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Questions tagged [refraction]

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

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problem of spherical refracting surfaces [on hold]

A glass sphere has radius R=5cm and index of refraction 1.6 When viewed through the paperweight, how far away does the tabletop appear to be to the observer?
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1answer
33 views

Spherical Refracting Surfaces

Why when given a question to find the image of a point object in a spherical refracting surface do you have to consider that there are two surfaces refracting the light? I assumed that one could ...
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1answer
20 views

At Home Experiment Shows Permanent Magnetic Field Does Not Refract

For an at home experiment I positioned a magnetic field so it would cross a boundary from air into water. I wanted to see if it would experience refraction similar to the refraction seen in ...
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4answers
51 views

Refractive index of mirror

What is the refractive index of a common mirror (mercury coated)? As a mirror completely reflects the light ray, do it have infinite refractive index?
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16 views

Are impedance matching, wave-vector matching and phase matching equivalent?

Suppose we are considering refraction (if I understand correctly, that is also a type of coupling of light to a second medium). Generally we equate the wave-vector component parallel to the interface ...
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1answer
34 views

Total internal reflection of sine wave vs smooth step function [closed]

If an electric field described by the function $$f(t)= \begin{cases} 0&\text{if}\ t<0\\ \sin(t)&\text{if}\ 0\leq t\leq \frac\pi2\\ \ 1&\text{if}\ t>\frac\pi2 \end{cases}$$ ...
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1answer
29 views

Why do the sides of my Fish Aquarium look like mirrors?

I bought a new fish aquarium which is square/cuboid in shape.My previous aquarium was spherical in shape. When I filled it with water and put the fish in two of them started acting very stressed so I ...
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2answers
59 views

Why does purple appear in a rainbow?

It is said that people and digital cameras have color sense only for red, green and blue. So when we see violet/purple in a rainbow, whether with our eyes or in a photo, we should be seeing a color ...
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0answers
27 views

Refraction through slanted glass [closed]

When searching on the internet, I can't find anything on how to find the angle of incident of a light beam through a slanted glass. I know how to find it when an angle is given or if the glass is in ...
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1answer
18 views

Dispersion of light in prism and change in medium [closed]

I have kept a source of light in air and there is prism through which light disperses. Now I keep the light source and the prism in water which has greater refractive index than air but less than ...
2
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0answers
38 views

What is the upper bound for the index of refraction of space?

It seems that gravitational waves and gamma waves travail at about the same speed, arriving within seconds of each other over distances in the ranges of $10^6$LY. Naively, I would assume this caps the ...
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1answer
32 views

Relativistic equations are medium dependent?

Einstein proposed that light travels with a universal velocity from Maxwell's equations on electromagnetism. But light has different velocity in different mediums, so does this imply that the ...
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1answer
34 views

Difficulty in understanding an optics question

So here's the question:- A thin film of transparent material of refractive index $1.52$ and thickness $0.42\ \rm \mu m$ forms a thin coating on glass of refractive index $1.60$. It is viewed by ...
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0answers
34 views

If the velocity of light is different in different medium is it wavelength changes or frequency changes?

We know that the velocity of light is equal to the product of it's wavelength and frequency. And when light goes from vacuum to any other medium it's velocity changes depending the mediums refractive ...
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1answer
19 views

Raise index of refraction of spherical lens

What happens to focal length and aperture of a spherical lens if you raise the index of refraction of the glass?
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0answers
24 views

In a transparent medium what does it mean if the group index is increasing?

I am new to Photonics and I lack the intuitive understanding about group indices and group velocities. I know group velocity is the velocity of the pulse in the medium. Does it mean that it is the ...
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1answer
34 views

Complex refractive index and absorption

I have a quite plain and simple question: Why is the imaginary part of the refractive index negative? I read it is to allow a positive sign in case of absorption. But how/why? I don't see why it ...
2
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1answer
26 views

Does total reflection occur when the wave is incident at a grazing incidence (angle of incidence equal to 90 degrees)?

