
New Quantum Paradox Clarifies Where Our Views of Reality Go Wrong (2018) - yboris
https://www.quantamagazine.org/frauchiger-renner-paradox-clarifies-where-our-views-of-reality-go-wrong-20181203/
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dang
A couple threads on this from when the paper came out:

[https://news.ycombinator.com/item?id=18666392](https://news.ycombinator.com/item?id=18666392)

[https://news.ycombinator.com/item?id=18023452](https://news.ycombinator.com/item?id=18023452)

I think there might have been others too.

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ttctciyf
The discussion at Scott Aaronson's blog[1] has some fascinating to-and-fro in
the extensive comments, including claimed refutations and detailed responses
to them from one of the paper's authors.

1:
[https://www.scottaaronson.com/blog/?p=3975](https://www.scottaaronson.com/blog/?p=3975)

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Pulletwee12549
If I understand correctly, the paper asks us to imagine Alice's friend making
a 'classical' coin flip, and Alice modeling and measuring her friend's lab as
if the coin flip were a quantum superposition of coin heads/coin tails.

But this is simply wrong. The error creeps in in the second assumption:

> An agent can analyze another system, even a complex one including other
> agents, using quantum mechanics

This is likely a good assumption, but quantum physics would tell Alice that
the coin's atoms are all firmly in a state corresponding to either 'heads' or
'tails'. The author is actually making the following assumption:

> What we classically think of as chance is completely interchangeable with
> the unpredictability of quantum superpositions.

This notion has already been proven wrong many times over.

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perl4ever
After reading a lot of comments about this, several of which said "there must
be something to this if there are so many different views on why it is wrong",
I think a better title would be "New Quantum Paradox Gratuitously Confuses
Where Our Views of Reality Go Wrong".

I can't say anything about physics, but when people disagree on why something
is inconsistent, that does _not_ mean it's consistent and correct, it just
means they are choosing different fixed points to reason from.

When someone (an author of the paper) keeps going "oh, you keep changing your
view of why I am inconsistent", I think they are just trolling. The attitude
seems to be, "if I confuse you, I win, and if I claim to be confused then you
lose".

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perl4ever
From the comments on Aaronson's blog analogizing why the paper is wrong: “I
have just enough money for one beer. I have just enough money for a sandwich.
So tonight, I will dine on a beer and sandwich”

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BadThink6655321
The Reference Frame also discussed this[1] and showed why the paper is wrong.

[1] [https://motls.blogspot.com/2018/04/frauchiger-renner-
trivial...](https://motls.blogspot.com/2018/04/frauchiger-renner-trivial-to-
see-that.html)

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cryptica
It makes me wonder whether quantum computers can actually solve problems...
Does this mean that each person can get a different result from the same
calculation done by the same quantum computer?

Doesn't this make quantum computers completely useless?

