# Tagged Questions

Waves are disturbances that propagate through space and time. Classically, they travelled through a medium, disturbing the particles but not changing their mean position. Electromagnetic waves/particle-waves need no medium; they are disturbances in their respective fields.

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### Pouring oil on choppy water to calm it , does it work and if so how?

Near where I live, local fishermen often bring cans of castor oil with them, to calm the water around their boats, if they feel bad weather is due. They claim this method of sea calming works, (...
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### Waves ionsphere?

Explain why the ionosphere can be treated as a plane mirror when transmitting short-wave radio, even though it is a curved surface. Is it because the area involved is small?
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### Why is the wave equation so pervasive?

The homogenous wave equation can be expressed in covariant form as $$\Box^2 \varphi = 0$$ where $\Box^2$ is the D'Alembert operator and $\varphi$ is some physical field. The acoustic wave ...
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### Why does sound wave suffer more diffraction than light waves generally?

Why do sound waves suffer more diffraction than light waves generally ? I would like more of a logical explanation rather than mathematical .
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### Velocity profile of a viscously damped wave

For a test case, I want to determine the velocity profile of a viscously damped standing wave. By linearizing the density ($\rho=\rho_0+\rho'$) and velocity ($ux=ux'$), the continuity and Navier-...
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### Waves interfere in angle equation

If we had two waves perpendicular to each other, with equations: $x=α \sin(ωt)$ (1) $y=β \sin(ωt+π/2) ==> y=β \cos(ωt)$(2) $\sin(ωt)^2+\cos(ωt)^2=x^2/α^2+y^2/β^2=1$ $x^2/α^2+y^2/β^2=1$ is an ...
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### Why is a sine wave considered the fundamental building block of any signal? Why not some other function? [closed]

It is mathematically possible to express a given signal as a sum of functions other than sines and cosines. With that in mind, why does signal processing always revolve around breaking down the signal ...
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### baryon acoustic oscillation

I have one question about baryon acoustic oscillation. I understand why we should have the baryon-photon fluid sound wave before recombination: Suppose we have a spherical overdense region. This ...
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### How are standing waves a result of constructive and destructive interferences?

For constructive I can understand. But destructive I can't. I can not picture the shape of two pulses or waves maybe that form the resulting standing wave. The places where waves are canceled just ...
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### Is sonic boom louder than the sounds that a object traveling at the speed of sound makes, if so why?

Here are the wave-front models for both: I am in an introductory physics course. Just learned about this. I am not entirely sure if sonic boom is louder. But from what I saw, it's loudness is ...
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### Reflection of an Electron

When a mechanical wave goes from one material to an other, some fraction of it returns back. Same thing with light (massless), but what happens with an electron? When the "wave function" changes ...
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### Question about intensity of EM waves

For electromagnetic wave if it's reflected from a perfect conductor standing wave can be form. I wonder why Poynting vector can be used to describe the intensity of standing EM wave. (see p.19 of http:...
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### Numerical Solution of the Propagation-Dispersion equation

I have asked this question on Computational Science and also on Mathoverflow, but no satisfactory answers so far. I thought maybe the physics community could shed some insight on the issue. I am ...
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### concerning the effects of temperature and density on the speed of sound [duplicate]

here is my relatively broad question: how does the temperature and density of a medium effect the speed at which sound travels through it? Now I shall elaborate: it is my understanding that there ...
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### What do light wave oscillations look like? [duplicate]

High school physics student here, so please bear with me for a moment. I know that light waves oscillate, but I don't know how. In textbooks and diagrams they're portrayed as wavy lines traveling ...
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### Two supersonic planes. Do they hear each others sonic boom?

Plane A is traveling at Mach 2 and is over taken by plane B traveling at Mach 3. Does plane A hear the sonic boom from plan B? If so when? Does plane B hear the sonic boom from the slower Plane A? ...
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### Can a standing wave form on a string with both end open

I am fascinated with an idea of an standing wave forming on a string with both end open. If we assume two identical waves coming in of an infinitely long string then for a short period of time, they ...
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### Is an infinite Doppler effect plausible?

When I was young (which I still am) I was amazed by the sound jet fighters make when they break the sound barrier - a sound similar to an explosion which caused my school to shake. Later I learned on ...
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### Interference of Beams with Different Polarizations

I have read in many places that orthogonally polarized light beams do not interfere. However, I also know that orthogonal vectors, such as force, do affect each other and give a resulting force. So, ...
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### what is the effect of a sound wave at the opposite side of its direction?

We know that a sound source produces a sound wave and a high pressure area is followed by a low pressure area, while they travel with 300m/s. My question is, if the sound source travels with 50m/s in ...