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

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2answers
36 views

Reflection during refraction

I have observed in a book (one that is different from the one that I study with in school) that a light ray reflects during refraction, which is a partial reflection, but when does that occur? Is it ...
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1answer
141 views

Dispersion in a rectangular prism

Why are the colours visible only at the fringes of the light refracted through a rectangular prism?
3
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4answers
4k views

Why does change in speed of a wave make it refract?

When a light wave enters a medium with a higher refractive index (e.g. from air to standard glass) and its speed decreases, why does that make it refract/bend? I understand that wavelength decreases ...
5
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2answers
194 views

Determining the refractive index of a foil

(59th Polish Olympiad in Physics, final stage, experimental part, 2010) You have at your disposal: a sample of blue foil of a homogeneous material, placed between two glass panes in a ...
1
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1answer
30 views

Effect of the refractive index of a transparent layer coating a particle?

I am modelling a cell as a particle coated by a layer of a material whose refraction index might change. This layer is to resemble the membrane. The purpose of the model is to simulate what happens ...
2
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1answer
23 views

Absorption Magnification

I'm working on an optical project about the absorption of glass sheet and I need to measure the intensity of laser beam that has passed the glass sheet and compare that with the intensity of laser ...
4
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3answers
167 views

How is it possible for the wavelength of light to change in a medium?

So my physics class has just finished a long unit on optics while at the same time I've been trying to teach myself relativity. I admit my understanding is probably rudimentary, but I figured all the ...
38
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5answers
4k views

If a lens focuses all incoming light to a point, how do we get 2D images?

How do lenses produce 2-dimensional images, if a lens bends all incoming rays of light to intersect at the focal point? Shouldn't this produce a single dot of light on a screen placed at the focal ...
0
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1answer
74 views

Way of measuring thickness of a glass [closed]

Imagine you have a laser pointer and a glass. You don't know the refractive index of the glass and you just have Wavelength of laser! How can you measure the thickness of glass? (I have some idea but ...
0
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0answers
24 views

Difference in Light's speed in various mediums [duplicate]

Light, despite not needing a medium and traveling due to oscillations of the electric and magnetic fields, slows down in mediums such as glass. I used to think it intuitively made sense, as we ...
2
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2answers
50 views

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 ...
2
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1answer
36 views

Refraction of white light through a glass slab: what does it actually look like?

When a collimated beam of white light enters a rectangular prism, it develops slightly coloured edges due to the dispersive refraction of the glass: each ray in the beam is displaced differently ...
0
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1answer
23 views

Does the order in which light comes into a rectangular prism affect its dispersion?

I read about how when light comes out of a rectangular prism, there are violet and red fringes on either side of the light spectrum. The website didn't give the specifics in this subject, so I am not ...
-1
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2answers
137 views

Reflection coefficient as a function of frequency

I am trying to relate the equation for reflection coefficient in oblique mediums to the frequency but can't figure out how the frequency affects the reflection of light. $n_1$= intrinsic impedance of ...
3
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3answers
537 views

Is there a way to increase the speed of light itself?

When light enters materials it slows down due to its refractive index (due to absorbing and re-emission of photons). But, is there a way to increase the speed of light itself? Can there be some ...
2
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2answers
516 views

radius of curvature and focal length

Is the radius of curvature of a convex or concave lens longer than the focal length of the lens? Does the center or curvature affect the focal point in a lens?
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2answers
278 views

Light-matter interaction and an 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 ...
3
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2answers
3k views

Wavelength-dependent refractive index

I read in a book about optical fibers that the different spectral components of a light pulse transmitted in the fiber propagate with different velocities due to a wavelength dependent refractive ...
-1
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2answers
52 views

Why is the index of refraction different for different wavelengths? [duplicate]

The index of refraction can be written as $$n=\frac{\lambda_v}{\lambda_m}$$ where $\lambda_v$ is the wavelength in a vacuum and $\lambda_m$ is the wavelength in the medium. I’ve been told that since ...
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1answer
361 views

Theoretically if you passed the speed of light in a medium, would there be a sonic boom equivalent?

I know that it is technically impossible to reach the speed of light in vacuum since the mass of the object traveling would reach infinity. However in a medium, would there be some sort of theoretical ...
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1answer
30 views

Can we measure the height of clouds using the sunset?

I was watching the sun set in San Francisco. As the Earth turns away from the Sun the tallest buildings remain lit longest. Light bending in the atmosphere allows this to last a bit longer. So, what ...
0
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2answers
8k views

Refraction, reflection, and what is total reflection?

So if light travels from one media to another with a different refraction index, what may happen happen? Refraction, reflection or total reflection? I am quite confused as to the differences between ...
3
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2answers
63 views

Using a transfer matrix to calculate beam width of off-axis Gaussian beam?

I have been reading a lot about ABCD matrices that are used for ray tracing. I can calculate the output offset $r_{o}$ (with respect to the optical axis) and the angle $\theta$ of the ray by $$ ...
1
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1answer
3k views

Refractive Index formula for denser to rarer medium

I learnt that the formula for refractive index when light travels from rarer to denser medium is $$\frac{\sin i }{ \sin r}$$ where $i =$ angle of incidence, $r =$ angle of refraction. Is the same ...
15
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1answer
1k views

Do neutrinos refract?

