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	Afshar experiment - Wikipedia, the free encyclopedia
		Papers by Afshar on the experiment have been published in the American Institute of Physics and SPIE conference proceedings; however, as of May 4, 2006, neither a description of the experiment, nor any discussion of its theoretical interpretation, has been published in a refereed physics journal.
		Afshar's claim that his experiment invalidates the complementarity principle would have far-reaching implications for the understanding of quantum mechanics, potentially challenging the Copenhagen interpretation and according to John Cramer, the many-worlds interpretation of quantum mechanics.
		Afshar's conclusion is that the light exhibits a wave-like behavior when going through the wires, since the light goes through the spaces between the wires when both slits were open, but also exhibits a particle-like behavior after going through the lens, with photons going to a given photo-detector.
	en.wikipedia.org /wiki/Afshar_experiment (1820 words)

	Afshar experiment - One Language (Site not responding. Last check: 2007-10-10)
		Using his experiment it is possible to detect interference fringes even when observing the path of a photon stream, indicating that the wavefunction does not collapse.
		In this experiment, Afshar creates a setup similar to the double-slit experiment, where the light generated by a laser is passed through two closely spaced pinholes.
		Afshar's response, found in his FAQ (http://users.rowan.edu/~afshar/FAQ.htm), compares Unruh's experiment to one in which the wings are removed from an airplane.
	www.onelang.com /encyclopedia/index.php/Afshar_experiment (1752 words)

	Re: Afshar and interpretations
		Suppose we modify Afshar's experiment so that the wires are no longer placed exactly at the minima of the interference valleys, and we send photons through the slit one at a time, in each case noting where the photon was registered, either at a wire or at one of the detectors.
		Afshar seems to be arguing that "complementarity" would lead you to predict that the frequency the photon hits each wire should show no interference pattern, that it should be the same as the frequency you'd predict if you placed a detector next to each slit.
		Maybe one could think of the Afshar experiment as a limiting case, where you start off with many wires in a row and keep removing the ones closest to the interference peaks until all that's left are the wires exactly at the minima of the interference valleys.
	www.lns.cornell.edu /spr/2004-08/msg0062879.html (389 words)

	PhilSci Archive - Why the Afshar Experiment Does Not Refute Complementarity (Site not responding. Last check: 2007-10-10)
		It is also shown that the Afshar experiment is isomorphic in key respects to a spin one-half particle prepared as ``spin up along x'' and post-selected in a specific state of spin along z.
		The terminology ``which way'' or ``which-slit'' is critiqued; it is argued that this usage by both Afshar and his critics is misleading and has contributed to confusion surrounding the interpretation of the experiment.
		Nevertheless, it is concluded that Bohr would have had no more problem accounting for the Afshar result than he would in accounting for the aforementioned pre- and post-selection spin experiment, in which the particle's preparation state is confirmed by a nondestructive measurement prior to post-selection.
	philsci-archive.pitt.edu /archive/00002199 (306 words)

	Afshar experiment (Site not responding. Last check: 2007-10-10)
		Fig.1 Experiment without obstructing wire grid Since there is a one-to-one relationship between the images and the pinholes, a photon that goes through pinhole number one would be seen only by detector number one, and if it goes through pinhole two, it would be seen only by detector number two.
		Thus this experiment seems to contradict the Principle of complementarity, since it shows both complementary wave and particle characteristics in the same experiment, for the same photons.
		In http://arxiv.org/abs/quant-ph/0502021, it is argued that the right way to understand the Afshar experiment is in terms of the analogous spin-1/2 measurement situation, and that the term "which-way" is misleading.
	afshar-experiment.iqnaut.net (1738 words)

	Quantum Rebel-S. Afshar
		His experiment does not state how it is done, but the usual way is to shine the light from a light source through a small pinhole in front of the two pinholes.
		In my experiment the two paths 1 and 2 are the analog of the two pinholes, and that coherenence is ensured by the first of the half silvered mirrors.
		In Afshar's experiment, the wires are taken to be very thin and placed in the dark spaces of the interference pattern.
	axion.physics.ubc.ca /rebel.html (1783 words)

	Talk:Afshar experiment - Wikipedia, the free encyclopedia
		It is possibly that Afshar's experiment may be able to shed light on decoherence, and may even be able to distinguish between rival theories of decoherence.
		This experiment was designed to investigate a very peculiar result of the well known double slit experiment of quantum mechanics, the dual wave particle nature of light, and in fact all matter.
		In Afshar's experiment there are no observable interfenece patterns since the wavelet from a particular aperture is not emperically observed during interference (apart from the minimal loss to the wires).
	en.wikipedia.org /wiki/Talk:Afshar_experiment (15131 words)

