10
votes
Accepted
Can taut membranes and strings that are clamped at both ends propagate non-standing waves?
Mathematically, a wave is a solution of a wave equation with the appropriate boundary conditions. A wave equation alone does not define a wave.
Now, if we have hard boundary conditions - like clamped ...
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4
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How was the speed of colored light measured in a vacuum?
The experiment that I am aware of which places the tightest limits is
Schaefer. Severe Limits on Variations of the Speed of Light with Frequency. phys.rev.lett. 82:4964-4966. 1999.
https://arxiv.org/...
- 105k
3
votes
Accepted
When a taut string is plucked, what will be the direction of the transverse wave's propagation?
if you pluck the string precisely at the midpoint of the string's length?
There will be 2 waves, propagating in opposite directions with transverse amplitude = plucked-amplitude/2
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3
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Creating pure monochromes by separating constituent waves
A filter that removes all frequency components outside a finite bandwidth, (compact support), must have an infinite long impulse response, see the Paley-Wiener theorem. As a consequence, no signal ...
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3
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How was this equation for the stability of a finite difference model Wave Equation derived? Von Neumann analysis?
Here is some partial answer that misses some steps/info to be complete and rigorous, but should be enough to explain the derivation. Firstly, since $\sigma_0$ doesn't appear in the formula, I'll ...
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votes
Waves, energy and matter
I'm not a physicist, and I'm not sure how the physicists will vote on this one; but IMO, instead of saying that a wave transports energy, I think it might be closer to the truth to say that a wave is ...
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2
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Accepted
How to "rectify" this wave-equation derivation for Longitudinal waves?
Yes, OP is right. In the discretization (1), OP's professor is effectively finding the Hooke's force at the position $x-\frac{1}{2}\Delta x$ and $x+\frac{3}{2}\Delta x$, which are the external forces ...
- 209k
2
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Creating pure monochromes by separating constituent waves
No filter will produce an ABSOLUTE 'pure monochrome'; there are line width limitations in colored-glass items, diffraction gratings have some non ideal features that are related to the 'blaze' ...
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1
vote
Need clarity about EM wave generation
First, consider a simple dipole antenna. In its immediate vicinity it produces an electric field from end to end, and magnetic fields in circles around its axis. These fields are pretty close to ...
- 28.8k
1
vote
Steady-state wave equation
When $u_{tt}$ is identically zero we have a static situation. A static electric and/or magnetic field for example. Or a body under static stress. There are no waves.
Edit: Besides static situations, ...
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When a taut string is plucked, what will be the direction of the transverse wave's propagation?
Wherever you pluck the string, you will create two instantaneous wave packets - combinations of waves of many different wavelengths - one travelling in each direction along the string. However, once ...
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Wave with mass transport?
There is more to the story about whether matter has net motion / displaced i.e. transported (spontaneously advected), in the linked video there is what is called stokes drift, and also the next link ...
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