
	Where results make sense

Topic: Bell test loopholes

Related Topics

Quantum mechanics

Timeline of quantum mechanics, molecular physics, atomic physics, nuclear physics, and particle physics

In the News (Tue 29 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Bell's Theorem (Stanford Encyclopedia of Philosophy)
		Bell suggests that C should consist only of propositions concerning particle 1, for otherwise the outcome of the measurement upon 1 will depend upon what operations are performed upon a remote particle 2, and that would be non-locality.
		The detection loophole could in principle be blocked by a test of the BCHSH Inequality provided that the detectors for the 1 and 2 particles were sufficiently efficient and that there were a reliable way of determining how many pairs impinge upon the analyzer-detector assemblies.
		This is the “communication loophole” in the early Bell tests.
	plato.stanford.edu /entries/bell-theorem (12693 words)

	Bell test experiments
		Bell test experiments is one of the topics in focus at Global Oneness.
		Bell's inequalities are tested by "coincidence counts" from a Bell test experiment such as the optical one shown in the diagram.
		Bell test experiments to date overwhelmingly suggest that Bell's inequality is violated.
	www.experiencefestival.com /bell_test_experiments (1195 words)

	Loopholes in optical Bell test experiments (Site not responding. Last check: 2007-10-13)
		The "fair sampling" (alias "detection", "efficiency" or "variable detection probability") loophole is, at least among professionals, a well known problem in tests of Bell's theorem, but in real experiments there are several other possibilities that make "local realist" explanations of Bell test violations possible.
		There is more than one "Bell test", the ones used in practice being the CHSH, CH74 and "visibility" tests and ones related to these.
		A loophole that is notably absent from the above section is the so-called “locality” or “light-cone” one, whereby some unspecified mechanism is taken as conveying additional information between the two detectors so as to increase their correlation above the classical limit.
	www.danceage.com /biography/sdmc_Bell_test_loopholes (1256 words)

	FQXi: Foundational Questions in Physics & Cosmology (Site not responding. Last check: 2007-10-13)
		In 1964, John Bell discovered that not only did the quantum mechanical phenomenon of entanglement violate local realism, an experiment could be performed which would rule out all local realistic theories.
		Now, due to recent advances in the science of creating and detecting entanglement, it may finally be possible to perform a completely "loophole-free" test of Bell's theory.
		We propose to perform this test and - 70 years after it was proposed - to unambiguously resolve the EPR paradox.
	www.fqxi.org /aw-kwiat.html (135 words)

	Clauser and Horne's 1974 Bell test - Wikipedia, the free encyclopedia
		Their intended use is to test quantum mechanics (QM) as against "local realism" or "local hidden variable theories", testing experimentally for quantum entanglement, a feature of quantum mechanics that had bothered Einstein and others right from the early days of the theory.
		The two-channel test does not require Bell's assumption about parallel detectors, though it does (in the currently-used form) need the fair sampling assumption and is consequently vulnerable to the "fair sampling loophole".
		The CH74 and related tests were used in all Bell test experiments of the 1970s and some later ones, notably two of Alain Aspect's (Aspect, 1981, 1982b).
	en.wikipedia.org /wiki/Clauser_and_Horne's_1974_Bell_test (1646 words)

	Bell test experiments - Wikipedia, the free encyclopedia
		The only theoretical assumption (other than Bell's basic ones of the existence of local hidden variables) that has been made in deriving (3) is that when a polariser is inserted the probability of detection of any given photon is never increased: there is "no enhancement".
		One of the main achievements of this new branch of physics is showing that violation of Bell's inequalities leads to the possibility of a secure information transfer, which utilizes the so-called quantum cryptography (involving entangled states of pairs of particles).
		The second was the first application of the CHSH inequality, the third the famous one (originally suggested by John Bell) in which the choice between the two settings on each side was made during the flight of the photons.
	en.wikipedia.org /wiki/Bell_test_experiments (1594 words)

