On Saturday, June 9, 2018 at 12:22:40 AM UTC, Bruce wrote:
>
> From: <agrays...@gmail.com <javascript:>>
>
>
> On Friday, June 8, 2018 at 12:55:13 PM UTC, Bruce wrote:
>
> The Schrödinger equation merely gives the time evolution of the system. To
> define the problem you have to specify a wave function. It is in the
> expansion of this wave function in terms of a set of possible eigenvalues
> that the preferred basis problem arises. So it is not really down to the SE
> itself, it is a matter for the wave function. Each expansion basis defines
> a set of worlds, and all bases give different worlds.
>
>
>
> * If we measure E, aren't we defacto measuring p, since the two
> observables are related by a simple mathematical expression? Yet you assert
> they represent different worlds. Is this because the measuring apparatus
> differs if the observable are different? AG *
>
>
> Measuring E or p can be related, as for a photon, or unrelated, as for a
> measurement of the energy levels of a molecule. But in either case, there
> are an infinite number of possible bases in which to express the energy or
> momentum of a state. These are the different worlds to which I am referring
> -- the difference between an energy or a momentum measurement is not
> relevant in this context.
>
*I don't follow. What is the distinguishing feature of worlds created by
measuring E and p? Isn't what is measured, distinguishes worlds, which are
allegedly copied under the assumption that what could have been measured in
this world, but were not, were measured in some identical copy?On the other
issue, if you find a cat alive and dead simultaneously absurd (or
fallacious), why is it any less absurd (or fallacious) if it happens for
only a short time, until decoherence occurs? And if you find Many Worlds
absurd (or fallacious) on multiple grounds, why do you affirm it when it's
implied by decoherence superpositions?AG*
That is correct, but the choice of the basis don’t change the relative
“proportion of histories”.
The choice of basis makes all the difference in the world. Now that we
understand decoherence, the only bases that are useful are those that are
robust against environmental decoherence. That is why we don't see
superpositions of live and dead cats -- that superposition base is not
robust.
*You seem to be regressing, or shall we say relapsing into the fallacy.
ISTM you have previously acknowledged that we don't see superpositions of
live and dead cats because of the fallacy of including macro entities in a
superposition -- which is what Edwin was trying to warn us against. Nothing
to do about robustness against environmental decoherence, which assumes an
actual superposition exists for some short duration. CMIIAW. AG*
Are you trolling? Who claimed that having macrosopic entities in a
superposition was a fallacy? Such superpositions are generally very short
lived because of decoherence, but they can certainly be formed. The basis
which would described such macrosopic superpositions is not robust against
decoherence -- which is all that I have ever claimed.
Bruce
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