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Photons going backward in time

Going for a blast into the real past

Apparently, they're going to shoot an ultraviolet laser into a crystal, and out will come two lower-energy photons that are entangled. For the first phase of the experiment, to be started early next year, they're going to shoot an ultraviolet laser into a crystal, and out will come two lower-energy photons that are entangled, searching for evidence of signaling between the entangled photons, and hoping to test for retrocausality (evidence of a signal sent between photons backward in time).

The second test will involve sending one of the photons down 10 miles of fiber optic cable, delaying it by 50 microseconds, then testing a quantum-mechanical aspect of the delayed photon. Due to quantum entanglement, the non-delayed photon would need to reflect the measurement made 50 microseconds later on the delayed photon. In order for this to happen, some kind of signal would need to be sent 50 microseconds back in time from the delayed photon to the non-delayed photon.

PS: funny to see that the link to the article refers to "292378_timeguy15.html"

posted by Goto @ 14:37