From: scerir (scerir@libero.it)
Date: Sun Jan 20 2002 - 08:18:18 MST
[Amara Grasp]
> What you present here, between Einstein and Bohr, looks to me as
> another example of a Bayesian versus a non-Bayesian point of view in
> science. In particular, the difference between our knowledge of
> reality, and reality itself.
Exactly. But the question here is: 'knowledge of what?'.
A theory need make no direct reference to reality, in order
to be successful and accurate, in its predictions. Probability
theory may predict the (probable) outcome of a roulette wheel,
knowing nothing about about the dynamics of the roulette,
perhaps even assuming nothing about the determinism or the
indeterminism of physical laws. But here, in the quantum
world, we even do not see roulettes, horse races, gambling
houses.
In example, the two-slit experiment. Interference suggests
that _physical_ waves are interfering. But wavefunctions are
not _physical_ waves, they are mathematical tools for evaluating
probabilities. And if we identify wavefunctions with physical waves
we are in trouble, many paradoxes arise. (btw, If we deny that the
change of the wf. that occurs during the measurement process is
a _physical_ process, then _what_ leads to the destruction of the
possibility of interference?)
Another one. The wavefunction of the four (outer) electron of a
carbon atom (in the ground state) produces a tetrahedral structure,
in the ordinary space, which yields to the structure of the diamond
crystal. But the wf. of those four electrons lives in a 12-d. space.
Another one. The Schroedinger's cat. Can this cat, a macroscopic
object, live in a superposition of states (unreal too)? Friedman et al
presented (Nature 406, 43 - 46, 2000) the experimental evidence that
a superconducting quantum interference macroscopic device (SQUID)
can be put into a superposition of two magnetic-flux states: one
corresponding to a few microamperes of current flowing clockwise,
the other corresponding to the same amount of current flowing anticlockwise.
> >But that is not the end of my story. It's interesting to note
> >that Heisenberg (but not Bohr) believed that the 'collapse' of
> >the 'wave packet' (thus also those 'spooky' actions) was _indeed_
> >a physical action, triggered by the 'indivisibility' of the particle
> >(The Physical Principles of the Quantum Theory, Un. Chicago P.,
> >page 39). Was he right ? It seems so.
> Here Heisenberg is mixing up realities of Nature, with incomplete human
> information about Nature.
Exactly, again. But, again: 'information about what?'.
Serafino
(I'll read those urls)
This archive was generated by hypermail 2.1.5 : Sat Nov 02 2002 - 09:11:49 MST