Interference Definition and 999 Threads

Homework Statement A student enters Best Buy prepared to buy a pair of speakers. Before he does so, he conducts an experiment with them. He places the speakers 4.0 m apart and connects a signal generator to both speakers that produces a single and consistent tone. (constant wavelength and...

Homework Statement See attached image, assignment a) Homework EquationsThe Attempt at a Solution Using ordinary trigonometry, I got simply $$\Delta = sin(\theta_i) 2 d tan(\theta_t) n_{air} - 2n_{oxide} d/cos(\theta_t)$$. However, even if I apply Snell's law, it's not the answer I'm supposed to...

Hi. Let's say two monochromatic laser beams superimpose in a single point in space in such a way that there's constructive interference. Because there's constructive interference there, the total intensity at that point will be larger than the sum of the separate intensities. Will this mean...

I came across this today, but wasn't quite sure how it worked. http://www.sciencedaily.com/releases/2015/04/150409081436.htm Are the two atoms fired from opposite directions?

I have been reading optics for the past few months. If light has the property of interference, when I look around, why don't I see any interference patterns. does it mean all the waves around me are in phase ? Another question is, why don't Cellphone signals interfere with each other ? they are...

This question is prompted by a recent discussion I have been following regarding the insertion of a 45 degree angle polariser between two polarisers at 90 degrees to each other. The insertion of the filter seems to restore missing components which would suggest that those components were present...

I’m looking to demonstrate destructive optical interference using a laser pointer. I’m splitting the beam with a prism and projecting the beams onto one point on the wall. Somehow I’m failing to get any effect, however. Setup: 1. I’m using a static laser pointer, a prism and a handheld mirror...

What is the production when two beams interference? 2 beams meet, and is there only one left after interference? Like vector.

Homework Statement Using the two-dimensional wave interference pattern shown and the two equations involving path difference, complete the following. i) measure the wavelength of the waves ii) measure the distance between sources iii) measure the path distance from each of the sources to the...

Homework Statement A student enters Best Buy prepared to buy a pair of speakers. Before he does so, he conducts an experiment with them. He places the speakers 4.0 m apart and connects a signal generator to both speakers that produces a single and consistent tone. (constant wavelength and...

So I have some big speaker amplifiers at home, and they sometimes pick up radio interference from the CB enthusiast next door (he uses AM, so I'm guessing this is inducing a signal inside my amplifier which amplifies it into my speakers). It isn't really a big problem so I'm not looking for a...

The condition for constructive interference is: n*lambda=d*sin(alpha) Bragg's law is n*lambda=2d*sin(alpha) The diffraction from a crystal cell will also create an interference pattern, so why do these equations differ?

Is he right there? Is there a principle that says "For every constructive interference, there is an equal (but opposite) destructive interference?" Is it impossible for constructive interference to occur without any destructive interference?I don't think so.Because when there is a constructive...

Homework Statement Two speakers (S1,S2), emitting sound waves of frequency 340Hz and separated by a distance of 3 m, are driven by the same oscillator. A listener starts walking from point A to S2 Along the line that joins A and S2> How many points of destructive interference will be observe...

according to book "...Let us look at a particular wave crest generated at the left end of the string by a fork. It travels to the right end of the string, is reflected back, and is reflected again at the fork.Now it interferes with the next wave..." doubt: the fork keeps vibrating and keeps...

I'm doing a problem where we have plane monochromatic waves incident on finite double slits (each of width a, separation d), and the transmitted light is observed in the focal plane of a lens of focal length f. The position of the lens isn't specified. So I have worked out that the intensity...

Homework Statement This isn't really a question about a specific problem, just about 2 formulas. I am not sure what the difference is when to use the two formulas. I have a hypothesis, but I need it confirmed or corrected. thankyou :) Homework Equations If you have the Halliday and Resnick...

Homework Statement Using the two-dimensional wave interference pattern shown and the two equations involving path difference, complete the following: (please see attachment)a)Measure the wavelength of the waves, the distance between the sources, and the path distance from each of the sources...

