All Questions
Tagged with electromagnetic-radiation wavelength
206
questions
25
votes
6
answers
129k
views
Do all frequencies of light have the same speed?
Is there any speed difference between blue or red light? Is there ever a speed difference? Or do all types of light move at the same speed?
- 939
12
votes
3
answers
16k
views
In electromagnetic radiation, how do electrons actually "move"?
I've always pictured EM radiation as a wave, in common drawings of radiation you would see it as a wave beam and that had clouded my understanding recently.
Illustration on the simplest level:
Which ...
- 135
41
votes
4
answers
191k
views
Why does wavelength change as light enters a different medium?
When light waves enter a medium of higher refractive index than the previous, why is it that:
Its wavelength decreases?
The frequency of it has to stay the same?
- 4,607
4
votes
4
answers
6k
views
Some questions about car radio and cellphone antennas
1-Why the antenna of the radio of cars is located outside the car and not inside?
2-If the answer to 1 is because that cars are like Faraday cages then how come my cell phone can receive signal ...
- 17.1k
21
votes
5
answers
20k
views
Why is it necessary for an object to have a bigger size than the wavelength of light in order for us to see it?
I keep hearing this rule that an object must have a bigger size than the wavelength of light in order for us to see it, and though I don't have any professional relationship with physics, I want to ...
- 313
4
votes
2
answers
6k
views
Wavelength-dependent refractive index
I read in a book about optical fibers that the different spectral components of a light pulse transmitted in the fiber propagate with different velocities due to a
wavelength dependent refractive ...
- 237
22
votes
3
answers
13k
views
What is the minimum wavelength of electromagnetic radiation?
As a first approximation, I don't see how a wavelength of less than 2 Planck distances could exist. The question is: Are there any other limits that would come into play before that?
For example:
...
- 1,269
5
votes
1
answer
350
views
Is the number of wavelengths of light spanning a distance invariant with respect to spacetime distortion?
I was recently asked by a friend how the expansion of spacetime affects photons. I gave him what I feel is a satisfactory general response, but it got me wondering how, exactly to calculate this ...
- 4,973
0
votes
1
answer
265
views
Merge different wavelength rays
Let's say an array of rays of light is given.
Each ray has a specific wavelength (in the range of visible light).
Example:
...
- 133
6
votes
5
answers
19k
views
Light emitted by an object according to its temperature
According to this picture
the light emitted by an object depends on its temperature.
That makes perfect sense when we heat a metal. As its temperature raises we see it red at first, then orange, ...
- 1,291
3
votes
2
answers
1k
views
Magnetron limits
What are the practical limits on generated wavelength in a Magnetron?
We know that Magnetrons could be used efficiently for generating microwaves for water heating, or for radar applications, but ...
- 2,409