The most benign of interactions is refraction. While neutrinos rarely interact with matter in a sense like the photoelectric effect, does that mean that they don't refract either?
0
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1answer
61 views

How is light slowing down in a medium thought of in the photon picture? [duplicate]

The speed of light in any medium besides vacuum is smaller than $c$. In a classical way, I just look at that as a wave that propagates less fast, the change in EM-field is passed on slower. How should ...
3
votes
1answer
118 views

Why do we use the index of refraction for yellow light?

When we do problems with optics and refraction, we’re usually given a set of indices of refraction to work with; for example, the index of refraction in air is about 1.00, the index of refraction in ...
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0answers
28 views

How to actually determine the Index of Refraction of an object in different colors of light?

I would like some guidance as to how the IOR of an object is determined in different colored lights. Taking for example diamond, I know that the base IOR is 2.417, and the respective wavelengths of ...
3
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0answers
60 views

False sunset and false sunrise time estimation

False sunset and false sunrise are described . Here is a sample day rise and set time according to AccuWheather site and calculated value of sunrise and sunset in my country. Could you please help ...
2
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1answer
1k views

Earth curvature refraction for dummies

I keep being presented with 'earth curvature experiment' videos recently, by flat/concave earth advocates. It seems to be their favorite "evidence" that Earth is not spherical. Debunking this gets ...
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1answer
43 views

Is there a formula to calculate the deviated angle of a ray passing through a prism?

I'm assuming the angle of incidence to be the number of degrees from a perpendicular line on the side of a prism the ray starts passing through... I'm trying to figure out the angle the ray would be ...
7
votes
3answers
696 views

Why does the index of refraction change the direction of light?

I've been studying in optics the macroscopic maxwell's equations, and how electromagnetic fields propagate through different mediums. Over there, the index of refraction appears, as a complex function ...
1
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3answers
110 views

The speed of light/EM waves in vacuum; as if there was another one in non-vacuum?

Q1: is there a speed of a photon other than in "vacuum"? Q2: isn't "speed of light in vacuum" misleading? If I understand, that light moves with speed of light until there is "something in between" ...
35
votes
4answers
4k views

Do rainbows have ultraviolet bands and infrared bands?

We have seen that rainbows looks so colorful as we are only able to see only the visible light. But Do they also have ultraviolet bands and infra-red bands, that we are unable to see? I know someone ...
0
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0answers
24 views

What are the physical optical limitations photonic metamaterials can offer?

Modern technology has introduced new photonic metamaterials that can extend optical properties beyond what standard materials can offer. For example a negative index of refraction is now possible ...
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4answers
1k views

How do “holographic plates” work?

I asked a question about laser stage lighting over at Audio Video Production, and received an excellent answer that explained that laser clusters are generated from a single beam via something called ...
0
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1answer
52 views

Conditions for having refractive index less than unity?

Is it possible to have an index of refraction, $n < 1$, giving the "illusion" of a speed greater than $c$. As far as I understand it, is only the phase-velocity (which does not carry any ...
0
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0answers
39 views

Why does pencil appear bent in water?

I know why: refraction. But I can't find a detailed explanation anywhere online. So I just asked. This is the most detailed image I can find, on physics classroom. But don't we see thing only when ...
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0answers
17 views

Is there a name for the squared refractive index?

In studying wave propagation through multilayers, the squared refractive index $n^2$ is a more pertinent parameter than $n$ itself. Is there a received name for $n^2$? Of course, as long as there is ...
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1answer
22 views

Why don't p-type seismic waves propagate along straight lines in the lower mantle?

Can you tell me why seismic waves (p-type shock wave) passing through the earth's lower mantle don't propagate along straight lines in particular?
-1
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1answer
63 views

Why we don't observe spherical rainbow?

We have seen or heard of rainBOW and circular rainbow but not any other shape probably due to the shape of water droplets. My question is why can't we see a spherical rainbow?
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1answer
51 views

Why does a panel of glass appear translucent when viewed from the edge?

Why does this happen? From the 'front' of the panel, the glass appears transparent. But viewed from the 'edges', it appears translucent...
13
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3answers
8k views

How does a photon travel through glass?

This was discussed in an answer to a related question but I think that it deserves a separate and, hopefully, more clear answer. Consider a single photon ($\lambda$=532 nm) traveling through a plate ...
1
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2answers
57 views

What polarizes a rainbow?

What polarizes the light from a rainbow. I already did some search and couldn't get a clear answer. All I could find was the light is polarized on the direction light is entering. What happens to the ...
0
votes
2answers
387 views

Why the light bent towards the normal when they pass from rarer medium to denser medium?

Whenever the light rays are entering the rarer to denser medium they bend toward the normal. Then why the rays choose the path toward the normal? Why it cannot choose the path away form the normal?
1
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1answer
3k views

What causes refraction of visible light? [duplicate]

Refraction is the bending of a wave when it enters a medium where its speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the ...
8
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3answers
558 views

Why do rainbows have distinct colors?

When I searched on the Internet for the reason of formation of rainbows, I got many explanations like this one & this. All the explanations consider only one spherical water droplet (like this ...
0
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2answers
959 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 ...
2
votes
0answers
21 views

Odd order of colour fringes around cloud

The other day I took this photograph of a thundercloud that moved between myself and the sun. Around the edge of the cloud there were some coloured fringes that I first took to be a variant on a ...
5
votes
1answer
90 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 ...