Wednesday, March 5, 2014

proposed: a new experiment on quantum reality

At arxiv.org this week, I posted a new paper which concludes with an interesting idea for a simple kind of decisive triphoton experiment, shown in figure 3:


Zeilinger's group (quant-ph/9810035) says they have a source which can produce a wave function I would write as
1/sqrt(2) ( (|1>a)(|1>b)(|2>c)+(|2>a)(|2>b)(|1>c)).

(Ouch! Blogger uses "gt" for the greater than character, the right angle bracket. Sorry. I can't fix blogger this morning. So MANY restrictive machines in our world!)

If c is far away, and tuned to a polarization angle of zero degrees, but a and b are close and tuned to 45 degrees (a) and ninety degrees (b),
then on a first glance it seems to me that it matters which polarizer is closer to the source, a or b, even if the distance is very small,
according to Copenhagen quantum mechanics. As soon as "a" is observed (detection or not), the rest of the experiment becomes like a Bell's Theorem experiment with 90 degree difference in polarizer angles. But when "b" is observed, what remains is a Bell experiment with only 45 degree separation.  I think that triple detection is absolutely impossible (zero probability) in the first case, but nonzero in the second.

If I understand what quantum mechanics predicts here, I view this as a kind of "Einstein Podolsky Rosen experiment, but at a new level."
Would quantum mechanics really fit this prediction, that a small change in timing of a and b would have a big effect? My alternative local causal model says it wouldn't.  If quantum mechanics is right, I think this implies FTL communication (which Bell's Theorem experiments do not allow),
because we could put the c polarizer a meter on one side, and a and b both 90 centimeters on the other side, yielding information flow from a and b to c as if c were only 10 centimeters away. If quantum mechanics is wrong, it could be seen as "Einstein wins round two." Either way it may be a very important experiment.


At present, it is hard for me to see a way around this logic. But of course, if there is, I would be grateful for quiet guidance.

======

A day later:

But of course it is important to just do the algebra on the wave function above. Hard to do, when in a state of panic, to try meet deadlines which become ever more frantic as people tighten up screws on all sides.

The difference between "M' and "M'" (defined in that arxiv paper) seems so glaring that there SHOULD be a way to find a decisive experiment, if not this way, some other way.
One would think.  Would an analytic approach work? How about trying to prove
no difference ever exists between predictions based on M and predictions based on M' -- in hopes that that effort would itself help us find a counterexample. But maybe it would be proven...

Not yet resolved.

=======

March 9: resolved. The algebra really does seem to give a decisive experiment.
It's pretty straightforward. Have uploaded a new paper with details (the paper to
be sent to SPIE for the May Quantum Computing Conference). 

Saturday, March 1, 2014

bad dreams about the Ukraine

Should I post this or not? Hard to say.  Not something I feel any confidence about, but not something so minor it should clearly be ignored.

Long ago, when looking at various types of social and economic dynamics, I noticed the analogy between the Weimar Republic, after World War II, and Yeltsin's government in Russia -- also a place where wonded pride, eocnomic problems combined with high technological capability, a "tribal" anthropology, and a low tolerance for cognitive dissonance. But could it really go so bad this time?

Then when Putin made some really nasty deals versus Exxon and so on, I basically felt support from them. Why should be put up with folks trying to take over the country? Though with Gazprom and nationalized oil, I wondered: will tis be yet another politically aggressive oil company in itself? Will Russia itself become an oil company, without any inhibitions.

I really did not intend to become emotionally entangled in the conflicts in the Ukraine. Even though I have been there, and feel some knowledge... I am 'way overextended, and do not want to do more harm than good, as is commonly the case when people feel obliged to act out of ignorance. After all, I am not the President of the US.

But two nights ago, in my usual meditation period... many, many subjects came up for discussion..
but I couldn't help think about the analogy between the violent irredentists in Crimea and the Sudenten Germans. Would Putin really find himself irresistably tempted by the great glory of following the path of Hitler?

The response was... "No, it's not like Sudentenland. Georgia was Sudentenland. This is like Austria.
Are we approaching peace in our time again?And the new ideological organization in Russia is a kind of plutocracy not unlike Mussolini's."

Of course, the Russian view is that it's the falt of those dirty Ukrainians fro wanting to have their own nation, and violating the treaty hundreds of years ago when some politician signed Ukraine away to Russia.  But what was Putin thinking when he offered to bail Ukraine out, on the condition that the government defy its people and cut off new ties to the rest of Europe?  Didn't he know exactly what he was doing, preparing the way for Anschluss?

Luda told me weeks ago to read Clancy's last novel, that it would as before all come out as planned. But now, they seem to expect Anschluss instead, as they expect no capabilities from OBbama or the US.
After Syria... and Ron Paul...

Meanwhile, of course, a lot of big money folks are very upset about the prospect of choosing between
Hilary Clinton and Paul or Cruz in 2016. The opportunity for McCain and Jeb Bush to come in and rescue defense spending , in response to what Putin plans, is very much on the table. It's odd that Putin thinks Congress is a passive place. Whatever else it is, quiet and passive is not such a god discussion.

Meanwhile, the chemocline is rising. That's the top of the huge reservoir of poison which is
steadly rising, to emerge on teh surface at the Black Sea. I even had sme mpression it could do so right in the middle of the Olympics... and prayed hard that no, because that would NOT be a good time.

But what of now? But if people start suddenly dying n the night in Sevastopol, will there be a miscalculation by folks always looking for others to blame, whihc could cause even wider conflict?

ON top of this, some folks say "Of course NATO will not act. They need Russia's gas, and Schroder, the one guy positioned to lead the EU to energy independence, has been bought off by Gazprom.
Really, it doesn't stop with Ukraine. Listen to the chants in Crimea... it is the Germans they want to humiliate more than anyone else."

Or there could be an interesting new civil war, which Islamic extremists would be happy to manipulate, just as they manipulated Syria, when Russia created the opportunity for them to do so.

"God help us."

Best of luck,

     Paul