Questions tagged [interference]

Interference describes different waves superposing to form a resultant wave of greater, lower, or the same amplitude. Normally, it involves interaction of waves that are correlated (coherent) with each other, either because they come from the same source, or because they have the same or nearly the same frequency. Interference effects can be observed with all types of waves, e.g., light, radio, acoustic, surface, or matter waves.

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68 views

Physical significance of the ket vector

I'm trying to understand/form an intuition for why a ket-vector, and its associated bra-vector, are appropriate tools to represent the spin of a qubit. Generally speaking, if a system has a state/...
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is this completely right? [on hold]

https://youtu.be/GzbKb59my3U this is basically saying that interference taught to me was just wrong that you can get the same result distribution of H/T in flip of a coin by using a single coin ...
53 views

Why does the soap bubble shine with the colours of the rainbow?

Is it because of refraction of light in water? a mixture of UV rays in sunlight? polarization of reflected light? interference of light reflected from external and internal film surface? or maybe ...
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Does the spectrum of two-beam interference also show an interference pattern?

I know when you interfere two beams you get an interference pattern with a fringe pattern of λ/(2*sin(θ/2)) in physical space. It seems that there must also be modulation of the spectrum. Is this ...
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A little doubt in Young's Doble slit Experiment [closed]

As title says ( https://imgur.com/a/G3AzaXr ) I want to know how I have no idea about this $A\cos\theta=a+a\cos\phi$ $A\sin\theta=a\sin\phi$
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Tilted screen in Young's double slit experiment

I was wondering what would happened if we titled the screen in Young's double slit experiment (YDSE) by a certain angle say $\theta$. What effect would it have on fringe patterns and their intensities ...
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In Young's double slit experiment, does the intensity of light depend on the slit width?

Here's a question I just came around In YDSE, the intensity of the maxima is I.If the width of each slit is doubled, what will be the intensity of maxima now ? here, we assume that no diffraction is ...
63 views

Why won't my interference pattern go away?

Bought a double slit diaphragm, laser pointer and some linear polarizing sheets off of Amazon so I could see the double slit experiment first hand. When I place a vertically aligned polarizer in ...
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Strange behavior of a light bulb?

What are these wave-like moving black areas shown in the following gif? Why do they start to appear when the exposure (or brightness) gets lower than a certain point? Why do the frequency and the ...
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Error due to assumptions taken to derive the formulae for interference pattern in young's double slit experiment

The screen is far away. So we assume w/D << 1 where w is the distance between the slit and D the distance between screen and slit. But if this assumption bring about error which is comparable to ...
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electron double slit experiment manipulating interference pattern

Let us suppose we can change the magnetic field and the charge on the interference surface like shown in the picture. Would it be possible to move our interference pattern along the y-axis by changing ...
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Superimposed Waves

This question has been bothering me for a very long time. Imagine a wire carrying electric current. It carries two alternating current (AC) signals of different frequencies (say $50$ Hz and $60$ Hz). ...
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What happens when two opposite EM waves which completely destructs each other hits a wall? [closed]

I have always wondered what happens when two opposite EM waves which completely destructs each other hits a wall? Does it reflects back or does it go through it. Would be good if anyone could give a(...
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Double slit diffraction and interference patterns

i'm a highschool physics student trying to understand diffraction and interference etc. I'm confused about this (in the context of the double slit experiment): if an underlying interference pattern ...
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Path difference that is between 0 and 0.5 or similar [closed]

A question in a new physics textbook we are using in school tasks readers with determining the path difference and them commenting on whether it would result in constructive or destructive ...
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Fringe spacing of the Interference pattern due to two in-falling coherent waves

It has been a long time since I have dealt with these kinds of interference/fringewidth problem, I cant figure out a way to start solving this problem. I was thinking about what the spacing between ...
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Interference using three slits

Lets say there is a Young double slit interference apparatus, but with three slits placed at $y= - d$, $0$, $d$, and where the screen is at $X = D$ parallel to the $y$ axis. Can there be any areas on ...
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Why do the LINES in a vertical soap bubble get thinner as we go down?

I understand that the soap bubble gets thicker at the bottom of the bubble due to gravity, resulting in a complicated array of different colors of different wavelengths being constructively and ...
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Quantum Interference Pattern with Perpendicular Sources

Imagine that there is a photon detector in front of me. Also imagine that there is a test photon traveling from my left to my right. As this test photon passes, I fire other photons right at the ...
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Do noise-cancelling headphones make a lot of unheard noise?

The way noise cancelling headphones work is by listening to sound, and created the inverted sound to 'cancel it out'. Doesn't this mean that the headphones create double the amount of noise, but our ...
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When two photons annihilate each other through destructive interference, where does the energy go? [duplicate]

When two photons annihilate each other through destructive interference, where does the energy go? Perhaps this is only answered by ‘wave type’ questions and answers? Does the conservation of energy ...
67 views

Multi electron interference in double slit experiment

Electrons have negative charge, and therefore repel each other. That should mean that their position, and momentum probabilities should get skewed away when in the presence of some other electron. I.e....
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If I know in advance I'm getting an interference pattern, wouldn't I have time to remove the splitter so the which-path information would be know?

Check the image below, from this excellent explanation of the quantum delayed eraser. My question, and please forgive me if it is a naive one, is that first the photon reaches detector A, which tells ...
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Can two waves interfere head on?

