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

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14 views

Refraction of light rays

My textbook says that the greater the refractive index of a medium, the lower the speed of a light ray passing through it. Seawater has a slightly larger refractive index than fresh water. Light ray ...
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1answer
28 views

How image is formed within the eye?

So our eye has a layer of nerves. Our eye lens refracts and concentrates light rays of different amplitudes, and that concentrated impulse (of a mixed amplitude) induces a signal on some nerve; since ...
2
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0answers
42 views

Breakdown of Snell [on hold]

I have reason to believe that if we are using an accurately formed thin prism, then very near the working apex, where there are few atomic layers in a latticed prism, there will be inaccuracies in the ...
2
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2answers
31 views

How does change in medium affect object distance/image distance?

Say,we have a container filled with a liquid of refractive index $7/5$ upto a height up $H$. There exists a plane glass mirror at the bottom of the container. Now if a fish were placed at a height of ...
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0answers
25 views

How to solve the following wave equation? [closed]

We have paraxial beam propagating in a uniaxial anisotropic media. When such is the case wave can be divided into two orthogonal parts: Ordinary wave beam Extraordinary wave beam. The ordinary ...
22
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1answer
828 views

How can my window not scramble the image of my yard?

How can an image pass through a window if the atoms in the glass randomly emit photons in any direction? I've read that glass is transparent because the atoms don't readily adsorb visible light, so it ...
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1answer
36 views

Does the angle of incidence change the refractive index?

I've been told if you plot a graph using the sine of the angle of incidence and the sine of the angle of transmission it should follow a linear regression $y = ax + b$. However, if you use certain ...
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1answer
23 views

Frequency dependence of electromagnetic reflection

I was surprised to see that the Fresnel equations for reflection depends on refractive index and angle of incidence, but they do not depend on frequency. Why is this case? Are they restricted to ...
2
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1answer
39 views

Does curving only the inner surface of a diving mask prevent blurred images?

Diving masks often have lenses built into the glass for divers who do not have perfect vision. The lenses in a diving mask faceplate often only have a curved surfaces on the inside glass. Why is this ...
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2answers
7k views

Why do I see better under water using swimming goggles? [duplicate]

I am myopic (I don't really know if this is relevant or not) and I usually swim without contact lenses. My vision is clearly better underwater when I am using swimming goggles. I have tried to ...
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2answers
249 views

Is light getting another color when travelling through a prism?

When white light travels through a prism the speed of this light is slowed down. Now there is a relation between speed of light, frequency and wavelength. So when a red light of 700nm enters a prism ...
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1answer
87 views

Does this picture look wrong to anyone else? [closed]

There is a typo. One which obfuscates the main point and makes it difficult for anyone unfamiliar with the problem to deduce the answer.
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3answers
70 views

Derivation of the group velocity

I know that the group velocity of a light pulse is defined as $$\begin{split}v_g&=v_p\left(1+\frac{\lambda}{n}\frac{dn}{d\lambda}\right)\\ ...
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1answer
32 views

Sphere, silver reflector, refraction questions

A sphere with its back silvered can act as a retroreflector. When a fine beam of light is directed to the sphere as shown, it is refracted at the front surface, and focused on the rear interior ...
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1answer
49 views

Can something go faster than the speed of light in a medium? [duplicate]

Since some mediums have an index of refraction more than 1, light goes slower than in a vacuum. Does this mean it is possible for particles to go faster than the speed of light in these mediums? If ...
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1answer
33 views

Is Snell's law a product of Gravitational Time Dilation?

Due to the proximity of atomic structures in a solid liquid or gas, does the gravity of these atoms warp time enough to cause light to move slower from the perspective of an outside observer?
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1answer
60 views

Why is glass green?

When I look at a glass block at an angle the edges appear green, but when I look at the edge sideways, so that is directly in front of my eyes it appears transparent. Why?
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1answer
73 views

When exactly do we substitute $\epsilon_0 \rightarrow \epsilon$ and $\mu_o \rightarrow \mu $?

