>
> Why do you need multiple, non-interacting universes, when a sigle
> everything-universe plus WAP will explain our existence? Purely because of
> flying rabbits?
>
> My solution, I remember now, is that the changes of one flying rabbit
> appearing for 10-43 seconds are one in a 10E43, say, so we should see one
> every second. But we dont notice because a Planck time is too small to
> notice. For a stable rabbit to appear, it would be 1 in 10E86 to appear for
> two planck-times, and if it were to be there for a whole second, that would
> be 1 in 10E1849.
>
> That's pretty unlikely.
This is part of the story, but not the whole story. I believe the
explanation I gave back in July explains why universes observationally
indestinguishable from a law abiding one will be vastly more probable
than ones where the laws observably break down just a little bit - eg
white rabbit universes. Alistair Malcolm agrees with this explanation,
and features it on his Web site.
What is interesting about this thread, is that Juergen Schmidhueber
has also thought quite a bit about this - I'm going to have to read
your paper Juergen to see what ground you've covered already. Thanks
for the ref.
Cheers
>
> > -----Original Message-----
> > From: hal.domain.name.hidden [SMTP:hal.domain.name.hidden.org]
> > Sent: Thursday, October 21, 1999 5:36 PM
> > To: hal.domain.name.hidden; james.higgo.domain.name.hidden.co.uk
> > Subject: RE: Turing vs math
> >
> > > What that postulates is that everything exists, and that means you exist
> > and
> > > I exist in an infinity of all possible variations. I'm perfectly
> > comfortable
> > > with this, as I am an MWI-er.
> > >
> > > In this view, the only reason you ever get a physical 'law' is that when
> > the
> > > random relationships we see as laws break down (which is most of the
> > time),
> > > we cease to be able to observe it, as the environment then ceases to be
> > > hospitable to life. The same reson an MWI-er will give for us never
> > seeing a
> > > vacuum collapse: they occur, but we don't observe those eigenstates in
> > which
> > > they do, as we aren't alive.
> >
> > Only if it's a major breakdown. Laws that have small exceptions and
> > loopholes would still be consistent with our existence.
> >
> > > The question is, given that all worlds exist, and that the WAP explains
> > why
> > > we find ourselves in a congenial environment, WHY have I never seen a
> > flying
> > > rabbit? Why should not the 'laws' break a little bit, to allow
> > non-lethal
> > > event like that, then repair themselves?
> >
> > Well, I just asked you the same thing in another message! I don't think
> > you can explain this without invoking multiple universes.
> >
> > The normal all-universe explanation is to consider two universes.
> > One has physical laws as we know them: F=ma (one of Newton's laws), etc.
> > The other has a law like "F=ma except when Merlin waves his magic wand".
> > This universe allows for flying rabbits and other magical objects, but
> > is otherwise basically lawful and people can evolve in it.
> >
> > Now, obviously the program to compute the second universe is much more
> > complicated than the program to compute the first one. It has all these
> > special exceptions in it for when magic is allowed to work, and how.
> > So it is a bigger program.
> >
> > We then invoke the principle that large-program universes are inherently
> > less likely than small-program universes, and presto! we have it more
> > likely that we live in a universe without flying rabbits, without
> > magic, etc. That's the general argument we are striving to achieve.
> >
> > I do think that this argument has some problems, but it is appealing and
> > if the holes can be filled it seems to offer an answer to the question.
> > What do you think?
> >
> > Hal
>
>
----------------------------------------------------------------------------
Dr. Russell Standish Director
High Performance Computing Support Unit,
University of NSW Phone 9385 6967
Sydney 2052 Fax 9385 6965
Australia R.Standish.domain.name.hidden
Room 2075, Red Centre
http://parallel.hpc.unsw.edu.au/rks
----------------------------------------------------------------------------
Received on Thu Oct 21 1999 - 18:38:41 PDT