Berabrado,
This is the link you posted and in the post I responded to :
http://physicsworld.com/cws/article/news/2007/apr/20/quantum-physics-says-goodbye-to-reality
this is the reasearch discussed in teha rticle:
"Markus Aspelmeyer, Anton Zeilinger and colleagues from the University of Vienna, however, have now shown that realism is more of a problem than locality in the quantum world. They devised an experiment that violates a different inequality proposed by physicist Anthony Leggett in 2003 that relies only on realism, and relaxes the reliance on locality. To do this, rather than taking measurements along just one plane of polarization, the Austrian team took measurements in additional, perpendicular planes to check for elliptical polarization."
Now this is the research mentioned in the paper, it is about Leggett's inequality not Bell's.
Now not suprisingly, there are different kinds of realism and models that sue that term in the physics around QM,
so i ask you again because it is important:
What is the first postulate of Leggett's inequality? Leggett's reference to a non-QM interpetation or one that is incorrect.
here I will be dumb and show you exactly what this is about:
"The Leggett–Garg inequality[1], named for Anthony James Leggett and Anupam Garg, is a mathematical inequality fulfilled by all macrorealistic physical theories. Here, macrorealism (macroscopic realism) is a classical worldview defined by the conjunction of two postulates:[1]
Macrorealism per se: "A macroscopic object, which has available to it two or more macroscopically distinct states, is at any given time in a definite one of those states."
Noninvasive measurability: "It is possible in principle to determine which of these states the system is in without any effect on the state itself, or on the subsequent system dynamics.""
Did you even read what it was before you started talking about it?
Do you know enough about QM to understand that QM qill always violate Leggett's inequalities, neither postulate is true.
http://www.nature.com/srep/2011/110926/srep00101/full/srep00101.html
Introduced as the Bell inequalities in time, the violation of LG inequalities excludes the hidden-variable description based on the above two assumptions. We experimentally investigated the single photon LG inequalities under decoherence simulated by birefringent media. These generalized LG inequalities test the evolution trajectory of the photon and are shown to be maximally violated in a coherent evolution process. The violation of LG inequalities becomes weaker with the increase of interaction time in the environment. The ability to violate the LG inequalities can be used to set a boundary of the classical realistic description.
So this is not about QM and its use of realism, and this is not about classical mechanics and realism, this is about an incorrect attempt to create a definition between the two, and Leggetts postulates are violated by QM right off the bat.
And here is teh final paragraph of teh discussion:
In summary, we experimentally violated two generalized LG inequalities in an all-optical system using a CNOT gate. The violation of generalized LG inequalities disproves the definite classical evolution trajectory of the single qubit20 and implies that at least one of the two assumptions in the classical realistic description is untenable. The ability to violate LG inequalities can be used to set the boundary of the classical realistic description.
Well duh, you can not use macroscopic scale interactions to model QM systems, that si a given in QM, the behavior of teh quantum realm is what it is.
So the violation of Leggett's inequality means that you can not define QM events by classical models.
Duh.
So in Leggett's definition of realism, yes, QM violates Leggetts inequality, which is established by the two postulates from the get go.
A macroscopic object is not going to be in a range of definable eigenstates, it will be decoherent and a mishmash of all the sub states of teh whole system.
There for it will never meet the first of Leggetts postulates.
Leggett's second postulate makes no sense either, there is no observational interaction taht does not change a QM system, even if it is part of a macroscopic object.
So a paper saying that QM violates Leggett's inequality is no surprise, duh. You can not model macroscopic objects as QM, not can you model QM objects as macroscopic.
DUH. So Leggett's definition of realism is false, there are many other used in physics and QM.