	Bell test loopholes (was Quantum effects of Gravity measured)
		Bell test loopholes (was Quantum effects of Gravity measured)
		The only thing that matters if one applies the rigorous test that Bell originally intended is that the detection events should depend only on factors pertaining to their own location.
		In practice, the rigorous test was not applied (it never is!) and so the experiment can be explained by local realist models that exploit the loopholes in the test.
	www.lns.cornell.edu /spr/2002-02/msg0039575.html (585 words)

	USATODAY.com - NFL drug program called flawed (Site not responding. Last check: 2007-10-13)
		Loopholes in the NFL's steroids program are under fire in light of allegations that three Carolina Panthers players received prescriptions for banned substances within two weeks of playing in Super Bowl XXXVIII in 2004 but were never found to violate league policy.
		The league, which has tested for steroids since 1989, doesn't have a test for human growth hormone, which experts say can be used in combination with the hard-to-detect cream for a performance-enhancing boost.
		The NFL staunchly defends its random and reasonable cause testing, agreed upon in collective bargaining with its players union, although it acknowledges a need for continued improvement as new substances and masking agents are developed.
	www.usatoday.com /sports/football/nfl/2005-03-30-drug-testing_x.htm (476 words)

	More Bell test loopholes (was Quantum effects of Gravity measured)
		Correlations between successive hidden variable values do not matter, so long as the total distribution is uniform (if you are applying a test that depends on this!).
		There is more than one Bell test and they don't all require the same assumptions.
		There are several more loopholes than most people are aware of.
	www.lns.cornell.edu /spr/2002-02/msg0039637.html (385 words)

	Experimental violation of a Bell's inequality with efficient detection : Nature
		The first might be termed the locality or 'lightcone' loophole, in which the correlations of apparently separate events could result from unknown subluminal signals propagating between different regions of the apparatus.
		Clauser, J. and Shimony, A. Bell's theorem: experimental tests and implications.
		Lamehi-Rachti, M. and Mittig, W. Quantum mechanics and hidden variables: a test of Bell's inequality by the measurement of the spin correlation in low-energy proton-proton scattering.
	www.nature.com /nature/journal/v409/n6822/full/409791a0.html (2992 words)

	Study Guide for PHA Exam 4
		In 1964, John Stewart Bell published a theorem (Bell's Interconnected Principle) based on Bohm's ideas on a clear way to test a wide variety of HV theories.
		Bell made only two basic assumptions (both of which EPR would have insisted upon): 1.
		Experiments have now been done and, despite possible far-fetched loopholes, seem to indicate that QM without HVs is correct, and that either one or both of the assumptions must be wrong and so must be abandoned.
	www.uark.edu /depts/physics/classes/pha/studyguide4.html (3374 words)

	Introduction to EPR
		My very first paper on the "Bell tests"-- tests designed to check the EPR challenge -- is published as The Chaotic Ball (see updated version, October 2002).
		The best proof I know for the test actually used in two out of Alain Aspect's three experiments is included as an appendix to my paper on the subtraction of accidentals, quant-ph/9903066.
		The tests had to be modified because in all real experiments it is known that detectors have low "efficiencies".
	freespace.virgin.net /ch.thompson1/intro.htm (656 words)

	FT.com / World / UK - New pension rules create IHT loophole (Site not responding. Last check: 2007-10-13)
		Andy Bell, managing director of AJ Bell, the pensions provider, said: "There are a number of loopholes in the new regulation and the industry is working with the Revenue to get rid of them.
		The group said it had provided high estimates to the Treasury to test whether the government was committed to allowing residential property to be put into pension plans.
		Yesterday, Mr Bell said: "I am deeply disappointed that the group is exploiting the loophole rather than working with the government to ensure a stable pension regime."
	www.ft.com /cms/s/b7eb9640-e21c-11da-bf4c-0000779e2340.html (570 words)

	An effective test of Bell's inequality
		Bell's inequality is important because it shows that quantum mechanics predicts macroscopic violations of locality.
		For this change to be sufficient to violate Bell's inequality requires that information about at least one (we cannot tell which one) polarizer setting influenced the more distant detector.
		Any attempt to enumerate and eliminate all loopholes is insufficient because one can never figure out all the ways that nature might out fox you.
	www.mtnmath.com /book/node83.html (702 words)

