Questions tagged [refraction]

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

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Refractive Index in Ionized Liquid from Micro Aspect

I learned about the refractive index of gases and dense materials, which is a function of the atom number per volume, wavelength of electromagnetic wave, etc. However, what is the refractive of ...
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Does phase change occurs on refraction at a lens?

There is no phase change between refracted (transmitted) rays and incident rays, according to boundary conditions of electric field and magnetic field, in accordance with the Maxwell's equations and ...
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How does a concave lens form a virtual image?

If rays of light are diverged upon exiting a concave lens, then they have no focal point. The rays completely spread out in random directions. Like diffuse reflection(which does not form an image) So ...
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Can light be sped up to go 30 times fast than the speed of light in a medium?

Here's the link: https://sciencebulletin.org/researchers-develop-way-to-control-speed-of-light-send-it-backward/ Here's the line that makes no sense to me: Abouraddy and study co-author Esat Kondakci ...
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Why can't $ε_r<1$ (at low frequencies)?

I've heard it said that the vacuum permittivity is the lowest possible permittivity for any substance, that no substance can have $ε_r<1$. Is this true? If so, why is this different from ...
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Predictions followed from Fermat's Principle, according to Feynman

In his book Lectures on Physics, Feynman mentions two predictions followed from Fermat's Principle (chapter 26-4). 1) Given three media air (1), water (2) and glass (3) with indices measured against ...
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Determining the refractive index of a glass slab using a travelling microscope

In this practical video of finding the refractive index, the reading is being taken by placing the travelling microscope perpendicular to the slab. But I've learned in another video(Frame Shot) if you ...
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Different Refractive indices in Anisotropic medium

In an anisotropic medium, if we consider the dielectric tensor to be diagonal and medium is isotropic in $\mu $ or ($\mu = \mu_0$). Then from fresnel equation we get a quadratic equation in 'n' (...
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TIRF mycroscopy with intermediate layer of different refraction index

I`m currently experimenting with through the lens TIRF microscopy in which an additional layer is used between the glass and the sample. This 10-30 μm layer has a higher refraction index than my ...
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Refraction of light with destructive interference

The wavelength of light determines it's refraction in a prism. But, what if two beams of light destructively interfere as they pass through a small prism, so there is no apparent wave or wavelength ...
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Is the refractive index neglected in the standard Michelson interferometer equation: $\lambda=2d/N$

Hoping someone can help with this. It's a simple question, but I can't seem to find the answer anywhere: I'm looking at the basic Michelson interferometer experiment, where you measure the wavelength ...
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Formation of a second image due to reflection at a boundary

To determine the refractive index of a transparent plate of glass, a microscope is first focused on a tiny scratch in the upper surface, and the barrel position is recorded. Upon further lowering ...
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Reflection coefficient derivation

from fresnel equations we have $$r_{parallel}=\frac{n_1\cos\theta_i-n_2\cos\theta_r}{n_1\cos\theta_i+n_2\cos\theta_r}$$ $$r_{perpendicular}=\frac{n_2\cos\theta_i-n_1\cos\theta_r}{n_1\cos\theta_i+n_2\...
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The ideal shape of a plano-convex lens

What's the type of the ideal shape of a surface of a plano-convex lens to focus a parallel beam at the point? Considering the lens turned its flat side to a beam. Surely it must be aspheric: ...
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Light propagating through a sound wave

We know that the speed of light depends on the density of the medium it is travelling through. It travels faster through less dense media and slower through more dense media. When we produce sound, a ...
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Why do prism split light at angle instead of curving it?

I assume that when light goes through matter, it doesnt really slow down, but the waveform is pushed back due to some resonance with the atoms. EDIT: Interference is probably a better word than ...
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Can Snell's law be said to fail in this condition?

I ran into a question in my textbook which asks me "when does Snell's law fail?". My first reaction was that it's a law, it can't fail but they gave the solution as the condition when light rays are ...
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Which colour comes out first from a prism?

When a narrow beam of white light is incident on a triangular prism. The speed of red light is maximum and violet is of minimum, red light bends less and travels less distance as compared to violet ...
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Which of these 2 methods for calculating the focal length of a concave mirror is more accurate?

I have done an experiment to measure $f$ the focal length of a concave mirror. I have a list of 8 values for $u$ the object distance and 8 values for $v$ the corresponding image distance. I ...
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Bending of light Ray in radially varying refractive index [duplicate]

If light passes near a massive object, the gravitational interaction causes a bending of the ray. This can be thought of as happening due to a change in the effective refrative index of the medium ...
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Velocity vectors during the propagation of photon in elastic scattering question [duplicate]

I have been trouble with the concept of energy of the photon during propagation in random scattered or random continuum medias. E = hf, where E is the energy of the photon in Joules; h is Planck's ...
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What is Snell's window?

Why is it that an underwater observer can see only a circular "window" and also can't see anything above the separating surface? Does the "window" depend on the depth?
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Maxwell's equations, nonlinear media, and dynamic response

Maxwell's equations in the vacuum with electric permittivity $\epsilon_0$ and magnetic permeability $\mu_0$ are given as: $$\nabla \cdot \vec E = \frac{\rho}{ \epsilon_0}$$ $$\nabla \cdot \vec B = 0$...
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Why Ewald–Oseen extinction theorem failed to explain refraction

One way to understand the refraction of light other than Huygens–Fresnel principle is by Ewald–Oseen extinction theorem, which states that light scatters only in forward direction with a slower ...
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How is the image distance negative?

