And the next time someone says that there are astronomical facts about the chemical make-up of water I will correct them as well. Which is to say I don't know what your point is and can only imagine you think I am arguing for something I am not. Perhaps it's worth clarifying things before we get glib?
In which case, you will be making a point - not that there are different facts, but that there are different languages. Of course, language is an invention - and there is no natural law that dictates the definition of the word "astronomy".
It is merely a convention that we have adopted a language in which the term "astronomy" does not cover chemical facts. But we could have selected a different language - and there is no law of nature dictating that we could not.
And, yet, these facts about language - these facts about the ways we define ...
Do you believe in an objective morality capable of being scientifically investigated (a la Sam Harris *or others*), or are you a moral nihilist/relativist? There seems to be some division on this point. I would have thought Less Wrong to be well in the former camp.
Edit: There seems to be some confusion - when I say "an objective morality capable of being scientifically investigated (a la Sam Harris *or others*)" - I do NOT mean something like a "one true, universal, metaphysical morality for all mind-designs" like the Socratic/Platonic Form of Good or any such nonsense. I just mean something in reality that's mind-independent - in the sense that it is hard-wired, e.g. by evolution, and thus independent/prior to any later knowledge or cognitive content - and thus can be investigated scientifically. It is a definite "is" from which we can make true "ought" statements relative to that "is". See drethelin's comment and my analysis of Clippy.