Nov 8, 2018 03:12 AM
(This post was last modified: Nov 8, 2018 03:17 AM by C C.)
https://www.symmetrymagazine.org/article...tanglement
EXCERPT: . . . The experiment was designed to study quantum entanglement, a phenomenon that connects quantum systems in ways that are impossible in our macro-sized, classical world. [...] Scientists have long speculated that previous experimental results can be explained best if the world does not obey one or both of the first two of Bell’s assumptions—realism and locality. But recent work has shown that the culprit could be his third assumption—the freedom of choice. Perhaps the scientists’ decision about the angle at which to let the photons in is not as free and random as they thought.
The quasar experiment was the latest to test the freedom of choice assumption. The scientists determined the angle at which they would allow photons into their detectors based on the wavelength of the light they detected from the two distant quasars, something determined 7.8 and 12.2 billion years ago, respectively. The long-traveling photons took the place of physicists or conventional random number generators in the decision, eliminating earthbound influences on the experiment, human or otherwise. At the end of the test, the team found far higher correlations among the entangled photons than Bell’s theorem would predict if the world were classical.
That means that, if some hidden classical variable were actually determining the outcomes of the experiment, in the most extreme scenario, the choice of measurement would have to have been laid out long before human existence—implying that quantum “weirdness” is really the result of a universe where everything is predetermined. “That’s unsatisfactory to a lot of people,” Hall says. “They’re really saying, if it was set up that long ago, you would have to try and explain quantum correlations with predetermined choices. Life would lose all meaning, and we’d stop doing physics.”
Of course, physics marches on, and entanglement retains many mysteries to be probed. [...] “No information can go from here to there instantaneously, but different interpretations of quantum mechanics will agree or disagree that there’s some hidden influence,” says Gabriela Barreto Lemos, a postdoctoral researcher at the International Institute of Physics in Brazil. “But something we all agree upon is this definition in terms of correlation and statistics.”
[...] entanglement may hold the key to some of the most fundamental questions in physics. Some researchers have been studying materials with large numbers of particles entangled, rather than simply pairs. When this many-body entanglement happens, physicists observe new states of matter beyond the familiar solid, liquid and gas, as well as new patterns of entanglement not seen anywhere else. “One thing it tells you is that the universe is richer than you previously suspected,” says Brian Swingle [...]
Such interesting properties are emerging from these materials that physicists are starting to realize that entanglement may actually stitch together space-time itself—a somewhat ironic twist, as Einstein, who first connected space and time in his relativity theory, disliked quantum mechanics so much. But if the theory proves correct, entanglement could help physicists finally reach one of their ultimate goals: achieving a theory of quantum gravity that unites Einstein’s relativistic world with the enigmatic and seemingly contradictory quantum world....
MORE: https://www.symmetrymagazine.org/article...tanglement
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RELATED: A New Way of Thinking About Spacetime That Turns Everything Inside Out
EXCERPT: . . . The experiment was designed to study quantum entanglement, a phenomenon that connects quantum systems in ways that are impossible in our macro-sized, classical world. [...] Scientists have long speculated that previous experimental results can be explained best if the world does not obey one or both of the first two of Bell’s assumptions—realism and locality. But recent work has shown that the culprit could be his third assumption—the freedom of choice. Perhaps the scientists’ decision about the angle at which to let the photons in is not as free and random as they thought.
The quasar experiment was the latest to test the freedom of choice assumption. The scientists determined the angle at which they would allow photons into their detectors based on the wavelength of the light they detected from the two distant quasars, something determined 7.8 and 12.2 billion years ago, respectively. The long-traveling photons took the place of physicists or conventional random number generators in the decision, eliminating earthbound influences on the experiment, human or otherwise. At the end of the test, the team found far higher correlations among the entangled photons than Bell’s theorem would predict if the world were classical.
That means that, if some hidden classical variable were actually determining the outcomes of the experiment, in the most extreme scenario, the choice of measurement would have to have been laid out long before human existence—implying that quantum “weirdness” is really the result of a universe where everything is predetermined. “That’s unsatisfactory to a lot of people,” Hall says. “They’re really saying, if it was set up that long ago, you would have to try and explain quantum correlations with predetermined choices. Life would lose all meaning, and we’d stop doing physics.”
Of course, physics marches on, and entanglement retains many mysteries to be probed. [...] “No information can go from here to there instantaneously, but different interpretations of quantum mechanics will agree or disagree that there’s some hidden influence,” says Gabriela Barreto Lemos, a postdoctoral researcher at the International Institute of Physics in Brazil. “But something we all agree upon is this definition in terms of correlation and statistics.”
[...] entanglement may hold the key to some of the most fundamental questions in physics. Some researchers have been studying materials with large numbers of particles entangled, rather than simply pairs. When this many-body entanglement happens, physicists observe new states of matter beyond the familiar solid, liquid and gas, as well as new patterns of entanglement not seen anywhere else. “One thing it tells you is that the universe is richer than you previously suspected,” says Brian Swingle [...]
Such interesting properties are emerging from these materials that physicists are starting to realize that entanglement may actually stitch together space-time itself—a somewhat ironic twist, as Einstein, who first connected space and time in his relativity theory, disliked quantum mechanics so much. But if the theory proves correct, entanglement could help physicists finally reach one of their ultimate goals: achieving a theory of quantum gravity that unites Einstein’s relativistic world with the enigmatic and seemingly contradictory quantum world....
MORE: https://www.symmetrymagazine.org/article...tanglement
- - -
RELATED: A New Way of Thinking About Spacetime That Turns Everything Inside Out
