On 3/2/2015 5:36 AM, Jason Resch wrote:
On Sun, Mar 1, 2015 at 11:33 PM, meekerdb <meeke...@verizon.net
<mailto:meeke...@verizon.net>> wrote:
On 2/28/2015 11:25 AM, Jason Resch wrote:
The best text on non-relativistic QM is by Asher Peres and it's
available
*free* online.
http://www.fisica.net/quantica/Peres%20-%20Quantum%20Theory%20Concepts%20and%20Methods.pdf
This is his treatment of MW:
*Everett’s interpretation and other bizarre theories*
Another attempt4 to salvage quantum ontology, without invoking a
collapse of
the wave function, is to assume that an entangled expression like
(12.1) does
represent the actual situation. More precisely, the right hand side of
(12.1)
is a part of the “wave function of the Universe,” in which the cat may
be
considered as the observer of the atom. However, the two branches of
(12.1)
correspond to different worlds, between which there can be no
communication,
once an irreversible process has occurred. This approach has several
variations5 which are called the “relative state interpretation” and
the “many
worlds interpretation.” None is satisfactory because they merely
replace the
arbitrariness of the collapse postulate by that of the no-communication
hypothesis. In particular, there are no objective criteria for the
occurrence
of the irreversibility which is needed to prevent communication between
the
various worlds (and there cannot be any such criteria, as we have seen
in
Chapter 11).
There have also been innumerable attempts to modify quantum theory (not
only to
reinterpret it) so as to avoid the dual nature of the measuring
instrument.
There is no experimental evidence to support any one of these mutations
of
quantum theory—there is much evidence against them. I shall not further
discuss
these groundless speculations.
He seems to be unaware of decoherence in his critique of Everett.
The term was not popular when he wrote the book, but he considers the
process and
the influence of the environment in latter part of chapter 11.
(1) The interference terms are not driven to zero, only to small values and
small
values in cross terms cannot just be neglected since they are not
necessarily small
in other bases.
What are the other bases where interference is not driven to zero, and do they really
have significance to observers?
Probably not, because we can't construct instruments whose interaction Hamiltonian would
measure in those bases. But that points to a deficiency in our understanding of the
world. In the simple "The SWE is all we need." theory of MWI there is no way to pick out
the "good basis" from any other.
(is your contention that if MW were true, it would lead to different observations than
what we apparently currently get)?
I don't think it's definite enough to say. It doesn't say exactly how communication
between worlds is avoided; that's where we need to develop Zeh's theory of einselection.
(2) They don't have a probability interpretation (without further
assumptions) which
would support an stat mech interpretation of no-communication.
What is your opinion of Russell's derivation of the Born rule and the
Schrodinger equation?
Dunno, I need to read it first.
Brent
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