Slashdot Mirror

← Back to Stories (view on slashdot.org)

Quantum Physics Parts Ways With Reality

Posted by kdawson on from the had-it-for-a-minute-there dept.

aeoneal sends us to PhysicsWeb for news guaranteed to induce headache in those wedded to the reality of, well, reality. Researchers from the University of Vienna have shown the violation of a stronger form of Bell's inequality known as Leggett's inequality. The result means that we must not only give up Einstein's hope of "no spooky action at a distance," we must also give up (some of) the idea that the world exists when we are not looking. From the article: "[Studies] have ruled out all hidden-variables theories based on joint assumptions of realism, meaning that reality exists when we are not observing it; and locality, meaning that separated events cannot influence one another instantaneously. But a violation of Bell's inequality does not tell specifically which assumption — realism, locality, or both — is discordant with quantum mechanics." From the Nature abstract: "Our result suggests that giving up the concept of locality is not sufficient to be consistent with quantum experiments, unless certain intuitive features of realism are abandoned." Only subscribers to Nature, alas, can know what features those are, as PhysicsWeb doesn't tell us.

3 of 568 comments (clear)

  1. Original paper... by aivuk · · Score: 5, Informative

    you can find here http://arxiv.org/abs/0704.2529.

  2. Re:What does it mean for us to observe something? by Ambitwistor · · Score: 5, Informative

    Humans don't have anything special to do with "observing" ("collapse of the wavefunction" or "state reduction"). A particle can be "observed" by a rock, or by any other "classical" macroscopic system with which it can entangle. Quantum decoherence in the consistent histories interpretation, IMHO, comes closest to explaining this process.

  3. Re:bye-bye! by Anonymous Coward · · Score: 5, Informative

    Am I the only one that thinks to themselves, "One of these days, some really smart person is going to come out with a new and better theory of reality that reveals all this quantum mechanics stuff to be a bunch of quackery."?

    Nope, and a lot of physicists think that quantum mechanics is fundamentally broken beyond the level of fixing - though it is a massively useful theory from a calculational point of view, it has deeper problems than just the ones involved in this experiment, including the measurement problem.
     
    Nobody is really sure what quantum physics says about reality or locality. Each of the interpretations is flawed or incomplete in some way. You might be interested to read about David Bohm's interesting theory - though a lot of people think it's garbage, it does illuminate the lengths you must go to to fashion a theory that is consistent with quantum mechanics yet doesn't completely shred your common sense notions of reality. I have no idea if the experiment in this article has anything to say about so-called "Bohmian mechanics," as the blurb was completely uninformative and I don't subscribe to Nature...