If everything is embedded into vacuum, why aren't Maxwells Equations always with $\mu_o$ and $\epsilon_o$? When exactly do we have to make the substitution $\epsilon_0 \rightarrow \epsilon$ and ...
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2answers
34 views

Difference between scattering and refraction?

I while back I learnt that when light is incident on a dipole the dipole will scatter the light, and when it is incident on a material of a different refractive index then the light refracts. From the ...
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1answer
898 views

Why is everything not transparent? [duplicate]

There is a related question on this site here: Why glass is transparent? Which explains that glass is transparent because the atoms in glass have very large energy differences between energy levels ...
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4answers
134 views

Why do the edges of glass blocks create a shadow?

I have always observed that the shadow of glass blocks becomes darker as the glass is moved away from the surface where the shadow falls. And I know this is because refracted light rays from the glass ...
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3answers
5k views

How can muons travel faster than light through ice?

When a neutrino traveling through ice hits and interacts with an oxygen atom, muons are created. Cherenkov radiation can be created when muons travel through ice faster than light and create a ...
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0answers
19 views

wave propagation modelling

what is the best modelling technique for modelling mm-wave propagation in electromagnetic environment. Right now,am working on how to use use Transmission-line matrix (TLM) and ray-tracing techniques
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1answer
29 views

Fresnel equations for perpendicular angle of entry [closed]

In many text books one finds for the fresnel coefficients for light perpendicular to the surface: $$r = \dfrac{n_1 - n_2}{n_1 + n_2}\quad\text{and} \quad t = \dfrac{2n_1}{n_1 + n_2}.$$ When I try to ...
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0answers
16 views

Where can i find the complex index of refraction in the radio spectrum for aluminium?

I am looking for the (complex) index of refraction or the dispersion relation of aluminium for frequencies/wavelengths roughly between 30Mhz/10m and 30GHz/1cm. I have found a few sources that give ...
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1answer
74 views

Would forcing a photon to travel under $c$ even after it leaves a medium break Relativity? [duplicate]

So, I stumbled onto this article which really blew my mind (http://www.bbc.com/news/uk-scotland-glasgow-west-30944584). To sum it up, these researchers set up some kind of material that slowed a ...
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2answers
73 views

Why aren't clouds multi-colored?

Clouds are made out of tiny droplets of water. These droplets, to my understanding, act like tiny prisms (which is why there are rainbows after rain). From my line of thinking, if we had a room with ...
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1answer
24 views

What's wrong with finding the maximum refraction angle? [closed]

I am wrong with this derivation of $1 = \mu^2$ for arbitrary $\mu$ obviously, but I can't find what's wrong. $\delta := \theta_{1} - \theta_{2} $ where $\frac{\sin \theta_{1}}{\sin \theta_{2}} = ...
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1answer
32 views

Mirage formation in deserts [duplicate]

Why does a person sees water in the desert even then when no water is present there at that time? How does this happens?
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0answers
25 views

Refraction Explanation From Particle Perspective

I was wondering if there was an intuitive way of understanding refraction from a particle perspective. By this I mean, that before entering a lattice, a photon has some momementum, it then enters at ...
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1answer
22 views

How lens for specs are manufactured for a given power? Do thickness, refractive index play role? [closed]

I read some where that if the prescribed glass power is more, glass must be made of higher refractive index to lessen the thickness. But from knowledge of physics, power just depends on focal ...
2
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2answers
85 views

Why is this laser beam being scattered(and not)?

I was shining a laser beam through a liquid filled test tube(an ester particularly),and I found this phenomenon rather intriguing.Have a look. Now when I passed the laser straight through the ...
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2answers
54 views

Can a laser beam be captured in prism?

is there a way to shoot a laser at a prism (or something) and have it glow when the laser hits it? I want to make a small box with a small hole in it. With the prism in the box, when the laser is ...
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1answer
38 views

Deep confusion with conventions and signs in geometric optics

This is an equation given in my book. The question is why have they used a negative sign on the LHS? Now, if you try to derive the mirror equation with simple geometry, you get 1/v +1/u =1/f . ...
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3answers
69 views

If light slows down while passing through a material, does it speed back up while in a vacuum?

