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1
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1answer
53 views

Doppler shift from a transversely moving plane mirror

Below is the diagram of the question I have on the Doppler shift of a light emitted from a stationary light source $S$ at an angle $\theta_1$ toward a transversely moving plane mirror $O$ having ...
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2answers
41 views

A car honking it's horn, how long until the car hears the sound reflected? [on hold]

A car is traveling with a constant speed v on a straight road which forms an angle α with nearby straight wall. When the car is at a distance l from the wall the driver presses the horn briefly. What ...
0
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2answers
39 views

Reflection during refraction

I have observed in a book (one that is different from the one that I study with in school) that a light ray reflects during refraction, which is a partial reflection, but when does that occur? Is it ...
4
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2answers
22 views

Refraction, diffraction or reflection of human voice

Why is possible to hear in an open space someone's voice even if he's not facing me? Is it because of refraction, diffraction or reflection of the sound wave?
1
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2answers
35 views

x-ray diffraction of crystals

In explaining x-ray diffraction of crystals, usually the approach is to consider the atoms absorb radiation and scatter it, at some angles constructive interference occur and bright spots can be ...
1
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1answer
30 views

Effect of the refractive index of a transparent layer coating a particle?

I am modelling a cell as a particle coated by a layer of a material whose refraction index might change. This layer is to resemble the membrane. The purpose of the model is to simulate what happens ...
0
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1answer
33 views

Reflection of EM waves

In reflection of e m waves at the boundary, to show the reflected magnetic fields we put negative sign in the unit vector, example, if the B is along z direction we put (-k) in he reflected wave, ...
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2answers
5k views

Why are gold mirrors yellow?

Why are golden mirrors yellow? Do they add a yellow component to the spectrum or absorb non-yellow components? If they absorb, then why are they used in telescopes being imperfect? If they add a ...
0
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1answer
33 views

What range of light wavelengths can a typical mirror reflect?

A typical mirror is capable of reflecting the full spectrum of visible light. Can it also reflect other wavelengths both longer and shorter? What is the range?
2
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2answers
52 views

Why is rainbow always circular?

From the article that I read on physics classroom website on rainbow, rainbow is formed with red on the top and violet on the bottom because violet refracts more, and has a smaller angle of deviation ...
0
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1answer
28 views

What are the properties of center of curvature of a parabolic mirror?

What is so special about the center of curvature of a parabola (since a parabola can't actually have a center) ? I mean, it must be something unique for it to be defined. Why is it twice the focal ...
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0answers
17 views

Polarized light from any suface?

From a textbook I read something like this: "When sunlight is reflected from a horizontal surface, the plane of incidence is vertical, and the reflected light contains a preponderance of light that is ...
0
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0answers
26 views

Does light accelerate when it meets a surface? [duplicate]

Does light accelerate when it meets a surface like mirror, we know that light changes path when it meets a surface like mirror.If light changes path,even if travelling at c,this means light has ...
2
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1answer
48 views

Reflection of an Electron

When a mechanical wave goes from one material to an other, some fraction of it returns back. Same thing with light (massless), but what happens with an electron? When the "wave function" changes ...
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3answers
75 views

Question about intensity of EM waves

For electromagnetic wave if it's reflected from a perfect conductor standing wave can be form. I wonder why Poynting vector can be used to describe the intensity of standing EM wave. (see p.19 of ...
1
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1answer
70 views

Inside a spherical mirror

imagine standing inside a sphere composed entirely of mirror surface; what does this look like? inside is lit by an invisible light source if each point encounters a reflection of itself, what is ...
1
vote
1answer
42 views

What's the need of a polished surface in a plane mirror?

In a plane mirror, my textbook tells me that in a plane mirror one surface is polished and the other is silvered. If light gets reflected from the silvered surface, why does the polished surface have ...
0
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1answer
77 views

Can QED explain this or do I have revert to the classical model of light?

I want to know can QED can explain this image,like why there are someplaces with low light (shadows) like behind the chair, and why there are some places that are bright(rest of the floor). I know ...
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votes
2answers
58 views

Why doesn't the sun reflect off Earth's oceans from space like a billiard ball?

According to Phil Plait, Earth is proportionally smoother than a billiard ball (http://blogs.discovermagazine.com/badastronomy/2008/09/08/ten-things-you-dont-know-about-the-earth). The water surface ...
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5answers
1k views

Why is the surface of the Moon white?

Why is the surface of the Moon white? Rather, what makes the surface white?
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0answers
46 views

How is it that light is reflected in this way in these photos?

I took 2 photos, in one there's a shutter and in the other there's the light that is reflected from the shutter to the ceiling. As you know and as you see from the first image, the shutter has ...
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1answer
448 views

Why is ice more reflective than liquid water?

Why is ice more reflective (has higher albedo) than liquid water? They're both the same substance (water). Is something quantum mechanical involved?
0
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1answer
30 views

What is Retracing in context of this Question?

My textbook Question is Two Mirrors are inclined at an acute angle theta.Light ray is incident parallel to one of the mirrors. Light will start retracing its path after third reflection if angle ...
3
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1answer
48 views

Why does roughened silver look gray while paper white?

Looking at reflectance spectrum of silver, given e.g. here, we can say that more than about $95\%$ of light is reflected by silver. Similarly for white notebook paper, the spectrum is given here, and ...
0
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1answer
60 views

Do parallel rays reflecting at a mirror not intersect at one point? [closed]

Let's take a concave mirror with $CP$ as its principal axis. Let's assume that a parallel ray $p$ to $CP$ reflects at $A$ to pass through the focal point $F$. Then, $\angle CAF=\angle ACF$, which ...
2
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1answer
50 views

Conserved quantity corresponding to reflection symmetry

I know about Noether's theorem, but I don't actually know how to use it myself. Suppose our universe were symmetric with respect to reflections about planes. What conserved quantity would then exist ...
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0answers
28 views

How to achieve transmission only at normal incidence?

