All Questions
Tagged with electromagnetic-radiation waves
139
questions
61
votes
4
answers
32k
views
Why do prisms work (why is refraction frequency dependent)?
It is well known that a prism can "split light" by separating different frequencies of light:
Many sources state that the reason this happens is that the index of refraction is different for ...
- 12k
60
votes
6
answers
82k
views
Phase shift of 180 degrees of transversal wave on reflection from denser medium
Can anyone please provide an intuitive explanation of why phase shift of 180 degrees occurs in the Electric Field of a EM wave, when reflected from an optically denser medium?
I tried searching for ...
WhizKid
49
votes
8
answers
23k
views
Amplitude of an electromagnetic wave containing a single photon
Given a light pulse in vacuum containing a single photon with an energy $E=h\nu$, what is the peak value of the electric / magnetic field?
- 1,056
13
votes
2
answers
9k
views
How do mirrors work?
My physics professor explained to me that electromagnetic waves are consisted of two components - electric and magnetic - which cause each other.
Which part of the mirror actually reflects the wave?
...
- 2,119
45
votes
4
answers
6k
views
Why is Huygens' principle only valid in an odd number of spatial dimensions?
Apparently Huygens' principle is only valid in an odd number of spatial dimensions:
https://mathoverflow.net/a/5396/21349
Huygen's principle in curved spacetimes
Why is this?
[EDIT] This is ...
user4552
6
votes
5
answers
2k
views
Existence of monochromatic pulses?
Why there can not be a monochromatic pulse? My physics professor told us that we can't generate a monochromatic light pulse and I was wondering what are the physical limitations causing this.
- 69
4
votes
5
answers
3k
views
Radio antenna producing waves in the visible spectrum [closed]
If a radio could produce waves in the visible light spectrum, what would the result be?
This is a thought experiment that I've pondered for a few years now. I realize there are a few/many real-world ...
- 171
17
votes
2
answers
3k
views
If light rays obey to the wave equation, why can they be thought as straight lines?
I'm a newbie with physics but I'm wondering how a ray of light can essentially be represented. I have always known that a ray of light proceeds in a straight line until it encounters another object (...
- 281
28
votes
6
answers
12k
views
Do the electric and magnetic components of an electromagnetic wave really generate each other?
Frequently when EM waves are taught, it is said that the change in electric field causes a change in the magnetic field, which then causes a change in the electric field, and so on and so forth.
But ...
- 545
22
votes
5
answers
12k
views
What exactly is meant by the wavelength of a photon?
I've been thinking about this for quite some time, and from looking online I haven't found a satisfying answer.
Lots of photons, such as visible-light photons have very small wavelength (which from ...
- 379
11
votes
4
answers
2k
views
Is light amplitude spatial?
In diagrams I often see light waves depicted as little sine waves that travel through space. And often when describing polarizers, the explainer will angle their hand to show the angle of ...
- 365
19
votes
6
answers
3k
views
How does Huygens Principle incorporate the unidirectional property of a traveling wave?
I was reading French's Vibrations & Waves where he discusses Huygens-Frensel Principle.
The principle talks about how secondary sources give rise to secondary wavelets to form the displaced ...
user36790
15
votes
1
answer
722
views
Why is the wave equation so pervasive?
The homogenous wave equation can be expressed in covariant form as
$$ \Box^2 \varphi = 0 $$
where $\Box^2$ is the D'Alembert operator and $\varphi$ is some physical field.
The acoustic wave ...
- 1,398
8
votes
9
answers
18k
views
Why do we think of light as a wave?
I've read that light travels in a straight line and has a wavelength of 400nm to 700nm. But I don't understand why does it have a wavelength and what creates its wavelength? I agree with the concept ...
- 213
15
votes
2
answers
28k
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What is light, and how can it travel in a vacuum forever in all directions at once without a medium?
I know there are many questions that are similar (maybe identical?). I am not a physicist nor a student - I am just interested in physics and have been watching many physics channels on youtube ...
- 253