The pantheon of impossible photon tricks grows ever larger. Today, a new addition from Andrew Shields and pals at Toshiba Research Europe in Cambridge, UK:
“We report an experiment in which two-photon interference occurs between degenerate single photons that never meet. The two photons travel in opposite directions through our fibre-optic interferometer and interference occurs when the photons reach two different, spatially separated, 2-by-2 couplers at the same time.”
Cool!
Ref: arxiv.org/abs/0709.0847 : Experimental Position-time Entanglement with Degenerate Single Photons
If we imagine the vacuum as a dense environment, composed of density fluctuations recursivelly (a sort of scale invariant Perlin noise of nested foam), then every perturbation affects the number of underlying layers of fluctuation hiearchy, where it can propagate by subtle way, but by superluminal speed.
http://superstruny.aspweb.cz/images/fyzika/quantum/spread.gif
Therefore it’s nothing very strange, a pair of photons can affect mutually at the distance. Compare the Aharamov-Bohm effect, for example.
Yes but this isn’t an interference effect due to a physical interaction, but rather interference due to cancellation of quantum mechanical probability amplitudes.