3quarksdaily: Scientists in Switzerland recently conducted another in a series of tests related to entanglement, the little understood quantum property whereby two entangled objects - in this case, photons - immediately share the same informational state once one of the objects is measured. In 2007 experiments, this "spooky action" was confirmed at a distance of 89 miles.
The Swiss test wanted to rate the speed at which this communication might take place. It turns out to be quite a bit faster than the speed of light, which raises questions about the nature of quantum communication since ordinary communication cannot exceed the universal speed limit of 186,000 miles per second.
In the everyday world, objects can organize themselves in just a few ways. For example, two people can coordinate their actions by talking directly with each other, or they can both receive instructions from a third source.
In both these cases, the information is communicated at or below the speed of light, in keeping with Einstein’s axiom that nothing in the Universe can go faster. But quantum mechanics allows for a third way to coordinate information (emphasis added)....
Scientific American - "Entanglement clocks in at 10,000 times the speed of light?" - has more on the story:
Theoretical physicist Terence Rudolph of Imperial College London, author of a commentary on the new paper, says that putting bounds on faster-than-light entanglement [which the Swiss experiment seems to have done] is useful for researchers trying to imagine theories that might extend beyond quantum mechanics.
What might such a theory look like? Rudolph says we're probably stuck with instantaneous entanglement, which seems impossible to us because we're stuck in everyday space and time. 'We need to understand how quantum mechanics sees space and time,' he says. 'I think there's probably much deeper issues.
In physics history, Einstein used the fact that communication was fast, but not infinitely fast, to question and to ultimately revolutionize Newtonian physics, which implied that gravitational effects were instantaneous over vast distances. Einstein's re-conception led to his spectacularly successful and empirically confirmed theories of special and general relativity, which show how space and time is a thing, bent and twisted.
In the current example, "quantum communication" may hint at limits subtler than those imposed by space and time, and, perhaps, at revolutions to come.
Wayne
Wikipedia: quantum entanglement
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