Slit Definition and 1000 Threads

  1. P

    Can double slit interference be explained by the influence of previous photons?

    The usual interpretation of the double slit experiment, when done with a single photon at a time, is that the photon must interfere with itself. However interference cannot be measured in a single-photon experiment - it requires a large number of photons to manifest a discernible interference...
  2. C

    Double slit experiment violates triangle inequality?

    Imagine a light source, double-slit, and a curved screen in vacuum, shaped so that all parts of the interference pattern are created simultaneously. Define distance as proportional to the time light requires to reach a point. Detectors at each slit can be operating or not. Call the source S...
  3. A

    Can Light Exhibit the Same Interference Pattern as Water Waves?

    Hello Lets make a few double slit experiments. Lets say we have water pond with a set of point size emitters on the left and a set of independent wave energy detectors on the right side. http://img560.imageshack.us/img560/571/slits1.png Now let each point emitter emits wave but with big...
  4. D

    Will My Double Slit Experiment Setup Using an Electron Gun Work?

    For my AP Physics course, I am trying to replicate the double slit experiment. My idea is to have a cathode ray tube from an old television set and take the electron gun out. The electron gun will be firing at a plastic or foil sheet with 2 narrow slits side-by-side. Behind the screen, I will...
  5. S

    Dual particle and dual double slit interference

    In short the question I am trying to answer is: 1. do the "waves-functions" from separate particle interfere? 2. do the Schrodinger equations predict the interference pattern caused by the interference of the "wave functions" of two separate particles? The above question is...
  6. T

    Why do light form an interference pattern when passing through only one slit?

    Hi guys, i know that if we were to have one water wave passing through two slit, an interference pattern would be form. However, i am still unclear of the kind of the pattern that will be form when a single water wave were to pass through a single slit. Will it form an interference pattern too...
  7. F

    Is a slit automatically also a detector?

    Suppose you're shooting electrons one at a time through a double-slit experiment. If we don't detect which slit an electron enters, you get a fringe pattern on the screen beyond the slits. If you detect which slit the electrons go through, then the fringe pattern is lost. However, wouldn't...
  8. F

    Determine the slit-with and slit-distance of a double slit laser diffraction

    Parallel laser light with wavelength 633 nm are incident perpendicular against a double slit. 2.50 m behind the double slit is a screen where the pattern can be seen (link below). Determine with the help of the figure the slit-with and slit-distance...
  9. S

    Why cant a particle go through one slit but behave as if it went through both?

    In all my reading on the dual slit experiment the idea that the particle went through a single slit is never even considered and yet I don't see any reason why this idea should be discounted. If an atom can decide to be in two places at the same time in order to give a certain result then it...
  10. jaumzaum

    Feymman's theory, double slit experiment - Stephen Hawking

    Hi all, I was studying Stephen Hawking's new book (very good, by the way). He was explainning Feymann's theory, that says a particle travels by all the ways possible to reach a given point. So single particles CAN have interference by themselves. Then he explain why, in the double slit...
  11. S

    Double slit confusion from observed particle dynamics.

    Hey Guys, I continue to get mixed messages about the nature of electron behaviour during the double slit experiment. I have heard the term observation used to describe an interaction with the electron (Obviously necessitating a change in it's behaviour to facilitate the ballistic outcome)...
  12. F

    Understanding the triple slit experiment

    I have been contemplating Sinha's 2010 triple slit experiment, and wondering about its meaning and implications. If I understand the results correctly, if we take the detections that we get when all three slits are open, and subtract them from the detections that we would get with the...
  13. F

    A question about the double slit experiment

    Just a thought. In the double slit experiment, is it possible that the particles don't actually interfere with themselves, but rather they encounter interference from all the other particles which either already have been, or subsequently will be sent through the experiment. After all, for the...
  14. L

    Youngs double slit experiment.

    can someone tell me the relation between the intensities (of a bright band and a dark band) and the amplitudes of the interfering waves ?
  15. C

    Double slit experiment with electrons

    In the double-slit experiment, without which-path information available, the diffraction pattern is usually shown as an even function with respect to the displacement from the midpoint of the slits: something like sin ay / y. (This is the case in Feynman's lectures, and many others.) The...
  16. menniandscience

    2 slit experiment, what happen with 3,4,5 ?

    it's all in the question, but i'll elaborate o:) the scientists shot one photon each time and discover it moves through both slits, i want to know, does the photon "divide" to countless particles or just 2? do the scientists tried the experiment with more than 2 slits? thanks :smile:
  17. J

    The Double Slit Experiment Blows My Mind

    This is seriously the most amazing thing ever. Pretty cheesy experiment, but amazing results. It still makes no sense to me how an observer completely changes the outcome. Its like the electron has a mind!
  18. B

