[ExI] [Extropolis] Cellular automata, downward causation, and libertarian determinism

[John Clark]

 Jason Resch  wrote:

*> If reality consists of a sufficiently large multiverse, then we can
> expect a vast plenitude of parallel universe states which are almost the
> same, but different only by the position of a single particle, for example.*


*I agree. Maybe somebody will come up with a better idea tomorrow but as of
today I think Hugh Everett's "Many Worlds" is the least bad quantum
interpretation; if it is not at the foundation of reality then something
even weirder is. *

*> Such parallel universes contain identical copies of brain states of all
> the conscious observers*


*According to Everett a universe splits if there is a change, if everything
is identical then there is no split. So in one universe an electron in your
lab goes to the left and your instruments register that it went to the
left, and the other universe the electron goes to the right and your
instruments register that it went to the right, but you would have no way
of knowing which universe you are now in until you look at your
instruments. *

*But how would Many Worlds explain bizarre things like  **quantum erasure
and the delayed choice experiment?  In Many Worlds a split happens when
there is a difference; and normally the universes will never coalesce again
because thanks to the butterfly effect even a tiny difference will
exponentially growing magnitude so its **astronomically unlikely they will
ever become identical again, but if the difference between 2 worlds is very
small, like the only difference between two universe is  that in the two
slit experiment in your lab an electron went through the left slit rather
than the right, and if you don't wait so long that other effects might
change then, then a very skilled experimenter can coax those worlds to
become identical again and coalesce back into just one world; but when
contemplating the history of that electron you will find evidence that it
went through the left slit but equally strong evidence that it went through
the right slit, and that is what some call "quantum indeterminism".  *

*The big advantage Many Worlds has over the Copenhagen interpretation is
that Copenhagen claims there are two separate laws of physics, one for
things that have been observed and another for things that have not been
observed, but Many Worlds says there is only one set of physical laws, and
it has no need to explain exactly what an "observer" is or how
consciousness works because those things have nothing to do with it. So
according to Occam's Razor it is superior.*

*> But once the measurement is made, the observer's mind state changes in a
> way that partitions the set of similar but not quite identical universe she
> is a part of. The observer is said to have "collapsed the wave function"
> but really, she has only adjusted her knowledge*


*Exactly, until you look at your instrument you don't know which universe
you're in. As for downward causality, the trouble with it is that even if
the laws of physics are completely deterministic, causality could still be
asymmetrical. For example the laws for **John Conway's "Game Of Life" are
very simple and completely deterministic so if you are given a pattern you
can always predict how it will evolve, but you can't determine what pattern
produced it. You can predict the future but you can't know the past. *

*John K Clark *
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20251028/6a354355/attachment.htm>