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

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2
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2answers
413 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?
0
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2answers
248 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 ...
-2
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0answers
17 views

Maximum angle of a prism to have an emergent ray [on hold]

the critical angle of the prism ABC is 40degree. for a ray of light incident on AB , to emerge from the face AB , what should be the maximum value of angle A? please explain how to do this ...
3
votes
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
43 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 ...
1
vote
1answer
354 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 ...
1
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1answer
134 views

Dispersion in a rectangular prism

Why are the colours visible only at the fringes of the light refracted through a rectangular prism?
3
votes
3answers
156 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 ...
0
votes
1answer
27 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
votes
2answers
54 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
vote
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
votes
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
57 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
111 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 ...
0
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0answers
27 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
votes
0answers
49 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
votes
1answer
732 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 ...
0
votes
1answer
39 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
678 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
vote
3answers
109 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
20 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 ...
5
votes
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
39 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
29 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 ...
0
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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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votes
1answer
20 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
61 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?
1
vote
1answer
46 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
vote
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
293 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
vote
1answer
2k 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
votes
3answers
545 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
895 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
89 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
vote
4answers
279 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?
6
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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?
2
votes
3answers
190 views

What really makes a rainbow happen?

Yes, a rainbow is formed when a raindrop refracts light, but why then does the whole sky not become a huge rainbow when it rains? Would the light not be dispersed into ordinary 'white' light? What ...
1
vote
1answer
36 views

Position dependent refractive index [duplicate]

How to determine the angle of refraction when the medium has position dependent refraction index? Lets say that the angle of incidence on the glassy slab is $\theta_1$ and the ray goes through the ...
0
votes
1answer
80 views

Determining the path of a light ray

Let's consider a ray in the plane $xy$. Let the refractive index be defined in any point of the plane with the function $n(x,y)$. In time $t=0$ the ray is located in coordinates $(x_0, y_0)$ and its ...
1
vote
1answer
37 views

Do the mediums decrease or increase the speed of light? (source to target) [duplicate]

If sun is the source of light then is it possible that the speed of light might increase depending on the mediums its going through or its not possible.
12
votes
2answers
3k views

Is true black possible?

Black is the absence of light because it absorbs light, but when we create black paint or black objects, light is always reflected, either in all directions in matte or smoothly in shiny black ...
5
votes
3answers
253 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 ...
0
votes
2answers
109 views

Could time dilation bend the path of a photon? Does time dilation have a refractive index?

The main question I am getting at is, does time dilation have a refractive index? What I mean is, if I were to shoot a laser past a black hole, would the laser's path "bend" strictly from time ...
1
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0answers
22 views

optical homogeneity of organic thin films

Prior to further analysis (like variable angle ellipsometric spectroscopy) I check thin films of organic materials vacuum deposited on glass substrates for their optical homogeneity under lineraly ...
3
votes
1answer
116 views

Rainbows at other wavelengths

I'm curious as to whether or not it is possible to have a rainbow at wavelengths other than visible light. I'm familiar with Snell's refraction law and why it is that they occur, but now what about ...
3
votes
0answers
65 views

Is refraction of light a thermodynamic process?

Is refraction of light a thermodynamic process? Can it be explained by conservation of energy? If so, does temperature has an effect on refraction of light?