Quantum theorem shakes foundations

[Jim__]

At the heart of the weirdness for which the field of quantum mechanics is famous is the wavefunction, a powerful but mysterious entity that is used to determine the probabilities that quantum particles will have certain properties. Now, a preprint posted online on 14 November1 reopens the question of what the wavefunction represents — with an answer that could rock quantum theory to its core. Whereas many physicists have generally interpreted the wavefunction as a statistical tool that reflects our ignorance of the particles being measured, the authors of the latest paper argue that, instead, it is physically real.

“I don't like to sound hyperbolic, but I think the word 'seismic' is likely to apply to this paper,” says Antony Valentini, a theoretical physicist specializing in quantum foundations at Clemson University in South Carolina.

Valentini believes that this result may be the most important general theorem relating to the foundations of quantum mechanics since Bell’s theorem, the 1964 result in which Northern Irish physicist John Stewart Bell proved that if quantum mechanics describes real entities, it has to include mysterious “action at a distance”.

Action at a distance occurs when pairs of quantum particles interact in such a way that they become entangled. But the new paper, by a trio of physicists led by Matthew Pusey at Imperial College London, presents a theorem showing that if a quantum wavefunction were purely a statistical tool, then even quantum states that are unconnected across space and time would be able to communicate with each other. As that seems very unlikely to be true, the researchers conclude that the wavefunction must be physically real after all.

(more: http://www.nature.com/news/quantum-theorem-shakes-foundations-1.9392 )

[ewagner]

1. anxious to read this...

addresses some of the great, anti-intuitive aspects of quantum physics...Schroedingers Cat for instance....locality vs no-locality...

for us amateurs this is exciting

[BadgerKid]

2. I wonder how it's related to Bell's theorem.

The thread over at Slashdot got me curious, so I'll have to read these later when I got time.

[TheMadMonk]

4. The cat observes itself. /nt

[Fumesucker]

7. Well, cats are some self absorbed little beasts.. n/t

[laconicsax]

3. Interesting. Thanks for posting.

[bananas]

5. Scott Aaronson, Lubos Motl, David Wallace and Matt Leifer have posted detailed reviews

http://www.kurzweilai.net/quantum-theorem-shakes-foundations

<snip>

Physics bloggers Scott Aaronson, Lubos Motl, David Wallace and Matt Leifer have posted detailed reviews with different opinions. — Ed.

[girl gone mad]

6. Lubos never disappoints.

I see he has decided that the authors hate QM and are on a mission to destroy it, which, naturally, leads him to conclude that only super elite people should be allowed to pursue Physics degrees.

My small, liberal, female brain would certainly disqualify me.

[snagglepuss]

8. Thank you for posting.Speaking as someone with no science background

I was able to glean some insight. Matt Leifer's review was the most accessible.