Letters archive

As Mary Menton and Felipe Milanez say, the policies of President Bolsonaro of Brazil may threaten the Amazon rainforest ( 10 November, p 24 ). But it is global policy on carbon pricing that fails to protect the forest. The Human Development Report 2007/8 points out that if carbon dioxide emissions are priced at $20 …

The plan to put 4425 satellites in orbit for Elon Musk's "space internet" seems impressive at first ( 10 November, p 5 ). But it is not just the financial cost that will be high. Does SpaceX plan to retrieve and recycle obsolete satellites? There is too much debris in orbit as it is. Simply …

Musk's plans require keeping 4425 working satellites in orbit. If each lasts an average of five years, the replacement rate would be 17 satellites a week. This would be several times the current total world launch rate for all purposes.

Chelsea Whyte reports people collaborating to play the game Tetris via electroencephalography (EEG) caps to record brain signals and a transcranial magnetic stimulation cap to transmit them ( 13 October, p 5 ). These seem rather cumbersome. Why not try receivers closer to the brain? People wear dentures right against the roof of the mouth. …

Alice Klein describes how clothes are "recycled" into flat panels ( 10 November, p 10 ). Work to reduce our waste is admirable, but this seems to me a misguided approach: downcycling the waste rather than recycling. Blending materials together removes any possibility of further recycling. The materials are still ultimately likely to end up …

You say that 10 million tonnes of landfill is generated from binned clothes in the US alone every year. Given a population of around 325 million, that is an average of 30.8 kilograms of clothes thrown away per person, per year: 68 pairs of jeans or 616 socks. Is this statistic pants? The editor writes: …

I look forward to reading Monica Gagliano's book Thus Spoke the Plant , and wish her the very best of success ( 24 November, p 40 ). Research into plant sentience has a patchy but interesting and important history. The first work devoted to it that I know of was a 1688 doctoral dissertation attributed …

Paul Barnfather correctly says that the average carbon footprint of UK electricity generation is falling due to the increasing proportion of renewable energy (Letters, 10 November ). But existing low-carbon generation is already at or near its maximum capacity, so a large increase in the numbers of electric vehicles will represent an additional demand that …

A man was apparently declared dead because DNA from a decomposed corpse was 99.92 per cent likely to be his (Feedback, 17 November ). When he turned up alive we were reminded to think of the 0.08 per cent. So should a jury in a murder trial be persuaded of a suspect's guilt by a …

Ray Vickers seeks a more accurate word for the F of "FRB" (Letters, 24 November ). Have his efforts in this direction been too... fleeting? The editor writes: • Three other readers had suggested this as we went to press.