Is nihilism the logical extreme of atheism?

[Thumpalumpacus]

I would argue that emergent properties would answer your objection.

That was addressed by this line.

...Nor can the brain, as a whole, can be broken down into smaller and smaller interpreters, each assigning meaning to lesser and lesser signs. Even the smallest sign requires an interpreter no matter how tiny. You cannot build something out of nothing.

No, it wasn't, because what you wrote actually supports what I'm saying: if something cannot be broken down into component processes, but is only present when all the processes are extant, and yet it is more than the sum of those processes, you have an emergent property. It is not "something out of nothing"; it is something out many things which sometimes produce surprising results.

... and we are back to humans defining their own morals and meaning.

a.k.a. nihilism.

My life has objective meaning. Ask my son, an external observer; he'll tell you.

See how easy that is? I have defined the meaning of my own life, but it is accepted as fact. Kinda like your god defining the meaning of your life, and you accepting it; but I'm responsible enough to do the heavy lifting myself.