"Quantum mechanics fundamentally

concerns the way in which we observers connect to the universe

we observe. The theory implies that when we measure particles

and atoms, at least one of two long-held physical principles is

untenable: Distant events do not affect one other, and properties

we wish to observe exist before our measurements. One of

these, locality or realism, must be fundamentally incorrect.

... Now Zeilinger and his collaborators ...

In Vienna experiments are testing whether quantum

mechanics permits a fundamental physical reality. ...

(Nobel Laureate Tony) Leggett doesn’t believe quantum mechanics is correct, and

there are few places for a person of such disbelief to now turn.

But Leggett decided to find out what believing in quantum

mechanics might require. He worked out what would happen

if one took the idea of nonlocality in quantum mechanics seriously,

by allowing for just about any possible outside influences

on a detector set to register polarizations of light. Any unknown

event might change what is measured. The only assumption Leggett

made was that a natural form of realism hold true; photons should have measurable polarizations

that exist before they are measured. With this he laboriously derived a

new set of hidden variables theorems and inequalities as Bell once had.

But whereas Bell’s work could not distinguish between realism and locality,

Leggett’s did. The two could be tested. ...

The experiment wouldn’t be too difficult, but understanding it would. It took

them months to reach their tentative conclusion: If quantum

mechanics described the data, then the lights’ polarizations

didn’t exist before being measured. Realism in quantum

mechanics would be untenable ...

In the past decade or so, Zeilinger and his

many collaborators were the first to teleport light, use quantum

cryptography for a bank transaction (with optical fibers in the

sewers of Vienna), realize a one-way quantum computer, and

achieve entanglement over large distances through the air, first

across the Danube River and then between two of the Canary

Islands. Zeilinger’s work had also previously shown the greatest

distinction between quantum mechanics and local realism. ...

“Quantum mechanics is very fundamental, probably

even more fundamental than we appreciate,” he said, “But to

give up on realism altogether is certainly wrong. Going back to

Einstein, to give up realism about the moon, that’s ridiculous.

But on the quantum level we do have to give up realism.” ...

With eerie precision, the results of Gröblacher’s weekend

experiments had followed the curve predicted by quantum

mechanics. The data defied the predictions of Leggett’s model

by three orders of magnitude. Though they could never observe

it, the polarizations truly did not exist before being measured.

For so fundamental a result, Zeilinger and his group needed

to test quantum mechanics again ...

Leggett’s theory was more powerful than Bell’s ...

In mid-2007 Fedrizzi found that the new realism model was

violated by 80 orders of magnitude;

the group was even more assured that

quantum mechanics was correct. ...

Last year Brukner and his student Johannes Kofler decided

to figure out why we do not perceive the quantum phenomena

around us. If quantum mechanics holds universally for atoms,

why do we not see directly its effects in bulk?

Most physicists believe that quantum effects get washed out

when there are a large number of particles around. The particles

are in constant interaction and their environment serves to “decohere”

the quantum world—eliminate superpositions—to create

the classical one we observe. Quantum mechanics has within it

its own demise, and the process is too rapid to ever see. Zeilinger’s

group, which has tested decoherence, does not believe there is a

fundamental limit on the size of an object to observe superposition.

Superpositions should exist even for objects we see, similar

to the infamous example of Schrödinger’s cat. In fact, Gröblacher

now spends his nights testing larger-scale quantum mechanics in

which a small mirror is humanely substituted for a cat.

Brukner and Kofler had a simple idea. They wanted to find

out what would happen if they assumed that a reality similar to

the one we experience is true—every large object has only one

value for each measurable property that does not change. In other

words, you know your couch is blue, and you don’t expect to be

able to alter it just by looking. This form of realism, “macrorealism,”

was first posited by Leggett in the 1980s.

Late last year Brukner and Kofler showed that it does not

matter how many particles are around, or how large an object

is, quantum mechanics always holds true. The reason we see

our world as we do is because of what we use to observe it.

The human body is a just barely adequate measuring device.

Quantum mechanics does not always wash itself out, but to

observe its effects for larger and larger objects we would need

more and more accurate measurement devices. We just do not

have the sensitivity to observe the quantum effects around us.

In essence we do create the classical world we perceive, and as

Brukner said, “There could be other classical worlds completely

different from ours.”

I am not sure if they are correct because of the emergence of

c-number order parameters that obey the nonlinear non-unitary

Landau-Ginzburg equation in ordinary space not the linear unitary

q-number Schrodinger equation in configuration space.

JOSHUA ROEBKE in May/June, 2008 http://www.SEEDMAGAZINE.COM Reality Tests