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

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7answers
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Why does light change direction when it travels through glass?

This was explained to me many years ago, by a physics teacher, with the following analogy: "If someone on the beach wants to reach someone else that is in the water, they will try to travel as much ...
1
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0answers
27 views

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

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 ...
1
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2answers
78 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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3answers
33 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 ...
0
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0answers
39 views

Determining focal length and positions of principal planes [on hold]

I have been stuck on this problem for a few days now, and I am still not confident which approach to take with this question. I am consider using the Gullstrand Equation, but I hear some of my ...
4
votes
3answers
255 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 ...
18
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1answer
10k 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 ...
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3answers
329 views

Why does a ray passing through optical centre remain undeviated?

How can it be explained using the laws of refraction that a light through optical centre of a lens passes undeviated? If we assume the portion of the lens in the middle to be made of even number of ...
3
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1answer
523 views

Why does light not slow down?

Clearly light bounces off of things, going really really fast. I'm curious to understand how light interacts with matter in order to bounce without: Applying force to the object Losing speed So my ...
1
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1answer
116 views

Explanation for Refraction of light (change of angle) and Reflection

Refraction: I want a qualitative Quantum Mechanical explanation of why do we see light rays -in the classical picture- bend when light goes from one medium to another. I read that it is due to ...
2
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2answers
28 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. ...
1
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0answers
43 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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2answers
2k 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?
2
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0answers
50 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 ...
14
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5answers
34k views

Why doesn't the frequency of light change during refraction?

When light passes from one medium to another its velocity and wavelength change. Why doesn't frequency change in this phenomenon?
-2
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1answer
40 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 ...
0
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0answers
26 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 = ...
3
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1answer
3k 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 ...
6
votes
3answers
6k views

Why does red light travel faster than blue light?

I know that light of all frequencies travel at the same speed in vacuum. But I wonder why their speed differ in any other medium, why does red light travel faster if it has less energy than blue ...
0
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3answers
80 views

Reflection during refraction

I have observed in a book that a light ray reflects during refraction, which is a partial reflection, but when does that occur? Is it related to the propagation of light from a greater to lesser ...
0
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1answer
29 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 ...
0
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1answer
24 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 ...
1
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1answer
52 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 = ...
0
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1answer
198 views

Dispersion in a rectangular prism

Why are the colours visible only at the fringes of the light refracted through a rectangular prism?
0
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0answers
13 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 ...
0
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1answer
37 views

Kerr Effect; Electro-refraction

First post here. is is possible to observe the Kerr effect in transparent materials, at low voltages (such as 3.8V)? If so, can you refract light enough to distort an image, in a way similar to that ...
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1answer
54 views

Why does the wavelength gets shorter in the denser medium in refraction? [duplicate]

In the refraction, the wavelength gets shorter if it enters denser medium. Why is that happening? Is it just a phenomenon?
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0answers
38 views

Confusion with Fermat’s principle of least time [closed]

Here is an illustration used in my book to prove format’s principle of least time. My book says that ACB will be the shortest path. It is obvious that light reaches E first, and then X. If the ...
3
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2answers
52 views

Mirages under water?

In Polynesian shallow water, the temperature difference from short place to place is so high that one can see the same trouble refraction that exist in air above fire or metal sheet in summer. So I'm ...
0
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1answer
22 views

Refraction inside a refracting medium

After a light ray gets refracted at the boundary of a refracting medium, why do sent the light ray keep refracting inside. Cause if you divide the medium into many boundary layers then light should ...
0
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4answers
219 views

Why does light bend?

I have just read about dispersion of light by a prism and the thing which i donnot understand is that WHY does the light bend at all? Through prisms and slabs? I came to know that red light has the ...
1
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2answers
27 views

Polarized light in single mode fiber

In single mode fiber the light propagates in two orthogonal planes. Input will be linearly polarized light, which state of polarization will be on output and why? And if there will be some different ...
0
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1answer
29 views

point particle explanation of refraction

Is there an explanation of refraction using the point particle model? Most explanations I have seen use the wave model or particles with width.
2
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1answer
33 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 ...
3
votes
1answer
83 views

How do opaque materials have an index of refraction?

