Patrick Leahy wrote:
[quoting Quentin Anciaux, who responded to Patrick's original post]
I thought of Observer Moment as containing the observer... What is the meaning of an OM (the same) which spread accross branches ? If you start by the assumption that OM are fundamental, then a "branch" is an OM. Or a branch is a consistent succession of OM ?
I'm also learning a new "language" here as well, so forgive me if I got it wrong. I was trying to put the best "spin" I could on the idea of multiple pasts. Personally I'm not sympathetic to the OM concept in the first place, except as a useful device for anthropic calculations.
By a "branch" I mean a branch of the wave function (Psi for short), which in MWI does literally have a branching structure in (configuration space + time). This is absolutely not an OM: for one thing, a branch is extended in time. Also, each branch of Psi describes a history for all the observers in the universe (not to mention all the non-self-aware bits), and hence contains (>>?) billions of OM at any given time. And of course a different OM for each observer at each moment.
If the split forever is correct, then does a consciousness spread accross all those branch where the OM is in ? or just in one branch, and in other branches with the same OM, this is not the same consciousness ?
This is really a matter of definition, I think. Is there a distinction between "consciousness" and "OM" ? I would say yes but I suspect many here would disagree. From my point of view, I'd prefer to say that each observer (and her consciousness) inhabits a specific branch and has only one past, even if it is indistinguishably different from that of a copy in another branch.
If the later, why can it be said that it is in fact the same OM ?
I'm with you. But if you take OM as fundamental, as some here do, you might prefer to re-sort the OMs scattered throughout the multiverse so that all identical OMs go into one "pot"; then you can choose to call this pot a single OM with a greater or lesser weight. In which case it is probably legitimate to talk about these having multiple pasts, though in another sense they have no past (they are self-contained moments!), only a memory of one (which is *not* multiple, by definition).
Observers and observer-moments are not incompatible ideas. OM's are simply the moments that make up an observer's stream of consciousness. You might reasonably argue, if OM's cannot stand in isolation, but are always grouped together in a particular instantiation of an observer (debatable, but let's grant this is so), then isn't the idea of OM's a needless complication, compared to the traditional concept of an observer who persists through time? The short answer is that it is very difficult to come up with a consistent definition of an observer which covers all eventualities (persistence through time, multiple copies in the same or different universes, upload to a computer, etc.), and the idea of OM's allows you to define an observer on the fly, aknowledging that the idea is ultimately arbitrary. See my recent thread on "observers and observer-moments" for a slightly longer reply.
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