If sentience is an undeniably real phenomenon that can never be identified as the direct consequence of any particular event at one place and time—not even the workings of a human brain—mustn’t it necessarily follow that sentience somehow characterizes the entire universe all at once?
Brian, I fail to see how you labeling various phenomena as 'God' (or as 'Not God') has to do with atheists. If, say, by my definition, I say that God is a forest, and, since a forest exists, therefore God exists, would you agree? Doubtful that you would. It seems to me, your ''challenge'' consists of little more than this sort of conjecture.
Sentience is one of these concepts, much like quantum mechanics, that is frequently abused to give a pseudo-scientific gloss to peoples' mystical indulgences. No harm in it, your entitled to your opinion, as they say, but I don't see your assertion as containing any ''challenge'' to atheists, new or old.
Atheists, of various grades, deny the existence of all the gods currently, or formerly, worshiped by humanity. I refer you to Bertrand Russel if you want to know my particular stance
"As a philosopher, if I were speaking to a purely philosophic audience I should say that I ought to describe myself as an Agnostic, because I do not think that there is a conclusive argument by which one can prove that there is not a God. On the other hand, if I am to convey the right impression to the ordinary man in the street I think that I ought to say that I am an Atheist, because, when I say that I cannot prove that there is not a God, I ought to add equally that I cannot prove that there are not the Homeric gods."
Until proven otherwise, I choose to regard all such entities as myths, legends and outdated explanations for life, the universe and everything in it. I can't prove a negative. I can't disprove God, or Thor (awesome movie by the way, way more fun than Passion of the Christ...the Norse gods get my vote!) no more than I can disprove leprechauns.
PS Sorry if I've missed anything out, but I haven't read the rest of the thread....