Over 100,000 Gamers from Around the World Prove Einstein’s Theory of Local Realism Wrong
Over 100,000 gamers from around the world have taken part in a new study, which has contradicted Albert Einstein’s ideas for a mind-boggling phenomenon that is a cornerstone of quantum mechanics, also known as the physics of the very small.
The study was led by the Institute of Photonic Sciences (ICFO) in Barcelona. It was conducted by an international team of physicists who ended up closing a loophole found in a common test of quantum mechanics.
The phenomenon in question for this study is called quantum entanglement, which happens when pairs, or groups, of particles, interact with each other in such a way that they defy the classical laws of physics. It appears that one object influences another simultaneously, even if they have no direct physical connection and are separated by great distances, for example, the length of the universe.
Although Einstein didn’t disagree with quantum mechanics entirely, he did find the idea of quantum entanglement to be problematic, once famously describing it as “spooky action at a distance.” He proposed that this quantum behaviour was impossible and that it could be explained by hidden “instructions” in the entangled particles, an argument based on two fundamental principles: locality and realism.
As Newsweek explained, locality says objects can only be influenced by causes in their immediate vicinity. (Part of this concept is that nothing can travel faster than light.) While realism states that objects in the universe have well-defined properties even when we are not looking at them. Meaning, matter has a reality independent of ourselves. Together, these principles came to be known as “local realism.”
Despite the fact that the concepts expressed by local realism may seem natural to us, growing evidence proposes that they are incompatible with quantum mechanics. First, quantum mechanics shows the simple act of observing particles in the universe can change their characteristics, which then violates the principle of realism.
Second, particles that are connected or can communicate over great distances in an instant—the “spooky action at a distance”—clearly violates the principle of locality. (In this case, some hidden form of information must be travelling faster than light between the two particles.)
A Bell test is the standard way to test quantum mechanics in relation to the principle of local realism. It was first developed by the CERN physicist John Stewart Bell in 1964. This is an experiment that ascertains whether the real-world is really as strange as quantum physics says it is. It accomplishes this by looking for the presence of hidden” variables, that are not part of quantum theory, to explain the behaviour of subatomic particles.
The researchers for this latest study set up a website where they explained that the Bell tests involve producing a pair of entangled particles and sending them to two separated measurement stations, typically called “Alice” and “Bob.” (Entanglement means that their properties are strongly correlated—for instance, if one particle spins left, the other must spin left, too, regardless of how far away they are from each other).
The authors wrote on the website that Alice and Bob make simultaneous, unpredictable measurements on the particles. Quantum mechanics says that the measurement Alice makes will instantly influence Bob’s particle, with the effect that the measurement results agree. In local realism, this influence cannot happen, and Bob and Alice’s measurement results will often disagree. This agreement or disagreement, called correlation, is the signal that allows an experiment to decide about local realism.
While many Bell tests over the years have seemed to confirm the ideas of quantum mechanics over those of local realism, there is a problem here. The Bell test necessitates random and independently generated number sequences to figure out which measurements to perform on quantum objects. However, generating truly random numbers is tricky. Researchers could be influenced by unknown biases, and most computerized random number generators are not truly random, among other factors.
This flaw in the Bell test is called the “freedom of choice” loophole. The potential that these “hidden” variables could be influencing the experiments. This then casts doubt on the fact that the measurements are truly random, which means it would not be possible to completely rule out the explanation provided by local realism for the behaviour of any given particles.
For this new work, published in the journal Nature, the physicists enlisted more than 100,000 volunteer gamers from across the globe to try to close this loophole by producing random numbers with sheer manpower.
The participants were asked to play a custom-made online game called The Big Bell Quest, where players had to tap two buttons repeatedly on a screen, representing the values one and zero. Players levelled up by creating unpredictable strings of these ones and zeros.
This gave the scientists over 90 million randomly human-generated binary digits, or bits—the smallest unit of computer data—which were then used in lab experiments around the world to ascertain how entangled particles were measured.
Andrew White from the University of Queensland, in Australia, who was involved in the study, said in a statement that people are unpredictable, and when using smartphones even more so. These random bits then figured out how various entangled atoms, photons and superconductors were measured in the experiments, closing a stubborn loophole in tests of Einstein’s principle of local realism.
The results of the study showed that quantum particles that are separated by vast distances can still instantly affect each other, contradicting Einstein’s principle of local realism.
Plus, since the experiment used so many people, the researchers can be sure that their results were exact.
The team wrote on the website that a common way to reduce the uncertainty on the result of an experiment is to repeat it many times and then check if the results are statistically significant. Every random number the community contributes enables the scientists to conduct another run of the experiment and to reach a more exact result. Furthermore, the more different individuals are participating, the more they are assuring the statistical independence that is so important for this kind of experiment.
What’s more, these results resonate with those of advanced experiments conducted in 2015, in which other groups of researchers also developed loophole-free Bell tests.
Although Einstein may have been wrong about this one, the great German physicist did come up with the groundbreaking special theory of relativity, which transformed physics and altered our understanding of the universe as we know it.
(The institutions involved in the latest study were: ICFO and the University of Seville, Spain; Griffith University, the Centre of Excellence for Engineered Quantum Systems and the University of Queensland, Australia; the University of Concepción, Chile; Linköping University, Sweden; Sapienza University of Rome, Italy; the Federal University of Rio Grande do Norte, Brazil; the University of Science and Technology of China; the University of Buenos Aires, Argentina; the Austrian Academy of Sciences; Ludwig Maximilian University of Munich, Germany; the University of Nice Sophia Antipolis and The National Center for Scientific Research, France; the National Institute of Standards and Technology, United States; and the Swiss Federal Institute of Technology in Zurich.)
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