Hello everyone! In a hypothetical 3D space, with no boundaries around, homogeneous normal conditions, what would happen to the advancement of a planar wave front produced at t=0 with 2cycles in length, λ=3.5m, moving with vector speed "c-arrow=1i-arrow" if an identical planar wave of 2cycles in...

I have a very fundamental question about interference and quarter-wave-plates. My setup contains only few elements: lightsource, QWPs, double slit and some detectors to see the interference pattern. (Detectors are missing from the bottom of the figure.) An important thing is that the two QWPs...

Hello Physics Forum! I'm in desperate need of proof that magnets or magnetic field will not effect the operation or range or wireless access (Wi-Fi). I have 1/2" rare Earth magnets within a metal housing every 5' within the same area as wireless routers and the customer is concerned that it will...

Hi all, I had a question that I can't seem to find an answer too. I was hoping people could point me in the right direction, or let me know if there is an "easy" method. It has to do with the classic example of two stones in water producing constructive and destructive interference...

I wonder can a sustained interference pattern be obtained in Young double slit experiment if we do not use single slit between source of light and the double slits when one has a monochromatic source in the experiment. Regards

I would like to have a better grasp of the relation between quantum interference and state superposition that are linked in QM. For instance in the photon double-slit experiment the interference pattern is seen as a consequence of the superposition of the wave function(pure state), and when...

I have a question about, perhaps, GCSE level physics, if not below, which, for some reason, is not explained anywhere I've looked up. Or, at least, I didn't find any explanation. The picture above is supposed to explain the concept of superposition. It depicts a pair of one-dimensional waves...

Dear fellow Physicists, For my project I wanted to measure the thickness of a glass plate with white light interference. Before being able to measure, I had to setup an interferometer. Unlike with a Laser, with white light it is hard to find the interference pattern since the coherence length...

Hello, I have a question about the mathematical expression of interference and second harmonic generation If we have two waves ##E_{1,2}(\Theta ,t) = E_{1,2}e^{j(\omega t + \Theta)} = \frac{1}{2}(E_{1,2}e^{j(\omega t + \Theta)} + c.c. )## According to the Euler's formula. Now - both...

I have been getting conflicting information so here are my questions, re: 1. Single photon interference 2. Interference between two photons 3. Two-photon interference 1. Some literature says that only single photon/particle interference exists. Can two photons interfere with each other? 2...

Hi, Apologies if this is a really basic question, but I'm not a physicist by training. I was wondering how two waves of plane-polarised light will interfere if they have equal intensity, are completely in phase, but their planes of oscillation are perpendicular to one another?

Consider two adjacent people speaking in cell phones. Why the signals don't interfere with one another? Does each phone communicate with a distinct frequency? If so, how?

Homework Statement In order to decide the thickness of a SiO2 layer(n=1.5) on Si, a wedge is prepared as shown in the picture. A total of 7 DARK fringes was observed, when light of wavelength 589nm shines prependicularly on the wedge. It is known that light reflected from the Si/SiO2 surface...

If I have a parallel beam of light parallel to x-axis, with the speed of light varying from bottom to top. Let it decrease from bottom to top. (To get such a beam one can pass the beam through a glass slab normal to its surface, whose refractive index increases linearly from bottom to top). Now...

Two loudspeakers are placed facing each 4.0 m apart. The speakers emit sound in phase with a frequency of 266 Hz. An observer at the center (2.0 m from each speaker along the line joining them) experiences constructive interference. The speed of sound is 343 m/s The lowest frequency at which...

I have an online homework question and my classmate told me the answer but I would really like someone to explain to me how that answer was determined. I do not understand. Q: Consider the electric field observed at a point O that is far from the two slits, say at a distance r from the midpoint...

Homework Statement A coating of n1 = 1.27 material is to be added to n2 = 1.50 glass, in order to make it "irridescent." a) What is the thinnest layer of material which will have a reflection maximum for normal-incidence light at BOTH 400 and 600 nm (vacuum) wavelength? b) This thickness will...

