The branches you discuss don't exist, and the MWI creates *hugely* more
problems than it solves. Maybe you should just accept the fact that the wf
is just epistemic (despite what some "experts" like Carroll claim) and the
horse racing example applies. As I explained, the wf doesn't disappear, or
otherwise by magic. Since we can't predict the outcome of a quantum
measurement, there's no reason to consider the wf probabilities as
essentially different from those in the horse race model. If probabilities
were ontological, you could kick them, and they'd kick back! There likely*
is* an unexplained mechanism in the measurement process, but your imaginary
branches are not the answer. AG
On Tuesday, November 19, 2024 at 5:52:34 AM UTC-7 PGC wrote:
The analogy oversimplifies the situation and misses the conceptual
challenge of the wavefunction's disappearance in quantum mechanics. In a
horse race, probabilities represent our lack of knowledge about the
outcome, and when the race concludes, we gain said knowledge, collapsing
the uncertainty into a definite result. This process doesn't imply that the
probabilities themselves were real entities that ceased to exist—they were
merely tools to represent our incomplete knowledge at an earlier point.
In QM, however, the wavefunction is often taken to represent more than just
epistemic uncertainty; it is considered an ontological concept describing
the state of a quantum system. When the wavefunction "disappears" upon
measurement, this raises the question of what happens to the other branches
of the superposition; unlike the horse race analogy, where the
probabilities were never "real" in the same way as the horses. The
wavefunction embodies a more fundamental description of reality in many
interpretations. Its abrupt disappearance therefore feels more like
invoking "magic" than a natural resolution, as it suggests an unexplained
mechanism or process that isn't present in classical probability theory.
This is why some folks find interpretations like MWI appealing—they
sidestep this "magic" collapse by maintaining all branches of the
wavefunction as physically real, avoiding the need to explain its vanishing
act. Call it taste/preference/tendency to find more plausible; not believe
literally. This list tends to be more refined than that (mostly). I won't
spoon feed you on details. Instead, I propose immersion in the literature
or Sean Carroll on why these things are commonly misunderstood, similar to
your reasoning on this point. You appear convinced without seeming to have
perused the menu of MWI interpretation. Get comfortable, make some orders,
and consider trying it for yourself instead of dismissing it outright +
with certitude.
On Tuesday, November 19, 2024 at 1:17:03 PM UTC+1 Alan Grayson wrote:
On Tuesday, November 19, 2024 at 5:05:29 AM UTC-7 Alan Grayson wrote:
1) IMO, fundamentally, for you the bottom line is "taste".
Presumably, you feel the MWI is in good taste so you affirm it. For me,
it's the opposite. MWI IMO is in bad taste, very bad taste. Have you ever
watched how an ant moves, or flying insects? They zig-zag, back and forth,
sometimes in small circles. Presumably, every slight change creates new
worlds according to the MWI, and copies of these insects come into being in
these worlds. And what about us humans? Are we also in these worlds? If
not, where is the cutoff? How does that come to be? It all seems totally
ridiculous, indeed UGLY. You write eloquently, with authority, very
educated. Probably a professor somwhere, at some prestigious university. So
it baffles me how you could arrive at, and support a theory which utterly
fails the smell test. But what could I know? After all, I'm just a simple
country lawyer. AG
On Tuesday, November 19, 2024 at 4:12:55 AM UTC-7 PGC wrote:
2) Your critique of MWI as "bad taste" because of its proliferation of
worlds is understandable, but for me, collapse is far stranger and less
intuitive. Infinite branching, while seeming counterintuitive on the
surface, feels consistent with the vastness suggested by math, particularly
since I first encountered the real numbers and their uncountable infinity
in High School. The idea that there are vastly more real numbers, even
between 1 and 2, than natural numbers and that extensions of the set are
efficacious tools in various domains, applied and theoretically, makess
natural numbers and countable sets the rare exception.
Collapse, on the other hand, feels - yes this is personal taste - seem
baroque and contrived. It assumes that the wavefunction, universal and
deterministic, inexplicably "chooses" one outcome over others at the moment
of measurement. This raises unsettling questions: Who or what triggers that
collapse? How is this reconciled with spacelike separations? For me, this
process seems far more arbitrary and less natural than the branching
structure of MWI, which flows directly from the unitary evolution of the
wavefunction. The funny thing is that I am always the guy accused of
believing in "magic", when - with collapse - the wavefunction just suddenly
disappears after we assume it exists. That feels like somebody pulling my
leg, and why I prefer the infinities in MWI.
No, I am not an expert in the field. Just a tourist with a notebook,
enjoying everybody's contributions here for years, eager to learn, as I
know nothing. Regarding your analogy with insects and their zig-zagging: in
MWI every possible quantum event contributes to branching, and humans are
no exception. There is no "cutoff" because the wavefunction applies
universally to all systems. Again, this may seem counterintuitive and even
extravagant, but it avoids the need for selective pruning and sudden
vanishing of the wave function required by collapse theories, which to me
feels more contrived. It feels like an awkward and artificial attempt to
fit quantum behavior into classical intuition, demanding far more
explanation than it provides. Therefore, I don't find the idea ugly. If it
holds, the only ugliness is that I'm just a bit annoyed that I'm not in a
branch where I'm making more money. A large set of those versions of "me"
seem to be having more fun, which is hard to accept, but better than "woosh
- wavefunction is gone, it never really was etc."
3) If wf collapse is the cause of your problem, IMO it's misplaced. It
was a bad choice of words by Bohr. The real underlying problem is that QM
is alleged to be *irreducibly* *random*. IOW, it's supposed to be random
without any rule about what, if anything, governs this randomness. For me,
this makes QM, or shall we say the *measurement* *problem,* unintelligible
for human consciousness. So, when we look at the wf, which generally has
many non-zero probabilities, we can think or model the occurrence of a
measurement as those probabilities converging to zero, save one of them,
which gets progressively larger, becoming exactly one (numerically 1), so
the net effect is that the wf converges to a *delta* *function* centered on
the measured value. I am not claiming any such transformation actually
occurs, and I never took the so-called collapse seriously, but rather as a
bookkeeping device. You can do the same, and focus on the real problem,
which isn't the non-existent collapse, but the fact that QM alleges to be
irreducibly random. I don't have an answer to this problem, but I refuse to
adopt MWI as the answer since it makes an enigmatic situation hugely worse.
AG
4) Concerning your problem of the wf disappearing when the measurement
occurs, consider this; when there's a horse race and each horse has a
probability of winning, do you have a problem with these probabilities
"disappearing" when the race is over? If not, why not? And why not apply
this perspective to the disappearance of the wf? AG
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