Slit Definition and 1000 Threads

I am just inhaling "The Grand Design" and am stuck in the chapter on the "buckyballs" double slit experiment. The authors say that in case of the experiment, a particle may take any possible way ("perhaps to Jupiter and back"), which then Feynman depicts as adding vectors to a result vector...

Hi. Firstly, I'm not a physics student but was just wanting some answers to questions from those that are, so I thought I'd try you lot. :smile: 1. Has anyone proved that quantum entanglement doesn't happen at the macro level? 2. Regarding the 2 slit experiment and how consciousness...

I'm new to quantum physics and the double slit experiment. If the person running the experiment collects the data but does not look at it, does the result of an interference pattern or no interference pattern on the CCD image sensor decide the future of whither that person decides in the future...

In the paper (AIP Conf. Proc. 810 (2006), 360): Mardari outlines three predictions of quantum self-interference, all of which empirical evidence is presented that appear to refute all three. The implications of the paper is interesting but of these I am particularly interested in the...

I am confused by an aspect of the infamous double slit experiment. It is said that one way to understand why a succession of single particles can give rise to an interference pattern is that a single particle could be going through both slits simultaneously and interfering with itself. But this...

In the aftermath of the recent Steinberg paper where they reconstruct average photon trajectories in the double-slit experiment, it has been pointed out several times that the reconstructed average trajectories strongly resemble the single-photon trajectories predicted by Bohmina mechanics...

Ok double slit experiment. Two slits send through one photon which passes through both slits due to wave/particle duality. So really we have two probablity waveforms now don't we? One passing through each slit and creating a wave pattern from the start of each slit. THat's how we get an...

Hi Folks Regarding the double slit problem, I read recently a theory that suggested that the universe itself split creating effectively two particles, which can interfere. Personally I think this is imaginative but it simply doesn't sit right, it seems somehow illogical and wasteful for...

Hello! I have a question? Does anyone know if scientists have tried to run the electrons through the double slit, record the particles that go through each slit, and before looking at the results, looking at the pattern on the screen. And THEN doing the EXACT OPPOSITE of what the screen...

1. Why are the slits necessary? Do 2 individual light sources of the same frequency without slits or cards create an interference pattern? If not, why not? 2. How do different frequencies of light alter the interference patterns? Any links to experiments of this nature? 3. How about 2...

The path of photons can be (almost) reconstructed in a double slit experiment! Observing the Average Trajectories of Single Photons in a Two-Slit Interferometer http://www.sciencemag.org/content/332/6034/1170.abstract Discussion: http://physicsworld.com/cws/article/news/46193...

i just don't understand diffraction in a double slit , ? how is it related to interference?? like if i want to find how many bright fringes within the central bright fringe of the diffraction envelope? or how many bright fringes are found between the bright fringes of the first and second of...

I have a question regarding the double slit experiment. I have been doing a little reading (The Grand Design, to be specific) and I was left with a burning question. First of all, I am not a physics major. I have taken only one college physics class, and although it is something that...

Homework Statement Consider a young double slit experiments where the two slits are spaced d = 0.1mm apart. If when the screen is at a distance of l=1m the first bright maximum is displaced y = 2cm from the central maximum, then find the wavelength of the light. Homework Equations...

Hi, I'm trying to perform a double slit diffraction experiment without using a laser, but instead using a super-bright, white LED. This LED has been placed inside a sealed box with a small pinhole opening (~1/32 inch diameter). This however introduces the problem that the light is incoherent...

I have what I believe is a simple question about the single photon (at a time) double slit experiment. This experiment does not use a coincidence counter correct? I understand that one, or more, is used for entanglement experiments, but is one necessary to determine an interference or lack of...

A single particle can behave like its interfering with itself by means of the following explanation (is it true or can you refute it?): Ballentine wrote in his 1970 paper "Statistical Interpretations of Quantum Mechanics": "As in any scattering experiment, quantum theory predicts the...

This little link here: says that if there is a detection device that observes the electron before it gets to the slits, the observation collapses the wave function. This leads to the electron behaving like a particle rather than a wave as it enters the slit, so two bands are produced on the...

(Hope this is the right forum) For my Physics EEI (year 12 extended experimental investigation) I'd really like do some sort of variation of the double slit experiment that can deviate into wave like behaviour of matter etc... I've found ways to have the interference patterns shown using a...

Hello, Quick question: Will radioactive particles give interference pattern if there is no measuring device?

Homework Statement so here i have shown the distances of two dark fringes ... from here ... fringe width is \frac{\lambda L}{2d} L is distance of screen ... d is distance b/w 2 fringes. but fringe width is \frac{\lambda L}{d} , right ? What mistake am i making?

After looking at the graphs of single slit and double slit interference of intensity vs. angle, it seems that the intensity drops off very steeply with single slit interference but doesn't drop off at all with double slit interference patterns. Why is that?

Even if you send a buckyball molecule in the emitter, does the detector always give you output in terms of electrons? Isn't there a way to actually check the buckyball located in the detector? Because in normal double slit with electrons. One can argue that the emitter send an electron field...

Quantum objects are particles, not waves. Particles are bundles of energy propagating on a field. It is the properties of the field that seem to give particles wave-like qualities. Thus in the Young's double slit experiment, a given particle goes through one and only one of the slits; it does...

I am trying to calculate how wide of a screen you would need in order to observe an interference pattern produced by Young's original real-life double slit experiment. He cut a single narrow slit (width ds) in a window shade, admitting a narrow sliver of sunlight into a dark room. He inserted...

