Interference Definition and 999 Threads

The classical physics developed by people such as Fraunhoffer and Fresnel seems to work very well at predicting the results obtained when observing interference and diffraction patterns. Quantum theory seems to work well also and can be used,for example when photons are sent one at a time...

Hello, In my textbook(Serway), Constructive interference of two rays hitting the first and the second planes , respectively, of a crystal lattice is derived as 2dsin(Θ)=mλ , where Θ is the angle shown in the picture. My question is: shouldn't the equation be 2dsin(Θ) = (m+1/2 )λ instead...

I cannot understand the following: Imagine you have 2 sound sources and build up an interference experiment, where far away from the sources you have a receptor. Imagine you put the receptor at the same distance from the sources. If you turn off one source the receptor will receive a sound...

Homework Statement Two speakers are 2m apart. You stand 5m back from the centre of the two speakers, and 2m to the side. The speakers are emitting sound at 700Hz, take the speed of sound to be 341 m/s. Are the waves in constructive or destructive super position? Homework Equations...

Here's a thought experiment : Two identical spherical waves exactly 180 degrees out of phase destructively interfere throughout all of space. Is the energy contained in them just lost ?

Hello, I have a question or two that I suppose will include the nature of light and how that links to electromagnetism. Sitting at my desk doing some work, listening to music over my speakers, I get a text. But I know I'm about to receive the text before my phone vibrates, because my...

This is another one of those things that I had always assumed to have a very simple explanation. After all, I've seen so many simulations of waves interfering with each other and forming the distinctive interference pattern, and even watched the patterns emerge in actual water waves. The pattern...

I would like to hear comments about interpretation of photon interference in context with Pfleegor-Mandel experiment "Interference of Independent Photon Beams". There is a blog post about this experiment: http://scienceblogs.com/principles/2010/11/19/interference-of-independent-ph/. Original...

I'm working on my physics prelab, but I can't seem to get this answer. The question states: Measuring the detector´s output as a function of its position along the goniometer (look it up!), we see that there are maxima and minima in the signal. Starting at one of the maxima, we find 6...

Homework Statement Plan plates of glass are in contact along one side and held apart by a wire 0.05 mm in diameter, parallel to the edge in contact and 20 cm distant. Using filtered green mercury light (λ = 546 nm), directed normally on the air film between plates, interference fringes are...

Hi all, I am looking to do some magnetic measurements for some research (chemistry...) but I'm hoping to get an understanding of how a SQUID instrument works. I was wonder if anyone could give me a qualitative overview or if anyone know any resources without math-heavy explanations. Thanks!

Homework Statement two point sources A and B generate sinusoidal waves in a water surface. The sources are 6.0 cm apart and vibrate in phase with the same amplitude and frequency. Points of destructive interference are observed on AB, the line joining the two sources. the two nearest such...

Homework Statement Look at the Moire pattern in "Oppgave 5" (assignment 5) in the attached pdf file. The Moire pattern you see is supposed to represent the interference between two plane EM waves whose directional ##\vec{k}## vectors form an angle ##\theta## with each other. Anyway, the main...

Homework Statement For two plane EM waves with identical amplitude, frequency, polarization and phase traveling in the directions of ##\hat{k_1}## and ##\hat{k_2}##, show that their average intensity is given by ##2I_0[1+\cos((\vec{k_2}-\vec{k_1}) \vec{r})]##The Attempt at a Solution Ugh...

Homework Statement In a young's double slit experiment the slits have the same width and are separated by a distance a. an observation screen is placed at a distance L=1m from the slits at a point on the screen a distance y from the optical axis the optical path difference between the 2 waves...

Hi, Can someone give me an explanation as to why coherent waves are needed for interference. I know coherent waves are when the phases difference between the waves is a constant and the frequency of the waves are constant. Thanks :)

Interference for a lattice with N slits OK, so check out the first formula (the one for intensity) in the following pdf: http://folk.ntnu.no/magnud/OvLf/bolge/oving11.pdf It's the formula for Intensity as a function of angle from the interference for a lattice with N very thin slits...

Homework Statement I'm having some trouble understanding the following solved problem: In Young’s experiment, narrow double slits 0.20 mm apart diffract monochromatic light onto a screen 1.5 m away. The distance between the 5th minima on either side of the zeroth-order maximum is measured...

Can anyone offer a description of what's actually going on in the observed interference of Fullerene? We're talking about molecules with a lot of complexity, with angular momentum, many internal degrees of freedom and that emit thermal radiation. How do we explain that they remain coherent in...

“Light is emitted with a central wavelength of 500 nm. First it is analysed with a Michelson Interferometer: starting from uniform illumination, one of the mirrors is displaced 2.5 mm until no new fringes can be distinguished. Then it is analysed with a Young´s Double Slit: it is observed that...

Can somebody explain to me what is the difference between double slit diffraction and double slit interference?, to me they are the same thing but my teacher says they have two different meanings, thanks.

In a standard 2 slit experiment setup when the interference pattern is visible - if the screen is moved forward the pattern must 'move' across the screen as the alignment of wave peaks and troughs change. I.e if we start with an intense band at the centre then move the screen forward half the...

Hi! I've been searching all over for a recommendation to my problem, but I've come to the conclusion it'd be better to ask. I am a controls engineer, design and produce a lot of large scale automation products. Our system uses a basic PLC system tied to a plant management server rack running...

Homework Statement Consider two point sources S1 and S2 which emit waves of the same frequency f and amplitude A. The waves start in the same phase, and this phase relation at the sources is maintained throughout time. Consider point P at which r1 is nearly equal to r2. a) Show that the...

