"Entangled photons could provide deep insights into our world that nobody, not even physicists, expected.

AFTER battling the strangeness of time and space, it must have taken a lot to freak out Albert Einstein. Yet there was one aspect of quantum physics that brought him out in a cold sweat: entanglement.

Take two photons, for instance, tie them together with an unbreakable quantum bridge and their link becomes so close it is almost telepathic.

Einstein described this apparently supernatural behaviour as "spooky". It seems, for instance, that performing an experiment on one photon of an entangled pair instantaneously affects its partner, whether they're in the same lab, or at different ends of the Universe. No surprise, then, that researchers in Austria have recently used this bizarre trick in quantum teleportation experiments (New Scientist, 14 March 1998, p 26).

But these may be nothing compared to the bombshell that Caslav Brukner of the University of Vienna has just dropped. As if our current understanding of entanglement between widely separated particles were not sketchy enough, Brukner, working with Vedral and two other Imperial College researchers, has uncovered a radical twist. They have shown that moments of time can become entangled too (www.arxiv.org/abs/quant-ph/0402127).


http://www.ap.univie.ac.at/users/Caslav.Brukner/media/New%20Scientists%202004%20Quantum%20Entanglement/article.jsp.html

http://www.ap.univie.ac.at/users/Caslav.Brukner/media.html



The weirdest link

New Scientist vol 181 issue 2440 - 27 March 2004, page 32

That spooky connection between tiny particles is appearing everywhere, and its consequences are even affecting the world that we experience. It seems to unravel the past, and may be what keeps us alive. Quantum entanglement just got a whole lot weirder, says Michael Brooks


ENTANGLEMENT. Erwin Schrödinger called this phenomenon the defining trait of quantum theory. Einstein famously dubbed it spukhafte Fernwirkungen: "spooky action at a distance". It is not hard to understand why. Set things up correctly, and you can instantaneously affect the physical properties of a particle on the other side of the universe simply by prodding its entangled twin.