A. Neumaier said:
You can read my refutation of the MWI in Chapter A4 of my theoretical physics FAQ
http://arnold-neumaier.at/physfaq/physics-faq.html#manyworlds
I don't consider it to be a serious interpretation, and won't waste my time on further discussing it.
I read it and here's a partial refutation of it. You wrote there that
"Q1 Who believes in many-worlds?
many- worlds is most popular amongst scientists
who may rather loosely be described as string theorists or
quantum gravitists/cosmologists. It is less popular
amongst the wider scientific community who mostly
remain in ignorance of it.
String theorists and quantum gravitists/cosmologists are those
physicists farthest removed from experiment and hence most free to
entertain fancy theories without stringent constraints that would
bring them down to earth. That the wider scientific community mostly
ignores MWI is a healthy sign of contact to reality."
Here's the refutation:
http://arxiv.org/PS_cache/quant-ph/pdf/0101/0101077v1.pdf
quoting
"An informal poll taken at a conference on quantum
computation at the Isaac Newton Institute in Cambridge
in July 1999 gave the following results:
~~
Which interpretation of quantum mechanics is closest to your own?
(a) Copenhagen or consistent histories (including postulate of explicit collapse): 4
(b) Modified dynamics (Schroedinger equation modified to give explicit collapse): 4
(c) Many worlds/consistent histories (no collapse): 30
(d) Bohm (an ontological interpretation where an auxiliary “pilot wave” allows particles to have well-defined positions and velocities): 2
(e) None of the above/undecided: 50
The reader is warned of rampant linguistic confusion in this area. It is not uncommon that two physicists who say that they subscribe to the Copenhagen interpretation find themselves disagreeing about what they mean by this. Similarly, some view the “consistent histories”
interpretation (in which the fundamental objects are consistent sets of classical histories) as a fundamentally random theory where God plays dice (as in the recent Physics Today article by Omn`es & Griffith), whereas others view it more as a way of identifing what is classical within the deterministic “many worlds” context. Such issues undoubtedly contributed to the large “undecided” vote on the last question."
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The reason many are going into Many Worlds camp is because of the following. Quoting again from the url:
"The simple double slit interference experiment, hailed by Feynman as the mother of all quantum effects, was successfully repeated for ever larger objects: atoms, small molecules and most recently a carbon-60 Buckey Ball”. After this last feat, Anton Zeilinger’s group in Vienna has even started discussing doing it with a virus. If we imagine, as a Gedanken experiment, that this virus has some primitive kind of consciousness, then the many worlds/many minds interpretation seems unavoidable, as has been emphasized by Dieter Zeh. An extrapolation to superpositions involving other sentient beings such as humans would
then be merely a quantitative rather than a qualitative one."