Unanswered Questions
1,055 questions with no upvoted or accepted answers
11
votes
1
answer
512
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Pressure underneath wave
I enjoy water sports and activities in the water. I've swam around and dived down enough to need to equalize my ears and in general have felt water pressure.
I've since taken up surfing and have ...
CommunityBot
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10
votes
0
answers
737
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Double slit - higher dimensions
The double slit experiment is a real-life manifestation of the Huygens principle. As is well-known, this principle depends on whether the number of dimensions is even or odd; as Evans1 puts it,
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7
votes
0
answers
168
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Can a "depressive soliton" wave exist? That is, can we have a trough without any crest? Why or why not?
I know that "soliton" waves can consist of a crest without a trough. One would expect the reverse to be true as well.
However, this Wikipedia excerpt says,
So for this nonlinear gravity ...
- 22.2k
6
votes
0
answers
121
views
Relation between the electric and magnetic fields for an arbitrary electromagnetic wave
When solving the wave equation for electromagnetic waves,
$$
\nabla^{2} \mathbf{E}=\mu_{0} \varepsilon_{0} \frac{\partial^{2} \mathbf{E}}{\partial t^{2}}, \quad \nabla^{2} \mathbf{B}=\mu_{0} \...
- 1,044
6
votes
1
answer
2k
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Why the fields of the quasi-TEM mode of microstrip line tend to concentrate in the dielectric as frequency goes higher?
A microstrip line is a waveguiding structure as shown below:
Because of the inhomogeneity, the fundamental mode of propagation is a quasi-TEM mode, which means that the z components of the E and H ...
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6
votes
3
answers
668
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Why is the speed of sound wave in a gas always lesser than the r.m.s. speed at the same temperature?
My book says that the speed of sound wave in a gas is always lesser than the r.m.s. speed of the gas at the same temperature. I understand that speed of sound is given by:
$$v_s=\sqrt{\frac{\gamma RT}{...
CommunityBot
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6
votes
0
answers
319
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Can ray-tracing be used to design a stealth air craft? Or is it necessary to use wave theory?
This question is inspired/kicked-off by a question over in Aviation SE asking about the design of stealth air craft.
Stealth technology is usually referred to when trying to make vehicles invisible ...
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6
votes
0
answers
452
views
Physical intuition for the solutions of the wave equation
I have been studying the wave equation in $\mathbb{R}^n$ for the cases $n=1,2$ and $3$. In the three cases, working all over $\mathbb{R}^n$. That is:
$u_{tt}(x,t)=c^2 \Delta_{x} u(x,t)$ for $x \in \...
- 161
6
votes
1
answer
4k
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Explaining phase shift from a half-silvered mirror
I am trying to understand why light undergoes a phase shift when reflecting off one side of a half-silvered mirror, but not the other side.
This Wikipedia page and this answer both give the following ...
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6
votes
1
answer
606
views
Can the Taylor expansion of Energy/Intensity be explained more in-depth?
In reference to the question, "Why is energy in a wave proportional to amplitude?" Ben Crowell answered with the answer attached. The original post is linked here. I did not respond to the ...
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5
votes
0
answers
150
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Does sound need an odd number of spatial dimensions?
In the book "when Einstein walked with Gödel" the author talks about Edwin A. Abotts "Flatland" stating that one problem which was unattended by Abott is the problem of acoustics ...
- 224k
5
votes
0
answers
761
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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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4
votes
0
answers
199
views
Why do water surfaces have persistent "average wavelength" patches?
Have you ever stood above a river or lake and noticed that the surface has visible "patches"? It looks like the surface has different average wavelengths in some areas, leading to the light ...
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4
votes
0
answers
166
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On sum of amplitudes in Wave Mechanics
Consider Schroedinger equation, which I write in the form $$ (\mathscr{L}+V)\psi=0$$where $\mathscr{L}$ is the kinetic and time-derivative operator. Now, imagine I have two point sources 1,2 with ...
- 2,099
4
votes
1
answer
280
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Can you observe Rayleigh scattering of water waves?
I understand roughly that Rayleigh scattering occurs when white light encounters particles smaller than the wavelength of visible light, and short wavelengths are preferentially scattered.
I'm ...
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