[ExI] Many Worlds (was: A Simulation Argument)

[Lee Corbin]

Kevin writes

> > It's important to point out that the worlds don't actually halve,
> > double or undergo any other special process at all when the
> > "split" occurs. Say there are two identical versions of you,
> > A and B, contemplating a quantum coin toss. Because A and
> > B are identical, there is no way for you to say that you are one
> > or the other. After the coin toss, A sees heads and B sees tails."
> 
> And how about C - who has the coin that lands on its side and rolls
> off into the distance?

A tiny part of the continuous stream becomes the world in which
this too happened.

> > <Can we regard the separate worlds that result from a 
> > measurement-like interaction (See 
> > <http://www.hedweb.com/manworld.htm#measurement
> > as having previous existed distinctly and merely differentiated,

That's sort of how several of us see it.

> > rather than the interaction as having split one world 
> > into many?

That's the same thing, if the measure-sum of the many
equals the measure of the original unsplit world.
  
> I have a question that may seem odd. Given how this works,
> if I were to throw a tennis ball at a brick wall, there is an
> extremely small possibility that the ball would pass through
> the wall. OK - not just extremely small, but extraordinarily
> small. Each particle in the ball would have to have the odds
> line up in favor of this on the same throw, but it's still more
> likely than impossible. So is another world created where
> the ball actually passes through?

Yes, on the reading that several of us here endorse, there is 
a world in which this unlikely event happened also. We see,
though, how tricky are all the words "split" "create" and so on.
So let's rehearse the river analogy again. When the Mississippi
"splits" at the delta, is a given small branch "created"?  Or should
we say that the water-stream that constitutes it already previously
existed (upstream) but merely became distinguished?  While the
words may not suit us well, I believe the idea to be internally
consistent, and even easily visualizable. 

The analogy works even further:  it might be tempting to say that
the "new" little delta branch should be regarded as infinitely many
worlds itself, since there may be no limit to how much further
branching may take place (at least down to the level of a single
stream of atoms, I suppose).  But it is better to think of this 
branch as just a single thing, since if we want to think of it as
composed of infinitely many sub-branches, they're all identical
so who cares?

> Another. Fingerprints are random. So is there a "me" born
> with every possible pattern?

Sure. On Everett's account, universes are cheap.  It's axioms 
that are dear. 

> This may have already been answered or may be silly questions,
> but I haven't put as much study into "many worlds" as I would
> like since I have other topics that interest me more - you know - 
> like problems I can actually solve.....

I'm feeling more and more like that every day.

Lee