# Tagged Questions

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### Why does vertical polarizer absorb the vertically polarized waves?

They explain that vertical wires serve as the secondary transmitter: the waves induce since oscillations of electrons in the wire effectively absorbing the wave. Ok, let's believe that wave is ...
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### Proving law of reflection using Huygens principle

So I was reading the proof of law of reflection using Huygens principle but as I am new on this website so I can't attach a picture,so I will try to explain by writing only. The problem I face is ...
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### Using a black hole as a mirror?

http://www.youtube.com/watch?v=ENd8Sz0AFOk The YouTube video is a good example how the gravity of this merging binary black holes bend light around themselves.
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### Does less heat equals more reflexion? [duplicate]

Does colder metal reflect more if hotter metal reflect less? Why?
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### Relation between radius of curvature and heat produced at focus when concave mirror is kept in sunlight [duplicate]

Hi I am newbie here and this is my first question so please do not mind if I don't use the correct language or anything. I want to know the relation between size of a concave mirror ( measured by ...
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### What are the right signs? [closed]

This is a question provided in my book: An object of height $2\ \mathrm{cm}$ is placed at a distance of $2.5f$ from a concave mirror where $f$ is the focal length. Find the height of the image. ...
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### How is sound affected when reflected off a vibrating membrane?

When sound produced at a frequency, say 200Hz is reflected off a vibrating membrane, vibrating at another frequency, say 10Hz, what are the properties of the reflected wave in terms of frequency and ...
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### Which gives the most realistic pictures, Mirror, camera or their combination? [closed]

By googling, I have found several different opinions about how to take one's own facial images more realistically: Some said photos taken by cameras (smartphone's cameras, if specific) are more ...
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### Bounced ray angle of normal direction? (SOLVED) [closed]

TL;DR whats the position of C. I'm currently programming something and for some reason I having problem figuring this one out, imagine having a ray / or ball bouncing (without mass or gravity etc) ...
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### If a silver atom scatters light isotropically, what happens if only a single photon is scattered?

From this question :Why is the light reflected at the same angle from mirror? and this part of the answer: The starting point it that a single silver atom is far smaller than the wavelength of light, ...
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### 100x magnifying optics system for short laser pulse

I am now designing an experiment that consists of a 400 nm short pulse (~300 fs). In the experiment, we need to magnify the transverse profile of the pulse by 100x. That's the problem. I was ...
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### Light and mirrors [duplicate]

When I shine a beam of light at a mirror why does the ray go in the exact opposite direction (tested with protractor). Why does it not go back in exactly the same direction? The beam is of an ...
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### Dimensional Paradox Demonstrated by Light Moving Between Parallel Mirrors

In a thought experiment, there are two parallel mirrors which are very long which also face each other. One has a hole in it and one flash from a strobe light shines into that hole. One observer in ...
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### Combination of mirror and lenses [closed]

I am a keen learner of physics, but I am unable to solve problems involving lenses and mirrors together. please can anybody tell me the method to solve these problems? for instance let us take a ...
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### 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 ...
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### how (n) number of eyes can see one dot (for example red dot) from different place at same time?

Today, me and my brother looked at red point of the wall (that was a red sticker for kids), and we saw the red point even we changed our locations in the room, and I can argue that everyone can see it ...
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### How to measure 8 μm surface bumps?

I want to measure surface bumps which are larger in size than $8\ \mathrm{\mu m}$ on a uncoated plastic mirror. So it can be any number of smaller bumps and that would not effect the application. I ...
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### 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 ...
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### Seeing multiple objects with penetrative EM reflections

If you had a static source of penetrating EM radiation, like a metal detector and you are trying to detect several types of known objects buried at different heights, orientations and potentially ...
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### Is there proof that a reflected photon is the original photon before reflection?

I came accross the DIRAC-Ansatz in On the Notation of MAXWELL’s Field Equations where it says Therefore as another consequence there must exist two different kinds of photons, which interact in ...
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### Is there any limit to distance between two waves when used in Huygens principle?

Apologising for not being clear. When I used Huygens principle to determine the spherical wavuefront of radius $R/2$ created by reflection from a spherical concave lens of radius $R$, I got amazingly ...
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### Wave reflection, boundary conditions?

When a wave-pulse is reflected such that initially it was moving in the denser medium, and towards the other side of the interface lay the rarer medium, will there have been a phase change post ...
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### Space station illuminated by the Earth

Let's say that we have a space station orbiting the Earth around the equator at a speed of 360 degrees per 24 hours, always being roughly on the line between the centers of the Earth and the sun. From ...
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### Boundary behaviour of a mechanical wave

Let us assume we have a taut rope and I introduce a pulse in it by whipping one end. Now if instead of a clamp, I have tied the other end of the rope to a denser rope, a part of the energy is ...
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### An intuitive explanation regarding propagation of mechanical waves

I was studying mechanical waves today and have questions regarding how a pulse is propagated on a string and its reflection and transmission at a boundary and I hope I can find help here. First, ...
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### Reflection and absorbtion of EM-wave in dielectric plate (calculate through dipole)

The task: there is a plate with thickness $h$. Also $\sqrt{|\epsilon|}kh \ll 1, k = \omega/c$. Find reflection and absorbtion of EM-wave in this plate. EM-wave falling normally on plate. What I did ...
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### Transmitted Power and Poynting's theorem contradiction?

