All Questions
Tagged with refraction dispersion
76
questions
6
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3
answers
1k
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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
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0
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37
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Is the relativistic energy-momentum relation fundamental? [duplicate]
The following relativistic energy-momentum relationship is taken to be fundamental:
$$E^2=p^2c^2+m_0^2c^4.\tag{1}$$
Let us specialize to massless particles ($m_0=0$) so that we have:
$$E=p\ c.\tag{2}$$...
- 5,925
0
votes
1
answer
39
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Can anyone explain the relationship between the refractive index, the speed, wavelength and angle of a wave?
Can anyone explain the relationship between the refractive index, the speed, wavelength and angle of a wave?
in my book is states that $$n = \frac{v_1}{v_2} = \frac{\sin θ_1}{\sin θ_2} = \frac{λ_1}{...
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1
vote
0
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The speed of light in medium with different frequency
We know that the speed of light in vaccuum can be expressed as $c=\frac{1}{\sqrt{\mu_0\epsilon_0}}$ and thus the speed of light in vaccuum is thus $$v=\frac{1}{\sqrt{\mu\epsilon}}=\frac{c}{\sqrt{\...
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1
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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
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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?
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10
votes
2
answers
2k
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Is it possible to witness a rainbow while facing the sun?
We know that a rainbow occurs due to the refraction and reflection of light inside raindrops. We also know that inside spherical raindrops total internal reflection is not possible. So some light is ...
- 123
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0
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43
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Why does the green light change to red in the prism? [duplicate]
I know that white light, upon entering another medium from air/ vacuum, disperses into its constituent colours. Essentially when travelling in the air, all of the constituent colours have the same ...
- 1,064
1
vote
2
answers
570
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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 ...
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33
votes
3
answers
3k
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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
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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
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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
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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
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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
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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
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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 ...
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1
vote
2
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278
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Is there a wave equation describing electromagnetic waves in materials?
Solutions to the usual wave equation for electromagnetic waves have the property that wave components of different wavelengths travel at the same phase speed $c$, so no dispersion occurs.
What I ...
- 8,660
1
vote
1
answer
45
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Non-dispersive mediums for light
Apart from the vacuum are there other mediums for which light velocity does not depend on frequency?
1
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2
answers
297
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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
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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 ...
0
votes
1
answer
239
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Why is the refractive index of blue light larger than red light in water while the refractive index of radiowaves is larger than both?
So I thought the reason why radio waves have a relatively high refractive index in water is because they have a low frequency which increases the permittivity, but blue light that has a higher ...
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20
votes
2
answers
3k
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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....
0
votes
1
answer
771
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QUESTION: why the the refractive indices of dispersed phase and dispersion medium differ greatly in magnitude for colloids (in Tyndall effect)?
I am JEE student in India and while I'm reading my chemistry book (NCERT class12), there mentioned a point that "the refractive indices of the dispersed phase and dispersion medium differ greatly ...
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0
votes
1
answer
82
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Does Lens disperse light along with refracting? Why doesn't it depict in diagrams? [duplicate]
Why we depicts every diagram studying in ray optics lenses as 'a ray that is passed after retracting from lenses'?
I mean to say , lens is made of glass with non parallel faces so it should disperse ...
1
vote
1
answer
373
views
Why we don't see a spectrum of colours above water?
Why we don't see a spectrum of colours above water?
When a light ray enters the water it will become dispersed, and after reflecting from an object in the water, say a pencil, or just the bottom of ...
0
votes
1
answer
466
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Why refractive index of same material is different for different monochromatic lights?
Yeah I know that refractive index is different for different monohromatic lights due to the change in velocity of light. And as frequency doesn't changes and only wavelength changes while travelling ...
1
vote
1
answer
2k
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In a rainbow, why is the top colour red and violet on bottom even though red emerges farther (42 degrees) than violet (40) when seen in a single drop?
I don't understand this image or why primary rainbow has red at the top even though in a single drop red is deviated most.
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15
votes
6
answers
6k
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Why are red and blue light refracted differently if they travel at the same speed in the same medium?
When I look at Snell's law
$\frac{\sin\theta_2}{\sin\theta_1} = \frac{v_2}{v_1} = \frac{n_1}{n_2}$
I don't see any reference to wavelength.
If red and blue have the same speed in the same medium, why ...
0
votes
1
answer
171
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In what media the speed of light is slower than the speed of radio waves, if any?
In what media the speed of visible light is slower than the speed of radio waves, if any?
Particles can be faster than visible light, but other electromagnetic waves?
1
vote
2
answers
214
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Dispersion in Rainbows
So I have tried searching for the working of a rainbow. I found many sources and the explanation was clear. I still have a problem though. Since dispersion happens due to different refractive indices ...
- 1,451
1
vote
1
answer
108
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Ampere's Circuital law in non-linear and dispersive medium
For a linear and non-dispersive medium $\vec{B} = \mu \vec{H}$.