    Working on a movie and have a question on observer and double slit experiment

    Is it safe to conclude from the double slit experiment that the observer actually affects what is being observed? I ask with regards to a project I'm writing which I wish to be scientifically accurate.
  19. S

    Exploring the 2 Slit Experiment: Particle Deflections and Gravity's Role

    2 slit, double slit, two slit I saw a previous topic where someone asked if anyone has tried the 2 slit experiment with bigger objects (not Bucky balls) like sand or golf balls, but it seems not? I wondered if the diffraction patterns could simply be a result of the particles deflecting off...
  20. I

    Variations of double slit experiment

    Hi, Have there been done variations of double slit experiment, particularly I'm interested in following scenarios: 1. Three slits instead of 2. (Would expect the same behaviour of wave interference) 2. An observer is installed at one of the three slits. (Again, wave interference should be...
  21. N

    Why Does Young's Double Slit Experiment Use n + 1/2 Instead of m - 1/2?

    Homework Statement Is this wrong or right? PLZ.The Attempt at a Solution http://www.kentshillphysics.net/optics36.gif I have a test tomorrow buy my teacher said it's m - 1/2 Why does it say n + 1/2 everywhere. >_<
  22. S

    Double slit experiment at home

    I just saw a video explanation about the double slit experiment , and how an electron behaves as wave / particle according to if it is observed or not. I am more intrigued to see in action how an electron will behave as a particle when consciously observed and as a wave function when it is...
  23. K

    Double slit interference with single pencil lead?

    Hi guys, Was trying out a home made double slit experiment as I've seen on youtube with a laser pointer and 2 pieces of pencil lead. Then I realized that I can obtain the same interference pattern with the single pencil lead. Is this equivalent to a double slit interference?
  24. F

    Dark Matter Galaxy Collision Galactic Double Slit Test

    I'm becoming more and more convinced that light isn't the only particle that can interfere with itself, and that the behavior may instead be a function of a particle's level of interaction. The multi-galaxy collision we witnessed not long ago may have been the first time we've had the scale...
  25. F

    Young's double slit experiment: reconciling facts and theory

    I've read in many places that if, in a Young's double slit experiment, you can determine by whatever method through which slit your photon goes through (enhancing the "particle" behavior of light), then the interference pattern dissapears. For this reason Zeilinger says that entangled photons...
  26. A

    Frightening Double Slit Experiment Interpretation

    I noticed a youtube video, where Thomas Warren Campbell, a physicist and author of the book trilogy My big TOE the last standing for Theory of Everything and apparently he also works for NASA, deducts some very disturbing things from a certain double slit experiment. Here it is, I marked the...
  27. P

    What Happens During the Double Slit Experiment in Quantum Mechanics?

    This is more a conceptual question, but after watching several videos about Quantum Mechanics, I noticed a little discrepancy about an explanation of the double slit experiment and it's implications. According to one video, the electron fired traveled through both slits at the "same time as...
  28. S

    Intensity and the Double Slit Experiment.

    In viewing a derivation of the formula describing the intensity of the interfering waves, I noticed how the electric field components were combined - one from slit a, the other from slit b. The intensity is then proportional to the square of this value. But this would mean that two in phase...
  29. P

    How accurate is this video? Double Slit experiment

    Today, my teacher showed us a video in class (AP physics B) as part of our quantum physics unit. I'm really skeptical about the video, and I wanted to seek the opinion of people who are actually knowledgeable in this field. Is there anything wrong with the information provided...
  30. T

    Double Slit Experiment - White Lite & Minimum Angular Displacement

    Homework Statement A two-component beam of light, consisting only of two wavelengths 650 nm and 520 nm, is used to obtain interference fringes in a double-slit experiment. The separation between the centers of the slits is 2.43×10−4 m and the distance of the plane of the slits from the...
  31. D

    Double Slit Experiment and Quantum Eraser

    Hello everybody, I am absolutely a novice in physics and although I generally have a good grasp of math I am pretty sure my knowledge of it is quite far from the one required by quantum physics. However, I am very interested to its main concepts and for this reason I am reading an...
  32. B

    Sum over histories and double slit?

