Re: [asa] Fw: Pilot-wave theory

From: <philtill@aol.com>
Date: Sun Jun 21 2009 - 18:32:44 EDT

 I'd have to read Valentini's articles, but the chief problem I can see is with the statement below, "In de Broglie's picture, particles never exist in
more than one place at the same time...In the two-slit experiment, for example,
each particle passes through only one slit."  This view has been unequivocally disproven since 1985 when Aspect showed how to test Bell's Inequality.  The test has been done many ways by many researchers, and there is no question that the particle cannot know which slit it is going through until later on, at the time it is being measured.  The particle does not have any local reality telling it what slit it is in.  If the particle is real, then it is not local.  That's established fact.

Well, to be a bit more precise, the only loophole in the above statement, AFAIK, is if half the QM information is traveling backwards in time (psi-star being a time-reversed signal).  Then local reality can be restored to QM.  But assuming all information travels forward in time, QM is definitely either non-real or non-local.

Phil

 

 

-----Original Message-----
From: Randy Isaac <randyisaac@comcast.net>
To: asa@calvin.edu
Sent: Sun, Jun 21, 2009 5:23 pm
Subject: Re: [asa] Fw: Pilot-wave theory

Here are couple of other paragraphs that I excised.
He claims Bohm picked up on de Broglie's proposal but both of them
failed.

The key, as Moorad pointed out, is whether his
cosmic wave background prediction ho
lds up and is verified.

 

Randy

 

"Some conference participants, most notably
Einstein, de Broglie, and Schrödinger, rejected Bohr's arguments.
Physicists today remember Einstein as Bohr's chief antagonist. But
their famed disputes over the validity of quantum theory must
have taken place off the record, Valentini says; the published
conference proceedings don't mention them at all.

The proceedings do, however, contain 24 pages of discussion of a
rival interpretation by de Broglie. Unlike Bohr, who viewed the
quantum wave equation describing a particle as a mathematical
abstraction, de Broglie thought such waves were real—he called
them pilot waves. In de Broglie's picture, particles never exist in
more than one place at the same time. All the mysterious properties
of quantum theory are explained by pilot waves guiding particles
along their trajectories. In the two-slit experiment, for example,
each particle passes through only one slit. The pilot wave, however,
goes through both slits at once and influences where the particle
strikes the screen. There is no inexplicable wave collapse triggered
by observation. Instead, Valentini says, "the total pilot wave, for
the particle and the detectors considered as a single system, evolves
so as to yield an apparent collapse."

Bohr, Heisenberg, and their supporters at the Solvay conference
were unimpressed. The details of the particle trajectories were
unobservable, and Bohr insisted that physicists shouldn't traff
ic
in hidden, unmeasurable entities. "De Broglie wasn't happy with
the Copenhagen interpretation," says Valentini, "but he gave up
trying to argue about it."

Bohr and Heisenberg's vision of quantum theory prevailed; de
Broglie's languished. David Bohm, a prominent American physicist,
rediscovered de Broglie's work in the early 1950s and expanded
on it. But Bohm's work, like de Broglie's, failed to attract
much support, because it could not be distinguished experimentally
from conventional quantum mechanics. "

  
----- Original Message -----

  
From:
  philtill@aol.com
  

  
To: wjp@swcp.com ; randyisaac@comcast.net

  
Cc: asa@calvin.edu

  
Sent: Sunday, June 21, 2009 3:54 PM

  
Subject: Re: [asa] Fw: Pilot-wave
  theory

  

  
I think this article is muddled
  on its physics history.  As I recall, it wasn't de Broglie who proposed the pilot
  wave -- that was David Bohm.  de Broglie's contribution was to argue that
  particles with mass should have a wave nature, just as massless light (being a
  wave) has a particle nature.  So it is true that de Broglie was
  interested in the wave behavior of quantum mechanics, but as far as I know de
  Broglie never proposed that the particles are a separate entity from a wave
  that exists to "pilot" them about.  That came much later from David
  Bohm.

I never liked Bohm's pilot wave concept because it requires the
  exis
tence of two entities where only one is needed. As far as I know, the
  pilot wave has no function except to appear at the proper time and push
  particles around.  It is immeasurable and is discerned (supposedly) only
  through the fact that the particles behave a certain way.  The particles
  meanwhile have no ability to get where thy are going unless the wave shows up
  and pushes them.  This seems to be a very inelegant theory, IMO.  It
  is substituting awkwardness for the usual abstraction of QM, and is that
  really a good thing?  I prefer the abstraction because we have good
  reason to expect abstraction in the fundamental reality of nature, and also to
  expect elegance. Furthermore,
  the pilot wave idea doesn't so lve the non-locality of QM (the violation of
  Bell's inequality); the pilot wave still needs to behave non-locally with
  information passing between its parts faster than light, so what good does it
  do?  In the final analysis, isn't it still abstract?

Phil

 

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Received on Sun Jun 21 18:33:23 2009

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