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興味深いOpEdがニューヨークタイムズにありました。現実はnothing more than a kaleidoscope of infinite possibilitiesというのです。

The Reality of Quantum Weirdness
FEB. 20, 2015
Gray Matter

IN Akira Kurosawa’s film “Rashomon,” a samurai has been murdered, but it’s not clear why or by whom. Various characters involved tell their versions of the events, but their accounts contradict one another. You can’t help wondering: Which story is true?

But the film also makes you consider a deeper question: Is there a true story, or is our belief in a definite, objective, observer-independent reality an illusion?

This very question, brought into sharper, scientific focus, has long been the subject of debate in quantum physics. Is there a fixed reality apart from our various observations of it? Or is reality nothing more than a kaleidoscope of infinite possibilities?

This month, a paper published online in the journal Nature Physics presents experimental research that supports the latter scenario — that there is a “Rashomon effect” not just in our descriptions of nature, but in nature itself.


Measurements on the reality of the wavefunction

Here we experimentally test this approach with single photons. We find that no knowledge interpretation can fully explain the indistinguishability of non-orthogonal quantum states in three and four dimensions. Assuming that some underlying reality exists, our results strengthen the view that the entire wavefunction should be real. The only alternative is to adopt more unorthodox concepts such as backwards-in-time causation, or to completely abandon any notion of objective reality.

ここで使われていたRashomon effectは英語の辞書にはまだ載っていないようですがWikipediaには詳しく説明されています。

The Rashomon effect is contradictory interpretations of the same event by different people. The phrase derives from the film Rashomon, where the accounts of the witnesses, suspects, and victims of a rape and murder are all different.

その例としてGone Girlも取り上げられています。

Gone Girl
The film relates the different accounts of events leading up to the disappearance of a woman, one account from said woman, as per her diary, and one account from the woman's husband, as he relates it.

Rashomon effectをグーグル検索するとスティーブジョブズの伝記の前書きで使われていたという報告がありました。以下がその箇所です。

I leave it to the reader to assess whether I have succeeded in this mission. I’m sure there are players in this drama who will remember some of the events differently or think that I sometimes got trapped in Jobs’s distortion field. As happened when I wrote a book about Henry Kissinger, which in some ways was good preparation for this project, I found that people had such strong positive and negative emotions about Jobs that the Rashomon effect was often evident. But I’ve done the best I can to balance conflicting accounts fairly and be transparent about the sources I used.

One Crime Four versions of the truthと予告編で伝えられるこの映画は芥川の『藪の中』が下敷きなんですね。一回くらい観ておかないとで(汗)

"In a Grove" (藪の中 Yabu no Naka?) is a short story by Akutagawa Ryūnosuke, first appearing in the January 1922 edition of the Japanese literature monthly Shinchō. Akira Kurosawa used this story as the basis for the plot of his award-winning movie Rashōmon.


Does the wave function directly correspond to an objective, observer-independent physical reality, or does it simply represent an observer’s partial knowledge of it?

If the wave function is merely knowledge-based, then you can explain away odd quantum phenomena by saying that things appear to us this way only because our knowledge of the real state of affairs is insufficient. But the new paper in Nature Physics gives strong indications (as a result of experiments using beams of specially prepared photons to test certain statistical properties of quantum measurements) that this is not the case. If there is an objective reality at all, the paper demonstrates, then the wave function is in fact reality-based.

What this research implies is that we are not just hearing different “stories” about the electron, one of which may be true. Rather, there is one true story, but it has many facets, seemingly in contradiction, just like in “Rashomon.” There is really no escape from the mysterious — some might say, mystical — nature of the quantum world.