	Afshar Experiment - RST Wiki (Site not responding. Last check: 2007-10-10)
		Shahriar S. Afshar has modified the well-known double slit experiment with results that may show that the long-held, quantum-mechanical doctrine of the so-called "superposition" of mutually exclusive states, whose ultimate resolution depends upon the act of observation, does not hold after all.
		If Afshar's experiment is eventually verified and accepted, it will greatly exacerbate the current state of affairs of modern theoretical physics that is already reeling from the effects of astronomical discoveries such as the unexplained forces of gravity and the unexpected Euclidian geometry of space.
		Already, critics are contending that the interference observed in Afshar's experiment mixes the two sources of light in the experiment and thus undermines any certain knowledge of which of the two photon paths a photon has taken.
	www.rstheory.com /wiki/index.php?title=Afshar_Experiment&printable=yes (406 words)

	Luboš Motl's reference frame: Violation of complementarity?
		Afshar's strategy is simply to arrange an experiment in which he argues that he can see a sharp interference pattern with V=1 (or at least, greater than 0.99), but he can also say which slit the photon chose (which means K=1).
		In Afshar's experiment the space-time region between the screen and lens would represent the situation before the state function reduction and the region between lens and detectors the situation after the state function reduction.
		Afshar measures angular momentum and angle (two conjugate variables.) The angular momentum here is that 'about' the center of the source, i.e., the actual AM is some crazy superposition of lots of l's.
	motls.blogspot.com /2004/11/violation-of-complementarity.html (9942 words)

	Afshar experiment - Art History Online Reference and Guide
		Using his experiment it is possible to detect interference fringes even when observing the path of a photon stream.
		Afshar's response, found in his FAQ, compares Unruh's experiment to one in which the wings are removed from an airplane.
		In [5], it is argued that the right way to understand the Afshar experiment is in terms of the analogous spin-1/2 measurement situation, and that the term "which-way" is misleading.
	www.arthistoryclub.com /art_history/Afshar_experiment (1764 words)

	afshar_experiment (Site not responding. Last check: 2007-10-10)
		SPIE 5866, 229-244 in July of 2005 [5].Afshar's claim that his experiment invalidates the complementarity principle would have far-reaching implications for the understanding of quantum mechanics, potentially challenging the Copenhagen interpretation and according to John Cramer, the many-worlds interpretation of quantum mechanics.
		Afshar's response [7] to their critiques was given in a response letter from Cramer published on August 21, 2004.
		Though Afshar's work is still the subject of ongoing interpretation and discussion, a significant portion of the scientific community is of the opinion that Afshar's experiment does not refute complementarity.
	www.travelawesomeplaces.com /wiki/?title=Afshar_experiment (1703 words)

	Rowan University - News & Happenings
		Afshar can tell what pinhole the particle goes through, and at the same time he can show that the particle?s path is affected by both pinholes.
		If the result of the experiment holds, it means that the standard theory of quantum mechanics is still incomplete, which was Einstein?s long-held view.
		In the experiment at Rowan, the team is using a single photon source instead of a beam.
	www.rowan.edu /news/display_article.cfm?ArticleID=965 (471 words)

	Kathryn Cramer: Shahriar S. Afshar: Quantum Rebel
		Afshar's claim seems to be that even though they knew which slit the photon went through, they still got interference, violating the principle of complementarity.
		The main problem with Afshar's interpretation, as I see it, is that the attempt to pick out which slit the photons went through comes AFTER they have had a chance to interfere with each other, at which point it is no longer possible to say with certainty which slit they came from.
		In fact, the classical two-path experiment itself makes it quite clear that performing a particle measurement after the interference has occurred does not somehow endow every point on the particle's path with a determinate position, because the final distribution of particles is emphatically not consistent with such a hypothesis.
	www.kathryncramer.com /wblog/archives/000674.html (6585 words)

	The Net Advance of Physics: (Site not responding. Last check: 2007-10-10)
		Afshar's Experiment to elucidate the interpretation of quantum mechanics:
		Complementarity and Afshar's experiment by Aurélian Drezet (2005/08) Denies that Afshar experiment undermines complementarity.
		Entanglement and quantum interference by Paul O'Hara (2006/09) Proposes a realist interpretation of the Afshar experiment.
	web.mit.edu /redingtn/www/netadv/Xafshar.html (91 words)

	Re: Afshar and interpretations
		The result is we > can detect both the particle like behaviour (detectors determine which > slit the particle went through) and the wave like behaviour (we place > barriers (wires) at where interference nodes would be and see no change > in the results).
		I'd hope the Copenhagen interpretation doesn't say this or it would contradict even the single photon two slit experiment.
		Afshar claims that because he has imaged the slits using a lens, he knows which slit each photon passes through.
	www.lns.cornell.edu /spr/2004-08/msg0062841.html (364 words)

	PhilSci Archive - The Afshar Two-Slit Experiment and Complementarity (Site not responding. Last check: 2007-10-10)
		It is shown that the Afshar experiment is isomorphic in key respects to a a spin one-half particle prepared as ``spin up along x'' and post-selected in a specific state of spin along z.
		The Afshar experiment is often dismissed on the basis that the wire grid acts as a "diffraction grating" which scatters photons.
		This author is in substantial agreement with Unruh's conclusions regarding the Afshar experiment.
	philsci-archive.pitt.edu /archive/00002187 (253 words)

