Interference Definition and 999 Threads

The "wireless power" thread made me think of this, but I have pondered it before when it comes to microphone arrays etc You can easily find documentation on the interference patterns N in-line sources of waves generate. E.g. The annoying thing here is that you have infinitely extending lobes...

I’ve been wachting a video here on interference maxima when light passes a grating and 3 questions came up. 1. The lecturer shows the following picture: He mentions that each purple line from each slit (distance ##d## apart) that meet at the same point on the right side (for constructive...

Homework Statement I have attached the question to this thread as it requires looking at a diagram. Homework Equations None The Attempt at a Solution We are supposed to attempt the question and mark it but I have a few questions if people could kindly answer for me please. In the main 6 mark...

Dear All, I have a couple questions on the double slit experiment I hope you can help shed some light (or photons) on. =) Arrival Timing of Photons In a normal double-slit experiment like the above setup, do photons always arrive at the detector at a constant speed (basically, speed of light)...

Homework Statement Three experiments involving a thin film (in air) sandwiched between two layers of air are shown with nair < nfilm. If t denotes the film thickness and λ denotes the wavelength of the light in the film, which experiments will produce constrictive interference as seen by the...

Hi, my answer is about the double slit experiment: the interference is observable with the water waves, them are particle in movment, but when we observe it with the electrons, what is the medium for those waves? Are the particles made of matter between the gun and the slits? Or is it something...

Hi, i have a question about the optical interference, supposing we have two LEDs which spectra are partially overlapped, can we have interferences?? is there any chance to have a partial coherence between the two lights??

When we touch the screen of a mobile or laptop we can see some colors on the sweat adhered to the screen.Which property of light can explain it? Is it for interference or for refraction?

Homework Statement Eyeglass lenses can be coated on the inner surfaces to reduce the reflection of stray light to the eye. If the lenses are medium flint glass of refractive index 1.62 and the coating is fluorite of refractive index 1.432, (a) what minimum thickness of film is needed on the...

I've recently been doing some learning about the double slit experiment and a bit about how, qualitatively, quantum electro dynamics works. Something that I wondered about for a long time was how momentum could be conserved in these systems when we assume that a particle could land in any number...

Homework Statement [/B] I was little bit confused about interference word problem in an old physics exam. I managed to ace the problem in the exam, by applying a little bit common sense to it, but I feel like I didn't understand the concept of the interference completely. (Loud)speakers A and...

Given the de Broile wave matter equation, wavelength = plank's constant / momentum,... 1) what's the maximum distance from the electron until its wave like behaviour stops interfering with its surroundings? 2) why the bigger the wavelength, the more the electron is to interact with its...

I've been trying to get my head around Polarisation and how it achieves orthogonality. I'm not sure if this should be in Physics or Electrical Engineering Section. (Mods can move this where appropriate) I know that 2 EM wave with linear polarisations where one wave is shifted by π, they would...

If I measured the velocity of an electron what happens to its position? Does it collapse into a specific position or is it still uncertain? Here's a thought experiment... we measure the velocity of an electron and then send it through the double slit at the same time. Does the electron still...

Hi, in every explanation of thin film interference I came across, little or nothing is said as to why the layer of transparent material creating the effect should be thin. What would go wrong if that is not the case? I'm asking because it seems to me that, in principle, the mathematic...

This is a really silly question and its bugging me. Do I lose energy through destructive interference? If not... then how can I get back what I invested before? Thanks, hope I understand the waves soon :)

I want to analyze the efficiency of my data communication between slaves and master in the presence of interference. The protocol what I am using is modbus, with baud rate of 9600 , I am using 1000 ft cable. What I am struggling to do is, how to couple the noise into the cable in a way it is...

<Moved from the homework section> 1. Homework Statement I have read several chapters of De Brogile's article "the theory of quanta".The motion of a particle could be analogious to a ray in general optics.This is an analogy between Maupertui's principle and fermat's principle. How to use this...