    I was recently studying Feynman's sum-over-histories approach to quantum probability. I also was reading an interesting paper on the double slit experiment. How do these two work together. Do some of the probability waves not have a out of phase partner to interfere with itself? On a related...
  33. H

    Finding the largest angle from the central maximum (single slit diffraction)

    Homework Statement A single slit, 1400 nm wide, forms a diffraction pattern when illuminated by monochromatic light of 490 nm wavelength. The largest angle from the central maximum at which the intensity is zero is closest to: A) 44° B) 38° C) 35° d = 1400 nm, lambda = 490 nm...
  34. D

    Phase difference in a two slit interference problem

    Homework Statement In the figure below, sources A and B emit long-range radio waves of wavelength λ = 390 m, with the phase of the emission from A ahead of that from source B by 90°. The distance rA from A to detector D is greater than the corresponding distance rB by 130 m. What is the phase...
  35. S

    Single particle single slit interference - question about the experiment

    Came across the below experiment, on Wikipedia, but don't understand how it was performed... It was shown experimentally that: in a double-slit system where only one slit was open at any time, interference was nonetheless observed provided the path difference was such that the detected...
  36. D

    Intensity Distribution of 4 Slit diffraction grating using convolution

    Hi all, I am trying figure out this diffraction problem. I have to find the intensity distribution of a four slit fraunhofer diffraction grating using the convolution theorem. I can do the math and all...but I do not know how to start it! The only information I am given is the slits have...
  37. zdcyclops

    Particle paths in relativity: frame of reference and double slit results

    The apparent path of an object is different for observers in different reference frames. A ball dropped from the top of the mast on a moving ship lands at the base of the mast. An observer on the ship sees the path as straight down while one on the dock sees the path as a diagonal. How many...
  38. L

    Very confused: why is the path difference in double slit interference dsinθ?

    Homework Statement The more I think about path difference, the more confused I get. First of all, HOW DO PEOPLE know that the path difference is dsinθ? Why do we draw a line coming from the first ray that is PERPENDICULAR to the second ray when determining path difference? Please see...
  39. V

    Q regarding Quantum decoherence, r.e. double slit experiment

    Hi all, My limited knowledge of quantum decoherence leads me to believe that it can be demonstrated experimentally via rather humble apparatus involving low power lightbulbs, a few sensors, & some plywood with holes in & some switches etc. I was just wondering what kind of pattern you get if...
  40. D

    Polarization, Double Slit, Single Slit

    Homework Statement This is an old test question that I failed, but this material will resurface for the final so I just wanted a detailed description of what the full answer would've been. I'll include the rubric too so you'll know what I'm up against. Can you include explanations and...
  41. P

    Multi World Hypothesis and The Double Slit Experiment.

    Greetings! From my last post, to this my understanding of QM has improved somewhat. (thanks mostly to these great forums). I was wondering how the Multi Universe Theory treats the observer effect in a basic Quantum Double Slit Experiment ? from howstuffworks.com :- "“When a...
  42. D

    Uncertanty in double slit diffraction

    In a double-slit experiment electrons are sent through a doule slit where an indicator determines the slit each electron went through. These indicators tell the y coordinate to within d/2, where d is the distance between the slits. If this is the case show that the diffraction pattern will be...
  43. jaketodd

    What is the scale or density when the double slit experiment stops working?

    I know even molecules can be used and the result still emerges. What is the density of [pick a type] of atoms or molecules when the experiment stops working? Also, as you increase the density of whatever you're using, does the result get less and less like what you get when you use photons...
  44. S

    Can a Temporary 'Mark' Affect the Double Slit Interference Pattern?

    I'm watching Leonard Susskind's online QM lectures, and in it he talks about the double slit experiment. He says that if the particle leaves a "mark", allowing you tell which slit it went through, (for example a "1" vs a "0" on a computer read out) this destroys the interference pattern. But...
  45. L

    Slit pattern, vertical or horizontal?

    This has already been asked: https://www.physicsforums.com/showthread.php?t=77835 It is a simple question but I am confused, if the slit or the slits are vertical the direction of the pattern is horizontal or vertical? Vertical: | | |...
  46. S

    Delayed double slit experiment

    Hello! I have this doubt with a variation of the double slit experiment: Let us suppose that we are sending electrons to the screen. When both slits are open, the wave function at a given point x of the screen is the sum of the functions phi1 and phi2, respectively corresponding to reach x...
  47. J

    Slit width order of wavelength

    In diffraction why the slit width has to be the order of wavelength of wave? I don't understand. The smaller the width of the slit i think the more effective diffraction becomes. Why the width has to be order of the wavelength?
  48. M

    The Double Slit Experiment: The weirdness of quantam physics

    particles act differently when being observed. WTF :confused: check out the video...weird... http://www.youtube.com/watch?v=wEzRdZGYNvA&feature=fvst
  49. M

    Ref for single electron double slit experiments

    Hi there, Single electron realizations of the double slit experiment is always mentioned as one of the standards 'proofs' of particle/wave duality, along with a series of pictures with single dots appearing in an interference pattern. Has anyone ever made the experiment with single...
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