The h Bar

12:51 AM

↑ breakthru experimental + theoretical evidence for a classical local hidden variable theory of quantum mechanics en.wikipedia.org/wiki/Local_hidden-variable_theory

dm__

1:45 AM

@vzn Bell's theorem: "No physical theory of local hidden variables can ever reproduce all of the predictions of quantum mechanics." It must be nonlocal.

Salvador Villarreal

2:02 AM

Hello guys! I was wondering if you knew some books/articles that have a good introduction to convexity in the context of variational calculus (functional analysis). I was reading Young's "calculus of variations and optimal control theory" but I'm not that far into the book and I don't know if skipping chapters is a good idea.

dmckee

I don't know of a good reference, but I'm pretty sure that just means that second derivatives have consistent signs over the region of interest. (That is certainly a sufficient condition for Legendre transforms.)

vzn

@dm__ yes have studied bells thm at length ~2 decades now. it might seem airtight and has stood the test of time over ½ century, but yet there is some fineprint/ loopholes that even phd physicists/ experts/ specialists are not all aware of. those who fervently believe like Bohm that no new physics will ever supercede QM are likely to be disappointed/ dashed, now or later...

oops lol typo ~~bohm~~ bohr

btw what is not widely appreciated either is that nonlocality can be an emergent property of a fairly simple classical system, it seems almost nobody has expanded this at length/ pushed it to its deepest extent. hint: harmonic oscillators + wave medium + coupling etc

Salvador Villarreal

2:26 AM

@dmckee then if I say that the functional is convex at some point "x" would require the second variation to have the same sign inside some open set containing "x"?

dm__

@vzn can you elaborate on said loopholes? proof seems pretty inarguable.

Salvador Villarreal

But I have seen that the convexity is associated to minimizers/maximizers of the functional, whereas the sign second variation is not a sufficient condition for that. That kind of makes me think that those concepts are not equivalent in the case of functionals...

vzn

@dm__ generally think sampling "bias" is not completely ruled out by existing experiments. some of this goes back to CHSH 1969. there is unquestioned reliance on this papers formulation by most subsequent experiments. am not saying its wrong, think only that theres very subtle loophole(s) in it that havent yet been widely discovered. there are many other refs to look into for someone extremely motivated/ ambitious (such individuals are rare). en.wikipedia.org/wiki/CHSH_inequality

see also en.wikipedia.org/wiki/Loopholes_in_Bell_test_experiments

dm__

@vzn the proof makes no unreasonable assumption, and is easy to follow. I fail to see any loopholes

vzn

@dm__ (lol doubt you clicked on any of those links.) exactly the same was said of von Neumanns proof. heard of it?

dm__

2:42 AM

@vzn yes, I clicked, and have seen the basis in local realism, and local realism is a box.

vzn

@dm__ there are conceptual boxes and rigorous mathematical boxes and massive effort is expended to align the two, and yet they dont always perfectly align (as thought/ intended).

dm__

if you give me a concrete logical flaw in Bell's proof, I'll be happy to discuss the ramifications

vzn

@dm__ it stands as a math proof ("based on certain assumptions"), have no objections. but its a thm aimed at physical reality. the translation into experiment requires extraordinary finesse, and the complex analysis starts with CHSH 1969. etc

Physics Meta

0

Q: Dealing with edited questions/answers

While it's not something usual, I've noticed that sometimes people edit my question or answer with a more complex notation or incorrect information/formulas. While I don't think this is done with malicious intent, it has sometimes confused people when I'm either asking or explaining something, as...

dm__

@vzn what do you make of the most recent (2015) experiments? "In 2015 the first three significant-loophole-free Bell-tests were published within three months by independent groups in Delft, Vienna and Boulder.