Say we have a particle, like an electron in a double slit experiment. And say that we have a measuring apparatus to detect it right after its fired out of the electron gun. And after that it goes through the double slit and hits the detector plate. Would we see an interference pattern? If the...

Homework Statement Two trains approach the train station from opposite sides each moving at an initialvelocity of 120 km/h with respect to the station and slowing down to a halt in 20seconds. If both trains are whistling at 5000 Hz, find the distance between the zeroand first order maxima as a...

Homework Statement the question details are given in the attachment Homework Equations momentum = √2mE where m is mass of neutron and E is its kinetic energy The Attempt at a Solution initially i accounted for the energy change during the path followed by the neutron but later i got...

Dear Every Smart Person, I am not a scientist or a physicist by any means, but I have a concept that has been literally driving me crazy all day. No matter how much I read, I can't make sense of it. Here it goes. I work in the LED Lighting space. In that space, there are two types of LEDs: a...

Homework Statement Find 3 careers that are in some way related to the interference of light. Give a brief description of each career. Homework EquationsThe Attempt at a Solution My examples are X-ray Technician, Photonics Engineering and Optical Physics. My question is, is optical...

How does MWI deal with the destruction of interference in the double slit experiment when a detector is placed at the slits? Since the wave function never collapses, and the universe doesn't actually split in MWI, how does the interference go away? Does the measuring device at the slits reshape...

Homework Statement This is not a homework question but I would like if someone could explain to me when to consider what equation constructive/destructive? I learned these two equations very vaguely in class: dsinθ = mλ or d(ym)/L=mλ dsinθ = (m+1/2)λ or d(ym)/L = (m+1/2)λ The power point...

[Mentor's note: Split off from another thread because it's a different question] I have a question about the single-photon double-slit experiment's results that isn't about the role of consciousness. Should I go ahead and ask it here or ask it elsewhere? (Briefly: If the results are lots of...

I want to measure the Ca and Mg concentration in a solution that contains up to 250 mg/L of PO43-. Apparently, orthophosphates interfere with both flame photometric methods and complexometric methods with EDTA (or so I've read). Is there a standard method for measuring Ca and Mg in this type of...

Homework Statement In a large water tank experiment, water waves are generated with straight, parallel wave fronts, 3.00 m apart. The wave fronts pass through two openings 5.00 m apart in a long board. The end of the tank is 3.00 m beyond the board. Where would you stand, relative to the...

Homework Statement Four equally spaced coherent light sources (n=4) with a wavelength of 500nm are separated by a distance d = 0.1mm. The interference pattern is viewed on a screen at a distance of 1.4m. Find the positions of the principle interference maxima and compare their width with that...

With sound you can create out of phase signals and they cancel out, this is not possible with light as it does not interact like sound does. If it was possible to create two light sources in that were exactly 180 degrees out of phase with each other and aim them at a common point (eg an...

Homework Statement Lisa makes a hole in aluminum foil. She wants to know the diameter of the hole. She points a laser through the hole. That picture is what appears on the wall that is 1,25 meters behind the aluminum. the distance between every circle is 8mm. the wave length is 633nm...

Hi. If we place two perpendicularly oriented linear polarizers at a double slit, there will be no interference pattern. In the wave picture, this is trivial: Two waves with perpendicular polarization cannot interfere. In a quantum picture, I've often seen the interpretation that the sheer...

Homework Statement I am working on a thin film interference problem where i have to find the phase difference. What is the relationship between external/internal reflection and the thin film interferenceHomework Equations for external: [/B] for internal: The Attempt at a Solution So far i...

Hi, What is the scientific definition of "synchronous sources" when we talk about the conditions of interference? Thank you.

[Mentors' note - this post has been edited to remove some discussion of the EM-drive. See https://www.physicsforums.com/threads/nasas-em-drive.884753/ for our current policy with regard to em-drive discussions] Hello. Imagine a closed box with reflecting walls. Inside you have two antennas...

