On 09 Dec 2017, at 02:48, Bruce Kellett wrote:
On 9/12/2017 11:49 am, smitra wrote:
On 09-12-2017 00:03, Bruce Kellett wrote:
On 9/12/2017 4:21 am, Bruno Marchal wrote:
On 08 Dec 2017, at 00:22, Bruce Kellett wrote:
On 8/12/2017 3:31 am, Bruno Marchal wrote:
On 06 Dec 2017, at 12:19, Bruce Kellett wrote:
But as I pointed out, thermal motion gives momenta of
magnitudes such that the quantum uncertainties are negligible
compared to the thermal randomness. And thermal motions are
not coherent.
You seem to work in Bohr QM, with some dualism between the
quantum reality and the classical reality.
Not at all. The (semi-)classical world emerges from the quantum
substrate; if you cannot give an account of this, then you have
failed to explain our everyday experience. And explaining that
experience is the purpose of physics.
No problem with this, except for your usual skepticism of
Everett's program (say).
Skepticism is the scientific stance.....
You are right that this does not change anything FAPP, but our
discussion is not about practical applications, but metaphysics.
No, we were talking about tossing a coin, we were not talking
about metaphysics. Your metaphysics has served merely to confuse
you to the extent that you do not understand even the simplest
physics.
That is ad hominem remark which I take as absence of argument.
You don't take kindly to criticism, do you Bruno?
All I said is that without collapse, shaking a box with some coin
long enough would lead to the superposition of the two coin
state. You seem to be the one confusing the local decoherence
with some collapse. The Heisenberg uncertainties are great enough
to amplify slight change of the move of the coin when bouncing on
the wall.
That is simply assertion on your part, without a shred of argument
or
justification. When one looks at the arguments, such as that put
forward by Albrecht and David (referred to by smitra), one finds
that
the emperor has no clothes!
Similarly, a shroedinger car, once alive + dead, will never
become a pure alive, or dead cat. It will only seems so for
anyone looking at the cat, in the {alive, dead} base/apparatus.
Superposition never disappear, and a coin moree or less with a
precise position, is always a superposition of a coin with more
or less precise momenta. The relation is given by the Fourier
transforms, which gives the relative accessible states/worlds.
I pointed out that for a macroscopic object such as a coin, the
uncertainty relations give uncertainties in positions and/or
momentum
far below any level of possible detection. And I gave an argument
with
an actual calculation -- not just an assertion. Uncertainties in the
constituents of the object are uncorrelated, random, and cancel out.
So although the superposition originating from the big bang is
intact
from the bird's point of view, it is so completely irrelevant for
everyday purposes that it is an insult to even refer to the
classicality of the world as FAPP -- it is complete. Relying on the
charge of "FAPP" as a justification for your assertions is nonsense.
It's not irrelevant if you don't have the information that locates
you in a sector where the uncertainties are indeed small enough.
You have to start with the complete state in the bird's view, and
then consider the sector where you have some definite information
and then project onto that subspace. If you do that, then your
coins are not at all in a precisely enough classical state but
rather in superpositions (entangled with the environment) that lead
to wildly different outcomes of coin tosses.
E.g. in the bird's view there exists exact copies of me that live
on planets that are not the same, some will have a radius of a few
millimeter larger than others. Here exact copy means exactly the
same conscious experience, which is then due to exactly the same
computational state of the brain described by some bitstring that's
exactly the same.
So, from totally different decoherent branches of the wavefunction
one can factor out some bitstring describing a conscious
experience, the reduced state of the rest of the universe in that
sector is then a superposition of a many different effectively
classical states.
If this were not true then each single conscious experience would
contain in it information about such things as the exact number of
atoms in the Earth, Sun etc. etc.
I prefer to live in the real world, so I would rather not indulge
your fantasies.
In (serious) metaphysics, invoking a "real world" automatically beg
the question. It is like criticizing the theory of evolution because
despite all its appeal it obviously fails to explain how God made all
that in six days as everyone know well.
The "real world" is what we search.
What Everett has shown, basically, is that the measurement paradox
arises from the addition of the axiom "one universe" (equivalent with
the collapse).
What I have shown is that the mind-body problem similarly arises from
the addition of the axiom "a universe".
I use "universe" in the usual Aristotelian sense of primary
ontological object. (Weak) Materialism is the belief in a universe (at
least one universe).
Many believe that there are empirical evidences for the metaphysical
assumption that there is a universe. But there are no direct or easy
one, as the dream argument illustrated. There are none so far.
Those person confuse the evidence for the physical laws (in the domain
of physics) with an evidence for a universe (in the domain of
metaphysics/theology).
There are evidence for physical laws, but both Digital Mechanism (in
cognitive science), and quantum mechanics (without collapse), suggests
that the "a universe" might not make sense. The appearance of a stable
universe might be due to a property of some classes of universal
machines "dreams" (a dreams being any computations supporting a Löbian
machine).
Nevertheless, the logics of the material "hypostases" illustrate that
we can test empirically the a-universe (materialism) and no-universe
(mechanism) assumptions. It is enough to show that any reasonable
quantum logic inferred from observation violate the logics S4Grz1,
Z1*, and X1* and other possible self-referentially based quantum
logics. That departure would measure somehow our degree of non-
mechanism (with or without oracle, and assuming no malevolent
"Bostromian" simulation).
Bruno
Bruce
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