Change in the direction of propagation of a wave when its transmitting medium changes.

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2answers
2k views

How does light speed up after coming out of a glass slab?

As I learned today in School, my teacher told me that when light enters a Glass Slab it slows down due to the change in density and it speeds up as it goes out of the Glass Slab. This causes a lateral ...
5
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6answers
4k views

Is it possible to witness a circular rainbow?

What conditions would make it possible to see a naturally occurring fully 360° circular rainbow? Would it even be possible?
0
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2answers
108 views

Light-Matter Interaction and Object's Appearance

I am taking a course in Computer Graphics, and the teacher said we could put materials in there main categories: mirror like glossy or specular diffuse He suggested that the law of reflection is ...
1
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4answers
38 views

How can a 360 Degree Rainbow be formed? [duplicate]

Just a while ago while I was reading news paper, I saw an amazing article. Someone had caught a photo of a 360 Degree Rainbow. But how is it possible. I mean after refraction the only rainbows that ...
0
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0answers
14 views

Prism formula base question [closed]

An equilateral prism has a refractive index of $\sqrt{3}$. A ray of light is traveling parallel to base of the prism. What is angle of incidence?
25
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4answers
2k views

What really cause light/photons to appear slower in media?

I know that if we solve the Maxwell equation, we will end up with the phase velocity of light being related to the permeability and the permittivity of the material. But this is not what I'm ...
0
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2answers
48 views

Why phase velocity is related to deflection angle?

Refractive index is a function of velocity in the medium.How is this related to deviation angle inside the medium?
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1answer
32 views

What's the relationship between velocity factor and refractive index?

Wikipedia on velocity factor explains: For optical signals, the velocity factor is the reciprocal of the refractive index. On refractive index, Wikipedia also has an explanation of refractive ...
22
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4answers
3k 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 ...
0
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0answers
40 views

Why can't we see Rainbows from its end points? [duplicate]

We see Rainbows many times, but we always see them Horizontally or from Sideways. Why can't we see it from under it?/From the point where it starts or ends(end points)? I also want to stress on that, ...
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3answers
64 views

Does light change phase on refraction?

I have seen a lot about when light undergoes a phase change when it is reflected. But does it undergo a phase change when refracted and if so why and if not why not?
2
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0answers
25 views

What property of medium is directly related to light propagation speed in that medium? [duplicate]

Refractive index is used to calculate phase velocity of light in medium, other than vacuum. Recently I had a discussion with somebody claiming that light is slower due to magnetic field of atoms. I ...
0
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1answer
59 views

Absorption of waves in a plasma

Suppose a plasma has characteristic frequency $\omega_p$. Since $$n = \sqrt{\left(1-\frac{\omega_p^2}{\omega^2}\right)} $$ For $\omega<\omega_p$, the refractive index will be imaginary - which ...
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2answers
59 views

Penny dropped in the water: What would you see if transmitted light is parallel to the incident surface

I'm working on a problem which asks what is the greatest diameter of a paper you can use to totally shield a penny dropped in the water from view. The question claims that if the transmitted ...
4
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3answers
225 views

How does one determine whether an object will make an EM wave refract in a qualitative way?

for example, i have a vague notion that the actual answer is that the permittivity and permisivity are different in each different material, so all waves refract at every boundary, but we only call it ...
3
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1answer
61 views

Does ordinary refraction exert a couple on the refracting medium?

Refraction gives rise to a momentum change orthogonal to the propagation direction. This must result in an equal and opposite change to the medium at the boundary. Entry and exit cancel, and the ...
-1
votes
1answer
38 views

Total internal reflection angle [closed]

For what angle does total internal reflection happen? I think that it happens for angle=k*pi where k is an integer with the possible values: 0, 1, 2, 3... Is my assumption correct?
1
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2answers
30 views

How is light trajectory affected by the trajectory of environment it passes through?

There's a sci-fi concept of slow light that I find very amazing: Imagine a glass material that has index of refraction $n$ say, $3,000,000,000$ which means: $$v_{glass} = \frac{c_{vacuum}}{n} = ...
1
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2answers
496 views

Colors in the secondary rainbow reverse of that in the primary rainbow

Why the colors of Secondary rainbow is reverse of that in the color in the Primary rainbow? What can be the possible reason among the following options Because it is formed by one internal ...
3
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1answer
528 views

Why would an object appear a different size when in water?

A friend of mine has a homework question and we're having some trouble figuring out what physical mechanisms come into play for this. An underwater swimmer sees a spherical air bubble that appears ...
0
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1answer
54 views

Two layers of glass reflection related to wave interference [closed]

A highly reflective mirror can be made for a particular wavelength at normal incidence by using two thin layers of transparent materials of indices of refraction $n1$ and $n2 (1 < n1<n2 ) $on ...
0
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1answer
18 views

if you're wearing goggles, will the light beam appear to travel straight?

if person A is outside a pool and person B is inside a pool with goggles, won't the light beam travel closer to the normal inside the pool but then away from the normal when it enters the goggles (due ...
0
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1answer
30 views

Any material to have a significant difference for different colors?

I am looking for a material whose refractive index for the colors green, red and blue to have a significant difference to be visible in simple geometrical optics experiments?! We use a microscope and ...
0
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0answers
23 views

Atmospheric refraction approximation

I am studying atmospheric refraction, reading ITU P.834 Effects of tropospheric refraction on radiowave propagation, and I have a question about an approximation. They say that refraction correction, ...
1
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1answer
56 views

Why doesn't frequency change? [duplicate]

I've seen a mathematical example where a wave was made from same source in water and air. but in both medium frequency was same but wavelengths were different in each medium. we know that velocity of ...
0
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2answers
42 views

Why does electromagnetic refraction happen?

