scerir wrote:

From: "Ben Goertzel"
> [...] but still the records
> could be kept somewhere,
> and one can ask what would happen
> if the records were kept somewhere else [...]

Not sure, but the quote below - about the information
'in principle' - might be helpful.

"The superposition of amplitudes is only valid if there
is no way to know, even in principle, which path the particle
took. It is important to realize that this does not imply
that an observer actually takes note of what happens.
It is sufficient to destroy the interference pattern,
if the path information is accessible in principle from
the experiment or even if it is dispersed in the environment
and beyond any technical possibility to be recovered, but
in principle 'still out there'".
- Anton Zeilinger, (Rev.Mod.Phys.,1999, p.S-288)

An example of this principle is that if you try to do the electron version of the double-slit experiment in open air rather than in a vacuum, the electron's interactions with the air molecules will destroy the interference, even though in practice it would probably be impossible for human experimenters to reconstruct which slit the electron went through by measuring all the air molecules.


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