All Questions
Tagged with refraction dispersion
76
questions
61
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4
answers
32k
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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
33
votes
3
answers
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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
25
votes
3
answers
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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
20
votes
2
answers
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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....
17
votes
5
answers
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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
15
votes
6
answers
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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 ...
13
votes
1
answer
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Why does the refractive index depend on wavelength? [duplicate]
Why do different wavelength get impeded more or less when in different materials? Moving with the same speed, but a longer physical distance would imply that the fields oscillate less times in the ...
user24082
11
votes
2
answers
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Why do convex lenses not disperse light like prisms, given that entry and exit points aren't parallel?
I understand that light entering a parallel block of glass at a non-90 degree angle will cause dispersion of colours within the block but that these will be refracted by the same degree upon exit so ...
- 121
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
8
votes
2
answers
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What really is the speed of light in a medium/vacuum, group or phase velocity?
While reading about refractive index 2 terms popped up, group velocity which alway slows down in a medium and phase velocity which may exceed speed of light. Say in a complete vacuum and using laser ...
- 13k
7
votes
2
answers
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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
6
votes
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
6
votes
2
answers
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Why is rainbow always circular?
From the article that I read on physics classroom website on rainbow, rainbow is formed with red on the top and violet on the bottom because violet refracts more, and has a smaller angle of deviation ...
- 1,361
5
votes
3
answers
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Which electromagnetic radiation is faster in water, microwaves or light?
Well I've been asked this question, but I haven't been able to come with an answer yet using books and some web searches. The point is as the title says, to answer the question with the whole ...
Alan
5
votes
1
answer
612
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Fermat principle: which index of refraction?
I am somewhat puzzled by a common formulation of the Fermat principle (light travel time), because it contains index of refraction related to phase velocity while light travel time through a slab of ...
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