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

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2answers
66 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?
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0answers
14 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 ...
2
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0answers
52 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
16 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 ...
2
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0answers
46 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 ...
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2answers
34 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:$$ ...
0
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1answer
14 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
1answer
45 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? ...
1
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1answer
31 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 ...
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3answers
76 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 ...
7
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3answers
153 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 ...
0
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1answer
35 views

Broken Thin Lens Algorithm [closed]

We all know the thin lens equation. For $o$ being a horizontal object distance and $f$ being the focal length, the horizontal image distance $i$ is described by: $$\frac{1}{f} = \frac{1}{o} + ...
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0answers
42 views

What is the refractive index of air at high temperatures (> 200 °C)

Is there a method/formula to calculate the refractive index of air at high temperature (e.g. 400 °C - 800 °C)? I could only find formulas specified up to 100 °C and our physicist at university ...
0
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2answers
44 views

How to define a convex surface in case of refraction?

In an exam at high school level, it was said, "ray goes from optically denser to rarer medium through a convex surface. It forms a real image...." this was a part of the question. Now I thought that ...
0
votes
2answers
71 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 ...
2
votes
1answer
72 views

How to calculate the refracted light path when refraction index continuously increasing?

Suppose an incident light from vacuum ($n_1=1.0$) into some media ($n_2=n_1+\mu\; x^2$) as in the figure below. How to calculate the refracted light path curve in closed form? Update: Try to set ...
3
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2answers
108 views

Refractive index of dielectric in different frames of reference

The setup A transparent isotropic dielectric medium moving in the negative $x'$ direction at speed $v$ in frame $S'$ is stationary in frame $S$, where it has refractive index $n$. In other words, ...
0
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1answer
61 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 ...
0
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1answer
26 views

How does Ptolemy's table, of angles in air and angles in water, fit perfectly on a parabola?

In "The Feynman Lectures on Physics" Vol.1 Optics Ch.26, Table 26-1 Ptolemy's list of angle in air and angle in water are given, in connection with Snell's law of refraction. I quote below values from ...
2
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1answer
511 views

why does the optical media have different refractive indices?

Optical density is a measure of the refracting power of a medium. In other words, the higher the optical density, the more the light will be refracted or slowed down as it moves through the medium. ...
5
votes
2answers
162 views

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 ...
2
votes
1answer
53 views

Can refraction of the atmosphere be so high that the surface of a planet seems concave to its inhabitants?

In their novel Inhabited Island by brothers Strugatsky, the inhabitants of a planet think they live on the inner surface of a giant sphere because the refraction of the atmosphere makes the surface ...
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2answers
176 views

Which of these theories on why light slows in media are true?

This question is similar to previously asked questions, but the responses to them are confusing and I think it may be better covered by listing out all the potential answers for clarity. It's a ...
0
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1answer
23 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 ...
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0answers
22 views

Refractive index variation with colors [duplicate]

To explain the spectrum formation in the prism, my teacher said that different colors have different speeds in a medium, so, refractive index is different for all. So, angle is different. But I don't ...
2
votes
1answer
63 views

Why does the speed of the Electromagnetic wave in the material depend on the frequency of the wave where as they are constant in vacuum (freespace)? [duplicate]

I am confused on why would the propagation speed of any EM waves at ANY frequency is constant in the free space (vacuum) but they seem to disperse in any other materials as the propagation speed of EM ...
2
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1answer
57 views

Reflection from multiple thin films: accounting for lost light due to small surface area

I have a problem similar to reflection of multiple thin films. I have light coming in from medium 1 and I want to find the total reflected intensity after being reflected inside 2 layers. However, I ...
0
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3answers
63 views

Double rainbows

In my garden, when I'm watering the plants I sometimes see a rainbow or two. How did two rainbows appear? Why can't I see three rainbows then, or how can I see three rainbows?
2
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1answer
33 views

Color in Different media

When a light wave passes from one medium to other, the wavelength of the light wave changes and the frequency remains constant. If then color of the light waves depends on changing wavelength or ...
22
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5answers
2k views

Why isn't the sunset/sunrise rainbow-colored

When the sun is rising/setting, it goes through a phase where the light is bending from the atmosphere. I believe this image will explain much better than I ever could. Now, if light goes through ...
1
vote
1answer
106 views

Anti-reflective coating effect on total internal reflection?

