One o’ the most bewilderin’ parts of quantum mechanics is its spooky action at a distance. Einstein couldn’t fathom it and other physicists have been a-puzzlin on it for decades. Today they gotta lil more to fret ‘n’ fuss about.<\/p>\n
Alexandre “Napkin” Matzkin at the Universite Joseph-Fourier in Grenoble has found a serious problem with the test that physicists use to measure spooky action at a distance. He says this test is so broad that it can’t tell a photon from a flock o’ parrots. And he’s proved it by showing that certain classical phenomenon pass the test for spooky action at a distance even though there ain’t nothin spooky about them.<\/p>\n
The background to this began in 1935 when Einstein and a few pals published details of what they saw as a flaw in quantum mechanics. When two quantum particles become entangled they share the same wavefunction; they are described by the same piece of mathematics. Now separate these particles by, say, the width of the universe and perform a measurement on one of them. According to the mathematics, a measurement on one instantaneously determines the state of the other, regardless of the distance between them. But how does the second particle ‘know’ the first has been measured?<\/p>\n
This instantaneous communication, the spooky action at a distance, would be a violation of relatively, says Einstein and his pals. So you quantum bods must be missin’ something somewhere.<\/p>\n
But the quantum bods just ignored him. Until 1966 when a physicist at CERN, John Bell, came up with a way of testing for spooky action at a distance. He derived a set of inequalities that if violated in experiment, would prove that spooky action at a distance was occurrin’. Since then, loadsa people have found violations o’ Bell’s inequalities for all kinds a quantum stuff.<\/p>\n
What Napkin Matzkin has done is show that it ain’t just quantum stuff that violates the inequalities. He’s gone and found a classical example of ordinary bricks ‘n’ mortar that also violates the inequalities.<\/p>\n
That don’t prove that spooky action at a distance ain’t occurrin’ or that quantum mechanics is in some way incomplete (although it might be). It shows that the assumption behind Bell’s inequalities are plain potty and somebody is gonna have to do some serious cogitatin’ n’ considerin’ to sort this out.<\/p>\n