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Sometimes I find it hard to understand how energy is conserved in destructive interference. Consider two waves on a string which interfere destructively such that the string is at its rest position. Where is the energy contained? Edit: the string example is not very good at illustrating what I...

Let's say we are doing interference experiment via say a Mach-Zehnder http://en.wikipedia.org/wiki/Mach%E2%80%93Zehnder_interferometer In the Mach-Zehnder two of the mirrors are half silvered. The photon has a 50% chance of passing through the half-silvered mirror and 50% chance of...

OK so before I begin I will ask that you forgive me because I do not have a working knowledge of the mathematics involved here and I am admittedly not even at a novice level of understanding these things. However I have done at least some research and understand how an interference pattern does...

I don't know if this would be considered a homework problem, so I hope I'm posting in the right place. I'm working through an independent learning course and just needs some help with the terminology in the book. It started expressing wavelengths in 1/2λ, and I can't find an explanation why...

Suppose that we have two light sources emitting monochromatic light with the same wavelength and amplitude, but opposite phases. Suppose also that the distance between the light sources is small compared to the common wavelength (this is probably unrealistic, so we can instead consider two...

Dear reader, I have written a paper which I require a reference for converging wave interference generating a caustic. When studying for my degree, I performed Young's double slit experiment with the addiction of a converging lens. I was trying to comprehend Afshar's...

'The colour seen when white light is used as a source for a Young’s double slit experiment are sometimes mistaken for the spectrum of visible light.' Why is this not possible with a two slit interference pattern? I know that the different wavelengths will all cause interference with each...

Hi all, I am a student and I am trying to understand how to achieve carrier phase stabilization for frequency comb using quantum interference. I found out that the interference leads to generation of current but I can't seem to find the derivation of the equations for the current generation...

Trying to get my head around constructive/destructive interference in thin film optics. The book does a good job of throwing formulas at you but I want some intuition. If we shine a laser with λ = 600 nm on a thin film of a material with refractive index 1.5, at what thicknesses will we get...

Sorry if the question is too basic. What happens when a pair of entangled particles are sent through a double slit? (Same time) ...in case they are 1. Only momentum entangled 2. Only position entangled 3. Only spin entangled

Hi, My interest in physics is relatively new and recently I've been trying to figure out the answer to what is probably a simple question. Here it is; if one is using an AC EMF meter to read the time varying current from a man-made electromagnetic field, will brandishing ferromagnetic...

Homework Statement A pair of eyeglasses has an index of refraction n-glass = 1.52. It is covered with an antireflection layer that has a thickness of 120 nm and an index of refraction that is less than n-glass. If the antireflection layer is designed to minimize reflection in the middle of...

How do i demonstrate thin film interference with microscope slides? Textbook questions all mention that you will get parallel fringes when you put a hair between two microscope slides. However, i have tried doing so, but don't get the parallel fringes. I used a red laser pointer, and a...

Double slit interference "missing" maximum problem Homework Statement In the double slit interference experiment, d is the distance between the center of the slits and w is the width of each slit. For incident plane waves, an interference maximum is "missing" when what relationship between d...

How in microscope there is a phenomena of differaction, and in case of telescope there is interference of light happens ?

If we have twin photons moving in the opposite direction. For the first photon we can pass it through a polarizer that will either output a photon with vertical polarization or a photon with horizontal polarization. after this experiment we now know what will the other unobserved photon...

Homework Statement Two waves propagate opposite directions along a string one is y_{1} = 0.6 cos[ \frac{π}{2} (\frac{x}{2.0m} - \frac{t}{8.0s}) ] and the other is y_{2} = 0.6 cos[ \frac{π}{2} (\frac{x}{2.0m} + \frac{t}{8.0s}) ] find the frequency \nu, wavelength λ and...

Hi all, Imagine a double slit experiment where each slit contains a polarization filter with some angle relative to each other (\alpha). If the polarization filters are parallel the usual interference pattern will emerge, and when they are perpendicular no interference pattern will emerge. What...

I am trying to find the minimum thickness that a sleeve (without relief) needs to be in order to not fail when assembled by interference fit. I know the interference value and the outer diameter of the shaft, but that's all... How do I solve for pressure, stresses, and ultimately the minimum...

I'm studying wave interference and having trouble to understand some concepts. I would like to ask what would happen in the 2 situations below Image 1 Image 2 Both waves are identical, have the same frequency, amplitude and velocity. They are polarized on the direction shown (first...

I have read in several places (such as this StackExchange reply) that wavefunction collapse is 'non-physical'. The explanations I have read seem clear and understandable to me and have helped me to understand EPR and the implications of Bell's Theorem. I am trying to reconcile this in my mind...

Homework Statement A five-slit system with 8.4*10-6 slit spacing is illuminated with 610*10-9 light. Find the angular position of the first two maxima, and the 3rd and 6th minima. Homework Equations For Maxima: d*sin(θ) = m*λ θ = sin-1((m*λ)/d) For Minima: d*sin(θ) = (m/N)λ θ =...

Hi, Homework Statement We ran an experiment for confirming the linearity of Faraday's Law (the relation between EMF and the rate of change of flux), by plugging a magnet to a motor rotating in the axis of a solenoid (inductor). In my graph of the amplitude of EMF wrt time, I noticed some...

Homework Statement A light of wavelength 500 nm interferes through a two slit experiment on a screen. The distance between the first minimum and fourth minimum is 1.68 cm. Find the distance between the central maximum and first order maximum.Homework Equations d*sin(θ) = nλ = Δ d = distance...

Homework Statement Please refer to the attached image. For the first question, The solution calculated the wavelength,λ by taking the whole length of the string (0.75m) as equal to 3λ/2. What I don't understand is, since the string have to bend to produce a wave, how can we just...