From James Fradgley, Wimborne, Dorset
I enjoyed Chanda Prescod-Weinstein’s article about a subject that has had us all confused: “What makes a galaxy?” We do have this powerful need to put everything into boxes and, alas, it doesn’t always work. For example, is Pluto a planet? This is a subject that seems to cause endless anguish. Another example is the definition of a species, which, when you consider examples such as ring species (which illustrate how populations diverge to the point that they can no longer interbreed), makes it all a bit arbitrary (21 March, p 18).
I’m not against categorising things, because it helps with understanding, but we need to accept that there will always be things that don’t quite fit the model, rather than trying to force them into one box or another.