Homework Statement I have to show that the interference of plane waves: f^{(\pm)}(\vec r,t)=\int \frac {d^3k}{(2\pi)^{3/2}}\int \frac {d\omega}{(2\pi)^{1/2}}e^{i(\vec k \cdot \vec r - \omega t)}\tilde f^{(\pm)}(\vec k, \omega) where the amplitudes are given as: \tilde f^{(\pm)}(\vec k...

We perceive intensity as the mod square of the electric field of light. As this electric field is varying sinusoidally then should we not see the interference fringes in a double slit diffraction pattern also vary sinusoidally in intensity as a result (albeit very quickly at the frequency of the...

Why is it possible to do this experiment at home and still see light as a wave? Isn't there loads of interference? Or does this have to do with wavelength? If you use a laserpen and 3 needles you can basicly do it at home without shielding off anything...

Homework Statement In a three-slit system, the first minimum occurs at an angular position of 5.00°. Where is the first maximum? Homework Equations dsinθ = mλ/N The Attempt at a Solution dsin5° = λ dsinX = λ/3 sinX = 3sin5° X = 1.66° I'm not sure if this is the right equation to find the...

Hi all I can't find any guidance on this on the internet, so hopefully someone here can help! Basically, I want to work out the intensity profile produced by a multiple slit experiment, with 4 slits. No problem there, but I need the separation between slits to be unequal! I've found mention of...

Homework Statement How many nodal lines are created by two point sources emitting at the same wavelength that are separated by a distance equal to 2.5 lamda? Homework Equations My textbook says, "If two coherent sources located a distance d apart emit identical waves of wavelength lamda, then...

How can light interfere with other light? I thought EM radiation only interacts with charges? Is it because, at your eye, the EM waves are out of phase? So the EM waves don't 'delete' each other, they both exist in superposition with each other, and one EM wave is pushing the electron one way...

Homework Statement A thin film of glass is in flush contact with a thin film of transparent plastic that has a higher index of refraction than the glass. Monochromatic light of a certain frequency is shown on both sides of this combination, and there is very little light reflected from either...

Homework Statement Monochromatic laser light is shown through a double-slit apparatus with a slit separation of onto a screen, but no interference pattern is seen because the thin transparent coating (index of refraction n=1.35) on the screen is creating a thin-film destructive interference...

Hi everyone, So my quantum physics teacher gave this problem to solve as homework: An experiment to watch neutron diffraction was made. The neutron wavelenght measured was 18.45 Angstroms. The double slit was created by putting a thread in the middle of a single slit. The dimensions of the...

Homework Statement https://portal.utoronto.ca/courses/1/Fall-2014-PHY100H5-F-LEC0101/ppg/quiz%2061016132114/f1q2g1.jpg The figure shows two sets of water waves, created by two sources labeled "A" and "B." The solid half-circles represent wave crests from A, and the dashed half-circles...

In the double slit experiment, when we send out one photon at a time, what does the appearance of minima in our interference pattern mean? When a single photon is fired, I understand (using "understand" very loosely) that the photon will interfere with itself. When this happens, does it still...

Homework Statement http://i.imgur.com/Mp77mDR.png Homework Equations Path length interference equation. The Attempt at a Solution Why is the answer to (a) a minima? 1. When the light wave hits the top surface of the top glass, a wave will be reflected with phase change of pi. 2. The...

Hi, I actually have two questions that are somewhat related so I am including them in one post. I add much more detail about the system then probably necessary because I'd like to see if I have a correct understanding of how the system works in addition to the question itself. Please bear with...

Homework Statement http://i.imgur.com/FiYb9OE.png Problem b). Looking at the attached document of my teacher, the visual representation of the answer does make sense. Homework Equations 2pi(delta(x1-x2))+delta(phase constant) Basic interference problem in One-Dimension. The Attempt at a...