	Quantum Nocality - Cramer
		Bell, following the lead of Bohm, had based his calculations not on measurements of position and momentum, the focus of Einstein's arguments, but on measurements of the states of polarization of photons of light.
		The assumption made by Bell that had been put to the test, therefore, was the assumption of locality, not the assumption of hidden variables.
		So far, these tests have all been negative, indicating that any non-linearities in the quantum formalism are extremely small, if they exist at all.
	www.npl.washington.edu /npl/int_rep/qm_nl.html (2861 words)

	INI : Abstracts : QISW01 : Proposal for a loophole-free Bell test using homodyne detection (Site not responding. Last check: 2007-10-13)
		The EPR argument gained a renewed attention in 1964 when John Bell derived his famous inequalities, which must be satisfied within the framework of any local realistic theory.
		So far, however, all these tests suffered from "loopholes" allowing a local realistic explanation of experimental observations by exploiting either the low detector efficiency or the time-like interval between the two detection events.
		A Bell violation exceeding 1% is achievable for a 6dB squeezed light source using single-photon detectors with an efficiency as low as 10%, provided that the homodyning efficiency lies around 95%.
	www.newton.cam.ac.uk /programmes/QIS/Abstract1/cerf.html (270 words)

	Chris Bell \| Texas Democratic Party (Site not responding. Last check: 2007-10-13)
		Bell, a former Houston councilman and former Congressman, promised to end what he called “high -stakes testing” of the Texas Assessment of Knowledge and Skills (TAKS) and give teachers more decision-making in determining if kids should advance from one grade to the next.
		Bell said he has no problems in making the TAKS into a diagnostic test that would “provide a snapshot of how our kids are doing up against their peers,” but that the “high-stakes nature of the testing must cease.”
		Bell said in his travels across the state he has been warmly received in red areas and cities.
	www.txdemocrats.org /taxonomy/term/44 (1108 words)

	LSP:Quantum Optics
		The project is pursued in collaboration with colleagues in the Service for Physics of Materials and Microstructures of the CEA Grenoble.
		’s theorem even more convincing by designing experiments that close the remaining “loopholes” or that exhibit the contradiction between the predictions of local hidden variables and physical reality in a particularly striking way.
		Robust long-distance entanglement and a loophole-free Bell test with ions and photons, Phys.
	www-lsp.ujf-grenoble.fr /eng/recherche/a1t4/a1t4a3/theory.htm (482 words)

	MIND Exchange
		The "loopholes" that they know are present are large enough to allow for perfectly straightforward explanations, with no sign of "non-locality".
		The bell tests have their own known loopholes, and can entirely be explained by local realist models.
		In testing this model I have implemented a series of experiments using spontaneous gamma-rays from either 109Cd or 57Co, whereby a primary gamma-ray is split and detected in coincidence in two detectors.
	www.kurzweilai.net /mindx/show_thread.php?rootID=50041 (4012 words)

	Colloquium Abstract (Site not responding. Last check: 2007-10-13)
		Major progress was achieved by Bell in 1964, whose inequalities made clear that a test of quantum mechanics against its classical counterparts is feasible.
		However, a definitive new test of the strong Bell inequalities has never been performed.
		This experiment will close the loopholes associated with previous photon based experiments; these are the detection efficiency loophole and the enforcement of the locality condition.
	www.physics.ohio-state.edu /~kilcup/colloquium/walther.html (209 words)

	Bell's Theorem and Negative Probabilities
		The Bell Inequalities can be presented in many forms, and most are essentially equivalent.
		Note that X, Y and Z can be separately tested anywhere in the world at any time and you still end up with the same conclusion once you combine the results per h.
		The reason I prepared a new thread was to highlight the existence of negative propbabilities which result from Bell in the Realistic view.
	www.physicsforums.com /showthread.php?p=429597 (4642 words)

