Letters archive

Chanda Prescod-Weinstein laments the shift to broad-spectrum white LEDs in towns and cities because of the impact on the night sky. However, go to any sizeable theatre today and you will see from the stage lights that LEDs can be any colour. It isn't obvious why most LED road lighting is white, and it isn't …

Prescod-Weinstein regrets that when street lighting was converted to LEDs there was no requirement that the white light be filtered to a single frequency, which would make it easier for astronomers to deal with. But that would defeat the purpose of converting to LEDs – their efficiency. Filtering out most of the frequencies would drastically …

In many countries, such as India, power generation is indeed moving noticeably away from fossil fuels, with significant reductions in carbon emissions for that sector. ( 4 May, p 8 ) However, the overall energy consumption and carbon emissions of many nations is changing far more slowly, if at all, due to continued reliance on …

You report that we are roughly in the centre of a very rare void in the universe that doesn't match our cosmological theories. What else seems to be vanishingly rare in our part of the universe, roughly in the centre of the void? Life. (20 April, p 36) That is either an impressive coincidence or …

Clearly, the reason that the Milky Way is near the centre of a cosmic void is that no other advanced life forms want to risk their worlds getting infected with Earth's planet-destroying virus. They aren't yet sure if it is catching, so they are keeping their distance.

Thank you for the article on indoor climbing walls and the concerns about inhaling chemicals in the rubber dust released by the shoes used in such facilities. It was excellent, and this is something I have worried about for a while. ( 11 May, p 10 ) In a similar vein, I also have concerns …

The statement that "plastic, rightly demonised as a scourge of the modern world, could be fantastic again" seems to go too far in its criticism of the material. ( 27 April, p 36 ) It takes less energy to make a plastic bottle than a glass one. Additionally, plastic films play a crucial role in …

The increasing frequency of heavy rainfall events in the United Arab Emirates – like the one we saw recently, probably driven to some extent by rapid climate change – may reduce dependence on energy-intensive desalination, which is currently a key source of drinking water in the region. ( 27 April, p 16 ) Interconnected underground …

If you eat meat, researcher Anthony Hulbert recommends you have grass-fed beef or lamb and wild-caught fish, as they are high in omega-3s, and avoid pork and chicken because they are high in omega-6s. I rarely eat fish as I don't want to contribute to the destruction of aquatic wildlife, and I avoid beef and …