2022-06-23, 11:23 PM
The Spooky Quantum Phenomenon You’ve Never Heard Of
Katie McCormick
Katie McCormick
Quote:“Nonlocality is spectacular. I mean, it’s like magic,” said Adán Cabello, a physicist at the University of Seville in Spain.
But Cabello and others are interested in investigating a lesser-known but equally magical aspect of quantum mechanics: contextuality. Contextuality says that properties of particles, such as their position or polarization, exist only within the context of a measurement. Instead of thinking of particles’ properties as having fixed values, consider them more like words in language, whose meanings can change depending on the context: “Time flies like an arrow. Fruit flies like bananas.”
Quote:Bell also proved a similar theorem about contextuality. He and, separately, Simon Kochen and Ernst Specker showed that it is impossible for a quantum system to have hidden variables that define the values of all their properties in all possible contexts.
Quote:In 2009, contextuality, a seemingly esoteric aspect of the underlying fabric of reality, got a direct application: One of the simplified versions of the original Bell-Kochen-Specker theorem was shown to be equivalent to a basic quantum computation.
Quote:In February, Cabello and Kim announced that they had closed every plausible loophole by performing a “loophole free” Bell-Kochen-Specker experiment.