Questions tagged [electromagnetic-radiation]
Propagating solutions to Maxwell’s equations in classical electromagnetism and real photons in quantum electrodynamics. A superset of thermal-radiation.
5,641
questions
0
votes
0
answers
27
views
dipole-radiation in semiclassical dynamics solid state
Using the semiclassical dynamics in solid state physics (electrons on a lattice with periodic potential, constrained to a band structure), we usually obtain that in the presence of external fields (...
- 51
0
votes
1
answer
745
views
What is the physical meaning of the complex field amplitude?
I see that the harmonic field is sometimes written in exponential form. But sometimes the complex amplitude of this form is just a constant and in others (like when talking about modes) is dependent ...
CommunityBot
- 1
2
votes
2
answers
233
views
How can we visualize electromagnetic radiation?
In so many classes I’ve been told that light is nothing more than an electromagnetic wave. While this makes sense, it’s never been nearly as clear as imagining a static charge. At every point in space ...
CommunityBot
- 1
0
votes
2
answers
395
views
Origin of electromagnetic radiation in the universe
I don't know if the total electromagnetic radiation in the universe is finite or not.
But either way: what is the origin of the electromagnetic radiation in the universe? Can we say that all of it ...
CommunityBot
- 1
0
votes
2
answers
51
views
Confusion about EM spectrum and the Fourier transform
Since courses on signal analysis and electromagnetism I have become confused about what the spectrum of electromagnetic radiation really means. I know light is when electric and magnetic fields become ...
- 35.4k
2
votes
2
answers
112
views
Single photon detection
Consider a thought experiment where we have a source emitting a single photon, like an atom/molecule going from an excited energy state to its ground state.
We have an infinite number of point ...
- 46.1k
0
votes
1
answer
25
views
Dipole radiation of a non-relativistic electron in elliptic motion [closed]
I'm trying to solve the following problem:
A non-relativistic electron is moving in elliptical motion inside a positively charged cylinder of homogenous charge density $\rho$. The initial radius ...
- 15
2
votes
1
answer
47
views
Is there a way to use the optical transfer-matrix method to determine the absorbance of each layer in a multilayer stack?
I've implemented the transfer-matrix method to determine the the transmittance and reflectance of a multilayer stack of thin films.
I know that (ignoring scattering) the absorbance of the entire stack ...
- 171
0
votes
2
answers
319
views
Why is this question indicating a Fraunhofer Region rather than Fresnel Region?
I was thinking that because the source plane is infinitely large would be analogous to having the source plane being infinitely close, which would imply a Fresnel region rather than Fraunhofer.
...
CommunityBot
- 1
-2
votes
1
answer
1k
views
Can Amps be used as a unit of measure for the amplitude of an EM wave?
As far as I know the definition for the amplitude of a wave is the distance between the line $y=0$ and the peak of the wave which in most cases is going to be a unit of length. I also understand that ...
5
votes
3
answers
2k
views
Is it possible to get an electromagnetic wave equation if the speed of light were infinite?
In an old question: How would night sky look like if the speed of light was infinite? the best answer was voted down to negative credits.
I cannot understand why. From Maxwell's equations, we derive ...
- 324
0
votes
1
answer
89
views
Lambertian surface and the luminous intensity
I am currently studying the basics of photometry to better understand the rendering equation of Kajiya. One thing I'm currently struggling with is Lambert's cosine law.
Let's go over the premises:
A ...
-1
votes
1
answer
57
views
Do bosons exist at different energy densities?
Excuse my rudimentary (at best) physics knowledge, but I was running a thought experiment earlier (read musing to myself). I was wondering whether a photon could be considered analogous to bowshock, ...
- 11
1
vote
1
answer
230
views
Induced charge density on perfect conductor
Assuming there is a perfect conductor at $x=0$ in $\mathbb{R}^3$ and a plane EM wave $\vec{E}_i(\vec{x},t)=\vec{E_i^0}e^{i(kx-\omega t)}$ is coming from $x=- \infty$. We know, that the wave $\vec{E_r}(...
CommunityBot
- 1
1
vote
3
answers
115
views
If quaternions are an extension of complex numbers, is there a study of EM wave theory in terms of quaternions?
I find that in standard textbooks and online resources, basic EM wave theory (such as radiation, plane wave solutions, polarization) is discussed by treating fields in terms of complex numbers. Is ...
