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

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1answer
47 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?
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1answer
114 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
312 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...
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3answers
225 views

Optical path difference

I have question about calculating optical path difference. $$\Delta L = \mathrm{(BC+CD)}\cdot n_2 - \textrm{BF}\cdot n_1$$ - why calculating path difference here we are subtracting $\mathrm{BF}$ ...
38
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4answers
5k 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 ...
2
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1answer
39 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 ...
1
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1answer
80 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 ...
1
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1answer
77 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.
14
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3answers
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 objects,...
0
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2answers
207 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 ...
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0answers
26 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
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1answer
147 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
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1answer
99 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?
2
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1answer
273 views

Light follows the shortest path, but to where?

I'm a high school student and I'm trying to understand why waves bend when they refract. I read a few answers on the site, and the explanation that they follow the shortest path makes sense enough to ...
4
votes
3answers
279 views

Is it true that all particles that have a speed less than the speed of light must also have mass?

I've previously learned that massive particles cannot achieve the speed of light. But recently I read that, concerning the gels that refract and bounce light within around enough that it can travel ...
0
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2answers
33 views

For a light of given frequency, what does the amount of refraction in a variable medium depends upon?

I want to know whether the amount of refraction of a given monochromatic light depends solely upon the density of the of the medium ( increase the density to increase the angle of refraction), or ...
0
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1answer
163 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
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1answer
81 views

Why the image is being formed at the surface?

Last week I encountered a very cool optical phenomenon. A photo was sandwiched between the two glass plate to make the paperweight. The cool part is the picture seems to have been pasted on the top ...
1
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0answers
68 views

How does light manage to change its course at the boundary of two media of different optical densities?

This is a conceptual question. I already know the law of refraction but I need something like an idea of the Physical process from both particle and wave theory standpoints. Why does a ray of light ...
3
votes
1answer
226 views

Wave interference on window film coating

"The windows in an office tower are coated with a film to minimize reflected light of wavelength 550 nm. If the glass has an index of refraction of 1.52 and the film coating has an index of refraction ...
3
votes
1answer
248 views

What is incorrect about the original statement of Fermat's principle?

Here are some statements about Fermat's Principle taken from Eugene Hecht's Optics book. The original statement of Fermat's Principle : "The actual path between two points taken by a ray of light is ...
3
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1answer
5k 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
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1answer
113 views

Difference between speed of light and of bullet after passing through a barrier [duplicate]

I just read that, when a ray of light traveling in vacuum at $c$ strikes a glass slab, its speed decreases and then when it re-emerges it gets back to its original speed i.e $c$. If I draw a ...
5
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2answers
340 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 ...
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3answers
13k 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 ...
4
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1answer
338 views

What causes these rainbow effects using a polarizing filter on an airplane?

I know that light reflected from a surface at 45° is polarized and that for a similar reason skylight arriving from a direction orthogonal to the sun is polarized too. Photographers make use of this ...
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2answers
344 views

Does the speed of light have a range of speeds due to medium-dependency?

An EM particle-wave propagates in a vacuum at a constant speed $c$, independent of the source/receiver but dependent on most mediums it moves through. Since the vacuum is a medium, and if logically ...
0
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1answer
325 views

Metal Refractive index

I'm working on Fresnel equation for calculation of reflection of a light (532 nm) on Iron. I've got a question: Is metals refractive index always a real number or it can be a complex number?
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0answers
49 views

Model of scattering in wet things

You know that clothes and some surfaces become darker when wet (covered in an earlier question: why wet is dark?), because of the disordered reflections or of the refractive index of water or ...
1
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1answer
229 views

Refraction of light marching band analogy

When trying to understand the refraction of light when it hits a slower medium, lots of people seem to be enlightened by the 'marching band' or 'marching soldiers' analogy, which 'explains' that when ...
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1answer
40 views

What is the phenomena where an object is repeated in a glass surface?

I don't understand why this happens. Is the image being repeated because the light is being bounced back and forth on the multifaceted surface?
0
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1answer
137 views

Light absorption for different liquid

when I was working on a cylindrical glassy bottle that filled with water, I found that the initial light intensity is less than the final light intensity. (It's clear but I experiment this) This is ...
2
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2answers
70 views

Velocity of light

Velocity of light decreases as it enters a more optically denser medium. So how far can the velocity of light be reduced? Which object has the highest refractive index?
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0answers
33 views

wave equation for a homegeneous prism object

Are there any textbooks showing how to get the solution to Maxwell's equation of a uniform prism object with refractive index n? I'm asking because I want to see the explicit connection between wave ...
1
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1answer
31 views

Black holes in a denser media

In Crown Glass, the speed of light is 1.52 times the speed of light in vacuum. Consider the following hypothetical situation: Hypothetical Situation If a black hole is surrounded by a giant crown ...
0
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0answers
237 views

Refractive index and electric susceptibility

Suppose we have a complex refractive index $n_{ref}=n+ik$ whose value is given at a precise frequency $\omega_l$ from experimental data. We know that the imaginary part is responsible for the loss/...
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0answers
13 views

Is the link between shadows a refraction of the light? [duplicate]

When two objects in the sunlight approach, if you look at their shadows, they form a link when they are really close, is that an example of refraction? If so, is it the same as the refraction we see ...
3
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2answers
4k 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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1answer
433 views

Does the speed of light vary depending on what it travels through? [duplicate]

The title is pretty much self explanatory. Does the speed of light vary depending on what it is traveling through? The speed of light through vacuum is 299792458 meters per second but does it change ...
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3answers
179 views

Frequency dependence of the speed of light in air

According to this link, the speed of light of different colors in a medium should be different. But if the refractive index of light in air is 1 then this means that the speed of light in air and ...
1
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0answers
56 views

Laser travelling through a radially graded index of refraction

A laser beam propagates through a region whose refractive index varies as $\mu=\mu_0(\frac{r}{r_0})$. At a distance of R the beam makes an angle of 30° with the normal. Find the minimum seperation ...
2
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2answers
751 views

How can we redirect light from any direction to one direction

Not just focused light. I mean whenever light come from sideway or any angle. What device it called to refract light from any angle to one angle
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0answers
37 views

Making sense of sinogram of perspex block in air

I'm confused trying to visualize what happened exactly during this experiment: Setup with a laser and a photo diode on the opposite side. A perspex block (2x2cm) in between. Take 200 measurements ...
0
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0answers
155 views

Reflection and refraction of light [duplicate]

When a light ray strikes an interface a part of it gets reflected, a part of it gets absorbed while another part gets refracted. Why does light reflect? Why does it refract?
0
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1answer
85 views

Ray diagram for refraction

I'm having trouble finding out any errors in a ray diagram. The question is as follows: A ray of light falls normally on the curved face of a semi-circular plastic block, it hits the horizontal ...
1
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1answer
119 views

Aether atmospheres

http://arxiv.org/abs/1004.1467 claims to have an alternative explanation of the interaction of light around massive objects. Many of the general-relativity-tests such as bending of light near a ...
3
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1answer
763 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 ...
0
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3answers
3k 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?
5
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5answers
331 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
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1answer
196 views

Chopsticks in Water [closed]

When you put chopsticks (or any other object) in a glass cup of water, why do the chopsticks seem curved or bent? Is it because of the shape of the cup, the water, or the chopsticks itself? Note: I'm ...