From John Woodgate Rayleigh, Essex, UK
In response to Chanda Prescod-Weinstein’s article on the research into dark matter: dark matter seems to me to be “aether with mass”. It can’t have any viscosity, for example, because if it did, normal matter passing through it would lose energy, which we would be able to detect. This applies at the cosmic scale even if dark mass particles are very loosely distributed (29 November, p 24).
