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1answer
142 views

Young experiment: square of classical real wave function

I can't understand why the sum of two real waves result in a time dependent wave, but not so for the complex waves. In details, I can't get this passage on p.38-39 in A.C. Phillips, Introduction to ...
0
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3answers
133 views

How do I determine where I can no longer hear sound?

A teacher stands well back from an outside doorway that is 95 cm wide and blows a frequency of 600 Hz. The door faces north. Assume the speed of sound is 340 m/s and that there are no reflections. At ...
1
vote
1answer
298 views

Kiessig fringes

I have come across many papers but still couldn't find the relationship between index of refraction or atomic scattering factors, and reflectivity. My flow of thought goes as follows: Get the ...
1
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2answers
564 views

Double slit experiment alternating holes

If we perform the double slit experiment by shoting photons covering one hole at a time, would we see equally the double slit interference?. That is, the same set up of double slit but fire photons ...
3
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2answers
250 views

Probability wave speed of dispersion and interference

I'm a layperson learning about quantum mechanics and probability waves. My understanding is that the probability wave for the position of a particle disperses throughout all of the universe. I have ...
2
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0answers
158 views

photon and Z boson interference?

I'm not certain that this question will make sense, but here goes... In most monte carlo generators, when Z events are produced, there is a lower mass cutoff on the Z pole. I've been told that this ...
2
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1answer
266 views

Considering the wave function is not 'real', what is interfering?

I find the idea of the wave function being 'just' a collection of numbers (probabilities) quite alluring, and elegant in explaining away the whole 'collapse' business (see Luboš' answer to this ...
2
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4answers
1k views

Single photon and double-slit experiment [duplicate]

Laser fires single particles of light, called photons, through the slits. Even though only single photons of light are being fired through the slits and They create three pattern again. How single ...
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2answers
376 views

Interference, photon's phase, and the Hilbert space

Dirac said that a photon can only interfere with itself. This is consistent with the tensor product of two photon spaces representation. On the other hand, it is known that there is interference ...
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3answers
190 views

supressing certain decay paths and enhancing others with interference

In a scattering reaction, there are many possible final states for the products, each with different production rates. Question: Is there a way in which we could in general supress certain rates ...
6
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3answers
748 views

Triple slit experiment

If the experiment is done with single photons and a "detector" at one of the slits the interference pattern breaks down. What happens if three slits are used with single photons and a "detector" at, ...
2
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2answers
344 views

A question on intereference experiment with water waves as given in the Feynman Lectures on Physics

I have a question related to the interference (thought)experiment with water waves given in the book Feynman Lectures on Physics Vol.3. When only one hole (hole 1) is open the measured wave intensity ...
1
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1answer
2k views

Light interference maximum and minimum intensity points

This is a very basic question, but I just forgot how to solve this. It's classical physics question. Suppose that there are two light sources. And some place away exists a screen. How do I find ...
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2answers
593 views

Can electrons change the frequency of light as they bounce off/around?

I know that light does not interact with other light, but can interfere it, at least its amplitude. With that said, lights frequency can be changed via bouncing off matter, where matter might absorb ...
1
vote
1answer
643 views

How Light or Water Intensity is equal to square modulus of wave function of Light or Water Waves $I=|\psi|^2 \,$?

I've seen the Wave Function as a psi $\Psi$ $\psi$. And always heard that the wave function is the Complex Number as Imaginary and real number. But I've never seen it I've never seen components of ...
3
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1answer
77 views

Describing quantum intereference with only currents and densities

I know about and believe to understand the general wave equation based Kirchhoff diffraction formula, which in the Fraunhofer limit leads to a farfield complex wave function by Fourier transforming ...
42
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10answers
12k views

What happens to the energy when waves perfectly cancel each other?

What happens to the energy when waves perfectly cancel each other (destructive interference)? It appears that the energy "disappear" but the law of conservation of energy states that it can't be ...
5
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3answers
502 views

Which is the biggest object which can interfere with itself?

I've heard that scientist proof that viruses of the Tobacco mosaic virus could interfere with themselves. I'm referring to quantum interference-- the same as photons. Unfortunately, I couldn't find ...
6
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1answer
348 views

Are two polarization states of light coherent?

Let's consider a situation: we have distant point source of unpolarized light in certain non-zero range of wavelengths (it's polychromatic). Let's divide this light into 2 beams depending on ...
4
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2answers
189 views

What are the lines visible between two cards held edge-to-edge?