I was reading Chapter 12.1 in Hayt & Buck "Engineering Electromagnetics" 8-th edition. Here they discuss the reflection of uniform plane waves at normal incidence. They derived the following ...
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### 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 ...
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### what happens to light energy when it is stored in a prism with angleA > angle R

In a glass prism if any light is incident for which angle of prism is twice the critical angle than it does not escape prism.Does it mean it has become like a black hole which eats away all visible ...
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### Why is light energy 100% reflected in total internal reflection?

during reflection of light energy transfer is not 100%. when light from a rarer medium like air strikes a denser medium like glass slab, some part of light is reflected back and some of it is ...
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### Why is it desired to have an aperture of a spherical mirror to be less than the radius of curvature?

In many instances, I have noticed that it is given that the aperture is less than the radius of curvature for a spherical mirror. Why is this given like that?
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### How do chirped mirrors compensate dispersion?

How do chirped mirrors compensate dispersion? I understand that if you have longer wavelengths penetrating deeper into a chirped Bragg stack, then there will be some anomalous dispersion because the ...
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### Can matter have 100% reflection?

Is it possible to have matter that reflects all the light and does not absorb light at all? If thats possible then we can store light inside it right? I think we can trap light inside that matter in ...
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### Optics - how a lens distorts the image

If we consider a small object of length $b$ that is placed flat along the axis of a concave mirror, how will the image produced be different from the object? I know that a lens will magnify or ...
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### Should a superconductor act as a perfect mirror?

I have been told that metals are good reflectors because they are good conductors. Since Electric fields in conductors cause the electrons to move until they cancel out the field, there really can't ...
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### The properties of light photons [duplicate]

Please consider a closed room with light reflecting walls and in the centre of the room there is a Lighting Bulb. Now if I switch on the bulb, the room is obviously illuminated with light. When I ...
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### Why doesn't dielectric materials have coloured reflections like conductors?

I'm a 3D artist trying to learn the basic (or perhaps even intermediate) level of physics of photorealistic rendering. But most artist and tutorials on the internet have little to no clue of the ...
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### Shining a laser onto a mirror

Theoretically, if I shined a laser at a mirror at an angle of 0 degrees so that the light was perfectly reflected back to the light source, then I should not be able to see the light because it is not ...
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### GRE practice: Total internal reflection question [closed]

Hi, I am having a lot of troubling figuring out how to solve this problem. Equations: Snell's law leads to a total internal reflection equation $$\theta_c = \sin^{-1}(1/n).$$ This angle corresponds ...
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### What is the physical explanation of Fresnel's equation?

When EM radiation is travelling between the media of different refractive indices, parts of it are reflected and transmitted according to Fresnel's equations. The amount of reflectivity and ...
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### What are diferent reflection percentages of different colors?

I don't need any accurate answer. Suppose reflection percentage for white is 100% (which is not even true for mirrors) then what will it be like for different colours like violet, green and red etc of ...
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### How can light cross $c$ in the given hypothetical experiment? Where I am wrong? [closed]

There is a concave mirror, which has somehow maintained the speed $\frac{c}{2}$ toward west ( for instance) , and there is a light wave or you can say a ray of light is moving in N-E direction. So we ...
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### Non-ideal black body's thermal radiation?

Planck's law neatly describes the thermal radiation of an ideal black body in thermal equilibrium. So the question is, what about things that are not black bodies? Like an object with a mirror finish?...
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### How does color (or reflection in general) work?

I'm confused, does the absorption and emission determine the color of something? Or does that only happen when something is emitting energy? When light hits an object, the photons get absorbed, then ...
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### Which one is better 40'' parabolic mirror or 34''x44'' fresnel lens?

I want to make solar concentrator which can reach 2000F or above temperature at focussed spot, so I came across parabolic mirror and fresnel lens but I can't decide which one is better. Also I will be ...
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### Why does water reflect light?

Why does water reflect light? What is actually happening when light is reflected by water? We know why metals reflect light; water, however, is not metal, but it still reflects light and we can see ...
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### Proof of reflected and refracted waves being in the same plane as that of the incident wave and its projection on a planar interface

Please give a proof of reflected and refracted waves being in the same plane as that of the incident wave and its projection on an ideal planar interface between two linear, homogeneous, isotropic, ...
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### Wave reflection and open end boundary condition intuition

I need to understand one seemingly simple thing in wave mechanics, so any help is much appreciated! When a pulse on a string travels to the right toward an open end(like a massless ring that is free ...