Talk:Double-slit experiment/Archive 3

message: This is a request for YOU:  Please read #29 "Questions about the double slit experiement", and, if you are able to do so, provide a commentary. God bless you. Honeychurch 09:38, 7 November 2007 (UTC)
thread_title:  Special Request 

message: "However these experiments performed with detectors are dubious because we do not find, know design and working of these detectors." What does the italicized portion mean?
"There is no reliable source to verify that these detectors do not mess up path and properties of electrons and photons involved in experiments." Is this encyclopedic language? 212.179.210.204 04:12, 18 October 2007 (UTC)
replies: text: I agree--these lines are vague and not encyclopedic-sounding.  What the hell does it mean to say that we don't know the design and working of the detectors?  Obviously SOMEONE does, because someone built them. I'm assuming they weren't gifts given to us by little green men. --Lode Runner 23:36, 23 October 2007 (UTC)
thread_title:  What does this mean 

message: The article cites as fact Rothman's doubt that Young actually carried out his experiment, spending a considerable amount of time on that issue.  It would be helpful to know who else doubts it besides those who accept Rothman on blind faith.  Repeating isolated theories as fact runs the risk of filling Wikipedia up with half-truths shouted at full volume.  One could then sympathize with the man who wanted to charge $10 per printed Wikipedia article, who when confronted with the statement in Wikipedia that it is free replied, "You believe everything you read in Wikipedia?"
If Rothman is right about the experiment not having been performed, we would have the interesting situation of someone who, in a culture totally wedded to the corpuscular theory of light, guesses its wavelength and then describes a gedankenexperiment that if carried out would demonstrate quantitatively the wave nature of light.  To accomplish this without actually doing the slit experiment, he or an accomplice would either have had to carry out some other experiment yielding that information involving for example Newton's rings (in which case why would he not report that experiment instead?), or be visited by a time traveler from the future.   --Vaughan Pratt 23:48, 22 July 2007 (UTC)
replies: text: Yeah, I'm not really sure why it's such a big deal for a scientist to reuse explanatory diagrams.  That seems to be the foundation of the entire suspicion.  — Laura Scudder ☎ 14:04, 23 July 2007 (UTC)
replies: text: It seems that this problem was disposed of long ago. P0M (talk) 07:29, 23 November 2007 (UTC)
thread_title: Doubting Rothman

message: I'm surprised that no one has mentioned this earlier, but the following statement in the article I would claim is not true:
The Copenhagen interpretation posits the existence of probability waves which describe the likelihood of finding the particle at a given location. Until the particle is detected at any location along this probability wave, it effectively exists at every point.
Given that the Copenhagen interpretation is the primary explanation given in most physics courses, I have never encountered any explanation regarding the existence of a particle at every point due to the wave-function changing in time.  Based on the copenhagen interpretation, we could claim that the probability distribution changes in time giving us the knowledge of where the particle is most likely at, but I do not think we can claim that the particle exists at all points at once... this would contradict the idea of the probability distribution.  Any thoughts on this? —The preceding unsigned comment was added by 71.117.4.108 (talk) 22:50, 16 April 2007 (UTC)
replies: text: I think I've fixed this problem. Have a look. P0M (talk) 07:27, 23 November 2007 (UTC)
thread_title:  Improper use of copenhagen interpretation? 

message: What is the scientific consensus on El Naschie's theory of fractal spacetime?
El Naschie says the theory explains the results of the double-slit experiment.
--70.130.45.233 09:38, 21 September 2007 (UTC)
thread_title:  fractal spacetime 

message: Single electron double slit experiment produce interference
pattern even though radio waves are present in room. But it is said
that it is not possible to detect through which slit electron entered.
Why don't they fix simple radiowave motion detector in one slit? The
electron will break radiowave signal triggering alarm and we will know
through which slit electron entered.
We can fix separate motion sensors in both slits and we can arrange second alarm with different sound.  —Preceding unsigned comment added by 6E656F (talk • contribs) 10:12, 6 October 2007 (UTC)
replies: text: I don't think there is any question that electrons could be detected. Whether there is a detector at one slit or at both slits does not really matter. It's a spooky way of talking about things, perhaps, but if something exists that leaves a sign of a particle having passed one way or the other, then interference will not occur. It's not that physicists have contrived some odd way that they think the universe ought to work, but that the universe works in certain ways and those workings drive the formulations that sound so improbable that people try to think of ways around them.  If people could detect the presence of an electron in such a way as to indicate that it had come out of one slit or the other and interference still occurred, then that result would be big news. Your idea sounds like it would be easy to put into practice in the real world. Probably people have already done it. The experiments are probably on record somewhere, but the news value would be something like, "Female collie gives birth to five pups." It would be a small town's second newspaper that would bother to publish such news.  P0M (talk) 07:20, 23 November 2007 (UTC)
thread_title:  Electron Motion sensors to detect 'which-way' info. 

