Letters archive

Chris Stokel-Walker says that one company could be a single point of contact for delivery of online shopping, removing duplication of vehicles ( 7 September, p 42 ). Older readers in the UK may remember a similar service provided by the Royal Mail. Unfortunately, legislation may now be required to reduce the half a dozen …

Stokel-Walker explains how online suppliers are looking to use technology to lower the cost of delivery to individual homes and reduce polluting van journeys. Why not use the existing home delivery service for milk? My milk supplier delivers to our house every other day using environmentally friendly electric vehicles along optimised routes. Any returns could …

Donna Lu describes the training of AI as requiring large data sets and reminds us that the process by which AI reaches its predictions is opaque ( 17 August, p 7 ). Human clinicians learn by being exposed to data, but need considerably less information as they are guided by others who already have this …

As Helen Thomson notes, a lot of back pain is due to bad posture ( 31 August, p 34 ). We need to sit and stand up straight, with our shoulders back, head held high and tail bone pointing down. That way, our core muscles support the spine and nerves don't get pinched. Designers have …

You present a graph of disability-adjusted life years lost to back pain. It seems to carry more information than was referred to in the article. Between 1990 and 2015, there was a shift in the age of peak pain that could be as great as 25 years. May the root cause be traceable to some …

You report bees in Puerto Rico evolving to become less aggressive ( 17 August, p 38 ). I believe a similar process is happening in the UK in response to the varroa mite. When I started keeping bees 15 years ago, these mites were a major problem, with all colonies in danger of dying out …

Many diseases may be caused by the spread of Porphyromonas gingivalis , as Debora MacKenzie reports ( 10 August, p 42 ). This reminded me of Colin Barras describing the recently discovered Candidate Phyla Radiation (CPR) microbes that parasitise the mouth bacterium Actinomyces odontolyticus and help it evade the immune system ( 10 April, p …

Discussing the detection of alien life, Sarah Rugheimer notes Fermi's paradox: where is everybody? Geometry may explain why we seem to be alone in the galaxy ( 31 August, p 42 ). Say the volume of our galaxy is about 10 14 cubic light years. Suppose one billion technological civilisations currently exist in it. On …

I sometimes joke about being a print addict, and now I see disturbing similarities between my reading habit and the behavioural addictions that Moya Sarner discusses ( 14 September, p 42 ). I look up and find I am somehow still reading at 4 am. I experience a "flow state" and am uneasy if deprived. …

Reading about addictions to behaviours , I realise I have become addicted to writing letters to New Scientist . I scan each issue, looking for some topic that I can pretend to be an expert in. As your article points out, unpredictable rewards strongly increase the addiction, and you contribute to this by only rarely …