[ExI] Many Worlds

Ian Goddard iamgoddard at yahoo.com
Wed Jan 9 02:00:40 UTC 2008


Stathis Papaioannou wrote:

>>  For example, describing the 'simplicity' 
>> criterion of scientific theories, Copi & Cohen 
>> cite Ptolemy's theory of celestial orbits versus 
>> the Copernican theory. The two theories were 
>> equally effective explanations and predictors of 
>> astronomical data. And *both* assumed epicycles. 
>> But according to Copi & Cohen, Ptolemy's model 
>> should be rejected because it assumed more 
>> epicycles. [1] So for each additional physical 
>> entity (an epicycle) there's an additional 
>> assumption for that entity. So saying assumptions 
>> in a theory are distinct from physical entities 
>> posited by that theory is not a clearly valid 
>> claim.
>
> Copernicus' model is geometrically simpler than 
> Ptolemy's, but it actually implied a much vaster 
> universe. 


 A theoretical model with more space between two
points doesn't posit more 'entities' between them. And
using Newton's razor of causal economy, a claim of
more space does not entail a claim of more causes. So
I don't see that different volumes of space affect the
application of Occam's or Newton's razors.


> Many Worlds is what is left if you remove the 
> assumption of an an arbitrary "collapse" of the
> wavefunction precipitated by an observation. The 
> trimmed down theory then explains all of the
> scientific evidence, and as a bonus preserves 
> realism, locality, determinism and does not bestow 
> on the observer any special status compared to the 
> rest of the universe.


 How does MWI explain Wheeler's delayed-choice
experiment? It's importantly unique:

   "Where the classic [ double slit ] experiment 
   demonstrates that physicists' observations 
   determine the behavior of a photon in the 
   present, Wheeler's version shows that our 
   observations in the present can affect how 
   a photon behaved in the past." [*]

It's important to understand that experiment, as that
difference makes a big difference. The description of
it starts toward the bottom of page 1 here:

[*] http://discovermagazine.com/2002/jun/featuniverse

In 1984 Wheeler's delayed-choice thought experiment
was confirmed at the University of Maryland. It was
confirmed again and published last February, '07:

http://www.sciencemag.org/cgi/content/abstract/315/5814/966


http://IanGoddard.net

Hume on induction: "When we have lived any time, and
have been accustomed to the uniformity of nature, we
acquire a general habit, by which we always transfer
the known to the unknown, and conceive the latter to
resemble the former. By means of this general habitual
principle, we regard even one experiment as the
foundation of [empirical] reasoning, and expect a
similar event with some degree of certainty."

 



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