More than one reality exists

[Sriram]

Hi everyone,

https://www.livescience.com/65029-dueling-reality-photons.html

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Can two versions of reality exist at the same time? Physicists say they can — at the quantum level, that is.

Researchers recently conducted experiments to answer a decades-old theoretical physics question about dueling realities. This tricky thought experiment proposed that two individuals observing the same photon could arrive at different conclusions about that photon's state — and yet both of their observations would be correct.

For the first time, scientists have replicated conditions described in the thought experiment. Their results, published Feb. 13 in the preprint journal arXiv, confirmed that even when observers described different states in the same photon, the two conflicting realities could both be true.

The authors of the new study found that even in their doubled scenario, the results described by Wigner held. Alice and Bob could arrive at conclusions about the photons that were correct and provable and that yet still differed from the observations of their friends — which were also correct and provable, according to the study.

if measurements themselves aren't absolutes — as these new findings suggest — that challenges the very meaning of quantum mechanics.

"It seems that, in contrast to classical physics, measurement results cannot be considered absolute truth but must be understood relative to the observer who performed the measurement," Ringbauer said.

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Interesting!

Cheers.

Sriram

[Sriram]

What..no dismissive comments at all?!! 

No one saying....'Oh... we knew all that already...nothing new'  or 'so what?...the 'normal' world has only one objective reality' or 'so...you think God is responsible!' or  'that's all been rubbished by so and so' or  'its not really what you think it is...'......

The philosophical implications of how such peculiar quantum behavior can lead to what we experience as a predictable 'normal' world, is quite staggering...

[Robbie]

I honestly don't know sririam but it is a charming idea, to me at any rate.
Dreaming could be described as an alternative reality.

[Sriram]

I honestly don't know sririam but it is a charming idea, to me at any rate.
Dreaming could be described as an alternative reality.

Hi Robbie...glad that you are ok.

[Stranger]

What..no dismissive comments at all?!! 

Sorry, I missed it. 

No one saying....'Oh... we knew all that already...nothing new'  or 'so what?...the 'normal' world has only one objective reality' or 'so...you think God is responsible!' or  'that's all been rubbished by so and so' or  'its not really what you think it is...'......

Well, it's not quite what the pop-science article says it is; they missed out a lot of caveats. The paper itself (pdf) makes clear that if you accept their definition of an observer, and if you accept locality, and if you accept "free" choices, and if you accept that QM is complete and accurate, then measurements are not absolute but relative to the observer. The first and last conditions being the most controversial. Their "observers" were actually quantum scale particle states - which kind of ignores most of the aspects of the measurement problem.

The philosophical implications of how such peculiar quantum behavior can lead to what we experience as a predictable 'normal' world, is quite staggering...

It's more of a scientific problem than a philosophical one, and it's not a new idea - the "Wigner's friend" thought experiment, on which it's based, was proposed in the 1960s. We already have tests of Bell's inequalities (since 1980s, IIRC), that tell us that locality and realism (observables having values independent of observations) are incompatible with QM.

We still don't fully understand exactly how QM gives rise to the classical world. That isn't news. This is an interesting result but it's been popularised to make it seem more significant than it is.