Homework Statement Two speakers A and B are 3.50m apart and each one is emitting a frequency of 444Hz. However because of signal delays, speaker A is 1/4 of a period ahead of B. Find all points relative to the centerline between A and B where there is constructive interference. Include angles...

Homework Statement Coherent electromagnetic radiation is sent through a slit of width 0.01 mm. For which of the following wavelengths will there be no points in the diffraction pattern where the intensity is zero? A. Blue light of wavelength ##\lambda=500 nm## B. Infrared light of wavelength...

Homework Statement Suppose you have two pulses, One is a trough, It's amplitude is 3 cm and the other is a crest and its amplitude is 9 cm. Assuming they have the same wave length when they overlap the energy of the created wave is: 1- 1/16 E 2- 1/4 E 3- E 4- 4E Homework Equations ##E## is...

Homework Statement ##d=0.52 cm,## ##\lambda=431nm##, ##L=119 m## Homework Equations ##dsin\theta=(m+1/2)\lambda## for constructive/bright fringes since there is a pi shift already The Attempt at a Solution a) $$sin\theta\leq1$$ $$(.0052/431e-9)-0.5=m=12064$$ 2 \e{3} $$ total bright fringes =...

Homework Statement [/B] Find condition of d that constructive interference occurs with m=1,2,3,... a)##(m-\frac{1}{2})\frac{\lambda}{2}## b)##m\frac{\lambda}{2}## c)##(m-\frac{1}{2})\lambda## d)##m\lambda## Homework Equations optical path difference (OPD) must equal ##m\lambda## The Attempt at...

Homework Statement As shown in the figure below, beams of light whose wavelength in air is 600 nm are perpendicularly incident upon two transparent thin films (A and B) in the same phase. The thickness of A and B is l. The refractive indices of A and B are, respectively, nA and nB. The...

Hi, I am new to this forum. I need to design an interference fit for a 1.5 mm thick SS ring. The interference fit is between this ring and another 1.5 mm thick SS sheet metal can without any groove. The ring is bent outwards at a specific angle.(please refer attached image) We know amount of...

Hello everyone, I have been thinking about binaural beats, and after learning about the inner workings of the ear, there is something that I cannot explain. A binaural beat is the pulsating effect perceived by the brain when slightly offset frequencies are played in each ear. In my example...

Hello! I am trying an interferometry experiment using the Michelson Morley experiment. I managed to obtain the interference pattern on a screen, but I want to use an photodetector and I am not sure what should I obtain. As I know, the oscilloscope shows the intensity of the light, so if I modify...

Does it cancel it, or just create an equilibrium of forces upon a point(s)? Example: If you had a string and you sent a wave down one end, and the opposite wave from the other, once they meet there will be an instant when the string is flat as if there had never been waves introduced. But, if...

While studying the wiki article for Quantum Superposition, I find this sentence: “An example of a physically observable manifestation of superposition is interference peaks from an electron wave in a double-slit experiment.” Can someone explain how interference proves (shows? demonstrates?)...

Hair/wire laser diffraction interference pattern - does it follow single-slit or double-slit? for single-slit interference, the equation nλ = d (y/D), (d is the width of the single-slit, y is the distance between central BRIGHT fringe to the nth DARK fringe, D is the distance from slit to...

Say I place a magnet on a table, and I have a metal in close proximity. Will its magnetic field change due to the presence of this metal, however minute? What if I had another magnet or the table itself is made of materials the magnet is slightly attracted to? Does this phenomenon even exist?

andrewkirk submitted a new PF Insights post Acoustic 'beats' from mismatched musical frequencies Continue reading the Original PF Insights Post.

Homework Statement Two loudspeakers, A and B, are driven by the same amplifier and emit sinusoidal waves in phase. Speaker B is L = 2.00 m to the right of speaker A. The frequency of the sound waves produced by the loudspeakers is f = 206 Hz. Consider point P between the speakers and along the...