Light slows down while passing through, say, water. After passing through the water, does the light speed back up to the "speed of light"? If so, how and why?
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1answer
49 views

Reflective angles from a CD [closed]

How do I estimate the diffraction angles of laser light which illuminates a CD? Does the storage capacity have an impact? Theories I have considered are: refraction diffraction $\sin(\theta)=\frac ...
3
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2answers
152 views

The refraction through hot air around a candle flame

Why the intensity of light is more around the region of hot air around the flame of candle in the shadow cast by the light from the collimated source ? Most of the articles mention it is due to the ...
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2answers
79 views

How come lenses alter the path of photons?

From what I know, photons are theorized particles and believed to be massless (just energy) and travel at the speed of light. How come a lens, which is an object made of atoms, can bend a light path? ...
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0answers
43 views

How to solve this problem : A glass sphere of radius 1 m and refractive index 1.5 is silvered…? [closed]

Problem: A glass sphere of radius 1 m and refractive index 1.5 is silvered at its back. A point object is kept at a distance of 1 m from the front face, as shown in the figure. Find the position of ...
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3answers
73 views

Application of Snells law

What i know about snell's law: It is applied when a ray of light meets the interface of some other medium and we can find the fourth quantity if we know any of the three quantities in the following ...
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2answers
99 views

How is refractive index related to the density of a medium (for example, air)?

I have a question regarding refractive index dependency on the density of a dielectric, specifically air. Background Let us start from Newton's second law form of driven harmonic oscillators ...
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2answers
44 views

Total internal reflection in a simple pane of glass - why can we see through?

Consider looking through a glass window pane at high angles of incidence. At the front face of the pane, there is no total internal reflection since the light is traversing an air to glass interface. ...
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0answers
47 views

WHY do waves diffract - what is the mechanism behind the diffraction?

Having recently studied wave diffraction at an introductory level, I don't feel that I understand why waves diffract like they do. What is it about the obstacle or the waves interaction with it which ...
2
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0answers
183 views

Why should angle of incidence be equal to angle of emergence for minimum deviation in a triangular prism?

When I was solving questions on Ray optics I encountered a question wherein I had to prove that when a ray of light undergoes minimum deviation through a triangular prism then both the angles of ...
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1answer
46 views

Calculating angle of refraction of water in this lab setup? [closed]

The setup of the experiment is as drawn in the picture (where the red circle is a rotating disk, the box is a laser and the straight line the laser beam and the semi circle in the middle of the ...
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0answers
42 views

What happens to the group and phase velocity of light as it travels through a medium?

We have all been told that when light travels from, say, a vacuum through water it slows down. What I want to know is what happens to its phase velocity and group velocity. Refractive index is $n = ...
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1answer
66 views

Does the speed of the Refracted Ray change if the angle of Incidence is 0 degrees?

While studying about Refraction, the following doubt came into my mind. The author of the textbook mentions that if the light wave is incident normal to the surface, it will travel "undeviated" in the ...
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1answer
25 views

Refraction and Internal Reflection

When a light is incident on the boundary of a medium with an angle greater than the respective critical angle, we obtain the angle of the refracted or reflected ray to be equal to the angle ...
2
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1answer
78 views

How to determine the radius of curvature of a convex lens?

Suppose there is an equi-convex lens made of glass which has a focal length ($f$) of 30cm. Then, can we not say that the radius of curvature, $R$ of the lens is twice the focal length, i.e. $R = ...
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16 views

The image of an object through a curved surface

We have a curved surface, separating two different medium, with refractive index n1 and n2. We know the radius R of the curve,then how can we find the position v of the image? I read that the ...