Can two waves (like sound or electromagnetic waves) interfere head on? If yes, and suppose they are out of phase with each other and thus interfere destructively, where does the energy of the waves go?...
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Can there be interference between a proton and an electron?

For example, we know that we can interfere two different electrons or two different protons by employing them in a double-slit experiment. Now suppose, we mix protons and electrons and shoot them ...
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Will two coherent sources of orthogonal polarization angle form the known interference pattern or there will be difference?

if i have a laser beam then i split it into two beams with ratio 1 : 1 then i take one of them to change its polarization angle (90) degree by passing it through an optically active substance then we ...
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Thin film Interference pattern

Why exactly for this minima condition is: path difference = $(2n-1)\lambda/2,$ instead of $(2n+1)\lambda/2$? And what is the starting order of minimal here? Also, what does a negative path difference ...
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What do fringe patterns have to do with VLBI?

I think I have fundamental confusions with how VLBI works. I don't know why: Resolution increases when incident rays meeting to a focal point from a farther separation along an axis perpendicular to ...
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Maintaining phase relationships and other general principles of interferometry

I have a few confusions with some basic principles of interferometry. Bob Campbell's So you want to do VLBI writes: Phase relationships among all points on the wavefront will be preserved ...
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Difference between 'white light' and spectral light for rings of Newton

In my book of waves and optics, there's a chapter about the rings of Newton and as a question there is: how is the interference pattern when we use white light, considering me it's : there are rings ...
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Michelson interferometr electromagnetic wave formula [duplicate]

I don't understand why we use this formula: Instead of this formula: I mean, why we ignore $\omega\cdot t$ part.
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Relationship between spatial coherence and location of interferences

When using an extended source to create interferences, let's say in a Michelson Interferometer setting, it's necessary to use some kind of lens to be able to see the interferences. It is also true ...
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Why do we need cross-polarised light for observing conoscopic interference patterns?

I've performed some experiments for projecting conoscopic interference patterns. In some set-ups are used two circular polarizers one before and one after the birefringent crystal. I can imagine that ...
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Formulae for destructive interference [closed]

There are two formulae for destructive interference. In which situation do we use them? $$(n+1/2)\lambda$$ and $$(n-1/2)\lambda$$ I'm confused as my book has mentioned the first one but In ...
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Destructive interference by a hard boundary

" Wavefronts on reflection off of a hard boundary ( rigid boundary ) have their phases inverted. " This is something I've learnt. " Waves with same amplitude and opposite phases destructively ...
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How did scientist get photos of wave function of electron in the double slit experiment?

In the double slit experiment I know that the electron fires as a particle one at a time then splits goes through both slits and recombined and interferes with itself and hit the wall creating a ...
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Least-square fitting to data (sine function): what is the error of the derived fit parameters?

I have a set of data. I want to fit it to a sine function of the form : \begin{equation} f(x)=A sin(\omega x+B)+C \end{equation} I use the least-square method to find the appropriate fit-parameters ...
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Photon bunching and polarizers

I'm trying to understand how polarizers affect bunched photons. Or, more generally, how a projection operator affects a two-photon state corresponding to photon bunching. Toy example: Imagine you ...
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Diffraction pattern vs Interference pattern

I am not confused with difference between Young's double slit experiment and diffraction. In Young's double slit experiment, the interference pattern is bright fringes separated evenly with ...
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Would a million slits experiment works?

I read that in triple or more slits experiment, the particle can sometimes though lower probability of going through all the slits and interfere with itself many times at once? I used to think it is ...
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Single photon interference, state “top” current theory [duplicate]

Is there a simple generally accepted explanation for single photon interference? Does each photon interact with or see both slits?
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Wavelength and Lattice constant - need to be the similar magnitudes to have interference?

I was taught that they need to have similar magnitudes but I did an exercise last week and the magnitudes were different by 3 decimal places. Before I also noticed them being either the same or maybe ...
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Macroscopic objects - Interference

In Mcintyre's QM book he writes: What does he mean by "a macroscopic object strongly interacts with the environment" for there to be no interference? Why/how does the wave function of macroscopic ...
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Why does light show a no interference result?

I was reading the first chapter in the Feynman lectures volume 3 about quantum mechanics and I understand the concept that 'interference' means $P_{12}=P_1+P_2$ as expected, however when the electron ...
49 views

Bubble optics, impact

My 8 years old daughter was blowing soap bubbles. Most of the bubbles had color. She randomly choses a bubble with colors and lands it on the wand. Instantly it's color is gone. If she blows this ...
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“Partial” Total Internal Reflection

Can partial TIR happen? Consider the image present in this link Here, at point D, TIR happens, but also there is transmission. Is "total" internal reflection a misnomer?
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Confusion regarding path difference by glass lab in YDSE

If in a YDSE experiment the setup is immersed in a medium $n_{med}$, and a glass slab of thickness t of another medium $n_{glass}$ is introduced in front of one slit, then is the path difference due ...
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Air wedge interferometer (Fringe separation)

From Hecht optics, From the setup, $\alpha = \frac {d}{x}$ $--> d = x \alpha$ $d$ is the varying thickness of the air wedge The condition for constructive interference, \$ ( m + \frac {1}{2} ) \...