Letters archive

Your special on consciousness was fascinating and thought-provoking ( 10 July, p 34 ). The section on whether machines could ever be "conscious" and "self-aware" seemed to ignore the role played by the fierce will to live and reproduce exhibited by living creatures. Where does this come from and where does it reside? One might …

When discussing consciousness, I am surprised that concussion isn't usually mentioned. Some years ago, I was in a concussed state for around an hour. I have no memory of this hour, but I was apparently talking and arguing with those around me. I have no doubt that I could have been eating, sleeping, mating and …

Emma Young writes that Christof Koch, in questioning the role of the prefrontal cortex (PFC) in consciousness, points to people who have had large regions of their PFC surgically removed. Koch is quoted as saying: "They go on living, by and large, a normal life, never complaining that they have been turned into zombies." May …

Surely the answer to the "hard problem" of consciousness must depend on the answer to the even harder problem: "What is life?" Life seems to be more than just chemistry, but what is that "more"? Does it make any sense to talk about consciousness that doesn't depend on life?

The only good climate change plan is zero fossil fuel use ( Leader, 10 July ). Net zero will see continued use of fossil fuels, compensating for this either by planting trees or removing the carbon produced in other ways. Greenpeace has shown that offsetting doesn't deliver , and absorbing carbon from the atmosphere would …

You mentioned the apocalyptic bushfires in Australia in 2019, and questioned the lack of climate action there. However, the climate damage had already been done, but not by Australia, which is responsible for less than 2 per cent of the world's carbon emissions . Those chiefly responsible are Europe, the US, China and India.

Mulling over Bryn Glover's thoughts on a "phased reduction" approach to achieving climate targets, I was struck by just how much reversal of "improving lifestyles" might be needed ( Letters, 10 July ). Things that were normal in my neighbourhood when I was young include heating just one room, water heater on once a week, …

You report research suggesting that after land-dwelling tetrapods evolved from fish, some tetrapod species "surprisingly" evolved to live in the water again ( 19 June, p 21 ). But is this surprising? We know that cetaceans made the same transition, even after becoming far more adapted to life on land than early tetrapods. More broadly, …

The final line of the box on missing lithium in our feature on gold (24 July, p 46) also went missing. The sentence in full should have read: Gas from that star falls onto the white dwarf, causing an explosion that may produce large amounts of lithium.

Your article on chemical pollution made some good points, but there is often confusion about what a "chemical" actually is ( 24 July, p 36 ). All materials are chemicals as there is no physical thing that is not made of chemicals. The idea of synthetic and natural chemicals is an artificial construct and often …