Letters archive

Michael Marshall's interesting discussion on when human species started to use fire – particularly for cooking food – suggests an increasingly early date. Inevitably, the evolutionary advantages of cooking are raised, focusing on the fact that it significantly increases the digestibility of many foods( 31 December 2022, p 24 ). My long years in agriculture …

Annalee Newitz highlights the grim year experienced by big tech, including in the blockchain-based cryptocurrency market. However, there is plenty to cheer about the blockchain, which is essentially a very efficient ledger. Even its critics admit the technology works well( 17/24 December 2022, p 31 ). What we are seeing now is the Perez cycle …

I very much enjoyed the article about cloud companies' storage of material on magnetic tape. However, the story of Google accidentally deleting emails from Gmail accounts and then restoring them from the magnetic tape archives made me think( 17/24 December 2022, p 66 ). What about that embarrassing photo of me with long hair, a …

Danielle Olsen is absolutely right in advocating that the arts should go hand in hand with science. The popular and much misguided tendency is to see the two as mutually exclusive, with the arts often dismissed as a mere frivolity( 7 January, p 21 ). While the arts may provide a different type of stimulus …

You report a plan to produce environmentally friendly food from bacteria using only green hydrogen, carbon dioxide and ammonia. The ammonia in this recipe will almost certainly be produced by means of the Haber-Bosch process, which is a major source of CO 2 emissions( 31 December 2022, p 16 ). The odd thing is that …

When it comes to the efficacy – or not – of melatonin for sleep, one group that got no mention is totally blind people( 31 December 2022, p 41 ). Random trials are hard to come by, as we are such a small group, but I know several blind people who say that melatonin makes …

If aliens are flying Jupiter-mass spacecraft around the galaxy, surely we are more likely to detect the effects of the drive required to accelerate and decelerate such a large mass – which is likely to travel at a significant fraction of the speed of light – rather than the minuscule ripples in space-time generated by …

You report that the use of sonification in astronomy to turn data into audio has led to surprising discoveries. Surely other scientific fields with vast quantities of data to be analysed, sometimes urgently, could benefit from the use of sonification( 31 December 2022, p 46 ). Areas that jump to my mind are volcanology, MRI …

Annalee Newitz's new novel, The Terraformers , reviewed by Sally Adee, raises the issue of how we assign the quality of personhood to non-humans( 7 January, p 30 ). Pet owners and animal lovers know that animals have personalities. I scatter birdseed each morning and enjoy seeing the doves and pigeons take it. There is …

You pondered solutions to save the world, including building a sunshade in space to confront global warming. I have another geoengineering idea. A canal dug between the Black Sea and the Caspian Sea would provide central Asian countries with access to global shipping and increase precipitation in the region. The extra rain would enable carbon-sequestering …