
Best attempts so far to skin Schrödinger’s cat (2016) - ZeljkoS
https://www.newscientist.com/article/2097199-seven-ways-to-skin-schrodingers-cat/
======
n4r9
Warning: you shouldn't be too quick to extrapolate anything about general
attitudes in quantum foundations towards various interpretations from this
"snapshot" poll. There exist at least two other polls I know of with very
different results[0,1]. Interesting quote from one of the abstracts:

> the results do strongly suggest several interesting cultural facts -- for
> example, that there exist, within the broad field of "quantum foundations",
> sub-communities with quite different views, and that (relatedly) there is
> probably even significantly more controversy about several fundamental
> issues than the already-significant amount revealed in the earlier poll.

Matt Leifer has a quantum foundations blog, and is one of the most impartial
voices that I know of. He has written up his opinion on these "snapshots" [2],
making the amusingly astute observation

> What we can conclude from this is that people who went to a meeting
> organized by Zeilinger are likely to have views similar to Zeilinger.

[0] arXiv:1303.2719

[1] arXiv:1306.4646

[2] [http://mattleifer.info/tag/survey/](http://mattleifer.info/tag/survey/)

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DennisP
> Everett, who believed his theory guaranteed him immortality in some world or
> other, had eaten, drunk and chain-smoked himself to an early death in 1982.

Sure, in this world, but in others he parties on.

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Animats
Another site that goes into an infinite reload loop on "googletag is not
defined" if tracking is blocked.

~~~
xelxebar
FWIW, it's readable for me with JavaScript disabled.

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wolfgke
What I miss in this list is the "superdeterminism" class of interpretation.

>
> [https://en.wikipedia.org/wiki/Superdeterminism](https://en.wikipedia.org/wiki/Superdeterminism)

In the last years this class of explanation had in my perception some kind of
comeback because of "The Cellular Automaton Interpretation of Quantum
Mechanics" by the Nobel laureate Gerard ’t Hooft:

>
> [https://link.springer.com/book/10.1007%2F978-3-319-41285-6](https://link.springer.com/book/10.1007%2F978-3-319-41285-6)

~~~
QAPereo
It also has a "comeback" because people are still very much enamored of
something which is virtually indistinguishable from, "The Hand of God." Along
with DeBB, it's still hanging on by the, "can't falsify this yet!" thread, but
as with DeBB it adds nothing at all to the predictive power of existing
theories.

~~~
wolfgke
> It also has a "comeback" because people are still very much enamored of
> something which is virtually indistinguishable from, "The Hand of God."

If we try to find a "social" explanation why superdeterminism has its
comeback, I would rather tend to the fact that progress in neuroscience gives
a lot of doubt concerning the existence of free will. Superdeterminism fits
quite well into this pattern, since it attempts to show that we can solve the
problem of the Bell violation by simply refusing the assumption of free will.

~~~
QAPereo
Trying to insert biology into physics is a real non-starter, IMO, especially
in QM. The standards are so massively different, and frankly, not comparable.
Bell tests, and more generally BSMs don’t measure anything like free will, and
don’t assume it. Worse, God or Superdeterminism isn’t going to be falsifiable.

------
everdev
If particles can be in multiple states simultaneously until an observer
interacts with them then it seems like a tree could in fact fall in the forest
and not make a sound.

~~~
crooked-v
Well, no. It's possible that a tree could fall in the forest and make any
number of different sounds the specifics of which are impossible to determine
until observed, though.

Keep in mind, too, that "an observer" includes basically anything interacting
with an otherwise closed system, not just a thinking creature.

~~~
jon_richards
>"an observer" includes basically anything interacting with an otherwise
closed system, not just a thinking creature.

Isn't that a bit of a philosophical debate? It could be that things are only
"observed" when their cone of causality reaches a thinking creature. I thought
that was half the point of the tree question in the first place.

~~~
Tade0
This is what I hate about the popular understanding of the Copenhagen
interpretation.

Bohr's original idea was that until there's some interaction it's pointless to
assign a specific state - you can only talk about certain probabilities.

Schrodinger's cat is not both alive and dead. We know nothing about its
current state, only how probable certain outcomes are.

~~~
coldtea
> _Schrodinger 's cat is not both alive and dead. We know nothing about its
> current state, only how probable certain outcomes are_

That's the case with any cat we throw in a box and ask somebody to kill it or
not based on a dice, and then we visit the place where the box is and open
it...

In other words, the cat is in a certain state, but we merely don't know which.

But this doesn't capture what the Schrodinger experiment is supposed to show.
Such an case wouldn't need the experimental apparatus Schrodinger describes
either.

The core idea of the experiment is that quantum uncertainty is not just of the
"we just don't know yet" kind, but of the fundamental "reality is inherently
mixed-up and uncertain / many things actually hold at the same time until
observed" nature.

The purpose of the Schrodinger's thought experiment then is to show how this
fundamental quantum uncertainty (i.e. not mere not knowing: actual "fuzzy"
reality) "pollutes" the macro world (in this case, a cat).

The quantum-based mechanism that releases the poison, is his trick to transfer
the uncertainty of the quantum state into the macro world (the box with the
cat). (Funnily, Schrodinger's purpose was to discredit this).

Those that believe it's clear that "the cat is in one state or another, we
just don't know which", haven't understood the problem.

~~~
n4r9
You've slightly misinterpreted the point of the previous post, or have at
least overlaid some assumptions.

You're arguing against what one might call an objective Bayesianism stance.
That is to say that our probabilities reflect our inadequate information
concerning an objective (classical) state of reality for the cat.

However the phrase

> Schrodinger's cat is not both alive and dead. We know nothing about its
> current state, only how probable certain outcomes are

suggests a perspective in which there is not an objective (classical) state of
reality for the cat. Rather, probabilities might be seen as subjective
assertions about the outcome of interactions with the system. It is
meaningless to talk about the cat being dead or alive before looking. This is
closer to what one might call a subjective Bayesian stance.

~~~
coldtea
> _It is meaningless to talk about the cat being dead or alive before looking.
> This is closer to what one might call a subjective Bayesian stance._

In actual classical reality, it's not at all meaningless to ask whether the
cat is "dead or alive before looking". It might be uncertain, but it's not
meaningless.

One might say "I think it's alive" and another "dead" \-- and they have a
chance to be right even before opening the box -- we'll just need to open it
and see which was right ALL ALONG.

In quantum physics, on the other hand, in most interpretations, none of them
is right before opening the box. If one says "the cat must be dead", and we
open the box and the cat is indeed found dead, that person, wasn't right all
along. He only became right upon the opening.

That's the whole paradox that Schrodinger tried to point out as an absurd
result of quantum mechanics -- but which nonetheless is accepted by physicists
not as a counter-example against QM, but as something still paradoxical that
actually illustrates a key point about QM.

