All Questions
101
questions
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 ...
- 59
1
vote
1
answer
87
views
What is light? how is it connected to electromagnetic radiation?
I am trying to understand how light works and electromagnetic radiation, from what I understand charges cause disturbances in electric fields, which triggers a magnetic field, and then the back and ...
1
vote
1
answer
51
views
Would we be able to see the superposition of two X-rays where the frequency of the modulation matches visible light?
Suppose I had the superposition of two electromagnetic waves whose angular frequency was in the X-ray region. Together they form a composite made of a carrier wave and a modulation wave where the ...
- 531
0
votes
1
answer
41
views
Is amplitude measured from the electric or magnetic fields of a wave?
When you measure amplitude, does that refer to the electric portion of the electromagnetic field, or does it refer to the magnetic portion? Or is an average of the two?
Another question is, are the ...
- 187
1
vote
0
answers
31
views
Why do light bulbs don't produce coherent waves? [duplicate]
My textbook says that light ways produced by light bulbs are not coherent but it doesn't describe the reason.
I was wondering how could two waves not be coherent regardless of the source they are ...
- 21
2
votes
1
answer
68
views
Poisson spot amplitude
The equation
$$
U(P) \propto \int_0^{2\pi} \int_0^{\infty} g(\rho,\theta) \exp\left[ \frac{i\pi}{\lambda}\left(\frac{1}{z_0} + \frac{1}{z_1}\right) \rho^2 \right] \rho \, d\rho \, d\theta
$$
or the ...
- 121
1
vote
1
answer
127
views
How do surfaces absorb and reflect light at the atomic level, and what does that have to do with color?
This is sort of a 2 part question that I'm really struggling to figure out.
When white light (which as far as I understand, is just a composition of most electromagnetic frequencies) bounces off, say,...
- 33
0
votes
0
answers
35
views
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
0
votes
1
answer
63
views
Is high school wave peak equation accurate enough for real world?
After preparing for my physics test I came across the equation for calculating peaks and valleys of light in double slit experiment - $N\lambda = dsin\theta$. But, looking at how it is proven. I'm ...
- 1
0
votes
1
answer
53
views
Paraxial Rays and Coma
In these slides it is stated that:
Coma is an abberration that afflicts off-axis light bundles in a
similar manner to the way in which spherical aberrations affects the
axial bundles.
About Coma, my ...
- 1,319
0
votes
1
answer
327
views
Thin Lens as phase transformation
In Introduction to Fourier Optics, J. Goodman, Chapter 5, the lens is analyzed as a phase transformation due to its variable thickness on the transverse plane xy.
Under paraxial approximation, the ...
- 1,319
-1
votes
1
answer
75
views
What do we actually mean when we say "light"?
light is an electromagnetic wave , but can we say all EM wave are light?
eg. infrared radiation , uv radiation ... can we say these as light?
- 29
1
vote
2
answers
94
views
Questions regarding light being depicted as a sine wave [duplicate]
Light waves are often depicted as sine waves...
Why is it so?
What's actually waving?
And what does the sine wave signify and represent?
What does wavelength of light mean/signify? and how is it ...
- 53
-2
votes
1
answer
260
views
What is the wavelength of red light in vacuum?
According to Wikipedia,
It has a dominant wavelength of approximately 625–740 nanometres.
However, I'm not sure in which medium this wavelength was measured. Was this wavelength measured in a vacuum?...
- 1,018
2
votes
2
answers
94
views
How ample is a wave amplitude?
Is it possible to actually measure/deduce the amplitude of a wave? We know that the length of am infrared wave is a fraction of a millimetre, do you have any idea what is the range of the physical ...
- 691