“Entanglement is the strange and beautiful property of certain quantum particles to become so deeply linked that they share the same existence. According to quantum theory, that link should be maintained whatever the distance between the particles, whether the width of an atom or the diameter of the universe.
This led Einstein to claim that the instantaneous effects of entanglement would lead to ‘spooky action-at-a-distance’ in violation of special relativity which prevents faster-than-light signals.
[Insert discourse on Bell’s Thm here and experimental tests of the completeness of Quantum Mechanics and the implied incompleteness of Classical and Relativistic physics]
…In every one of these tests [which test to see if Quantum Physics or Classical Physics is more “correct”], the results agree entirely with the predictions of quantum mechanics. And yet naysayers continue to unearth loopholes that allow them to claim that there is a way in which the results are fixed, perhaps because quantum mechanics works only only over the short distances that can be exploited on Earth or by the existence some kind of hidden variable that determines in advance how the particles will behave when they are separated. [Well, not quite… unless the idea the author is trying to get at here is that “hidden variables” come into play at large distances or velocities]
There is one way to settle the matter for sure: send entangled photons to two orbiting astronauts on board different spacecraft with large relative velocities. That leaves no room for hidden variable theories or any other fix because the peculiarities of special relativity allow both astronauts to claim the measurement on their photon was performed before the other.
Today Anton Zeilinger from the University of Vienna in Austria, says he wants to try just such an experiment and has put together an impressive international team to design and promote idea. The team has submitted its proposal, called Space-QUEST, to the European Space Agency in the hope that one end of the experiment could hosted on the Columbus module, Europe’s orbiting laboratory attached to the International Space Station.”
Read the full article here.