According to Richard Feynman, the double-slit experiment contains the only mystery of quantum mechanics. After we have unveiled the mystery, we will be able to understand quantum mechanics. Someone has allegedly solved the double slit mystery and unveiled the secret of Quantum Mechanics...

Homework Statement A single slit forms a diffraction pattern, with the first minimum at an angle of 40 from the central maximum. Monochromatic light of 410 nm wavelength is used. The same slit, illuminated by a different monochromatic light source, produces a diffraction pattern with the...

When we want to show quantum behavior (like tunneling or double slit) of a large object like a buckyball molecule, what do we need to watch out for in an experiment? Is it the following? a, that all constituents of the object (the single atoms of the buckyball) are described by one coherent...

Double Slit and "The Observer" Hi! First of all, I am just getting started in Physics, so I apologize if this is a silly question. I was talking with my boyfriend (who has a degree in physics) about the double slit experiment. Obviously, if you perform the experiment one electron (or...

Sorry for the rambling nature of this post. Hello,I am not a student or teacher.Just a regular person,browsing Youtube.I came across the delayed choice eraser. http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser I am confused... Does that mean that anything that will never be...

I tried to do the double slit experiment at home with a green laser (for a science project at school and for fun). I failed but someone succeeded with a red laser. Is it true that a red laser works better because it has a longer wavelength?

I have no idea where to start with these questions. I am pretty sure I have to use these equations 1. theta = tan^-1(x/D) 2. wsintheta = nlambda 3. dsintheta = nlambda Which order m of in the two-slit interference pattern will give the least uncertainty in the slit spacing, d? a) m = 1 b)...

Lets say I have a double slit interference experiment set up. Now if I cover one slit what CHANGES would be observed ? I know I would see fewer bright fringes and that the intensity of the bright fringes would fall. Is there anything else ?In a different scenario I have a diffraction grating...

Homework Statement A single slit 10-4m wide(a) is illuminated by plane waves from helium-neon laser ( l = 6.328*10-7m). If the observing screen is 10m(D) away, determine the width of the central maximum(y). Homework Equations sin(alpha)=(m+0.5)*l/a tan(aplha)~sin(alpha)=y/2*D...

Homework Statement 3 narrow slits with spacing of d and 3d/2 as in picture, the slits are irradiated from left with a plane of monochromatic light with wavelength 2d/5. If the bottom slit is covered with a filter that introduces a half phase change, how many principal maxima will be...

Experimentally how do we make sure that the ejected electrons are coherent?

In my modern physics course we learned that electrons, when shot through two close together slits, will produce an interference pattern just light light. However, when you set up an experiment to observe which slit the electron goes through, there is no longer an interference pattern. To my...

What if: 1) we put a swtich gate on the bottom slit. The bottom slit is normally closed, but we time it so we open it just before a photon/electron MAY arrive. so far this will yeild the same result as traditional experiment? 2) usually the two slits are close by, but we move it very...

Homework Statement When a 450-nm light is incident normally on a certain double-slit system, the number of interference maxima within the central diffraction maxima is 5. When 900-nm light is incident on the same slit system, the number of interference maxima within the central diffraction...

Question Suppose molecules are placed next to the slits that fluoresce when electron passes, emitting a photon that can be imaged. Explain why this is no better than direct illumination, and explain how the two-slit interference pattern is destroyed. My Answer In direct illumination, a...

Whilst skulking through Youtube videos for a deeper understanding of quantum mechanics I noticed that vidoes offering accurate, legitimate, remotely-science-based information were few and far between. The rest seemed to be videos of people saying that we, as thinking beings, create the...

Ok so I was sitting out back one day listening to some music with some friends around. We had some music playing on a stereo inside the house and we were out the back with the glass door open about 10 cm's. I thought I noticed that some sounds with different frequencies seemed louder then...

　 Buckyball Double Slit Experiment I've been reading old archives here and even the FAQ and still not definite about the answer. It is said that a buckyball composed of 60 carbon atoms can still form interference pattern at the screen. It is not the complexity of the object but the fact...

Homework Statement (a) In a double-slit system, what value of d/a causes diffraction to eliminate the third bright side fringe? Homework Equations I(\theta) = I_mcos^2(\beta)(\frac{sin(\alpha)}{\alpha})^2 \beta =\frac{\pi d}{\lambda} sin \theta \alpha = \frac{\pi a}{\lambda} sin \theta...

Hello, I was wondering if I could get any help with the following question/thing: Why does a stream of photons (let's say that one is fired every 3 seconds) at a double slit as shown in Young's double slit experiment create an interference pattern although there is no interference because the...

If electrons are strings (in string theory), what happened to the string between emission at the double slit experiment and detection on the screen after it passes thru the 2 slits? Does the string splitted and joined again after the slits? Before string theory, we just say particle...

Homework Statement See figure attached. Homework Equations The Attempt at a Solution \Delta L = asin\theta = m \lambda If the waves are in phase, we would expect L to me a integer number of wavelengths, when they are out of phase, L should be an odd number of wavelengths, but...

The double slit experiment is often described like this: (I'll describe the photon version, but of course the electron one is the same) "We fire individual photons at a screen with two slits. An interference pattern appears. But when we try to look at the slits to figure out which slit the...

Homework Statement This is the light intensity on a viewing screen behind a rectangular opening in a screen. Is the shape of the opening (1), (2), or (3)? Homework Equations w=(2λL)/a where w is the width of the central maximum, L is the distance to the viewing screen, and a is...

A friend of mine pointed out this website to me. http://www.doubleslitexperiment.com/ The site posts an interesting theory; I'll take a quote from the sites document: "For some unknown reason that haunts scientists, everything we perceive as having mass is just a wave of information (or...