From: Dan Fabulich (daniel.fabulich@yale.edu)
Date: Wed Aug 25 1999 - 23:10:15 MDT
On Wed, 25 Aug 1999 jmcasey@pacific.net.sg wrote:
> Then doesn't this bring me back to my original question. The photon
> that passes through gate A in Universe 1 and gate B in Universe 2 goes
> on to be absorbed by particles X and Y respectively, and unless and
> until we devise a measurement that allows us to precisely trace its
> "actual" trajectory, we never know for sure which universe we're in.
> Right? And since this sort of subatomic interaction takes place
> googols of times a second, universes are being created googols of
> times a second. And because measurement of these phenomena takes place
> on only a laughably small fraction of the total, alternate universes
> collapse only rarely.
>
> And if I'm still following a valid logical chain, what particular set
> of events causes us to perceive *this* particular universe over all
> the others, or is it just chance?
Try imagining a split just ABOUT to happen. During this split, one split
version of you will go on to exist in "Universe A," while the other split
version of you will go on to exist in "Universe B." From this past
perspective, it obviously doesn't make sense to ask "Why will I perceive A
and not B?" because, in point of fact, you (that is, the unsplit you) will
perceive both (once you split). Why X? Not X.
The reason your question is harder to think about after the split is
because when a split version of you thinks about the other split version
of you, the other split version necessarily seems a little less real.
This is not a fact about physics; this is a fact about psychology and the
way we use language.
Suppose the A version of you is thinking about the B version of you.
When the A version says "I," it means the A version and ONLY the A
version; not the B version. The B version is different from the A
version; since we are very used to the idea that "I" refers to only one
thing and not two different things, it's quite natural to think, right or
wrong, that after the split, you are not the same person as the other
version of you in the other branch. Since you seem very, very real to
yourself, anything that is not you (in this case, version B) seems
slightly less certain; slightly less real. [Or, in the case of an
abstract theory like MWI, perhaps far, far less certain/real indeed.]
Now we return to your question, "why do I perceive A and not B?" I'd
argue that this is because it's very natural for one to think of a person
on one side of the branch as different from the person on the other side
of the branch. The other version of you is perceiving B, but since that
version isn't "you," "you" aren't perceiving B. That is why "you"
perceive A and not B. If you were to call both splits in both branches
"you," which comes quite naturally BEFORE the split, since before the
split both versions DO seem more like yourself, the question would seem
pretty meaningless.
(You know, sometimes I wonder if I'm in John Clark's killfile.)
-THAT THAT IS IS THAT THAT IS NOT IS NOT-
This archive was generated by hypermail 2.1.5 : Fri Nov 01 2002 - 15:04:53 MST