I think that using this notation is misleading. If I am understanding you correctly, you are saying that given an individual, we can derive their morality from their (real/physically grounded) state, which gives real/physically grounded morality (for that individual). Furthermore, you are using "objective" where I used "real/physically ground". Unfortunately, one of the common meanings of objective is "ontologically fundamental and not contingent", so your statement sounds like it is saying something that it isn't.
On a separate note, I'm not sure why you are casually dismissing moral nihilism as wrong. As far as I am aware, moral nihilism is the position that morality is not ontologically fundamental. Personally, I am a moral nihilist; my experience shows that morality as typically discussed refers to a collection of human intuitions and social constructs - it seems bizarre to believe that to be an ontologically fundamental phenomenon. I think a sizable fraction of LW is of like mind, though I can only speak for myself.
I would even go further and say that I don't believe in objective contingent morality. Certainly, most people have an individual idea of what they find moral. However, this only establishes that there is an objective contingent response to the question "what do you find moral?" There is similarly an objective contingent response to the related question "what is morality?", or the question "what is the difference between right and wrong?" Sadly, I expect the responses in each case to differ (due to framing effects, at the very least). To me, this shows that unless you define "morality" quite tightly (which could require some arbitrary decisions on your part), your construction is not well defined.
Note that I expect that last paragraph to be more relativist then most other people here, so I definitely speak only for myself there.
I think that using this notation is misleading. If I am understanding you correctly, you are saying that given an individual, we can derive their morality from their (real/physically grounded) state, which gives real/physically grounded morality (for that individual). Furthermore, you are using "objective" where I used "real/physically ground". Unfortunately, one of the common meanings of objective is "ontologically fundamental and not contingent", so your statement sounds like it is saying something that it isn't.
I used 'o...
I have noticed that the term 'nihilism' has quite a few different connotations. I do not know that it is a coincidence. Reputedly, the most popular connotation, and in my opinion, the least well-defined, is existential nihilism, 'the philosophical theory that life has no intrinsic meaning or value.' I think that most LessWrong users would agree that there is no intrinsic meaning or value, but also that they would argue that there is a contingent meaning or value, and that the absence of such intrinsic meaning or value is no justification to be a generally insufferable person.
There is also the slightly similar but perhaps more well-defined moral nihilism; epistemological nihilism; and the not-unrelated fatalism.
Here, it goes without saying that each of these positions is wrong.