Quantum weirdness: two realities at the same time (Introduction)

by David Turell , Monday, March 25, 2019, 04:01 (1861 days ago) @ David Turell

Predicted by Wigner and now proven:

https://www.livescience.com/65029-dueling-reality-photons.html?utm_source=ls-newsletter...

"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.

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"When an observer in an isolated laboratory measures the photon, they find that the particle's polarization — the axis on which it spins — is either vertical or horizontal.

"However, before the photon is measured, the photon displays both polarizations at once, as dictated by the laws of quantum mechanics; it exists in a "superposition" of two possible states.

"Once the person in the lab measures the photon, the particle assumes a fixed polarization. But for someone outside that closed laboratory who doesn't know the result of the measurements, the unmeasured photon is still in a state of superposition.

"That outsider's observation — their reality — therefore diverges from the reality of the person in the lab who measured the photon. Yet, neither of those conflicting observations is thought to be wrong, according to quantum mechanics.

***

"The two friends of Alice and Bob, who were located "inside" each of the labs, each measured one photon in an entangled pair. This broke the entanglement and collapsed the superposition, meaning that the photon they measured existed in a definite state of polarization. They recorded the results in quantum memory — copied in the polarization of the second photon.

"Alice and Bob, who were "outside" the closed laboratories, were then presented with two choices for conducting their own observations. They could measure their friends' results that were stored in quantum memory, and thereby arrive at the same conclusions about the polarized photons.

***

"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.

"Quantum mechanics describes how the world works at a scale so small that the normal rules of physics no longer apply; over many decades, experts who study the field have offered numerous interpretations of what that means, Ringbauer said.

"However, 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."

Comment: as weird as usual, but in our larger reality we don't experience it. Yet it is the basis of the universe.