All Questions
21
questions
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2
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123
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Diffraction when the wavefront is not parallel to the plane
I am studying Feynman's chapter on the origin of the index of the refractive index (see this link).
If I am not mistaken, what he does is to prove that when a wave enters a medium (modelled as a ...
- 507
0
votes
1
answer
37
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Ray separation in waveplates
In a birefringent medium, the ordinary and extraordinary rays have different Pointing-vector directions and, therefore, different propagation directions, since the direction of the Poyting-vector ...
- 47
0
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0
answers
35
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Why does a light wave travel at a different speed when the density of medium is different [duplicate]
Why does light waves travel at different speeds when the density of medium changes? Can you slow down light?
- 5
1
vote
1
answer
59
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How does index of refraction changes with horizontal range
I am reading this ITU recomendation, and it says that the refractive index varies mainly with altitude as shown below:
What does it mean "mainly"? I understand how vertical change is ...
- 177
0
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0
answers
105
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Why is the refractive index $n$ linked to the wavevector $\hat{n}$?
Preamble: I'm studying light-light scattering in Effective QED but I notice that I don't remember a single thing from my EM/Optics courses so I decided to review some things.
Question: why is the ...
- 5,931
2
votes
2
answers
779
views
Wavefronts, refraction, and the marching soldiers analogy
I am not a physicist, but rather a middle school science teacher. Please be gentle. The marching soldiers has been a really good analogy for explaining why a change of direction is caused by hitting ...
- 43
1
vote
3
answers
2k
views
Are the amplitudes of the electric field and the magnetic field of an electromagnetic wave equal?
In an electromagnetic wave, is the maximum amplitude of the electric field the same as that of the magnetic field? I ask this question which may seem silly because on all the diagrams representing an ...
2
votes
4
answers
453
views
How we can explain bending of electromagnetic waves in a different optical media?
How can we explain the bending of light when it moves through different optical media by Maxwell's equations treating light as an electromagnetic wave?
0
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0
answers
39
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If both violet light and red light was incident on the center of a semi circular block, and refracted, would they have the same refraction angle?
As the violet and red light have the same speed in air, with the incident angle being less than the critical, with the violet light and the red light coinciding on each other, (like on top of each ...
- 101
-1
votes
2
answers
619
views
Speed of light and wavelength
Does the speed of Electromagnetic wave depend on its wave length? For vacuum I'm aware that it's a constant $c=\frac{1}{\sqrt{\mu_o\epsilon_o}}$. Similarly can we say speed of light in any medium is a ...
- 1,161
0
votes
1
answer
1k
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Dielectric constant change in the atmosphere?
I'm curious about the refractive index changing in the atmosphere. As I understand it (and I may very well be wrong/naive) when a ray of light enters from one medium into another, the electric field ...
- 90
3
votes
1
answer
1k
views
Do clouds reflect radio waves?
Do clouds reflect radio waves? Specifically, those waves used in radars.
And, what kind of matter refracts or reflects radio waves?
- 31
2
votes
1
answer
94
views
Why does light behave according to the left picture and not according to the right?
Light changes its speed, because the new medium is either more, or less dense; but why does it change direction?
- 33
1
vote
2
answers
2k
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Why is air transparent? [duplicate]
I made a rough calculation (probably having made a miscalculation though) following here and here to find out the number of air molecules in 1 cubic centimetre of air.
The first website says there ...
- 563
-1
votes
1
answer
96
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How I can prove refractive index in an environment is this? [closed]
in "Applied Quantum Mechanics" by A.F.J. Levi, is a problem that I couldn't solve it can any solve it:
if electrical filed is:
$$
\mathbf{E}\left(\mathbf{r}, \omega \right) =\mathbf{E}_{0}\left(\...
- 189