All Questions
69
questions
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What happens when a linear polarized EM wave encounters a perpendicular mesh of wires (which are electrically connected)?
Assume a radio wave with wavelength 1 m is traveling in the negative z direction when it encounters a grid of closely spaced wires (say, 10 cm separation) laying in the xy plane, with each wire ...
- 93
2
votes
4
answers
133
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Reflection due to wave nature of light
In my high school, I am studying geometrical optics. I studied why smooth surfaces like mirrors form an image of an object but rough surfaces like a wall don't (due to regular reflection and irregular ...
0
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1
answer
47
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Why are Fresnel coefficients not symmetric?
When talking about reflection, we have the following coefficients for the electric field:
$$r_{\perp}=\frac{n_1\cos(i)-n_2\cos(t)}{n_1\cos(i)+n_2\cos(t)} \\ r_{\parallel}=\frac{n_2\cos(i)-n_1\cos(t)}{...
- 267
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0
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46
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How can a greater than 1 reflectance coefficient be explained in $\rm SiC$-$\rm SiO_2$ interface?
I ran a simulation using the Transfer Matrix Method to plot the R,T and A curves for a SiC->SiO2 interface. There's a region of incident energies where the |r|^2 I get is higher than 1 and the ...
- 11
3
votes
1
answer
158
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Infinite reflection inside a glass loop
If you had a loop made of completely transparent glass (or other material), in the shape of a donut; think atomic collider (but probably not needing to be so large :) ), and you introduced light from ...
1
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1
answer
57
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Why are things reflective, absorbent, transparent etc? [duplicate]
What determines whether a material reflects, absorbs or transmits a certain wavelength of light? Just a layman's question.
- 111
0
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1
answer
28
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Fresnel coefficients with permanent magnetism
I am familiar with the standard derivation of the Fresnel coefficients for linear magneto-dielectrics (for instance https://en.wikipedia.org/wiki/Fresnel_equations#Derivation). However, I was ...
- 352
2
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0
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81
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How does photon reflection work quantum mechanically? [duplicate]
When a single photon strikes a mirror, it is reflected back such that the incident angle= the reflected angle. When the photon interacts with the surface lattice of the mirror, what exactly is ...
- 719
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1
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105
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We know that a window can actually reflect light. But if the window has some dirt sticking to it, the image we see sometimes get magnified. Why?
Well, I was traveling in a bus yesterday and saw this occur. The board that separates the passengers from the driver's had something written on it and I saw that the window that was a few meters away ...
- 3
4
votes
1
answer
812
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Sunscreen protection, SPF, and amount applied: relationship?
In the article How SPF Changes with How Much Sunscreen You Use (last updated Dec 29, 2017), the author says that insufficient sunscreen disturbingly decreases protection exponentially, in other words, ...
- 804
3
votes
1
answer
260
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Light on reflection at junction point
When a light (or any other EMW) is striking a reflecting surface it is expected that it would reflect back with same angle as of incidence with normal to the point. Considering wave nature of light, ...
- 75
2
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1
answer
357
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Why is the law of reflection true?
When a bunch of photons strike a surface then they get absorbed by the electrons on that surface which then starts oscillating and thus re - emit some photons but they do it in the same plane as that ...
- 8,230
1
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0
answers
27
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Reflection of EM waves on furniture
I just put my phone next to a piece of furniture with wood finish on it. The reflection of the wood on the wood was purple-ish in appearance. What is the Physics behind this?
1
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0
answers
416
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Does reflection depend on wavelength?
I'm aware of processes like Rayleigh scattering, Compton scattering and pair production. But as these processes treat light as being particles(?) I'm not sure whether they are helpful to understand ...
- 1,507
1
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2
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2k
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Phase Shift of Light upon Reflection
In waves other than electromagnetic waves (e.g. waves on a string assuming small transverse displacement), when propagating across the boundary between two media, a fraction of a wave will be ...
- 107