All three tests simultaneously addressed the detection loophole, the locality loophole, and the memory loophole. This makes them “loophole-free” in the sense that all remaining conceivable loopholes like superdeterminism require truly exotic hypotheses that might never get closed experimentally."

vzn

2:55 AM

@dm__ yes blogged on those. they are more airtight than previous experiments. but still seem based on CHSH. urge you to think deeply about CHSH in a way that physicists are not paying attention. ah, voila even wikipedia spells it out! amazing

> The CHSH paper lists many preconditions (or "reasonable and/or presumable assumptions") to derive the simplified theorem and formula. For example, for the method to be valid, it has to be assumed that the detected pairs are a fair sample of those emitted. In actual experiments, detectors are never 100% efficient, so that only a sample of the emitted pairs are detected.
> A subtle, related requirement is that the hidden variables do not influence or determine detection probability in a way that would lead to different samples at each arm of the experiment.

↑ suspect entire general LHV theory of QM lurks in these loophole(s)! there has been very little attn focused in this area... :o

how about this for a radical idea? the hidden variables determine the probability of detection...! :o o_O

dm__

@vzn honest question, would there ever be an experiment that would fundamentally rule out nonlocality to you? and if so, what would that be? what would fundamentally show, in your opinion, that the universe is inherently local?

vzn

@dm__ my feeling is that something more can be milked out of bell experiments that has not been revealed so far. suppose that one could experimentally control the degree of violation, wouldnt that be extraordinary? and theoretically problematic? my feeling/ suspicion is that must be the case. it seems to relate to detector efficiency maybe. but anyway, do believe that nonlocality can be found in classical systems as an emergent property as stated...

dm__

if we go into detector efficiency, there is no end to that hole. and my beliefs have no weight. my suspicion is screaming absolutely not, as the classical is emergent from the quantum, not the other way around

vzn

its more than a belief, think it has been proven by La Cour Ott 2015 phys.org/news/2015-05-quantum-emulated-classical.html

@dm__ your suspicion is also perfectly aligned with conventional wisdom (bordering on crystallized dogma), so congratulations on that :P

dm__

3:11 AM

@vzn have remained civil, but you are being quite immature and condescending. I'd urge you to put aside the human perspective and not insist that physical reality align with what you expect it to be. all the best

vzn

@dm__ ?!? no condescension intended...? am striving to be accurate with my words... you say your "beliefs have no weight," but your beliefs are essentially perfectly aligned with the establishment view...

Secret

Speaking about physical reality...:

Last night dream, introduced a strange reference frame based disease called Forced motion blindness. It is a strange eye disease where the lens is such that to the patient, anything stationary wrt the floor is moving forward in a certain direction, causing them have to keep walking to catch up with them. At the same time, the normal person think they are stationary wrt to floor. The result of this discrepancy is the patient kept bumping to the normal person. In order to not bump, the person has to walk at the apparent velocity as seen by the patient. The only known way to cure it is to remo…

And to make things even more confusing:

Such disease is never possible in real life, for it involves two incompatible realities to coexist and coinfluence in a pluralistic fashion. In particular, as seen by those not having the disease, the patient kept ran into the back of the normal person, but to the patient, he never ran into him and is walking normally

It seems my mind has gone f88888 up enough to envision two realities that with fundamentally incompatible observations, influencing each other in a consistent fashion

It seems my mind is getting more and more comfortable with dialetheia now

vzn

4:04 AM

"dialetheia" huh? reminds me of "nonduality" or "nondualism" plato.stanford.edu/entries/dialetheism/#DialEastAsiaPhil en.wikipedia.org/wiki/Nondualism

PM 2Ring

4:18 AM

The Planck force guy is at it again... physics.stackexchange.com/a/467751/123208

@vzn There's blatant nonlocality in Newtonian mechanics: gravity acts instantaneously. Eg, the force vector attracting the Earth to the Sun points to where the Sun is now, not where it was 500 seconds ago.

PM 2Ring

4:33 AM

@Blue ASCII is a 7 bit encoding, so it can encode a maximum of 128 characters, but 32 of those codes are control codes, like line feed, carriage return, tab, etc. OTOH, there are various 8 bit encodings known as "extended ASCII", that have more characters. There are quite a few 8 bit encodings that are supersets of ASCII, so I'm wary of any encoding touted to be "the" extended ASCII.

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