Questions tagged [refraction]
Change in the direction of propagation of a wave when its transmitting medium changes.
-3
votes
0answers
11 views
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?
1
vote
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 ...
2
votes
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 ...
1
vote
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?
0
votes
0answers
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 ...
0
votes
1answer
34 views
Total internal reflection of sine wave vs smooth step function [closed]
If an electric field described by the function
$$f(t)= \begin{cases}
0&\text{if}\ t<0\\
\sin(t)&\text{if}\ 0\leq t\leq \frac\pi2\\
\ 1&\text{if}\ t>\frac\pi2
\end{cases}$$
...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
-1
votes
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
votes
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 ...
0
votes
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 ...
0
votes
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 ...
1
vote
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 ...
0
votes
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?
-1
votes
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 ...
1
vote
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
votes
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
votes
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 $...
1
vote
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?
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
1
vote
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 ...
0
votes
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 ...
1
vote
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.
...
2
votes
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 ...
-1
votes
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?
39
votes
5answers
13k views
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 ...
2
votes
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 ...
0
votes
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 ...
0
votes
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
votes
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 ...
1
vote
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?
0
votes
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. ...
0
votes
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.
...
2
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
61
votes
4answers
11k views
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 ...
1
vote
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 ...
0
votes
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.
1
vote
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.
...
1
vote
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
votes
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 ...
2
votes
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 ...
0
votes
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 ...