message: The last chapter of the Scott Adams book The Dilbert Future mentions (page 231) a variation of the double slit experiment that goes something like this:
Detectors are put in place, with the familiar result. Then, the detectors are programmed to automatically delete the recorded data the moment after it's recorded, so that no one gets a chance to see it--the post-event act of data deletion supposedly altered the pattern the photons left. The self-purging detectors caused the photons to leave the same pattern as if there were no detectors at all.
I remain sceptical, because Adams freely admitted that he was explaining it all from memory and had probably gotten some things wrong, but if anyone can confirm that this variation of the experiment has actually been performed I think it definitely merits mention.  If the experiment took place like Adams described, I think it would without a doubt support the (currently pretty shaky and pseudoscientific) consciousness causes collapse concept.  If, on the other hand, Adams was mistaken and such an experiment never took place, then we can mention that in the book's article. --Lode Runner 09:47, 23 October 2007 (UTC)
replies: text: creepy  —Preceding unsigned comment added by 68.106.248.211 (talk) 10:31, 1 November 2007 (UTC)
replies: text: This is "quantum eraser" stuff. It is very interesting. It reminds me of the experiments that show that when a time frame in chosen in which there are two maxima and one minima, and an interference effect can occur wheneven the maxima is there -- but you can't tell whether it is the earlier or the later maximum that is involved in the real-world phenomenon under observation.  It's hard for me to digest this stuff because I almost have to write out a script with notes to myself about what we measure and what we know in all aspects of the experiment and at all times in one run of the experiment.  It is very easy for me to let in some assumption from the macro world.  I'm looking for clear accounts, accounts that will help me avoid stupid mistakes. Of course if anyone wants to write such an clear account and supply citations then I won't need to do the work, and there is less chance that I will make a mistake. I'm starting to wish for half-silvered mirrors, etc. P0M (talk) 07:44, 23 November 2007 (UTC)
thread_title:  A rumored variation of this experiment  

message: Just a quick note as to why I've tagged this article for cleanup and reference improvement.  Large sections of this article are written less like an encyclopedic entry and more like a textbook--inline questions, enthusiastic descriptions of the experiments, and so on.  Tidying up these sections should take care of the style issues.
The references tag should be pretty self-explanatory; six references in an article (with three whole sections having no references at all) of this importance is simply not enough.  Given the relatively wide appeal of this experiment, the number of times it has been repeated, and the speculation it invites, I would imagine that a veritable cornucopia of references could be found.
I'll do my part once I get a shot, but I just wanted to put down the specific issues I saw to help ensure these improvements get made. --jonny-mt(t)(c) 09:21, 31 October 2007 (UTC)
replies: text: I've asked this editor to give indications of what things still seem to require citations. So far nothing has been done. Is there still any reason to post a wolf ticket at the top of the article? P0M (talk) 01:31, 21 November 2007 (UTC)
thread_title:  A note on the templates 

message: I have just wiped out the nonsense about "a single band" being produced by one slit. Strangely, even Sears made the same mistake in his Optics although his own photograph show otherwise. Anyway, wrong is wrong and lots of places have the right information.  I will tuck in some of the references I have found when I get a little more time. I made my own photos of both the single and double slit results from the same basic apparatus, which gives the reader what one really will see when the experiment is done. The photos in Sears are better, but they are copyrighted. My equipment cost a couple dollars. I suspect that his equipment cost a bit more. P0M 04:15, 6 November 2007 (UTC)
thread_title:  Beginning to respond to the templates and critique 

message: The paragraph that starts
A remarkable result follows from a variation of the double-slit experiment
Are there any citations to back this idea up?  If one photon can go through two slits at the same time, what happens if two photons arrive at those two slits at the same time? At the same time? How does anyone know which instances of transit through the two slits occur at exactly the same time?  And if one photon goes through two slits anyway, isn't it going to interact with itself regardless of what any other photon does? What would be predicted if two photons were entangled and one or both of them went through a detector that absorbed and re-emitted it? How else would one get two photons known to be temporally matched? P0M 06:35, 6 November 2007 (UTC)
thread_title:  problematical content 

message: The article says:
In case two pinholes are used instead of slits, as in the original Young's experiment, hyperbolic fringes are observed. This is because the difference in paths travelled by the light from the two sources is a constant for a fringe which is the property of a hyperbola.
Does a hyperpobola have a property?  Maybe, although I do not believe that mathematicians ordinarily speak of a definition that corresponds to the word "hyperbole" and maybe the lines that can be drawn on the basis of such a definition.  And is the property supposed to be a fringe or a constant? The syntax is totally bonkers. Can somebody rewrite it so that it is a statement that is true or false? That would be a start. P0M 06:16, 12 November 2007 (UTC)
thread_title:  A sentence that does not make sense. 

message: Is anybody else monitoring this article? The request for more citations, etc., was very vague. Perhaps someone would like citations regarding specific issues. Please provide such notices.
Right now the article probably is suffering from its own lack of coherence. It is difficult to change things one by one without creating problems of repetition or even inconsistency. P0M (talk) 06:25, 23 November 2007 (UTC)
thread_title:  present state of the article 

message: Is it possible to reference figures exactly rather than by "in the graph below", "The second drawing", "third drawing" or "the second photograph above)"?  Of course, someone would have to label the figures as 1, 2, 3 first.  CowardX10 (talk) 00:32, 30 October 2008 (UTC)
thread_title:  reference to figures and graphs