All Questions
43
questions
6
votes
3
answers
1k
views
Why can't thin clouds form rainbows?
Sunlight easily passes through THIN layers of clouds, composed of small water droplets/vapor, what is the problem accounted by the light rays that they are not able to form a rainbow?
- 401
1
vote
0
answers
109
views
The speed of light in medium with different frequency
We know that the speed of light in vaccuum can be expressed as $c=\frac{1}{\sqrt{\mu_0\epsilon_0}}$ and thus the speed of light in vaccuum is thus $$v=\frac{1}{\sqrt{\mu\epsilon}}=\frac{c}{\sqrt{\...
- 83
0
votes
1
answer
74
views
Let's say I have manufactured a prism from a non-dispersive medium, then light coming from air wouldn't split into colours right?
Let's say I have manufactured a prism from a non-dispersive medium, then light coming from air incident on the prism wouldn't split into colours, right? I mean light still changes direction, but all ...
- 959
0
votes
1
answer
56
views
Generally speaking, the speed of a wave depends on the medium and the wave type, so waves of the same type in the same medium attain the same speed [duplicate]
My question is, given the above statement, why electromagnetic waves attain different speeds in media other than vacuum even though they are of the same type and propagate in the same medium?
- 959
1
vote
2
answers
570
views
Does refraction depend on the colour of light?
Consider passing red and yellow lights separately through the same interfaces and with the same angles of incidence.
Light of which colour will be refracted more?
This question was given to me. All I ...
- 119
33
votes
3
answers
3k
views
A Rainbow Paradox
I was studying the phenomena of the formation of a rainbow. In my book, the following diagram is given:
So, the rays at the red end of the spectrum make a larger angle with the incident ray than the ...
- 1,064
0
votes
1
answer
62
views
Refraction of light with different wavelengths [closed]
A red light and blue light enter a rectangular glass block normal to its surface at the same time. Strictly speaking, after passing through the block, which pulse exits first?
Should I consider their ...
- 13
0
votes
1
answer
140
views
Is there any physical explanation for negative extinction coefficient, $k(E)$, over a spectral range of energies?
Measured data for $n(E)$ of air were fitted to equations for $n(E)$ and $k(E)$. The measured data for n(E) spanned 0.734 to 6.702 eV. To obtain fits to the equations for n(E) and k(E) in the absence ...
- 1
3
votes
1
answer
4k
views
Why does Cauchy's equation for refractive index contain only even power terms?
Cauchy's equation is an empirical relation that defines the refractive index of a material in terms of wavelength:
$$ n(\lambda) = A + \frac{B}{\lambda^2} + \frac{C}{\lambda^4} + ...$$
While I ...
- 727
2
votes
1
answer
365
views
How did Newton explain why a prism bends light rays causing the colors to separate?
We know today that light has wavelike properties. This explains why the rays are bent when they enter the prism. Light slows down when traveling through a medium, as the trough enters the prism before ...
- 121
1
vote
0
answers
134
views
Refractive index dispersion relation of stainless steel
I am lookin for the refractive index dispersion relation of stainless steel.
I tried to search for it at https://refractiveindex.info/ and on google but I couldn't find anything.
I mainly need the ...
0
votes
1
answer
51
views
What is the definition of absolute refractive index of a medium?
I know the definition is the ratio of the speed of light in vacuum to the phase velocity of light in the given medium. Here, which color of light do we consider while calculating the ratio? For ...
- 11
1
vote
2
answers
297
views
Can X-rays travel quicker than visible light in a medium?
I have seen while reading a few books that the refractive index depends on lambda as follows by the Cauchy equation.
$${\displaystyle \eta(\lambda )=A+{\frac {B}{\lambda ^{2}}}}$$
From this, the book ...
1
vote
3
answers
387
views
How does a rainbow show all of its colours?
My question is tied closely to this one, asked a while back on the website. As far as my understanding goes, a rainbow is formed by sunlight undergoing two refractions and a reflection inside ...
20
votes
2
answers
3k
views
Why does the light passing through a prism get bent in the same direction twice?
Whenever I see a 2D drawing of dispersion occurring when light travels through a solid prism, I see the rays get bent downwards on entry and downwards on exit again. For example here: https://www....