	The Afshar Experiment: Farewell to Copenhagen?
		This experiment appears to be a confirmation of Kathryn's father, John Cramer's Transactional interpretation of quantum mechanics.
		In the double slit;it experiment, the probabilities are totally dependent on the photon's property distribution at the point of interaction with the screen, since the exact structure of the screen is unknown and it presents an equal opportunity for interaction with the various portions of the photon state distribution.
		Since the experiment has demonstrated, albeit indirectly, that interfernce is taking place during the experiment, then this implies that the wavefunction at each detector MUST contain components from both slits.
	www.kschroeder.com /blog/1083095035/index_html (1241 words)

	Afshar's experiment
		Afshar concludes from\nthis that when both pinholes are open all the light at one of the\ndetectors came only from it\'s associated pinhole, and all the light at\nthe other detector comes from the other pinhole.
		I suspect the two are equivalent apart from these conceptual\ndetails.\n\nandgt;In Afshar\'s experiment the light from the two pinholes is wavelike, it\nandgt;undergoes wavelike interference at the lens (in fact this interfernce\nandgt;occurs at every point between the pinholes and the detection screens)\nandgt;and is eventually detected at one of the detectors.
		Afshar seems to think that on\nandgt;detection the whole history of the particle collapses down to some\nandgt;classical trajectory.\n\nI doubt that from the article as he says its best explained optically.\nLight is a wave in optics and so has no particle-like qualities.\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease.
	www.physicsforums.com /showthread.php?t=36643&highlight=Afshar (6333 words)

	Official Afshar Experiment Blog Questions 2 :: Questions Welcome!
		Afshars experiment is conducted in such a manner that it is the setup of the experiment coupled with the conservation of momentum that allows us to know exactly which slit the photon has gone through.
		Afshar will not blame me that I have "cut the wings of the plane", because my critique is clear - he shows that there is "mixing of information" by detectors 1 and 2 about slits A and B and says that this "mixing" is 10^-6, but this is major loophole.
		F^-1 is seen in Afshar experiment, because the image plane is 0.38 m behind the focal plane, so I expect higher order diffraction maxima, while the "classical scenario" CANNOT predict these outer maxima, but just expects enlargement of the central Airy discs.
	irims.org /blog/index.php/2005/03/13/questions_welcome_1 (12880 words)

	Afshar 2 slit experiment--peer review
		I had a question about Afshar's experiment : a lens is a momentum analyzer, it is a device that serves to measure impulsion.
		It seems that the claims that Copenhagen and MWI are disproved and TI is confirmed came originally from Cramer instead of Afshar.
		The Afshar experiment more or less assumes its interpretation as being acceptable without giving too much weight to the opposition view.
	www.physicsforums.com /showthread.php?t=62460&page=2 (1280 words)

	APS - 2006 APS March Meeting - Event - The Afshar Experiment and Complementarity (Site not responding. Last check: 2007-10-10)
		Abstract: D40.00011 : The Afshar Experiment and Complementarity
		It is also shown that the Afshar experiment is isomorphic in key respects to a spin one-half particle prepared as ``spin up along x'' and post- selected in a specific state of spin along z.
		Nevertheless, it is concluded that Bohr would have had no more problem accounting for the Afshar result than he would in accounting for the aforementioned pre- and post- selection spin experiment, in which the particle's preparation state is confirmed by a nondestructive measurement prior to post-selection.
	meetings.aps.org /Meeting/MAR06/Event/40525 (235 words)

	Afshar Experiment - Advanced Physics Forums (Site not responding. Last check: 2007-10-10)
		Not according to the recent experiment by Prof.
		Im not sure but this experiment claims to violate complementarity, showing that though we are detecting which hole the electron is coming through, interference also occurs.
		But I dont see how this violates anything bcos, we know which hole the electron comes through only after the image is formed at the detector.
	www.advancedphysics.org /forum/showthread.php?t=1300 (428 words)

	Official Afshar Experiment Blog Questions 1
		Official Afshar Experiment Blog Questions 1 Official Afshar Experiment Blog Questions 2
		0) For a brief description of the experiment please visit http://en.wikipedia.org/wiki/Afshar_experiment.
		2) If you are writing a paper on my experiment, you can use http://www.irims.org/quant-ph/030503/ as a permanent reference for my pedagogical paper that contains the experimental details as well as most of the theoretical arguments.
	www.irims.org /blog/index.php/questions (509 words)

	[extropy-chat] more on Afshar Experiment, as of 7 weeks ago (Site not responding. Last check: 2007-10-10)
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		--- BillK wrote: > On Sun, 19 Sep 2004 14:31:38 -0500, Damien Broderick wrote: > > > > > > July 29, 2004 > > > > Afshar Experiment for a Single Photon > > > > It seems that Afshar is still unpublished and formal peer-review has > not happened yet.
	lists.extropy.org /pipermail/extropy-chat/2004-September/008939.html (268 words)

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