The index of refraction defines how much light is bent as it passes through an object, right? So how can opaque objects, which don't transmit light, have a value for the index of refraction? (e.g., ...
29
votes
3answers
4k views

How does light speed up after coming out of a glass slab?

As I learned today in school, my teacher told me that when light enters a glass slab it slows down due to the change in density and it speeds up as it goes out of the glass slab. This causes a lateral ...
1
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1answer
29 views

Will the ray of light follow the laws of reflection at the interface of two media?

Suppose at the boundary of two optical media,of different refractive indices a mirror is kept perpendicular to surface of the boundary.If a ray of light travels through one of the media and then ...
2
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2answers
83 views

Is it possible to create an optical medium where sound can travel faster than light?

The speed of light decreases with increase in the density of the optical medium whereas the speed of sound increases with increase in the density of the medium. So is there any possibility to ...
1
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2answers
39 views

Let's suppose I am to display the letter R on mirror as well water , will I get the same images?

As far as my practical experience goes both look quiet the same when an image of any object is formed on them, yet I wanted to be ascertained is there any actual visible differences between both the ...
4
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1answer
175 views

If refraction slows down light, isn't it possible to hold light still?

I have a quick question about the refraction of light, and I'm sorry if it seems a bit simplistic or even stupid, but I'm still learning. We know that when light passes through a denser medium, it ...
4
votes
3answers
3k views

intensifying a light source

When trying to intensify a beam of light by refracting it through a lens, (as in a lighthouse fresnel system or similar railroad style switch lamp from years past), is the beam intensity increased by ...
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1answer
33 views

How are neutron refractive indices calculated?

I have been informed of the fact that neutrons refract similarly to light in accordance to Snell's Law. How would one calculate the refraction index for a neutron?
2
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2answers
74 views

How the speed of light is constant in the universe if it decreases in water and glass and some other objects? [duplicate]

My teacher told me that speed of light is constant in the universe. But in optics it is clearly shown that speed of light slows down in some objects. Please help.
0
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2answers
73 views

Why does the critical angle for refraction exist?

When light moves from a medium with a high refraction index to a medium with a low refractory index (water to vacuum), that there exists a "critical angle" at which no more refraction occurs. What is ...
1
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1answer
59 views

Why phase velocity of light is slower in a dielectric than vacuum?

Why does light speed suffer a reduction when it passes through a homogeneous dielectric medium? I know my math says so, i.e.- a highly polarizable ($\chi$) medium is associated with high $\epsilon$ ...
3
votes
1answer
82 views

Special Relativity in water

If there are 2 observers in water moving relative to each other as well as to water, they measure different speeds of light. So does time dilation occur for them? (since Time dilation is based on ...
0
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0answers
36 views

What will the point of view be when you move faster than light in a medium?

In water the light become slower to the point where electron in water moving faster than light (in the same medium). So in electron frame of reference what will electron's point of view be? From what ...
27
votes
10answers
26k views

What determines color — wavelength or frequency?

What determines the color of light -- is it the wavelength of the light or the frequency? (i.e. If you put light through a medium other than air, in order to keep its color the same, which one would ...
2
votes
0answers
37 views

How does refraction work? [closed]

https://www.youtube.com/watch?v=YW8KuMtVpug&feature=iv&src_vid=CiHN0ZWE5bk&annotation_id=annotation_187211 Start the above video at 8:15. How does the phase velocity affect the apparent ...
2
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0answers
40 views

Aquarium/refractive indices/detector

Quick question: I'm currently fiddling around with this homework of mine and I seem to be lacking some basic optics knowledge apparently. An aquarium is filled with a fluid as seen in the figure ...