science = determinism? (Schrodinger: algorithm or phenomena?)
kenneth Collins
kpaulc at earthlink.net
Tue Nov 30 05:44:24 EST 1999
if you 'wonder', i stand on what i've posted.
K. P. Collins
Maynard Handley wrote:
> In article <81omtn$f9e at web.nmti.com>, peter at abbnm.com (Peter da Silva) wrote:
>
> >In article <383FAD5A.5DA023B4 at earthlink.net>,
> >kenneth Collins <kpaulc at earthlink.net> wrote:
> >> they are engineered with the a priori presumption of 'particles', so
> they 'see
> >> particles', when everything is continuous.
> >
> >You know, Einstein's Nobel Prize was for explaining an experiment that saw
> >particles when everyone assumed everything was continuous. If you can come
> >up with a better explanation of the photoelectric effect, or with some kind
> >of experiment that would differentiate your energy soup universe from the
> >one everyone else works with, you might be able to get somewhere.
>
> I'm happily ignoring most of the crap in this thread, but I'd like to
> clarify this because this misunderstanding is one of the reasons people
> get so bent out of shape about QM.
>
> (1) There are no particles, only fields. There is an EM field, an electron
> field etc.
> (2) In a model of NON-INTERACTING fields, the "amount" of field (VERY
> roughly, it's amplitude, more carefully its energy) can only change by
> discrete amounts. This is in contrast to a classical field where the
> amount of energy can change by any amount no matter how small.
> (3) Because the relevant equations of the NON-INTERACTING fields model are
> linear, one can model this change in the field as a simple count of
> identical "fragments" of field---this field consists of 16 fragments of
> type A and 4 fragments of type B. These fragments are what what
> mathematical physicists call photons or electrons. Note that they a
> mathematical construct based on a simplified theory.
> (4) What really makes a field theory a quantum field theory (and gives you
> the behavior above) is that the entity one cares about, the state, the
> element of one's Hilbert space, is now a superposition of all the possible
> classical field configurations weighted with some complex number.
> (Appreciating this also makes it clear the link between QFT and
> statistical mechanics where one likewise deals with configurations of all
> possible classical fields weighted in some fashion, only this time by
> Exp[-kT].)
> (5) When one adds in interaction, life becomes a whole lot messier. One
> can try to approximate what happens by constructing states that
> approximate the real world by summing states from our idealized
> non-interacting world. How satisfactory this is depends on what you're
> after. For calculating QED effects it works pretty well. For QCD it seems
> like a kinda lame starting point.
>
> However in all of this, particles never appear. The interactions that are
> claimed as particle interactions (eg photoelectric effect, compton effect)
> are still field-field interactions (electron field interacting with EM
> field) with all that entails with respect to being spread over space and
> time.
>
> Apart from the mathematical photons and electrons discussed above, there
> are "experimental" photons and electrons that are supposedly the particles
> one sees when one looks at a bubble chamber photograph, or a scintillation
> screen. What you have to appreciate here is that one is not literally
> seeing an electron in a cloud chamber photograph. What one is seeing is a
> metastable state that is constructed so as to amplify the effects of any
> quantum interactions. The interaction that occurs with an electron is
> spread out over space-time in our usual field scheme, but something
> happens to squelch the various superposed classical field states to
> project out just one of them which happens to correspond to localized
> fields. What is causing the localization is NOT that the entities involved
> are particles, but that whatever it is that causes collapse of the wave
> function (which as I have said before looks to be gravity) favors a
> particular basis for Hilbert space which is based on localized fields.
>
> Yes this stuff is hard and abstract. To understand it well, one needs to
> start by learning a lot of somewhat recondite mathematics, and one then
> has to wade through some pretty badly written QFT texts. None of that
> changes the fact that in dumbing it down and presenting poorly understood
> accounts of it, one loses pretty much all that is essential in the theory,
> all that gives it coherence, and one lands up with merely a bunch of
> mumbo-jumbo mystic incantations, "wave-particle duality, virtual
> particles, uncertainty principle", much like say the atomic theory of
> Democritus.
>
> Maynard
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