And I have never said "there was no world". Nor have I said there was a world. I don't think either statement has meaning, for the reasons DaleSpam has already given--there's no experiment you can do to tell whether "the world" as you define it is "real" or not.If you mean the "world" is constructed after the fact--after the observer has already received light signals from all the events in his "world" at some instant--then that's something different than what we've been discussing up to now, because the observer will have to wait for some time *after* a given event before he can construct his "world" at that event. (In fact, if he wants to construct his *entire* "world" at a given event, he might have to wait an infinite amount of time--to the best of our knowledge, the universe is spatially infinite.)
On this view there is no reason to claim that the "world" is "real" at event E; you're only claiming events are "real" after you've received light signals from them, so you know what happens in them. In other words, you are limiting your claims to what's actually known--what's in your past light cone.
Only if they insist on identifying their "world" with their simultaneous space at a given event. But since no events spacelike separated from a given event can affect what any observer observes at that event, their different choices of simultaneous space have no observable consequences, as DaleSpam has pointed out. So there's nothing that *requires* them to disagree. They could both just say that the entire set of spacelike separated events is "elsewhere" (Roger Penrose's term), and defer making any claims about them until they receive more information (as discussed above).
Or, if either one wants to extrapolate from what's known, what's in their past light cone, to *predict* what might be happening at some event that's spacelike separated from them, why would either one need to restrict his predictions to just his own simultaneous space at a given event? Why couldn't observer A make a prediction about what might be happening at an event that is simultaneous with observer B at event E? Why must each one restrict their predictions to their own "world"? Or even to the other's "world"? Why couldn't either of them make a prediction about *any* event that's spacelike separated from them? There's nothing stopping them; they have the same amount of information (in the past light cone) to extrapolate to *any* spacelike separated event. So there's nothing that even picks out either one's "world" as being any different from any other set of spacelike separated events.
I haven't called any of the worlds "real", so this doesn't apply to me.
I have never said the world is only a dream. How are you getting that out of what I said? Are you actually reading what I post? You seem to be making a lot of assumptions about what I am saying that are invalid.
Of course not. If you had actually read what I posted, it would be obvious; I talked explicitly about multiple observers and what each one observes, constructs, etc. I never said that any observer, including me, was "privileged" in any way; they are all on an equal footing.