Hold two cards (say credit cards) edge to edge, anything from a very slight touch to about 1/3 mm separation, in front of any ordinary light source. When I do this I see several fine dark parallel ...
4
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4answers
1k views

Young's double-slit experiment with detectors

Related: Accuracy of various optical instruments In many books, it's written that knowing which slit a photon passes through (by placing a detector before the slit) in a Young's double-slit setup ...
4
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1answer
3k views

Purple doesn't occur in rainbow - or does it?

Usually, when asked whether the purple color exists rainbows, an answer similar to this is given: The purple color is perceived by human eyes via the activation of both red-sensitive and ...
2
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3answers
764 views

What does the differential of $d_s\sin(\theta) = m\lambda$ help us see, with respect to waves through diffraction gratings?

With respect to waves traveling through a diffraction grating, we have an equation like this one: $$d_s\sin(\theta) = m\lambda.$$ Where $d_s$ is the distance between slits in the grating, $\theta$ is ...
4
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3answers
2k views

Why does light in a room not form constructive and destructive interference patterns?

This is something that I have wondered for a long time. How come when I walk around why do I not see random black spots where light has collided destructively and bright spots where it has collided ...
2
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1answer
627 views

Why do I hear beats through headphones only at low frequencies?

I was recently playing with this Wolfram Demonstrations applet, which demonstrates beats. At first I thought the app didn't work because I couldn't hear any beats. Then I realized that the applet ...
5
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2answers
306 views

Two paths having the same phase in the path integral approach

In the path integral approach to Quantum Mechanics, can two distinctly different paths of the possible infinite paths have the same phase, i.e can there be a bimodal distribution of the phases ...
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6answers
3k views

How come an anti-reflective coating makes glass *more* transparent?

The book I'm reading about optics says that an anti-reflective film applied on glass* makes the glass more transparent, because the air→film and film→glass reflected waves (originated from a paraxial ...
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3answers
3k views

Why don't waves with different wavelengths interfere with each other in white-light?

The book I'm reading about optics says at some point that "each color (wavelength) contained in the white light interferes only with itself". But why is this so? Edit: I moved the rest of the ...
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2answers
834 views

Wave diffraction explanation [closed]

I'm trying to understand wave diffraction and I found this wikipedia article. It's in Czech so I'll explain a bit. I'm interested in the 4 images I couldn't find on english wikipedia. The first one is ...
6
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3answers
722 views

Recently publicized experiment on destructive interference between two laser beams

Recently I've had several non-physicist friends ask me, independently of each other, about an experiment where two collinear laser beams destructively interfere along a certain length. Everybody wants ...
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4answers
3k views

Energy conservation and interference

I have a problem with energy conservation in case of interfering waves. Imagine two harmonic waves with amplitudes $A$. They both carry energy that is proportional to $A^2$, so the total energy is ...
1
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1answer
366 views

Double-slit experiment with alternating on-off switch

Suppose we perform a double-slit experiment with a detector placed at a position of minimum intensity (maximum destructive interference), off-center where the path lengths differ by half a wavelength. ...
1
vote
2answers
251 views

Double slit experiment and perforated walls' properties

I have a doubt about how double slit experiment is made. Let's think about the perforated wall, what are the requirement for it? Can a photographic plate could be used as a wall ? I see a problem ...
1
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2answers
330 views

What's inside the slit in double slit experiment?

If double slit experiment is done in a environment with air, then slits could also contain air made up of (approx. 80% nitrogen, 20% oxygen), then there is not empty space inside the slit. How can it ...
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5answers
3k views

Does a photon interfere only with itself?

I sometimes hear statements like that: Quantum-mechanically, interference pattern occurs due to quantum interference of wavefunction of a photon. Wavefunction of a single photon only interferes ...
2
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2answers
296 views

Find drop-off rate of magnetic interference from a mass of pure iron on a magnetic compass

How can I find the magnetic interference a stationary 35000 kg block of 100% pure iron would have on a magnetic compass and what the drop off rate of the interference would be. So if said 35000 kg ...
8
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5answers
5k views

Interference of polarized light

Does polarized light interfere?
19
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4answers
2k views

Newton's rings: What causes the other rings?

This is from an experiment we did in physics class. We shone a sodium light at a convex lens on top of a sheet of glass - and this image was captured by a USB microscope. I know what causes the main ...
11
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5answers
867 views

Double slit experiment near event horizon

What happens if you perform a double slit experiment near an event horizon, if one of the slits is outside, one is inside the event horizon?