer that uses yarn sounds very much like knitting, and in particular a Jacquard machine (17 May, p 21) . This specialised loom uses a device to carry the yarn over a series of programmable knitting needles, allowing various 3D articles to be made. One could use yarns with …

• Our logic got fuzzy when considering the likelihood of conscious robots (17 May, p 12). The outputs should be swapped in our description of an XOR logic gate.