Is there any material that only transmits normally incident radiation and reflects it when it's incident at any other angle? Or any way to achieve such an effect? For example, a mirror that if you ...
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votes
4answers
488 views

Does radiation force depend on group velocity or on phase velocity?

What is the radiation force $F$ due to a beam of photons of power $P$ undergoing perfect reflection? Is it $$a) F = 2 P / c$$ or $$b) F = 2 P / v_g$$ where $v_g$ is the group velocity ? Note that ...
0
votes
1answer
32 views

Geometry confusion with incident E field

My geometry is very rusty and I'm having trouble understanding why for the incident E field the X component is multiplied by cos and the -Z component is multiplied by sin instead of the other way ...
4
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0answers
25 views

3D glasses and reflection/polarisation [duplicate]

Hi all, Tonight I'm going to see a 3D film so I thought I'd check whether I had any old 3D glasses around the house. Found a pair of "RealD" glasses. Anyhow, I assume that the glasses use some ...
0
votes
1answer
60 views

Why mirrors form image and others don't?

In the case of mirror, I understand how a image is formed, If I replace plane mirror by wood or some other opaque material in the above image and position of object(bottle) and eye remain the same , ...
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2answers
64 views

reflection of light and the uncertainty principle

I've heard that light reflects the same angle that it falls and so if we know the position of photon (the spot where it hits the surface) and the direction of where it shall go - that's violation of ...
4
votes
5answers
216 views

What about a surface determines its color?

Light falls on a surface. Some wavelengths get absorbed. The other are reflected. The reflected ones are the colors that we perceive to be of the surface. What is the property that determines, what ...
0
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0answers
24 views

About the property of the mirror [duplicate]

It is actually said that left appears to be right and right appears to be left in a mirror. But when I stood in front of the mirror and raised my right hand, then according to this property my mirror ...
2
votes
0answers
23 views

statistical property of light reflected from a coarse mirror

This is a problem comes up in my study in correlation reflectometry. I'm wondering if there is a straight-forward way to interpret the phase and amplitude of the reflected light from a perturbed ...
0
votes
1answer
61 views

combination of mirror and lens [closed]

a convex lens forms a real image of a point object at a distance of 50 cm from convex lens. a concave lens is placed 10 cm behind convex lens on image side. on placing a plane mirror on the image side ...
2
votes
3answers
118 views

Violation of conservation of energy?

Imagine a perfectly spherical mirror with 100% reflection. Imagine a point source of light in the center. The point source keeps radiating light. Will the light undergo destructive interference ...
0
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0answers
21 views

Why does a circle of light form around a wire when a laser is pointed at it? [duplicate]

Referencing this video: https://www.youtube.com/watch?v=9Q_4SNbpBfo Why does a circle of light form? I've seen previous Phys.SE posts on this topic relating the answer to reflection, but I have ...
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votes
1answer
69 views

Long, blurry reflections in wet road [duplicate]

When driving on a wet highway at night, any surface emitting or reflecting light will have a reflection right under it that is blurry and seems to stretch to infinity. This is not exactly what I am ...
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5answers
5k views

Does a well-lit mirror weigh more than an unlit mirror?

If you weighed a mirror in a room with no light, and then weighed a mirror in a well lit room so that the mirror reflects light, would the weight be different?
1
vote
1answer
34 views

Polarization and Reflection [duplicate]

The polarization is a property of waves that can oscillate with more than one orientation. Given this, when the light is reflected from a surface, does the reflection change the property/orientation ...
0
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0answers
15 views

Is image scale the same as focal length?

I am supposed to show using a diagram how image scale is related to focal length. But my formula for image scale is $$\text{image scale} = \frac{y}{\theta} = F$$ where $y$ is the image size on the ...
0
votes
1answer
47 views

If I observe a planet because of reflected sun-light, how does the radiant flux vary with distance?

I wish to figure out how the flux of the sun's reflected light from a planet varies with distance, so assume an observer is on the sun, looking at a planet, and the light originating from the planet ...
0
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0answers
36 views

Why the underside of an object isn't a different colour after light reflects off a different coloured surface

If you were to place a blue plate in front of a green background and shine a light at the blue plate. The light that hits the blue plate would reflect the blue wavelength and when the reflected ...
1
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0answers
28 views

Help with finding an equation to work out the length of cable required to produce loss of colour on an analogue video signal

When I briefly taught Broadcast Engineering I set up an experiment in order to demonstrate the effect of signal reflections along coaxial cable on an analogue PAL waveform. It involved getting the ...
3
votes
1answer
34 views

Polarisation by Reflection - oscillation direction

I'm currently studying polarisation by reflection, and have come across two pieces of information from the same source, which I can't seem to understand on how they differ. The oscillation direction ...
12
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2answers
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 ...
3
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0answers
41 views

What are the limitations on the Paraxial Approximation?

What my physics book referred to as the paraxial approximation derived to be thus: $$\frac{1}{s}+\frac{1}{s'}=\frac{2}{R}$$ as a way of showing that in a concave spherical mirror, all reflected rays ...
1
vote
1answer
74 views

Minimum glare from reflected sunlight [closed]

I'm studying for the IB Physics HL exam, and I came across a question neither my physics teacher or I can solve. It has a diagram like so: The text of the question is this: A person wearing ...
1
vote
1answer
71 views

Can a one-way mirror effect be reversed?

I understand to get the effect of the one-way, one side needs to have light to produce the mirror, leaving the darkened side with the ability to see through. I would like to know if there is a way to ...