	SD7 - Chris Bell Message
		It is time to put principals and teachers back in control and provide them with the technology and equipment they need to keep kids interested and engaged.
		The Bell way would be to replace our broken franchise tax with a more equitable and broad-based business tax with far fewer loopholes, so that no single industry has to bear too great a burden.
		The Perry way is to let the businesses with the best lobbyists get away without paying their fair share while we pay high property taxes.
	web2.airmail.net /sgross/sd7/chris_bell_message.html (1138 words)

	Nina Bell - Northwest Environmental Advocates
		DS: This is Donna Sinclair from the Center for Columbia River History, today is April 21st 2000 and I'm interviewing Nina Bell of Northwest Environmental Advocates in Portland, Oregon.
		As a family we worked on trying to stop the Amchitka nuclear blast on Amchitka Island, nuclear testing, we were Greenpeace Seattle [laughs] at the very beginning, the four of us.
		Well, storm water controls are at the very beginning stages of development and implementation, I've been to meetings at the city where they're saying, "Well, we're trying these swales," or "We're trying this wetland treatment area," or "We're trying this thing over near this piece of freeway," or whatever.
	www.ccrh.org /comm/slough/oral/ninabell.htm (2561 words)

	"Presidential Aptitude Test" by Stephen Pomper and Nicholas Thompson
		Start with the loopholes: The tax code is riddled with subsidies that cost billions of dollars a year.
		The deal behind the Act was that Congress would close corporate loopholes worth tens of billions of dollars but give something back to the monied classes by lowering the top marginal tax rate to 28 percent, its lowest post-war level.
		In 1998 he proposed "The Senior Citizens' Freedom to Work Act" that would eliminate much of the limited means testing that there is in our current social security system: for every $3 that a senior citizen earns over $20,000, she loses $1 in social security benefits.
	www.washingtonmonthly.com /features/2000/0001.pomperthompson.html (8398 words)

	Comments to the Federal Reserve Board Regarding Proposed Changes to HOEPA
		This is a very weak standard and, we strongly urge the Board to use the "net tangible" test instead.
		But, it is really no more subjective than the test that the Board proposes as an exception to the rather meaningless limitation of refinancing within one year.
		The payday loan industry picked up on that and has convinced at least two judges that payday loans were not governed by the TILA before the compliance date.
	www.consumerlaw.org /initiatives/test_and_comm/comments_frb.shtml (11080 words)

	SYNOPTIC LINKS:
		Better yet, maybe it was all a test to see if you were sucker enough to believe Them when They told you Mundania was the end-all reality.
		Maybe They actually wanted you to pass the test and be liberated.
		Maybe it was a test designed to select only those humans who were smart enough to doubt and brave enough to try.
	www.fortunecity.com /victorian/mehetebell/41/harmyth2.htm (12335 words)

	Pacific Bell - Information (Site not responding. Last check: 2007-10-13)
		Bell Center is doton Center.png Location of Center, Wisconsin Center is 0.00 Islander U.S. Census Islander, Brian born December births Brian pt:Brian John Hatcher October John category:1904 deaths John category:American paleontologists John the Rock Signal sea.
		Bell was made Dr. appeared as, succeded Hugh and then assisted John died in Category:Bishops John Category:1556 deaths John Category:English prelates Bell, John, Northwest Ballet Washington National Bank Bank Northwest Bell, a Daniel Daniel Bell born 1919 past, Bell taught sociology time, was attacked that has lost Society Bell outlined a oriented.
		Monon is the The is a locomotive from the the was introduced Monon was introduced The has been the Bell.
	www.freewebs.com /information24/pacific-bell.html (295 words)

	Bibliography
		The whole theory behind their method of producing the light and their test for "non-classicality" (involving interpretation of distributions of homodyne detection voltage differences and negative Wigner densities) is highly suspect.
		In about 1980 the idea of using two-channel polarisers and the CHSH Bell test, abandoned in about 1970, was revived.
		The essay is in two parts, the first concerned with erroneous experimental "facts" in Modern Physics, drawing largely on material from Forgotten History and from my Bell test studies, the second introducing the key ideas of the Phi-Wave Aether as in Phi-waves and forces.
	freespace.virgin.net /ch.thompson1/bibliography.htm (1809 words)

Try your search on: Qwika (all wikis)