You seem pretty convinced. Let me see if you're talking about the same pedantic distinction that oh_my_goodness was.
A: "an urn containing either a white ball or a black ball".
B: "I notice that the ball in the urn A is white".
I would say that initially the entropy of our ball-urn system is 1 bit, and that with observation B, we have reduced the entropy of our ball-urn system to 0 bits.
But if you are going to take the view that even knowing the ball in this particular urn is actually white doesn't change the fact that the entropy of <<"an urn containing either a white ball or a black ball">> is 1 bit and not 0, and that that's the entropy that we're discussing, then I won't argue about it any further.
The entropy of the system was always 0 bits. Knowledge is irrelevant.
If the urn actually contained nothing and would materialize a black or a white ball randomly then this can occur with or without your knowledge. When the ball materializes and nothing more can be done THEN the entropy has changed. Because there's no more possible microstates.
You not having knowledge about microstates DOES NOT change available microstates. You seem to think that if you don't know about something, anything goes.
You're really arguing abstract philosophy. Did a tree in the forest fall if no one was around to see it? Yes it did dude. Your knowledge of it has nothing to do with whether it fell. Same with entropy. And if you deny the fact that a tree in the forest never fell, then you're the one going off onto a pedantic tangent.
I'm surprised to hear that "the entropy of the system was always 0 bits."
Let's say that the urn contains a ball that changes its color from black to white and viceversa every thousand years (relative to January 1, 1970 midnight UTC).
Given that "macrostate" there are two possible and equally probable "microstates". The entropy is positive. If I look into the urn and find that the ball is white was the entropy of the system always zero? Or is it always positive in this example?
What I'm seeing in your other reply is actually you not even reading my reply. Your making statements on things I already touched upon.
It makes you seem not intelligent. But that would be a rude thing to say would it? There's no point. If you want to have a discussion probably smart to say things that will keep the other person engaged rather then pissed off.
This is actually bad enough where I demand an apology. Say your sorry, genuinely, or this thread won't continue and you're just admitting your mean.
A: "an urn containing either a white ball or a black ball".
B: "I notice that the ball in the urn A is white".
I would say that initially the entropy of our ball-urn system is 1 bit, and that with observation B, we have reduced the entropy of our ball-urn system to 0 bits.
But if you are going to take the view that even knowing the ball in this particular urn is actually white doesn't change the fact that the entropy of <<"an urn containing either a white ball or a black ball">> is 1 bit and not 0, and that that's the entropy that we're discussing, then I won't argue about it any further.
Except for the obligatory xkcd: https://xkcd.com/221/