So amperes circuital law in integral form (without Maxwell's correction term) can be written in two ways
$\oint_C \vec{B}\cdot\vec{dl} =...
-1
votes
1
answer
53
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Confusion on the indice of refraction: is it dependent on the frequency or not? [duplicate]
I saw in my course than when light hit a medium, it makes some dipole oscillating with the same frequency as the one of the light $\omega$. By a classical mechanics reasoning, one can show that the ...
- 183
2
votes
2
answers
75
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What role does bulk of a prism play in dispersion?
I know that a prism deviates light because the refractive index of glass is a function of the wavelength of light used. However what role does bulk of the prism play in dispersion? i.e only the ...
- 7,980
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votes
0
answers
39
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If both violet light and red light was incident on the center of a semi circular block, and refracted, would they have the same refraction angle?
As the violet and red light have the same speed in air, with the incident angle being less than the critical, with the violet light and the red light coinciding on each other, (like on top of each ...
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0
votes
1
answer
377
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Why is the two-term form for the Cauchy equation sufficient?
The general Cauchy equation for the relationship between refractive index and wavelength is given by,
$$n = A + \frac{B}{\lambda^{2}}+\frac{C}{\lambda^{4}}+...,$$
but this is often approximated to
$$...
- 1
0
votes
0
answers
697
views
Dispersion, refractive index against frequency graph
From Hecht optics page 74, the plot of $n$ , the refractive index, against $\omega$ , the angular frequency of the incoming wave is
And the relation between $n$ and $\omega$ is:
Where each $\omega_{...
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3
votes
2
answers
916
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Does recombination of light in a glass slab happens in the same way like in Newton's inverted prism experiment?
I know that refraction is due to different speeds of different wavelengths of light. So, How can those colors recombine to form a beam of white light (since different colors have different speeds)?
...
0
votes
2
answers
5k
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Which of the following phenomena are responsible for rainbows?
Which of the following phenomena of light are responsible for the formation of a rainbow?
1) reflection, refraction, dispersion
2) refraction, dispersion, total internal reflection
3) ...
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1
vote
1
answer
142
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Are there optical materials with larger mean deviation with little to zero angular dispersion?
The following statement is from Concepts of Physics by Dr. H.C.Verma, from the chapter "Dispersion and Spectra", page 434, topic "Dispersive Power":
The mean deviation depends on ...
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17
votes
5
answers
5k
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Do colors differ in terms of speed? [duplicate]
Here is a very simple question about light. As far as I remember from the school program, each color is merely one of the frequencies of light. I also remember that each color's wave length is ...
- 665
2
votes
1
answer
656
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Speed of light in different mediums with different frequencies
As I know the speed of the light doesn't change while it travels through a vacuum. But while it travels through a prism, it shows different deviation angles to different frequencies.
So ...
- 319
1
vote
1
answer
613
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Why violet light bends the most? [duplicate]
I have read about refraction through a triangular prism,rainbow formation and other natural phenomena.They all told about the strong bending of violet light .
I know that it has a shorter wavelength ...
1
vote
2
answers
5k
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Why does violet light bend the most? [duplicate]
When white light passes through a prism, refraction occurs and it splits into its seven constituent colours. If the spectrum is obtained on a screen violet light appears much more bent than red light.
...
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7
votes
2
answers
1k
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Do gravitational waves disperse/refract (like EM waves in a prism)?
I have read this question:
What is the relationship between a gravitational wave and a graviton?
where kingledion says:
Gravitational waves were theorized a century ago and recently ...
- 29k
3
votes
1
answer
65
views
Why does the intensity of the scattered light vary when a monochromatic laser is shined into a transparent object?
When a laser is shined into a glass ball such as this video (link) or a bottle of water (link) the light is refracted through the whole transparent body. However, the intensity of the light scattered ...
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25
votes
3
answers
9k
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Why doesn’t a normal window produce an apparent rainbow?
When light refracts in a prism it creates a rainbow. My question is, why don’t all windows or transparent objects create this dispersion, i.e. why is the refractive index dependent on frequency in a ...
- 969
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2
answers
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Dispersion through Glass Slab
My questions related Dispersion through Glass Slab:
Why does a parallel surface makes a difference?
Why is that light do get disperse in a prism and a glass slab at surface one but at backs normal ...
user232991
1
vote
2
answers
359
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What does it mean to say that glass has refractive index 1.5?
The refractive index of a material depends on the wavelength of the light incident upon it which is why dispersion happens. When we say that glass has refractive index 1.5 which wavelength do we have ...
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0
votes
1
answer
104
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Speed of electromagnetic wave [closed]
On dispersion , speed of wave is inversely proportional to its wavelength . Therefore, gamma has max speed. But then in visible light , violet has least wavelength still it has least speed in visible ...
0
votes
0
answers
226
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How does refractive index increase in anomalous dispersion?
Refractive index generally increases with decrease in wavelength but in anomalous dispersion it decreases with decrease in wavelength. What causes it to be like that?
user167524