[Advaita-l] What is the meaning of illusion (according to advaita, obviously)?

[Suresh]

Dear Friends,

Thanks so much for helping. I still have a few doubts, though. It may sound a little dvaiti, so hopefully, no one will be offended.

Let's consider the examples that were given, namely shirt-thread, gold-bangles etc. From this, I understand that without gold, golden objects cannot exist, but the former can exist without the latter; and therefore, gold is real and the objects are mithya. My problem here is, why the confusion 'neither real nor unreal,' why can't we simply say gold is independently real, whereas golden objects are not. I am wondering why the word mithya, when something simpler could suffice. 

What I am trying to say is: gold=sat, golden object=sat (as long as it exists), and asat when it disappears. Two categories seem to be enough. Because no object can be sat and asat at the same time, when the golden object exists, it exists (sat), and when it doesn't, it doesn't (asat). So why mithya at all? This seems to be the source of my confusion.

Finally, I don't understand how time factor comes in here. Why do we define the real as something that lasts forever, and the unreal as something that doesn't. I know scriptures say this, but I am wondering as to why. Why is it we relate this to time?

Suresh