Letters archive

David Holzman reported that exposure to blue light at night can restrict levels of melatonin (7 May, p 44) , with possibly serious effects on the body clock and health. I first heard about this in 2007 during the European Symposium for the Protection of the Night Sky, in Bled, Slovenia. It was suggested that …

Your rather wonderful feature "The next wave" ( 14 May, p 30 ) listed technologies predicted to be big in the next decade and suggested what a "lexicon of tomorrow" might contain. How about shifting your suggestion of "digital litter" to the lexicon of today, as a useful term for the many websites that can …

Your article "Cruelty-free quantum probes" (30 April, p 8) invoked Schrödinger's famous thought experiment involving a cat in a closed box which also contains a booby trap with a quantum trigger. The cat is both dead and alive until it is observed, raising the question as to whether a conscious observation is required to determine …

Creating nitrogen-fixing, non-leguminous crops (7 May, p 8) to boost food supply could support an increased human population, only to have it face the "end" of mineral nutrients extracted from the earth, such as phosphorus and potassium. Nitrogen is an atmospheric plant nutrient, along with carbon, oxygen and hydrogen. We are not at risk of …

Learning to talk to dolphins is a charming, romantic notion, but it seems a big jump from the researchers using their software to analyse footage of sign-language and gym routines (7 May, p 23) . Unnecessarily big. Wouldn't it have made more sense to try it with some obscure human languages first? The investigators and …

The story about another hint of the elusive Higgs boson amounting to nothing (7 May, p 6) set me thinking. As a 16-year-old physics student, I find myself enraptured every time its tentative discovery is reported. Most times, I am disappointed. However, the longer the Higgs remains elusive, the greater my hope grows that we, …

I was fascinated by "Our forgotten years", your article on childhood memory (30 April, p 42) . I have a distinct early memory but the events are incomplete and I have always thought the full version must be buried in my brain. Now I realise it might not be. I was about 3 and wearing …

In the story on dangerous ice build-up on aircraft (30 April, p 17) , Paul Marks stated that "as ice accretes on the wings and tail, it changes their shape, creating drag. That, in turn, reduces the airspeed which is needed to generate lift – leaving the aircraft at risk of stalling". This wasn't quite …

The description of three levels of technological complexity in "We've made a world we cannot control" (14 May, p 28) , to describe function, network interactions and, lastly, an unfathomable interplay with the wider world, seems a very useful idea. Maybe we can take it further by giving them descriptive names: level 1 = stand-alone, …

BBC environment analyst Roger Harrabin's plan to publicly compare the reliability of weather forecasts (7 May, p 28) is to be applauded. Next, could someone do something similar for economic forecasts?

The "lightcraft" and the heat-exchanger rockets in "Beam riders" (30 April, p 38) may succeed in launching the next generation of spacecraft, but why bother with lasers and microwave generators? A large solar furnace could collect the reflected sunlight from an array of mirrors covering several thousand square metres, and focus it into a narrow …

• In the diagram in our solar systems feature (14 May, p 46) the four outer planets were mislabelled. From left to right, they should have been Jupiter, Saturn, Uranus and Neptune.