If the surface of prism is coated with an anti-reflective coating, (specifically an index matching, refractive index gradient, or moth-eye structure), and light impinges at a greater than critical ...
1
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1answer
191 views

Compression vs Rarefaction in Sound Waves

I am currently looking into solutions for Sound Classification, and I came across Ludvigsen's methodology (if anyone wishes to refer to it). The problem is that a sample graph of amplitudes in one of ...
0
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2answers
51 views

Ray tracing in a inhomogeneous media

If I have an optical transparent slab with refractive index $n$ depending on the distance $x$ from the surface of the slab, the refractive index can be described by: $$n(x)=f(x)$$ where $f(x)$ is a ...
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1answer
31 views

light color and refraction

I'm a bit confused on the topic of refraction, some starting premises: 1) When light refracts from exiting a medium with a low n and entering a medium with high n the light bends. 2) The index of ...
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2answers
37 views

optical diffusion (scattering) versus refraction

When an electromagnetic wave meets an interface a part of it is reflected and part of it is refracted (and from the refractive index I can calculate the angles of propagation and the intensities using ...
5
votes
2answers
106 views

Why does light travel in a straight line through a liquid?

So I was reading a document that stated that when traveling through a material (I'll use a liquid here, maybe water), a photon actually always traveled at 300,000 km/s, it was just that it ...
2
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2answers
50 views

Surfaces that refract, but do not reflect

I know there exists surfaces that only reflect light (mirrors), but are there surfaces that only refract light? If so, how does that happen?
0
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2answers
86 views

Image formation at surface of water

Consider a lake full of water which has an object immersed in it. Now, if an observer was at the surface at a sufficient distance so that the light ray from the object is internally reflected, should ...
0
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1answer
49 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 ...
3
votes
3answers
166 views

Why is the phase velocity used in the definition of the refractive index?

I'm aware of the so-called group index but why is the phase velocity used in the standard definition of the index of refraction? What advantage does this offer?
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1answer
35 views

Reflection vs indices of refraction [closed]

A magician during a show makes a glass lens with refractive index 1.47 disappear in a trough of liquid. What is the refractive index of the liquid? Could anyone please demonstrate with a ray diagram?
-2
votes
1answer
36 views

Evaluating angle of refraction [closed]

Can someone show me how to evaluate the angle of refraction for white light where the angle of incidence is 30 degrees if medium A is air and medium B is water. The answer is 22 degrees. I don't know ...
0
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2answers
148 views

Does this* refraction experiment correctly conclude faster than light travel?

This question asks if a particular experiment is correct in its conclusion. This experiment, conducted by Alfred Leitner, is shown in a 1975 physics instructional movie. It claims that the experiment ...
2
votes
1answer
67 views

Why is a flower shaped diffraction occluder the best solution for controlling diffraction?

According to this TED talk by Jeremy Kasdin, Nasa is planning to spend $1bn on a "Starshade" project, where a giant flower shaped metal eclipser 20 meters wide is placed 50k kilometers in front of a ...
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3answers
529 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
votes
1answer
337 views

Diver view of refraction

I'm studying the refraction in optics. If a red light monocromatic beam of red light (700 nm) passes from air to water it becomes with a wavelenght of aprox 526 nm. So, my question is: How is going ...
4
votes
2answers
117 views

Is refraction sharp or smooth?

Refraction: light changes direction of propagation when entering a material with a different refractive index. Does the direction of propagation of light change sharply and almost instantaneously ...
1
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1answer
94 views

Imaginary number for extinction coefficient in complex refractive index

In complex refractive index on a material, $n=n'+ ik$, the imaginary part $k$ is physical meaning, as it shows absorption in the material but it is an imaginary. How we measure an imaginary values in ...
3
votes
1answer
59 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 ...
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0answers
94 views

Difference between the increase in optical path due to refraction and that due to reflection

If we place two glass plates of refractive index n and each having thickness t,on the way of a light ray the increase in optical path becomes (S2P-S1P)=2(n-1)t due to refraction through them,and the ...