Why does refraction happen? In high school textbooks, it is stated that it happens because the speed that electromagnetic waves propagate in the media change. But why cant they continue propagating in ...
1
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2answers
67 views

light ray undergoing total internal reflection thrice inside a prism

Can it ever be possible that a light ray going inside a triangular prism of refractive index n having refracting angle A undergo total internal reflection thrice before emerging out? Note:I know it ...
1
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2answers
108 views

Can we get the refractive index of a prism by using white light?

Can we get the refractive index of a prism by using white light ? I guess since white light is non chromatic, it is not possible.
0
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2answers
26 views

Laser Refraction

Can you take a laser beam of high intensity and refract it in a way to convert it to a safe level? White light traveling through a prism refracts into the individual wavelengths, could something ...
8
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5answers
12k views

Why frequency doesn't change during refraction?

When light goes through one medium to another it's velocity and wavelength changes. Why frequency doesn't change in this phenomenon?
0
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1answer
43 views

Dependence of scattering on particle size and refractive index

How does the intensity of light scattered by a medium depend on the refractive index and the size of the particles dispersed in the medium? I found plenty of literature about the dependence of ...
1
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2answers
66 views

Sellmeier Refractive Index of Standard Air

The question: What is the Sellmeier description of the refractive index of air at some reasonable temperature, pressure, and water content? The description must be in the following form:$$ ...
5
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3answers
4k views

Real and imaginary parts of dielectric constant vs refractive index?

So for a complex dielectric constant $\epsilon = \epsilon_a + i\epsilon_b$, the wave vector and index of refraction are related to it through $k = \frac{\omega}{c}n$ and $n = \sqrt{\frac{\mu ...
3
votes
2answers
125 views

Why can't we reach the ends of rainbow?

Rainbows are spectacular things. But I imagine why we can't reach to the ends of rainbows. Do rainbows have no ends ? If so, why can't we reach at them? If you go closer,they will go further. Why?
2
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3answers
602 views
0
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0answers
24 views

In the analogy of turning car wheels related to bending of light while entering glass through air, does that imply that two photons are “connected”?

There's a famous analogy that explains the bending of light when it enters glass from air. But doesn't that imply that two photons, represented by the adjacent wheels of the car, are connected by ...
18
votes
7answers
13k views

What determines color — wavelength or frequency?

What determines the color of light -- is it the wavelength of the light or the frequency? (i.e. If you put light through a medium other than air, in order to keep its color the same, which one would ...
2
votes
0answers
62 views

Can time pass for a photon if it's moving in a medium? [duplicate]

If time does not pass for a photon traveling at the speed of light, which can only occur when traveling in a vacuum, what happens when it is slowed down by traveling through non vacuum space like ...
0
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0answers
20 views

can wave length changes if there is a change in refractive indices? [duplicate]

can we change the wavelength of the light that incident ? IF it is possible then after the incident wave entered and refracted through a medium into the emitted medium will the wave's wave length ...
1
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3answers
978 views

What happens to the index of refraction of a lens if placed in water?

What happens to the index of refraction and focal length of a lens that is initially in air that is then placed in water?
3
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0answers
52 views

How would we see the earth if refraction of light was significantly stronger?

On worldbuilders there is a question about the cosmological consequences of a world with super-high refraction and atmosphere opaqueness. I'm assuming the easiest way to minimally change the laws of ...
0
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1answer
27 views

Index of refraction appearing in the radiative transfer equation

In this publication the Radiative Transfer Equation (RTE) (eq. (7)) contains the following emission term: $$n_i^2\kappa_{d,i}L_{b,i}(\mathbf{r})$$ where $n_i$ is the refractive index of component ...
0
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1answer
76 views

Gravitational lensing of massless photons

I recently got a more complete proof of photons having no mass. (I knew it before, but now I really know it.) But now, I'm curious how gravitational lensing can occur without a mass to act on. I have ...
2
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1answer
63 views

Why is a particular wavelength favored by transmission through a thin film?

A sheet of glass is coated with a $500\text{ nm}$ thick layer of oil ($n=1.42$). For what visible wavelengths of light do the reflected waves interfere a) constructively? b) destructively? ...
10
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3answers
48k 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?
0
votes
1answer
29 views

Refraction through converging lens: finding image distance and image height

So in this situation there is a 1.79 meter tall person standing 30 meters from a 150 mm converging lens and I'm trying to find where the image will form and how tall it will be. My problem is in ...
2
votes
3answers
122 views

What “exactly” happens when a ray is incident at the critical angle?

The question arose when my physics teacher taught me geometrical optics and told that the phenomenon of both refraction and $reflection$ occur by change in medium. First of all, I'm not sure about the ...
1
vote
1answer
37 views

How to get the direction of bending light?

When light passes from a more dense to a less dense substance, (for example passing from water into air), the light is refracted (or bent) away from the normal. My question, is there any ...
2
votes
2answers
380 views

Air vs Glass refraction coefficient

I have a rather strange question, let's say I can play with the temperature and atmospheric pressure conditions in a sealed room. What will I need to do to make the air's refraction coefficient ...
7
votes
3answers
267 views

How can a particle in a medium ever travel faster than light? [duplicate]

In some media, mass-carrying particles can go faster than light: Cherenkov radiation, ... is electromagnetic radiation emitted when a charged particle... passes through a dielectric medium at a ...