On 5/25/2018 10:07 AM, Bruno Marchal wrote:
On 23 May 2018, at 05:46, Brent Meeker <[email protected]
<mailto:[email protected]>> wrote:
On 5/22/2018 6:55 PM, [email protected] wrote:
On Wednesday, May 23, 2018 at 1:45:39 AM UTC, Brent wrote:
On 5/22/2018 5:59 PM, [email protected] <javascript:> wrote:
On Wednesday, May 23, 2018 at 12:44:06 AM UTC, Brent wrote:
On 5/22/2018 3:46 PM, [email protected] wrote:
On Tuesday, May 22, 2018 at 10:41:11 PM UTC,
[email protected] wrote:
On Tuesday, May 22, 2018 at 10:06:39 PM UTC, Brent wrote:
On 5/22/2018 6:39 AM, [email protected] wrote:
I'm OK with getting rid of the projection
operator. Are you now claiming information
is lost or inaccessible in these orthogonal
subspaces and therefore quantum measurements
cannot be reversed?
They are inaccessible to the people of any
one world of the MWI.
No! Irreversible FAPP! Think heat bath or Bucky
Balls.
https://en.wikipedia.org/wiki/Quantum_decoherence
<https://en.wikipedia.org/wiki/Quantum_decoherence>
Examples of non-unitary modelling of decoherence
Decoherence
<https://en.wikipedia.org/wiki/Decoherence> can
be modelled as a non-unitary
<https://en.wikipedia.org/wiki/Unitary_operator>
process by which a system couples with its
environment (although the combined system plus
environment evolves in a unitary fashion).^[4]
<https://en.wikipedia.org/wiki/Quantum_decoherence#cite_note-Lidar_and_Whaley-4>
Thus the dynamics of the system alone, treated in
isolation, are non-unitary and, as such, are
represented by irreversible transformations
<https://en.wikipedia.org/wiki/Irreversibility>
acting on the system's Hilbert space
<https://en.wikipedia.org/wiki/Hilbert_space>, H
{\displaystyle {\mathcal {H}}} {\mathcal {H}}.
Since the system's dynamics are represented by
irreversible representations, then any
information present in the quantum system can be
lost to the environment or heat bath
<https://en.wikipedia.org/wiki/Heat_bath>.
Alternatively, the decay of quantum information
caused by the coupling of the system to the
environment is referred to as decoherence.^[3]
<https://en.wikipedia.org/wiki/Quantum_decoherence#cite_note-Bacon-3>
Thus decoherence is the process by which
information of a quantum system is altered by the
system's interaction with its environment (which
form a closed system), hence creating an
entanglement
<https://en.wikipedia.org/wiki/Quantum_entanglement>
between the system and heat bath (environment).
As such, since the system is entangled with its
environment in some unknown way, a description of
the system by itself cannot be made without also
referring to the environment (i.e. without also
describing the state of the environment).
Notice that this doesn't explain how one gets to a
single result.
I did, but you're avoiding the key point; if the theory is
on the right track, and I think it is, quantum
measurements are irreversible FAPP. The superposition is
converted into mixed states, no interference, and no need
for the MWI.
You're still not paying attention to the problem. First,
the superposition is never converted into mixed states. It
/approximates/, FAPP, a mixed state/in some pointer/ basis
(and not in others). Second, even when you trace over the
environmental terms to make the cross terms practically
zero (a mathematical, not physical, process) you are left
with different outcomes with different probabilities. CI
then just says one of them happens. But when did it
happen?...when you did the trace operation on the density
matrix?
I think the main takeaway from decoherence is that information
isn't lost to other worlds, but to the environment in THIS world.
But that ignores part of the story. The information that is
lost to the environment is different depending on what the
result is. So if by some magic you could reverse your world
after seeing the result you couldn't get back to the initial
state because you could not also reverse the "other worlds".
What "other worlds"? If they don't exist, why should I be concerned
about them? AG
That's pretty much the CI attitude and that of most working
physicists. But those interested in fundamental questions would
still like to pin down the time and how of the process of branching
and especially how the classical world arises from this process.
Metaphysicians like Bruno want to use a kind of implied
"everythingism" to simplify their overarching theory of the world by
saying that "everything happens"...just somewhere else. If you say
only your world exists then you are committed to an inherent
randomness in the world...some find that anathema.
No. I am just saying that if the brain and our bodies are natural
physical digitalis able machine, then There is no ontological
universe, physicalism is false, and we have to extract the physical
laws by the measure given of the first person points of view imposed
by machine’s incompleteness.
No. You're also saying that arithmetic and all possible computations
exist. Not just those consistent with our observations and theories of
physics.
Then I show that if we are willing to abandon the collapse
superstition, the facts sides much more strongly on (weak) mechanism
than on physicalism.
I am a logician. I prove that any rational machine understand this
point. The fact that the (Löbian) machine proves their own
incompleteness, makes eventually physics a branch of the
theology/metaphysics of numbers.
I want to use nothing. I derive all proposition that I say in two
ways: intuitively with the thought experiences, and mathematically
with the universal machine interview.
I just say that if mechanism is true, materialism (duality or monist)
just can’t work, and that the evidence favour strongly mechanism on
materialism.
You say that until I challenge you to explain how the world appears to
us who watch the shadows on the cave wall. If computationalism has to
entail everything in order to explain any particular thing then it fails
to explain at all.
The everything is then given by the universal dovetailer/the universal
machine/the sigma_1 propositions.
I it existed.
And the measure is the unique one that we should be able to derive
from one of the three quantum logics offered by the universal machine
for the observable.
To discard those conclusions, you have to introduce actual infinities
in the working of the brain, and very special and testable one. But
the test so far, our inferred physics, rather fit well with mechanism,
thanks to QM (without collapse).
But your theory doesn't entail QM, much less the working of the brain.
Brent
Everett was just ignorant that once he had defined the first person
identity of the observer by the memories sequences, it *has* to
justify why the quantum computations seems to win below the digital
substitution level.
Bruno
Brent
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