I've posted the picture below from Introduction to Electrodynamics by Griffiths, 3rd edition. Is the phenomenon described talking about total internal reflection? Is it necessary for the incident ...
2
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1answer
51 views

Why does reflectivity suddenly change around critical angle?

Why does reflectivity suddenly change around critical angle? For example, consider the situation when incident light travel in dielectrics A and go in to dielectric B. Assume the dielectric constant $...
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1answer
49 views

Refractive screen for myopia [closed]

Is it possible to create a screen for a computer monitor to allow a Myopic person to see the screen without glasses?
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1answer
67 views

Looking through a glass hemisphere [closed]

I've found the following question on IsaacPhysics.org . I've been working on it for a couple of hours but I cannot figure it out. A looking glass is used to read an ancient scroll. This lens has a ...
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1answer
30 views

Part of reflection/transmission of an impinging beam under 90°

I would like to know if there is something like a thumb of rule for a light beam impinging a surface under $90°$. In regards to Snelius there will be no refraction. But what about the amount of ...
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2answers
40 views

Working principle of an optical stretcher

I understand that while using an optical stretcher experimental apparatus we attach a small dielectric ball to the specimen of study which can either be a DNA molecule, a Biological cell or any ...
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1answer
32 views

Photon frequency when transitioning from one medium to another

$E=h\nu$ where $\nu$ is frequency and $h$ is Planck's constant. The frequency, wavelength and speed are related as $c=\lambda\nu$. When transitioning from one medium to another the speed decreases by ...
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1answer
39 views

Why does light bend towards the normal when passing through a denser medium?

When light passes from a medium with less refractive index to a medium with higher refractive index, it bends towards the normal. But why normal . Of course we can take an example of a car moving from ...
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1answer
64 views

What type of mirage is this?

I am very new to the world of mirages and would like some information as to the type of mirage in this picture which I took this morning. It is the cargo ship African Kalmia which passed my location ...
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2answers
33 views

Interference of 2 particular waves in Newton's rings experiment

The rings formed in this experiment are due to the interference of light reflected from the top and bottom surfaces of the thin film of air between the plano convex lens and the glass plate below it. ...
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1answer
55 views

Refraction of X-rays

According to Snell's Law, refraction occurs when an electromagnetic wave passes from one medium to another. My question is, how are x-ray images able to be produced if the x-rays refract as they pass ...
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2answers
88 views

Is the speed of light in the Universe always $c$?

Every one here knows that $c=(ε'×μ')^{-1/2}$. But what if ε' and μ' are different values in other parts of the visible universe. Maybe near the center of a Quasar galaxy or even a Neutron star?
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5answers
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Is light actually faster than what our present measurements tell us?

It is well established that the light speed in a perfect vacuum is roughly $3\times 10^8 \:\rm m/s$. But it is also known that outer space is not a perfect vacuum, but a hard vacuum. So, is the speed ...
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2answers
71 views

How does light actually interact with different materials? - PBR

I am a computer graphics guy in the area of physically based rendering and recently I've been searching on the net to figure out how physical is Physically Based Rendering (PBR). The nature of the ...
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1answer
32 views

Literature on Reflection/Refraction of Waves

I completed the first year of my bachelor in Physics and astronomy in July. One of the courses was 'Waves and Optics' which we used the second half of Alonso & Finn's 'Fields and Waves' for. I ...
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1answer
39 views

What determines the property of vacuum that allows EM field to propagate?

As in case of sound it the disturbance that propagates by exchange of energy between particles. what is analogously related to em wave, where there is propagation of energy stored in electric and ...
2
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2answers
48 views

Is the reason the sunshine is 'extra bright' after rain due to refraction of the additional water in the air?

Quite frequently after the sun comes out after rain I experience a 30 minute period where the sunshine is 'unusually bright'. Such that it makes my eyes water. My question is: Is the reason the ...
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0answers
33 views

Is refractive index a property of the material or the light ray?

