Quantum Physics Parts Ways With Reality

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.

Original paper...

[aivuk]

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

Re:What does it mean for us to observe something?

[Ambitwistor]

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.

Re:bye-bye!

[Anonymous Coward]

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 [wikipedia.org].
 
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 [amazon.com] - 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...

Re:Logic?

[Arker]

Aristotelian logic is not [wikipedia.org] the entire set of logic, not by a long shot.

Link to article

[Sploff]

As per the tradition in new-school quantum physics, the original article is of course available for everyone at arxiv.org: http://arxiv.org/abs/0704.2529 [arxiv.org]. (Nature articles are a bit special -- they are submitted to the "preprint archive" after they are published...)

Re:bye-bye!

[zippthorne]

No, that's not what a law is at all. Newton's laws for instance are clearly incomplete from a theory point of view. He was, for instance, able to describe gravity's effects pretty well, but he made no attempt to describe what gravity was.

Physical Laws are analogous to mathematical axioms. We use them to derive theories and learn about the universe. They are declared assumptions.

Re:Entanglment Applications Exist

[Carewolf]

Only problem with that application is that it is not usefull for transferring information, which in other words means that it is not usefull at all.

Re:A layman's view

[l0b0]

Occam's Razor only lets you choose between two hypotheses which both adequately account for the data.

No [skepticreport.com]

Re:bye-bye!

[Ox0065]

or is it because Quantum Mechanics has always been a model of what could be determined re: the properties of a particle at that time.
That time being when some now dead academics were having a tiff. Perhaps its because that model predicted the laser to be impossible.
Perhaps its because that model predicted it was impossible to bring an electron to rest for a year and measure its properties... ...EXTREMELY ACCURATELY

There is nothing wrong with a search for truth.

Re:bye-bye!

[Anonymous Coward]

The "many worlds" interpretation is popular with science fiction (such as Stargate SG-1).

pssst, SG is a single universe. Sliders [tv.com] was "many worlds".

Re:Observation

[Goaway]

It has already been stated several times, but as it is kind of being drowned out by the noise, I will add my voice to the chorus:

Waveform collapse is not relative to the observer!

It might seem like it should be, because it is slightly more intuitive that way, but it is not. This is very important.

Your explanation is entirely incorrect, and you're kind of doing a disservice to those who read it an think they now understand QM a bit more, when in fact you have just led them further astray.

Re:Well, it makes sense

[stonecypher]

Perhaps you are joking, but I've often wondered if quantum effects are caused by the universe having limited floating-point accuracy.

Max Planck and Claude Shannon beat you to it.

MEASURE, not OBSERVE

[DynaSoar]

There's a whole passel of improperly informed people yakking on about consciousness and its relation to reality and other ridiculous notions, specifically because people insist on confusing the necessary MEASUREMENT with the irrelevant OBSERVATION. Collapse of quantum wave functions requries interaction with another non-entangled wave function such as a measuring device. All of the results which support the inequalities tested and referenced here were produced using equipment which measured the phenomena and gave results well before any observation occurred. The parent, and the blurb in Nature both imply the mistaken idea by using terms that refer to a observer. Nature should know better. Everybody else that's really interested in understanding it should learn better. It makes the science much more interesting. But then it weeds out the semi-informed speculativists and the newage (rhymes with sewage) pseudoscientific-spiritual theorists. Being the vast majority, they obviously tend to revolt at the insistence on being correct.