!WOW!  -the World Students Society is greatly honoured to acknowledge the highest accomplishment of this Great Master Professor of Physics at M.I.T.

Some fleeting-minuscule, and an extremely small strand of this great  professor's life, is woven from and out of Karachi, Pakistan. That should be levitating enough to lift the Pakistani nation's, and the Pakistani students',... frozen spirits.

While !WOW! hopes to cover the profound magnitude of Professor Nergis's work, in a detailed future post, I use this glorious moment to help lay the context of her research proof : detecting Einstein's gravitational waves  

In the  1930s Master Albert Einstein was greatly troubled by a phenomenon that came from Quantum theory. Entanglement, as it is called, forever intertwines  the fates of objects such as subatomic particles, regardless of their separation.

If you measure, say,  ''up''  for the spin of one photon from an entangled pair, the theory suggests that the spin of the other, measured an instant later, will surely be  ''down''   -even if the two are opposite sides of the galaxy.

This was an anathema to Einstein and others: it looked it looked as if information was travelling faster than light, a  no-no  in the special theory of relativity. 

Einstein was quotably derisive, calling the idea  ''spooky action at a distance'' . But after  80 years  of physicists fretting a cunning experiment reported recently that such action is in fact how the world works.

To save physics from the  spooky, Einstein invoked what he called hidden variables [through others might describe them as fiddle factors]  that would convey information without breaking the universal speed limit.

It took until  1964, to tame this woolly idea into testable equations. John Bell, a British Physicist, worked out the maximum effect hidden variables could have on a given test.

Any influence beyond that,  his equations suggested, must be down to spooky action. 

The Bell inequality, as it became known, sparked decades of clever experimenting   -sending entangled photons or atoms hither and thither with detectors triggered by this  or  that  -each designed to catch nature out, to banish hidden variables once and for all.

Yet a number of loopholes remained -ways that hidden variables might exert some influence, though the purported mechanisms became increasingly contrived as years and experimental finesse advanced.        

One was the detection loophole. Reliably catching a single photon, for example, is tricky; lots of them go amiss in a given experiment. But if an experiment does not capture all of its participants, the loop hole idea goes, perhaps hidden variables convey information through the missing ones.

Another as the communication loophole. If the two measurements happen near enough to one another, some hidden-variable signal might be passing between them {as long as the signal does not go faster than light}.

Plenty of experiments have closed one or the other of those loopholes, for example by detecting particles that are more reliably caught than photons, or by sending photons so far apart that no slower-than light signal could flit between them to have an effect.

By now most physicists reckon that the  hidden-variable idea is flawed. But no test had closed both loopholes simultaneously  -until very recently.  

Ronald Hanson of the  University of Delft and his colleagues, writing in Nature, describe an experiment that starts with two electrons in laboratory separated by more than a kilometre.

Each emits a photon that travels down a fibre to a third lab, where the two photons are entangled. That, in turn, entangles the electrons that generated the photons. The consequence is easily measured particles [the electrons] separated by a distance that precludes any shifty hidden-variable signalling.

Over 18 days, the team measured how correlated the electron measurements were. Perhaps expectedly, yet also oddly, they were far more so than chance would allow -proving that Quantum mechanics is as spooky as Einstein had feared.

Though this experiment marks an end to hidden variables, Dr. Hanson says it is also a beginning : that of unassailably secure  ''quantum-enabled cryptography. It was shown in 1991, that the very Bell tests used to probe hidden variables could also serve  as a check on quantum-cryptography.

A loophole free Bell test, then, could unfailingly reveal if a hacker had interfered with the fundamentally random, quantum business of generating a cryptographic key.

So-called device-independent quantum ciphers would, Dr. Hanson says, be secure from hackers   'even if you don't trust your own equipment   -even it's been given to you by the NSA''.   

There remains, alas one one hitch that could explain all these counterintuitive findings, just maybe, every single event that will ever be, from experimenters' choices of the means of measurement to the choice of article you will read next-

Were all predetermined at the universe's birth, and all these experiments are playing out just as predetermined.

That, however, is one for the metaphysicists.

With respectful dedication to all the Scientists, Students, Professors and Teachers of the world. See Ya all on !WOW!  -the World Students Society and the Ecosystem 2011.

''' Quantum-Quantum '''

Good Night and God Bless

SAM Daily Times - the Voice of the Voiceless


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