Why does it vary for e-ray and o-ray in nicol prism?
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0answers
27 views

Connection between wave equation of voltage and refraction coefficients

We have the solution to the wave equation of voltage $$U(x,t)=(U_+e^{-x\nu}+U_-e^{x\nu})e^{i\omega t}$$ But when we calculate the voltage at a particular time, we use the refraction coefficients. ...
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0answers
21 views

Seeing double images behind a plastic ruler

The side view of my plastic ruler (sorry for the bad drawing) When I look through the ruler at the tipp-ex behind you can see the logo twice. However, when I put the ruler close it disappears. ...
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1answer
101 views

In refraction how does light interact with electrons if it is not absorbed? [duplicate]

What I (think I) understand: When light is refracted in a medium (say glass), the light interacts with the electrons in the medium and the electrons create new waves. Summing the waves with the ...
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1answer
41 views

Why do our eyes perceive changes in apparent position of stars as twinkling?

Okay, so we all know that the changes in refractive index leads to continuous changes in star's apparent position but then why don't we see them moving up and down rather than brighten and dim in ...
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0answers
30 views

Computation of refractive index of the upper atmospheric air using pressure, temperature and humidity measurements

Upper Air Sounding Systems (UASS) measure the properties of the atmosphere typically till a vertical height of 30 km from Mean Sea Level (MSL). The balloon-suspended sensors used over here measure ...
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0answers
22 views

Clarify an assertion about refracted and reflected waves in Feynman

In The Feynman Lectures vol. 1, chp. 33, Feynman is disucssing about intensity of light and says that: The principle that we must understand is as follows. The currents that are generated in the ...
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2answers
78 views

Contradiction on the behavior of refractive index

The refractive index is given by: $$ n = \sqrt{\mu_r \epsilon_r} $$ This equation is symmetric about wavelength and is same for all wavelength of light i.e. since $\mu_r$ and $\epsilon_r$ are ...
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4answers
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What's the physics behind XKCD #2027 (time between lightning flash and radio wave burst)?

XKCD usually has solid (and often contemporary) science behind it. Lightning Difference, #2027 one says: Q: What’s that trick for telling how many miles away lightning is? A: Just count the ...
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1answer
38 views

resulting refractive index of multiple layers with different indexes

I am wondering whether my chain of thought is right because this seems very counterintuitive to me. But I calculated that if I have multiple layers with different refractive indexes stacked onto ...
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0answers
12 views

Does the speed of a light wave decrease in Earth's atmosphere? [duplicate]

Light wave is made up of photons, which exchange energy with the atmospheric molecules.
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2answers
23 views

what is the refraction index in the upper atmosphere(e.g Theromosphere)?

I've been searching for the refraction index in the upper atmosphere such as Stratosphere and Thermosphere but I can't find it, all that I've seen is all equation without any number that I can use it. ...
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1answer
44 views

Does the optical density of a medium depend upon its mass density?

The optical density of a medium is quantified by its refractive index $n$. Does it have any correlation with the mass/number density of the medium? In other words is an optically denser medium must ...
2
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2answers
114 views

Can you burn invisible jelly balls with a laser?

Suppose you have some jelly balls with similar refractive index as that of water, like in this video. You put them in water, making it invisible. So, the optical behavior of the balls should be ...
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1answer
28 views

What refractive index should be used while calculating the focal length of lens using lensmaker's formula?

Suppose a lens is half dipped in liquid. Then should the refractive index of liquid with respect to air should be taken. Or should refractive index of glass wih respect to liquid be taken. Or perhaps ...
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2answers
46 views

What happens to a light ray after it enters a perfect sphere? [duplicate]

I am assuming a sphere which can reflect, refract and diffuse a light ray. So when a light ray hits the surface of the sphere from outside, a part of it gets reflected, a part of it gets diffused and ...