Following is a problem from book: "The near point of a person's eye is 53.0 cm. To see objects clearly at a distance of 24.0 cm, what should be the focal length of the appropriate corrective lens?" ...
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How is energy conserved during simultaneous refraction and reflection of light?

My question is regarding the partial reflection and refraction of light when incident on a refracting surface. Here, the energy of Incident Ray is E=hv of Reflected Ray is E=hv and that of Refracted ...
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Why does a laser beam stay coherent when it passes through glass?

If I have a coherent laser beam and I shine it through some glass, the light will slow down because it will interact weakly with the atoms in the glass. However, the beam that comes out the other side ...
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Microwaves in other media

I saw a video on how microwaving grapes make plasma. He said that the refractive index of microwave is about 10 inside the grape. Now, we don't know the wavelength of the microwaves in the grape or ...
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How does every ray of light or photon can follow the same Snell's law in a very random states of matter like gases and liquids?

We know that to study refraction at the interface of two media, we use Snell's law which is $$μ=\frac{\sin(i)}{\sin(r)}$$ or $$μ=c/v$$ (for vacuum as one of the media). I know this is an ...
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Refraction of a circular polarised wave

I'm trying to derive the expression for the fields $E_{1}$ and $E_{2}$ in terms of $n_{1}$, $n_{2}$ and $E_{0}$. Where: $E_{0}$ Is the incident field amplitude of circular polarised light $E_{1}$ Is ...
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Gravitational lensing, indices of refraction and the size of the universe

Been pondering the following question for over 15 years now. Is it possible that the size of the universe has been over estimated due to the effects of gravitational lensing and boundary indices of ...
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Refraction on the edge of mediums

Say I have this setup : Here a light ray (in red) is incident on the point A in such a way that it is collinear with AB, and the indices of refraction are as mentioned in the figure. So my question ...
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How To Calculate Wavefront Error of a Lens

The wavefront describes the Optical Path Difference (OPD) of an optical system. Typically the OPD has the unit of microns. The OPD is the difference of the Optical Path Length (OPL) of an arbitrary ...
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What is happening to a wave at a media boundary?

Say we have a light wave going from air to plastic, refractive indexes 1 and 1.5 respectively. What exactly is happening to the properties of the wave and why? Taking wavespeed as v, frequency as f, ...
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Mathematics supporting the classical explanation of why the phase speed of light slows down in a medium

Consider the answer here by Chad Orzel which explains how a monochromatic light can slow down in a medium. He explains, You can think each of the atoms (of the medium) as being like a little dipole,...
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What does it mean to say that glass has refractive index 1.5?

The refractive index of a material depends on the wavelength of the light incident upon it which is why dispersion happens. When we say that glass has refractive index 1.5 which wavelength do we have ...
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Can light in a medium travel faster than speed of light $c$ in vacuum?

Refractive index of medium $m$, $n_m$, is given by $$n_m = \sqrt{\mu_r\epsilon_r}$$where $\mu_r$ and $\epsilon_r$ are permittivity and permeability of the medium respectively. And, velocity of light ...
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What is Cherenkov radiation? [duplicate]

What is Cherenkov radiation? I came across this concept when I was learning SR. Why can't particles moving at speed of excess of speed of light in the medium. Why it does not violate the limitation ...
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The Speed of Light and Its Medium's Density

When reviewing a refractive index chart there is a relationship to the density of the medium and the velocity of electromagnetic radiation through the medium. The lower the density the greater the ...
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Speed of electromagnetic wave [closed]

On dispersion , speed of wave is inversely proportional to its wavelength . Therefore, gamma has max speed. But then in visible light , violet has least wavelength still it has least speed in visible ...
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Does TIR obeys laws of reflection?

After reaching the critical angle, do Snell's laws and laws of reflection hold good?
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Amplitude of wave

Does amplitude of wave changes during refraction of wave If it will changes,why? I have been searched for internet but still cannot find a complete answer
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light travels the fastest path of two points, how do you determine those two points?

so in this diagram from Richard Feynman's book: QED Strange Theory of Light and Mater the light takes the fastest path from S to P and the lens makes it so that there are many fastest paths that go ...
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Reflection and transmission of EM waves

I'm reading "Introduction to Electrodynamics" by David J. Girffiths and the following assumption is confusing me: We have an EM wave inciding on a surface, Then, when applying the boundary ...
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How much does temperature affect the time of sunrise?

Please forgive me if this is a dumb question, or if my understanding of basic physics is wrong. Please feel free to correct me. As I understand it, if the Earth didn't have any atmosphere, then the ...
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Is snow falling too fast or too reflective to produce rainbow?

Imagine millions of water molecules suspending in the air starts to turn into snow, I like to know the exact reason why we cannot have snow bow, is it due to the speed of each snow falling very fast ...
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Why do lens (convex) not introduce any path difference to light incident on it?

My understanding is that the top rays spend less time inside the lens where the speed of light is slow and the middle rays spend more time inside the lens so the time is kind of compensated . But I'm ...
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Are rainbows three dimensional? If so, what determines their depth? [duplicate]

I am wondering whether rainbows are three dimensional, and if so, what determine their depth? How to calculate the depth of a rainbow, given its radius? From what I understand, all rainbows are ...
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Why does reflection occur on transparent materials? [duplicate]

Why does reflection occur on transparent materials? For example, air/glass or air/water (two different interfaces) Mostly it's refraction that's occurring, but I also see some reflection. Why is that?...
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Refraction of matter waves

My question is a bit messy, so here is the background: Normally the trajectory of a massive particle in the presence of a gravitational field is described in the context of general relativity. ...