Since our early childhood we know in our bones that in order to interact with an object we have either to go to it or to throw something at it. Yet, contrary to all our daily experience, Nature is nonlocal: there are spatially separated systems that exhibit nonlocal correlations. In recent years this led to new experiments, deeper understanding of the tension between quantum physics and relativity and to proposals for disruptive technologies.
Since our early childhood we know in our bones that in order to interact with an object we have either to go to it or to throw something at it. Yet, contrary to all our daily experience, Nature is nonlocal: there are spatially separated systems that exhibit nonlocal correlations. In recent years this led to new experiments, deeper understanding of the tension between quantum physics and relativity and to proposals for disruptive technologies.
Since our early childhood we know in our bones that in order to interact with an object we have either to go to it or to throw something at it. Yet, contrary to all our daily experience, Nature is nonlocal: there are spatially separated systems that exhibit nonlocal correlations. In recent years this led to new experiments, deeper understanding of the tension between quantum physics and relativity and to proposals for disruptive technologies. Consider two spatially separated quantum systems, one controlled by Alice, the other by Bob, in a pure state . Alice and Bob may perform some measurements x and y on their systems and collect the results a and b, respectively. This situation is described by a conditional probability distribution p (a,bj x,y). In general this correlation doesn’t factorize: p (a,bj x,y) 6 p (aj x) � p (bj y), i.e. the two systems are correlated. At first, this is no surprise, correlations are everywhere. For example, consider two cups of the same color, either both red or both green, one in Alice’s and one in Bob’s hands. If they looks at the color of their cups, Alice and Bob’s results are correlated. In this example the origin of the correlation is obvious, Alice and Bob had only partial information: they knew that both have the same color, but they ignored which color. This differs deeply from the quantum situation, as quantum theory claims that a pure state provides a complete description of the two systems. This led EPR[2] to believe that quantum theory is incomplete in the same sense as the description ”of the same color” provides only an incomplete description of the color state of the cups.
While we do not yet know how Nature is nonlocal, interdisciplinary research in the areas of physics, biophysics and neuroscience going back over 4 decades, reveals that Nature is nonlocal. Nonlocality appears to have been observed between human subjects’ brains, human neural stem cells and in quantum coherence in muscle contraction in single actin filaments. And, since the neurons are entangled, this introduces the concept of biological quantum nonlocality being ‘generated’ or ‘accessed’ each time that they fire, and an action potential is achieved. This could then provide not only for a resolution of the binding problem and the reverse direction problem, since this biological quantum nonlocality containing information, is not only being ‘generated’ and shared by the neurons continuously and instantaneously but, could lead to biology pointing the way to new physics!
In his article in Science, Nicolas Gisin claimed that quantum correlations emerge from outside space–time. We explainthat they are due to space-time symmetries. This paper is a critical review of metaphysical conclusions found in many recent articles. It advocates the importance of contextuality, Einstein -causality and global symmetries. Bell tests allow only rejecting probabilistic coupling provided by a local hidden variable model, but they do not justify metaphysical speculations about quantum nonlocality and objects which know about each other’s state, even when separated by large distances. The violation of Bell inequalities in physics and in cognitive science can be explained using the notion of Bohr- contextuality. If contextual variables, describing varying experimental contexts, are correctly incorporated into a probabilistic model, then the Bell–CHSH inequalities cannot be proven and nonlocal correlations may be explained in an intuitive way. We also elucidate the meaning of statistical independence assumption incorrectly called free choice, measurement independence or no- conspiracy. Since correlation does not imply causation, the violation of statistical independence should be called contextuality; it does not restrict the experimenter’s freedom of choice. Therefore, contrary to what is believed, closing the freedom-of choice loophole does not close the contextuality loophole.
Abstract In the strange new world of quantum physics we have consistently uncovered aspects of physical reality at odds with our everyday sense of this reality. But no previous discovery has posed more challenges to our usual understanding of the “way things are” than the amazing new fact of nature known as nonlocality. This new fact of nature was revealed in a series of experiments testing predictions made in a theorem developed by theoretical physicist John Bell in response to a number of questions raised by Albert Einstein and two younger colleagues in 1936. Although Bell’s now famous theorem led to the discovery that physical reality is non-local, this was not his primary motive for developing the theorem, and he was quite disappointed by the results of experiments testing the theorem.
Nonlocality is arguably among the most counterintuitive phenomena predicted by quantum theory. In recent years, the development of an abstract theory of nonlocality has brought a much deeper understanding of the subject, revealing a rich and complex phenomenon. In the current work, we present a systematic experimental exploration of the limits of quantum nonlocality. Using a versatile and high-fidelity source of pairs of polarization-entangled photons, we explore the boundary of quantum correlations, demonstrate the counterintuitive effect of more nonlocality with less entanglement, present the most nonlocal correlations ever reported, and achieve quantum correlations requiring the use of complex qubits. All of our results are in remarkable agreement with quantum predictions, and thus represent a thorough test of quantum theory. Pursuing such an approach is nevertheless highly desirable, as any deviation may provide evidence of new physics beyond the quantum model.
Nonlocality is arguably among the most counterintuitive phenomena predicted by quantum theory.In recent years, the development of an abstract theory of nonlocality has brought a much deeper understanding of the subject, revealing a rich and complex phenomenon.In the current work, we present a systematic experimental exploration of the limits of quantum nonlocality.Using a versatile and high-fidelity source of pairs of polarization-entangled photons, we explore the boundary of quantum correlations, demonstrate the counterintuitive effect of more nonlocality with less entanglement, present the most nonlocal correlations ever reported, and achieve quantum correlations requiring the use of complex qubits.All of our results are in remarkable agreement with quantum predictions, and thus represent a thorough test of quantum theory.Pursuing such an approach is nevertheless highly desirable, as any deviation may provide evidence of new physics beyond the quantum model.